MAX8895V [MAXIM]
Li-Ion Chargers with Smart Power Selector, Adapter Type Detection, and USB Enumeration;型号: | MAX8895V |
厂家: | MAXIM INTEGRATED PRODUCTS |
描述: | Li-Ion Chargers with Smart Power Selector, Adapter Type Detection, and USB Enumeration |
文件: | 总45页 (文件大小:4176K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
EVALUATION KIT AVAILABLE
MAX8895V/MAX8895W/
MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
General Description
Features
The MAX8895_ USB-compliant linear battery chargers
operate from either a USB port or dedicated charger with
automatic detection of adapter type and USB enumera-
tion capability. The MAX8895_ integrate the battery dis-
connect switch, current-sense circuit, MOSFET pass ele-
ments, and thermal regulation circuitry, and eliminate the
external reverse-blocking Schottky diode to create the
simplest and smallest stand-alone charging solutions.
S Enables Charging from a USB Port*
S Automatic Detection of Adapter Type
S Enumeration Capability Without Processor
Intervention
S USB Low-Speed Operation Without External
Crystal (MAX8895V/MAX8895W/MAX8895X)
S USB Full-Speed Operation Using an External
Crystal (MAX8895Y)
The MAX8895_ includes an automated detection of
charge adapter type, making it possible to distinguish
between USB 2.0 device, USB charger, and dedicated
charger devices. Furthermore, the MAX8895_ include a
USB enumeration function that automatically negotiates
with a USB host, making it possible to achieve the highest
current available from a USB 2.0 device or USB charger
without processor intervention. The adapter type detec-
tion is compliant with USB 2.0 specification as well as USB
charging Revision 1.1.
S Compliant with USB 2.0 Specification
S Compliant with USB Charging Specification
(Revision 1.1)
S Adaptive Input Current Limit for Dedicated
Charger
S Input Overvoltage Protection to 16V
S Automatic Current Sharing Between Battery
Charging and System
The MAX8895_ controls the charging sequence for single-
cell Li+ batteries from initial power-OK indication, through
prequalification, fast-charge, top-off, and finally charge
termination. Charging is controlled using constant cur-
rent, constant voltage, and constant die-temperature
(CCCVCTj) regulation for safe operation under all condi-
tions. The maximum charging current is adaptively con-
trolled by subtracting the system current from the input
current limit, ensuring that the charging current is always
maximized for any given operating condition.
S Smart Power SelectorK Allows Operation with
Discharged or No Battery
S NTC Monitoring of Battery Temperature
S No External MOSFETs Required
S Thermal Regulation Prevents Overheating
S 2µA Shutdown Current
S Tiny 2.36mm x 2.36mm, 25-Bump, 0.4mm Pitch
WLP Package
The MAX8895_ features optimized smart power control
to make the best use of limited USB or adapter power.
Battery charge current is set independently of the
SYS_ input current limit. Power not used by the system
charges the battery. Automatic input selection switches
the system from battery to external power. This allows
the application to operate without a battery, discharged
battery, or dead battery.
Applications
®
Bluetooth Headsets
Charging Cradles
Portable Devices
Other features include undervoltage lockout (UVLO),
overvoltage protection (OVP), charge status flag, charge
fault flag, power-OK monitor, battery thermistor monitor,
charge timer, and a 3.3V output.
Ordering Information and Typical Operating Circuit appear
at end of data sheet.
The MAX8895_ operates from a +4.0V to +6.6V sup-
ply and include overvoltage protection up to +16V. The
MAX8895_ is specified over the extended temperature
range (-40NC to +85NC) and are available in a compact
2.36mm x 2.36mm, 25-bump WLP package (0.4mm pitch).
Bluetooth is a registered trademark of Bluetooth SIG.
Smart Power Selector is a trademark of Maxim Integrated
Products, Inc.
*Protected by US Patent #6,507,172.
For pricing, delivery, and ordering information, please contact Maxim Direct
at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.
19-5205; Rev 4 9/12
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
ABSOLUTE MAXIMUM RATINGS
BUS_ to AGND...................................................-0.3V to +16.0V
XIN, XOUT, INT_3V3 to AGND.............................-0.3V to +4.0V
ENU_EN, SUS_EN, RWU, D+, D-, PREQ, CHG, UOK,
FLT, BAT_, SYS_, CEN, STDBY, DET_DONE,
I
, I
, and I
Continuous Current...........1800mA
BUS_ BAT_
SYS_ RMS
Continuous Power Dissipation (T = +70NC)
A
25-Bump, 2.36mm x 2.36mm WLP
(derate 19.34mW/NC above +70NC)..........................1560mW
Operating Temperature...................................... -40NC to +85NC
Junction Temperature .....................................................+150NC
Storage Temperature Range............................ -65NC to +150NC
Soldering Temperature (reflow) ......................................+260NC
IBUS_DEF, CHG_TYPE to AGND.....................-0.3V to +6.0V
KB_TM, ISET, THM, IDN,
CT to AGND...................................-0.3V to (V
+ 0.3V)
INT_3V3
DGND to AGND ..................................................-0.3V to + 0.3V
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(THM = CEN = SUS_EN = AGND, V
= 4.2V, V , CT, PREQ, CHG, UOK, FLT, DET_DONE are unconnected, T = -40NC to
BUS_ A
BAT_
+85NC, unless otherwise noted. Typical values are at T = +25NC.) (Note 1)
A
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
USB-TO-SYS PREREGULATOR
USB Operating Range
Initial V
voltage before enabling charger
4.0
6.6
14
V
V
BUS_
USB Standoff Voltage
V
BAT_
= V
= 0V, I
< 650FA (max)
SYS_
BUS_
Time from BUS_ within valid range until UOK
logic-low
BUS_OK Debounce Timer
t
500
4.0
650
ms
USB_DB
UOK logic-low,
Before initial detection of
external device
3.85
4.15
V
BUS_
rising,
100mV hysteresis
USB 2.0 low-power
device
UOK logic-low,
3.75
3.95
3.9
4.1
4.05
4.25
USB Undervoltage Lockout
Threshold
V
BUS_
falling
V
USB 2.0 high-power
device
UOK logic-low,
falling
V
BUS_
Dedicated charger or
USB charger
V
V
V
UOK logic-low,
falling
SYS_
SYS_
SYS_
-100mV + 50mV + 200mV
V
BUS_
USB Overvoltage Protection
Threshold
UOK logic-low, V
hysteresis
rising, 100mV
BUS_
6.8
6.95
7.1
V
MAX8895V/
MAX8895W/
MAX8895X
Charge type detection,
I = I = 0mA,
SYS_
0.5
I
DETECT
BAT_
V
CEN
= 0V
MAX8895Y
2.5
USB 2.0 enumeration in progress,
I
100
ENUMERATE
I
= I
= 0mA, V
= 0V
SYS_
BAT_
CEN
USB Input Supply Current
(Note 2)
MAX8895V/
MAX8895W/
MAX8895X
mA
0.5
Suspend mode, I
= I
=
SYS_
BAT_
I
SUSPEND
0mA, V
= 3.3V
STDBY
MAX8895Y
2.5
100
T
T
= 0NC to +85NC
USB 2.0 low-power
device detected
A
A
I
USB_100mA
= -40NC to +85NC
102.5
500
I
USB 2.0 high-power device detected
During suspend
USB_500mA
I
0
SUS
I
During USB enumeration
40
80
45
55
98
ENU
USB Input Current Limit
mA
I
USB 2.0 low-power device detected
USB 2.0 high-power device detected
90
USB_LP
I
460
475
490
USB_HP
2
Maxim Integrated
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
ELECTRICAL CHARACTERISTICS (continued)
(THM = CEN = SUS_EN = AGND, V
= 4.2V, V , CT, PREQ, CHG, UOK, FLT, DET_DONE are unconnected, T = -40NC to
BUS_ A
BAT_
+85NC, unless otherwise noted. Typical values are at T = +25NC.) (Note 1)
A
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
V
-to-V
On-
BUS_
SYS_
200
320
mI
V
BUS_
= V
CEN
= 5V, I = 400mA
SYS_
Resistance
V
-to-V
Reverse
When SYS is in regulation and charging
stops, V falling, 50mV hysteresis
V
V
V
BAT_
SYS_
BAT_
BAT_
BAT_
V
Regulation
- 80mV - 50mV - 20mV
SYS_
Input Limiter Soft-Start Time
Input current ramp time
50
100
Fs
NC
Thermal-Limit Start
Temperature
T
+110
DIE_LIM
Thermal-Limit Start
Temperature Hysteresis
10
5
NC
Thermal-Limit Gain
I
reduction/die temperature (above +110NC)
%/NC
SYS_
V
regulation threshold where input
BUS_
V
Adaptive Current
V
+ V
+
BUS_
SYS_
SYS_
current limit is regulated for dedicated
charger or USB charger
V
Regulation Threshold
440mV 550mV
+ V +
BAT_
V
BAT_
V
> 3.45V, I
= 1mA to 1.6A,
V
BAT_
SYS_
SYS_ Regulation Voltage
V
V
= V
= 5V
140mV 210mV
BUS_
CEN
Minimum SYS Regulation
Voltage
V
V
= 6V, I
= 5V
= 1mA to 1.6A,
BUS_
SYS_
3.3
3.4
3.55
CEN
CHARGER
BAT_-to-SYS_ On-Resistance
I
= 200mA
falling
BAT_
55
2.85
3.00
1
80
3.1
mI
V
SYS_
V
V
2.60
2.75
BAT_UVLO_F
BAT_ Undervoltage Lockout
Charger Soft-Start Time
BAT_ Leakage Current
PRECHARGE MODE
V
V
rising
3.25
BAT_UVLO_R BAT_
Charge-current ramp time
ms
FA
V
not connected
2
6
6
BUS_
BUS_
2
V
connected, V
= 5V
CEN
BAT_ Precharge-Current
Set Range
R
= 30kIto 1.875kI, V
>1.4V
>1.4V
ISET
BAT_
I
I
/10
A
V
PCHG
FCHG
(Note 3)
V
V
rising
falling
2.7
2.6
2.8
2.7
2.9
2.8
BAT_ Prequalification
Threshold
BAT_PCHG_R BAT_
V
V
BAT_PCHG_F BAT_
FAST-CHARGE MODE
R
ISET
= 30kIto 1.875kI, V
BAT_
0.1
1.85
A
BAT_ Charge-Current Set
Range
(Note 3)
I
FCHG
ISET = INT_3V3 (Note 3)
600
1850
600
mA
R
ISET
R
ISET
R
ISET
= 1.875kI
= 5kI
0000
540
90
0000
660
BAT_ Charge-Current
Accuracy, Charger Loop in
Control
V
BUS_
= 5.5V
mA
V
(Note 3)
= 30kI
100
110
V
BAT_
rising threshold, where charging
V
3.9
3.7
4.0
3.8
4.1
3.9
BAT_FCHG_R
current I
is reduced to I
TCHG
FCHG
BAT_ Fast-Charge Threshold
V
BAT_
falling threshold, where charging
V
BAT_FCHG_F
current is increased to I
FCHG
Maxim Integrated
3
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
ELECTRICAL CHARACTERISTICS (continued)
(THM = CEN = SUS_EN = AGND, V
= 4.2V, V , CT, PREQ, CHG, UOK, FLT, DET_DONE are unconnected, T = -40NC to
BUS_ A
BAT_
+85NC, unless otherwise noted. Typical values are at T = +25NC.) (Note 1)
A
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
TOP-OFF CHARGE MODE
0.6 x
FCHG
Top-Off Charge Current
I
R
R
= 30kIto 1.875kI(Note 3)
= 240kIto 15kI
A
mA
V
TCHG
ISET
I
10
160
BAT_ Charge Termination
Current Range
IDN
I
CHG_DONE
IDN = INT_3V3
I = 0mA
BAT_
80
T
T
= +25NC
4.179
4.158
4.200
4.200
4.221
4.242
A
A
BAT_ Regulation Voltage
V
BAT_REG
= 0NC to +85NC
Recharge threshold in relation to V
state going into top-off mode (Figure 20)
in DONE
BAT_
BAT_ Recharge Threshold
V
-100
-200
-300
mV
BAT_RECHG
CHARGE TIMER
From V
end of prequalification
charge mode,
falling to
CEN
C = 0.068FF
16
20
T
Maximum Prequalification
Time
t
Min
PCHG
C = AGND
T
V
= 2.5V
BAT_
C = 0.068FF
100
120
4
From V
falling to
T
CEN
Maximum Fast-Charge Time
Maintain-Charge Time
Timer Accuracy
t
Min
Min
%
FCHG
V
falling
C = AGND
T
FLT
C = 0.068FF
T
t
MTCHG
C = AGND
T
5
C = 0.068FF
T
-30
-30
+30
+30
C connected to AGND
T
Percentage of charge current below which
timer clock operates at half speed
Timer Extend Threshold
50
20
%
Percentage of charge current below which
timer clock pauses
Timer Suspend Threshold
ADAPTER TYPE DETECTION
D- Current Sink
%
MAX8895V/MAX8895X/MAX8895Y
MAX8895W
50
64
86
86
150
102
0.7
I
FA
DM_SINK
D+ Source Voltage
V
I
= 0 to 200FA
0.5
0.25
100
40
0.6
0.32
V
V
DP_SRC
DP_SRC
D+ Detection Threshold
D+ Source On-Time
V
0.40
DAT_REF
t
ms
ms
DP_SRC_ON
DP_SRC_HC
D+ Source to High Current Time t
MAX8895V/MAX8895W/MAX8895X only,
external series resistor = 33I
D- Pullup Resistor
R
1.425
1.425
1.500
1.500
1.575
1.575
kI
kI
DM_PU
MAX8895Y only, external series resistor =
33I
D+ Pullup Resistor
R
DP_PU
D+ Charger Detection
Pullup Resistor
R
R
connect to INT_3V3
200
0.8
330
600
kI
DP_CD_PU
DP_CD_PU
D- Weak Current Sink
D- Logic-High Threshold
I
0.1
2.0
FA
DM_CD_PD
V
V
DM_IH
4
Maxim Integrated
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
ELECTRICAL CHARACTERISTICS (continued)
(THM = CEN = SUS_EN = AGND, V
= 4.2V, V , CT, PREQ, CHG, UOK, FLT, DET_DONE are unconnected, T = -40NC to
BUS_ A
BAT_
+85NC, unless otherwise noted. Typical values are at T = +25NC.) (Note 1)
A
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Time from start of enumeration process
until enumeration must be completed; if
not completed, the MAX8895_ retries to
enumerate
Enumeration Time Limit
t
10
s
ENUM
Time from failed enumeration to adapter type
detection reenabled
Reconnect Timer
t
3
s
FAULT
Time from enumeration fail at 500mA until
enumeration is retried at 100mA or time from
enumeration fail at 100mA until reconnect
timer is started
Enumeration Fail to Reconnect
Timer
t
87
ms
ENU_FAULT
Time from when the MAX8895_ has entered
suspend mode until it reenumerates,
RWU = AGND
Reenumeration Timer
t
100
ms
RE_ENUM
Oscillator Frequency
Accuracy
MAX8895V/MAX8895X only (internal
5.91
6.00
6.09
10
MHz
FA
V
oscillator), T = +25NC
A
XIN Input Current
MAX8895Y only, V
MAX8895Y only
MAX8895Y only
= V
= 3.3V
XIN
STDBY
2/3x
INT_3V3
XIN Logic-High Input Voltage
V
INT_3V3
V
XIN Logic-Low Input Voltage
0.4
V
THM
When charging is suspended, rising
threshold, 2% hysteresis
% of
INT_3V3
THM Cold Threshold
THM Hot Threshold
THM Threshold, Disabled
THM Input Leakage
T
72
26
74
28
3
76
30
AMB_COLD
V
When charging is suspended, falling
threshold, 2% hysteresis
% of
INT_3V3
T
AMB_HOT
V
V
When THM function is disabled, falling
threshold, 2% hysteresis
% of
INT_3V3
T
T
= +25NC
= +85NC
-0.1
0.001
0.01
+0.2
THM = AGND or
INT_3V3
A
FA
A
LOGIC I/O: CHG, FLT, UOK, CEN, PREQ, KB_TM, RWU, STDBY, SUS_EN, ENU_EN, DET_DONE, CHG_TYPE, IBUS_DEF
High level
Low level
Hysteresis
1.3
V
Logic-Input Threshold
0.4
1
50
mV
FA
T
T
= +25NC
= +85NC
0.001
0.01
A
A
Logic-Input Leakage Current
V
= 0 to 5.5V
BUS_
Logic-Low Output Voltage
(CHG, FLT, UOK, PREQ,
DET_DONE, CHG_TYPE Only)
Sinking 10mA
35
100
1
mV
Logic-High Output-Leakage
Current (CHG, FLT, UOK,
PREQ, DET_DONE, CHG_
TYPE Only)
T
T
= +25NC
= +85NC
0.001
0.01
A
A
V
SYS_
= 5.5V
FA
Maxim Integrated
5
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
ELECTRICAL CHARACTERISTICS (continued)
(THM = CEN = SUS_EN = AGND, V
= 4.2V, V , CT, PREQ, CHG, UOK, FLT, DET_DONE are unconnected, T = -40NC to
BUS_ A
BAT_
+85NC, unless otherwise noted. Typical values are at T = +25NC.) (Note 1)
A
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
USB DATA INTERFACE
Differential-Receiver Input
Sensitivity
|V - V
|
0.2
V
V
D+
D-
Differential-Receiver
Common-Mode Voltage
0.8
2.5
D+, D- Input Impedance
D+, D- Output Low Voltage
D+, D- Output High Voltage
Driver Output Impedance
300
kI
V
V
R
R
= 1.5kIfrom V to 3.6V
0.3
3.6
11
OL
LOAD
D-
V
OH
= 15kIfrom D+ and D- to AGND
2.8
2
V
LOAD
Excludes external resistor
7
3
I
Only valid when an adapter type is detected
as a USB 2.0 device; time BUS_ is inactive
until charging current is reduced to I
BUS_ Idle Time
t
ms
ms
IDLE
RWU
SUSPEND
Time delay from when the MAX8895_ is put
into suspend mode until they request the host
for a remote wake-up
USB Host Remote Wake-Up
Timer
t
100
MAX8895V/MAX8895W/MAX8895X only, C =
L
50pF to 600pF, (Figures 5 and 6)
75
4
250
20
D+, D- Rise Time
(Note 5)
t
ns
ns
RISE
MAX8895Y only, C = 50pF (Figures 5 and 6)
L
MAX8895V/MAX8895W/MAX8895X only, C =
L
50pF to 600pF (Figures 5 and 6)
75
250
D+, D- Fall Time
(Note 5)
t
FALL
MAX8895Y only, C = 50pF
L
(Figures 5 and 6)
4
20
120
110
2.0
2.0
MAX8895V/MAX8895W/MAX8895X only, C =
L
50pF to 600pF (Figures 5 and 6)
80
90
1.3
1.3
Rise-/Fall-Time Matching
(Note 5)
%
V
MAX8895Y only, C = 50pF
L
(Figures 5 and 6)
MAX8895V/MAX8895W/MAX8895X only, C =
L
50pF to 600pF (Figures 5 and 6)
Output-Signal Crossover
Voltage (Note 5)
MAX8895Y only, C = 50pF
L
(Figures 5 and 6)
INT_3V3 REGULATOR
INT_3V3 Voltage
V
V
= 5V, I
= 0 to 10mA
3.0
3.3
3.6
V
BUS_
INT_3V3
ESD PROTECTION (D+, D-, V
)
BUS_
Human Body Model
bypassed with 1FF to AGND
Q8
kV
BUS_
Note 1: Specifications are 100% production tested at T = +25NC. Limits over the operating temperature range are guaranteed by
A
design and characterization.
Note 2: Sum of input current limit and current used for INT_3V3.
Note 3: Maximum charging current is adaptively regulated to I
- I
with a maximum value of I
.
IN_LIM SYS_
CHG
Note 4: All devices are 100% production tested at T = +25NC. Limits over the operating temperature range are guaranteed by design.
A
Note 5: Guaranteed by design, not production tested.
6
Maxim Integrated
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
Typical Operating Characteristics
(V
BAT_
= 4.2V, V
= 5V, ISET = IDN = CT = SUS_EN = INT_3V3, STDBY = ENU_EN = RWU = CEN = KB_TM = AGND, circuits
BUS_
of Figures 4 and 5 (MAX8895V/MAX8895X and MAX8895Y, respectively), T = +25NC, unless otherwise noted.)
A
MAX8895V/W/X V
INPUT SUPPLY
(SUSPEND MODE)
INPUT SUPPLY
(CHARGER ENABLED)
MAX8895V/W/X V
INPUT SUPPLY
BUS_
(CHARGER DISABLED)
BUS_
BUS_
CURRENT vs. V
CURRENT vs. V
BUS_
BUS_
400
350
300
250
200
150
100
50
2.5
2.0
1.5
1.0
0.5
0
2.5
2.0
1.5
1.0
0.5
0
BATT UNCONNECTED
SUS_EN = ENU_EN
= CEN = AGND
V
= 4.2V
BAT_
CEN = INT_3V3
SUS_EN =
ENU_EN = AGND
SUS_EN = ENU_EN = CEN = AGND
STDBY = INT_3V3
0
0
2
4
6
8
10 12 14 16
0
2
4
6
8
10 12 14 16
0
2
4
6
8
10 12 14 16
V
(V)
V
(V)
V
(V)
BUS_
BUS_
BUS_
MAX8895Y V
CURRENT vs. V
INPUT SUPPLY
(SUSPEND MODE)
MAX8895Y V
INPUT SUPPLY
(CHARGER ENABLED)
INPUT SUPPLY
BUS_
(CHARGER DISABLED)
BUS_
BUS_
BUS_
CURRENT vs. V
BUS_
500
450
400
350
300
250
200
150
100
50
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
BATTERY UNCONNECTED
CEN = AGND
V
= 4.2V
BAT_
CEN = STDBY = AGND
CEN = INT_3V3
0
0
2
4
6
8
10 12 14 16
0
2
4
6
8
10 12 14 16
0
2
4
6
8
10 12 14 16
V
(V)
V
(V)
V
(V)
BUS_
BUS_
BUS_
BATTERY LEAKAGE CURRENT
vs. TEMPERATURE
CHARGE CURRENT vs. BATTERY VOLTAGE
(DEDICATED CHARTER)
BATTERY LEAKAGE CURRENT
vs. BATTERY VOLTAGE
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
700
600
500
400
300
200
100
0
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
ENU_EN = SUS_EN = AGND, R
ISET
= 5kI
BUS_ UNCONNECTED
CEN = AGND
-40
-15
10
35
60
85
2.0
2.5
3.0
3.5
4.0
4.5
3.0
3.5
4.0
4.5
TEMPERATURE (NC)
BATTERY VOLTAGE (V)
V
BATT
(V)
Maxim Integrated
7
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
Typical Operating Characteristics (continued)
(V
BAT_
= 4.2V, V
= 5V, ISET = IDN = CT = SUS_EN = INT_3V3, STDBY = ENU_EN = RWU = CEN = KB_TM = AGND, circuits
BUS_
of Figures 4 and 5 (MAX8895V/MAX8895X and MAX8895Y, respectively), T = +25NC, unless otherwise noted.)
A
CHARGE CURRENT vs. BATTERY VOLTAGE
(LOW-POWER USB)
CHARGE CURRENT vs. BATTERY VOLTAGE
(HIGH-POWER USB)
CHARGE CURRENT (DEDICATED CHARGER)
vs. AMBIENT TEMPERATURE
100
90
80
70
60
50
40
30
20
10
0
600
500
400
300
200
100
0
610
609
608
607
606
605
604
603
602
601
600
CHARGER IN DROPOUT
ENU_EN = INT_3V3, SUS_EN = AGND
ENU_EN = SUS_EN = AGND
2.0
2.5
3.0
3.5
4.0
4.5
2.0
2.5
3.0
3.5
4.0
4.5
-40
-15
10
35
60
85
BATTERY VOLTAGE (V)
BATTERY VOLTAGE (V)
TEMPERATURE (°C)
SYS_ OUTPUT VOLTAGE
SYS_ OUTPUT VOLTAGE
vs. BATTERY VOLTAGE
BATTERY REGULATION VOLTAGE
vs. AMBIENT TEMPERATURE
vs. V
BUS_
4.400
4.375
4.350
4.325
4.300
4.275
4.250
4.225
4.200
4.175
4.150
4.125
4.100
4.075
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
4.215
4.210
4.205
4.200
4.195
4.190
4.185
4.180
I
= 0A
SYS_
I
= 0mA
I
SYS_
= 20mA
SYS_
I
= 100mA
SYS_
V
= 4.2V
BAT_
7
V
BUS_
= 5V
3
4
5
6
8
2.0
2.5
3.0
V
3.5
(V)
4.0
4.5
-40
-15
10
35
60
85
V
(V)
TEMPERATURE (°C)
BUS_
BATT
SYS_ DROPOUT VOLTAGE
vs. LOAD CURRENT
SYS_ OUTPUT VOLTAGE vs. LOAD CURRENT
(HIGH-POWER USB MODE)
SYS_ OUTPUT VOLTAGE vs. LOAD CURRENT
(DEDICATED CHARGER)
140
120
100
80
4.40
4.30
4.20
4.10
4.00
3.90
3.80
4.40
4.35
4.30
4.25
4.20
4.15
4.10
4.05
4.00
3.95
3.90
V
= 4.2V, NOKIA AC-10U
V
= 4.2V
BAT_
BAT_
BUS_ UNCONNECTED
DROPOUT MEASURED WHEN
SYS_ DECREASES BY 10%
V
SUPPLEMENTED
SYS_
V
SYS_
SUPPLEMENTED
BY V
BUS_
BY V
BUS_
SYSTEM LOAD SWITCH
IN DROPOUT
60
40
20
SYSTEM LOAD SWITCH IN DROPOUT
0
0
500
1000
(mA)
1500
2000
0
500
1000
(mA)
1500
2000
0
500
1000
I (mA)
SYS_
1500
2000
I
I
SYS_
SYS_
8
Maxim Integrated
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
Typical Operating Characteristics (continued)
(V
BAT_
= 4.2V, V
= 5V, ISET = IDN = CT = SUS_EN = INT_3V3, STDBY = ENU_EN = RWU = CEN = KB_TM = AGND, circuits
BUS_
of Figures 4 and 5 (MAX8895V/MAX8895X and MAX8895Y, respectively), T = +25NC, unless otherwise noted.)
A
CHARGE PROFILE
(NOKIA AC-10 CHARGER)
INT_3V3 VOLTAGE vs. BUS_ VOLTAGE
3.35
3.30
3.25
3.20
3.15
3.10
3.05
3.00
4.30
4.20
4.10
4.00
3.90
3.80
3.70
3.60
3.50
1000
900
800
700
600
500
400
300
200
100
0
V
BAT_
100mA CHARGE
50mA CHARGE
CURRENT
CURRENT
MOTOROLA BC60 860mAh
C
CT
= 0.2µF
R
ISET
R
IDN
= 1.87kI
= 243kI
I
BAT_
V
= 4V
BAT_
7.0
3.0
4.0
5.0
V
6.0
(V)
8.0
0
25 50 75 100 125 150 175 200 225 250 275 300
TIME (min)
BUS_
CHARGE PROFILE
(USB 2.0 CHARGER)
MAX8895V/W/X EYE DIAGRAM
4.30
4.20
4.10
4.00
3.90
3.80
3.70
3.60
3.50
3.40
3.30
500
450
400
350
300
250
200
150
100
50
3.6
3.1
2.6
2.1
1.6
V
BAT_
MOTOROLA BC60 860mAh
C
= 0.2µF
= 3.74kI
= 243k
CT
R
ISET
R
IDN
I
1.1
0.6
0.1
I
BAT_
0
0
1.0
2.0
3.0
4.0
-7
5.0
6.0
0
25 50 75 100 125 150 175 200 225 250 275 300
TIME (min)
TIME (x 10 ) (s)
DEDICATED CHARGER CONNECT
MAX8895Y EYE DIAGRAM
MAX8895W/X/Y toc24
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
5V/div
0V
5V/div
V
BUS
V
SYS
0V
5V/div
V
0V
5V/div
0V
D+
V
D-
-0.5
200ms/div
0
1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0
-8
TIME (x 10 ) (s)
Maxim Integrated
9
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
Typical Operating Characteristics (continued)
(V
BAT_
= 4.2V, V
= 5V, ISET = IDN = CT = SUS_EN = INT_3V3, STDBY = ENU_EN = RWU = CEN = KB_TM = AGND, circuits
BUS_
of Figures 4 and 5 (MAX8895V/MAX8895X and MAX8895Y, respectively), T = +25NC, unless otherwise noted.)
A
DEDICATED CHARGER DISCONNECT
MAX8895V/W/X HIGH-POWER 2.0
MAX8895W/X/Y toc25
MAX8895W/X/Y toc26
V
5V/div
0V
BUS_
5V/div
0V
5V/div
V
I
BUS
V
INT_3V3
0V
500mA/div
0A
BUS
5V/div
0V
V
V
D+
SYS_
5V/div
0V
5V/div
0V
5V/div
0V
V
BAT_
V
D-
R
= 100I
SYS_
200ms/div
400ms/div
MAX8895Y USB HIGH-POWER
2.0 CONNECT
MAX8895V/W/X USB HIGH-POWER
2.0 DISCONNECT
MAX8895W/X/Y toc27
MAX8895W/X/Y toc28
5V/div
0V
V
I
5V/div
0V
BUS_
V
BUS
BUS
BUS_
100mA/div
500mA/div
0A
I
0mA
2V/div
0V
V
D+
5V/div
0V
V
D+
V
D-
5V/div
0V
2V/div
0V
R
SYS_
= 100I
V
D-
400ms/div
20ms/div
MAX8895Y USB HIGH-POWER
2.0 DISCONNECT
MAX8895V/W/X USB AUTOSUSPEND
MAX8895W/X/Y toc30
MAX8895W/X/Y toc29
2V/div
V
5V/div
0V
BUS_
BUS_
V
V
0V
D+
D-
2V/div
200mA/div
I
0V
0mA
2V/div
0V
V
D+
V
1V/div
FLT
0V
I
200mA/div
0mA
2V/div
0V
BUS_
R
= 100I
SYS_
V
D-
1ms/div
2ms/div
10
Maxim Integrated
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
Typical Operating Characteristics (continued)
(V
BAT_
= 4.2V, V
= 5V, ISET = IDN = CT = SUS_EN = INT_3V3, STDBY = ENU_EN = RWU = CEN = KB_TM = AGND, circuits
BUS_
of Figures 4 and 5 (MAX8895V/MAX8895X and MAX8895Y, respectively), T = +25NC, unless otherwise noted.)
A
MAX8895Y USB AUTOSUSPEND
MAX8895V/W/X USB RESUME
MAX8895W/X/Y toc32
MAX8895W/X/Y toc31
V
D+
V
D+
2V/div
2V/div
0V
0V
2V/div
2V/div
V
V
D-
0V
D-
0V
V
FLT
V
1V/div
1V/div
0V
FLT
I
BUS_
0V
I
200mA/div
0mA
200mA/div
0mA
BUS_
1ms/div
1s/div
PREQUALIFICATION TIMEOUT
vs. CT CAPACITANCE
MAX8895Y USB RESUME
MAX8895W/X/Y toc33
1600
1400
1200
1000
800
600
400
200
0
2V/div
V
D+
0V
V
D-
2V/div
0V
2V/div
V
FLT
0V
I
BUS_
200mA/div
0mA
0
20,000 40,000 60,000 80,000 100,000
(pF)
1s/div
C
CT
FAST-CHARGE TIMEOUT
vs. CT CAPACITANCE
10,000
9,000
8,000
7,000
6,000
5,000
4,000
3,000
2,000
1,000
0
0
20,000 40,000 60,000 80,000 100,000
(pF)
C
CT
Maxim Integrated
11
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
Pin Configurations
TOP VIEW
(BUMP SIDE DOWN)
MAX8895W
1
2
3
4
5
+
STDBY
BAT_A
BAT_B
UOK
SYS_A
BUS_A
A
B
C
D
E
ISET
IDN
CHG_
TYPE
SYS_B
KB_TM
FLT
BUS_B
AGND
D+
DET_DONE
IBUS_DEF
THM
ENU_EN
SUS_EN
CT
CEN
INT_3V3
DGND
D-
WLP
TOP VIEW
TOP VIEW
MAX8895V
MAX8895X
3
MAX8895Y
(BUMP SIDE DOWN)
(BUMP SIDE DOWN)
1
2
4
5
1
2
3
4
5
+
+
STDBY
BAT_A
BAT_B
UOK
SYS_A
BUS_A
STDBY
BAT_A
BAT_B
UOK
SYS_A
BUS_A
A
B
C
D
E
ISET
IDN
A
B
C
D
E
ISET
IDN
CHG
PREQ
RWU
THM
SYS_B
KB_TM
FLT
BUS_B
AGND
D+
CHG
PREQ
RWU
THM
SYS_B
KB_TM
FLT
BUS_B
AGND
D+
ENU_EN
SUS_EN
CT
XIN
CEN
CEN
XOUT
CT
INT_3V3
DGND
D-
INT_3V3
DGND
D-
WLP
WLP
12
Maxim Integrated
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
Pin Description
NAME
PIN
FUNCTION
MAX8895V/
MAX8895X
MAX8895W
MAX8895Y
Maximum Fast-Charge Current Selection. Connect a resistor from ISET to
AGND to set the fast-charge current from 0.1A to 1.85A.
I
= 3000/R
ISET
FCHG
A1
ISET
ISET
ISET
If ISET is connected to INT_3V3 the default I is set as maximum charge
FCHG
current.
ISET can also be used to monitor the actual current charging the battery.
See the Monitoring Charge Current section for details.
Standby Mode Enable. Connect STDBY to AGND to enter automatic detect
mode. In automatic detect mode, the MAX8895V/MAX8895W/MAX8895X
determine when to enter suspend mode depending on the status of the
SUS_EN logic input. When using the MAX8895Y, the IC always starts in
automatic suspend mode. Connect STDBY to INT_3V3 or drive logic-high to
force the MAX8895_ into suspend mode regardless of external conditions.
A2
STDBY
STDBY
STDBY
Li+ Battery Connection (V
to DGND. The battery charges from V
). Connect a single-cell Li+ battery from V
BAT_
BAT_
A3
B3
BAT_A
BAT_B
BAT_A
BAT_B
BAT_A
BAT_B
when a valid source is present
SYS_
at V
. V
powers V
when V
power is not present, or when
BUS_ BAT_
SYS_
BUS_
the V
load exceeds the input current limit. Bypass V
to DGND with
SYS_
BAT_
a 10FF X5R or X7R ceramic capacitor. Both BAT_A and BAT_B must be
connected together externally.
System Supply Output (V
). V
is connected to V
through an
SYS_
SYS_
BAT_
internal 55mIsystem load switch when V
is invalid, or when the V
SYS_
BUS_
load is greater than the input current limit. When a valid voltage is present
at V , V is limited to 4.35V when using the MAX8895V/MAX8895X/
A4
B4
SYS_A
SYS_B
SYS_A
SYS_B
SYS_A
SYS_B
BUS_ SYS_
MAX8895Y, and 4.53V when using the MAX8895W. When the system load
current (I ) exceeds the V current limit V also powers V to
SYS_
BUS_
BAT_
SYS_
maintain the load current. Bypass V
to DGND with a 10FF X5R or X7R
SYS_
ceramic capacitor. Both SYS_A and SYS_B must be connected together
externally.
USB Power Input (V
the MAX8895_ identifies the type of connection established and set the input
current limit accordingly. Bypass V to DGND with a 10FF X5R or X7R
ceramic capacitor. Both BUS_A and BUS_B must be connected together
externally.
). During initial connection of an external device,
BUS_
A5
B5
BUS_A
BUS_B
BUS_A
BUS_B
BUS_A
BUS_B
BUS_
Charge Termination Current Threshold. Connect a resistor from IDN to AGND
to set the termination current threshold from 10mA to 160mA.
B1
IDN
IDN
IDN
I
= 2400/R
TERM IDN
If IDN is connected to INT_3V3, the termination current is set to the default
threshold.
I
_
CHG DONE
Maxim Integrated
13
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
Pin Description (continued)
NAME
PIN
FUNCTION
MAX8895V/
MAX8895X
MAX8895W
MAX8895Y
Active-Low, Charging Indicator. CHG is an open-drain output that is pulled
low when the battery is in prequalification mode, fast-charge mode, or top-off
states. Otherwise, CHG is high impedance.
—
CHG
—
CHG
B2
CHG_TYPE is used to indicate capacity of input current. IF CHG_TYPE is
high, the input current can be greater than or equal to 500mA. If CHG_TYPE
is low, the input current is 100mA from the USB 2.0 host.
CHG_TYPE
—
—
Crystal Oscillator Input. Connect XIN to one side of a parallel resonant
12MHz ±0.25% crystal and a capacitor to AGND. XIN can also be driven by
an external clock referenced to INT_3V3.
—
XIN
Automatic Enumeration Enable. Connect ENU_EN to AGND to allow the
MAX8895V/MAX8895X to automatically perform enumeration. Connect to
INT_3V3 or drive logic-high to force the input current limit to 100mA without
performing an adapter type detection.
—
ENU_EN
—
—
C1
Automatic Enumeration Enable. Connect ENU_EN to AGND to allow the
MAX8895W to automatically perform enumeration. By connecting ENU_EN
to INT_3V3 or drive logic-high, disables automatic enumeration and sets the
input current limit to level determined by the IBUS_DEF if a USB 2.0 device is
detected.
ENU_EN
—
Active-Low, Prequalification Charging Output. PREQ is an open-drain output
that is pulled low when the charger enters the prequalification state.
—
PREQ
—
PREQ
—
C2
Active-Low Adapter-Type Detection Done Output. DET_DONE is an open-
drain output that is pulled low when adapter detection is completed. DET_
DONE is high impedance in suspend mode.
DET_DONE
Active-Low, V
pulled low when a valid input is detected at V
Power-OK Output. UOK is an open-drain output that is
BUS_
C3
C4
C5
UOK
KB_TM
AGND
UOK
KB_TM
AGND
UOK
KB_TM
AGND
.
BUS_
Keyboard Test Mode. In normal operation, connect KB_TM to AGND. This
input is only used during USB certification.
Analog Ground. Both AGND and DGND should be connected together at the
negative terminal of the battery.
Crystal Oscillator Output. Connect XOUT to one side of a parallel resonant
12MHz Q0.25% crystal and a capacitor to AGND. Leave XOUT unconnected
if XIN is driven by an external clock.
—
SUS_EN
—
—
XOUT
—
D1
D2
Automatic Suspend Mode Detection Enable. Connect SUS_EN to AGND
to disable the automatic suspend mode detection. Connect SUS_EN to
INT_3V3 or drive logic-high to enable the automatic detection of suspend
mode.
SUS_EN
RWU
Remote Wake-up. Connect RWU to AGND or logic-low for remote wake-
ups whenever the device is put into suspend mode and the supervisor
determines that more current is needed.
RWU
Sets USB Input Current if Adapter is Detected as a USB 2.0 Device and
ENU_EN is Logic-High. If IBUS_DEF is connected high, the input current limit
is set to 500mA. If IBUS_DEF is connected low or to ground, the input current
limit is set to 100mA.
IBUS_DEF
—
—
14
Maxim Integrated
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
Pin Description (continued)
NAME
PIN
FUNCTION
MAX8895V/
MAX8895X
MAX8895W
MAX8895Y
Charger Enable Input. Connect CEN to AGND to enable battery charging
when a valid source is connected at V . Connect CEN to INT_3V3 or
BUS_
drive logic-high to disable battery charging. In this condition the USB state
machine is still active, and V is powered from V under normal
D3
CEN
CEN
CEN
SYS_
BUS_
conditions and supplemented from V
if sufficient current is not available
BAT_
from V
input.
BUS_
Active-Low Fault Output. FLT is an open-drain output that is pulled low when
the battery charger timer expires before prequalification or fast-charge
completes. FLT is also pulled low during adapter type detection or if USB
enumeration fails.
D4
D5
FLT
FLT
FLT
USB D+ signal. Connect D+ to a USB “B” connector through a 33Iseries
resistor. The 1.5kID+ pullup resistor is internal to the device (for MAX8895Y
only).
D+
D+
D+
Timer Set Capacitor. Connect a capacitor from CT to AGND to set the fault
timers for prequalification and fast-charge.
t
t
t
= 16min x (C /0.068FF)
CT
PREQUAL
E1
CT
CT
CT
= 100min x (C /0.068FF)
FCHG
CT
= 4min x (C /0.068FF)
MTCHG
CT
If CT is connected directly to AGND, the default timers are used.
Thermistor Input. Connect a negative temperature coefficient (NTC)
thermistor that has good thermal contact with the battery from THM to AGND.
Connect a resistor equal to the thermistor at T = +25NC resistance from
A
E2
E3
THM
THM
THM
THM to INT_3V3. Charging is suspended when the thermistor is outside
the hot and cold limits. Connect THM to AGND to disable the thermistor
temperature sensor.
LDO Output. INT_3V3 is the output of an LDO that powers the internal
INT_3V3
INT_3V3
INT_3V3
circuitry. INT_3V3 is powered from the V input. Connect a 0.1FF
BUS_
capacitor from INT_3V3 to AGND.
Digital Ground. Both AGND and DGND should be connected together at the
negative terminal of the battery.
E4
E5
DGND
D-
DGND
D-
DGND
D-
USB D- Signal. Connect D- to a USB “B” connector through a 33Iseries
resistor. The 1.5kID- pullup resistor is internal to the device (for MAX8895V/
MAX8895W/MAX8895X only).
Maxim Integrated
15
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
USB POWER
MANAGEMENT
BUS_A
BUS_B
SYS_A
SYS_B
TO
SYSTEM LOAD
V
BUS_
Li+ BATTERY
CHARGER AND
SYS LOAD SWITCH
OUT OF
RANGE
VALID
UOK
SET INPUT
CURRENT LIMIT
V
BUS_
ISET
I
I
SYS_
LIM
I
I
-
SYS
LIM
CHARGER
CURRENT
VOLTAGE
CONTROL
I
CHG
R
ISET
SET INPUT
CURRENT LIMIT
IC THERMAL
REGULATION
I
CHG_MAX
BAT_A
BAT_B
I
LIM
BAT+
BAT-
USB ADAPTER
TYPE DETECTION
AND
ENUMERATION
V
BUS
D+
R
T
R
D+
THM
THERMISTOR
MONITOR
D+
D-
NTC
R
D-
MAX8895V
MAX8895X
R
TB
D-
INT_3V3
3.3V FOR INTERNAL
USB TRANSCEIVER
GND
C
INT_3V3
CHARGING
TERMINATED
CHARGING
SUPPORT REMOTE
WAKE-UP
FORCE REMOTE
WAKE-UP
RWU
CHG
IN PROGRESS
PRECHARGING
TERMINATED
PRECHARGING
IN PROGRESS
CHARGE
TERMINATION
AND
AUTOMATED SUSPEND
ENABLED
AUTOMATED SUSPEND
DISABLED
USB INTERFACE
LOGIC
PREQ
SUS_EN
ENU_EN
KB_TM
STDBY
MONITOR
AUTOMATIC ENUMERATION
DISABLED
AUTOMATIC ENUMERATION
ENABLED
IDN
R
IDN
KEYBOARD TEST MODE
ENABLED
KEYBOARD TEST MODE
DISABLED
FLT
CT
NO FAULT
FAULT
FORCED STANDBY
MODE
AUTOMATIC STANDBY
MODE
CHARGE
TIMER
C
CT
POR
CEN
CHARGER DISABLED
CHARGER ENABLED
INT_3V3
DGND
AGND
Figure 1. MAX8895V/MAX8895X Block Diagram
16
Maxim Integrated
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
USB POWER
MANAGEMENT
BUS_A
BUS_B
SYS_A
SYS_B
TO
SYSTEM LOAD
V
BUS_
Li+ BATTERY
CHARGER AND
SYS LOAD SWITCH
OUT OF
RANGE
VALID
UOK
INPUT
CURRENT LIMIT
V
BUS_
ISET
I
I
SYS_
LIM
I
I
-
SYS
LIM
CHARGER
CURRENT
VOLTAGE
CONTROL
I
CHG
R
ISET
SET INPUT
CURRENT LIMIT
IC THERMAL
REGULATION
I
CHG_MAX
BAT_A
BAT_B
I
LIM
BAT+
BAT-
USB ADAPTER
TYPE DETECTION
AND
ENUMERATION
V
BUS
R
T
R
D+
THM
THERMISTOR
MONITOR
D+
D-
NTC
D+
R
D-
MAX8895Y
R
TB
D-
INT_3V3
3.3V FOR INTERNAL
USB TRANSCEIVER
GND
C
INT_3V3
CHARGING
TERMINATED
CHARGING
SUPPORT REMOTE
WAKE-UP
FORCE REMOTE
WAKE-UP
RWU
CHG
USB INTERFACE
LOGIC
IN PROGRESS
PRECHARGING
TERMINATED
PRECHARGING
IN PROGRESS
CHARGE
TERMINATION
AND
KEYBOARD TEST MODE
ENABLED
KEYBOARD TEST MODE
DISABLED
PREQ
KB_TM
STDBY
MONITOR
FORCED STANDBY
MODE
IDN
AUTOMATIC STANDBY
MODE
R
IDN
POR
FLT
CT
NO FAULT
FAULT
CHARGE
TIMER
INT_3V3
C
CT
XIN
CEN
OSCILLATOR
CHARGER DISABLED
CHARGER ENABLED
XOUT
DGND
AGND
Figure 2. Differential Input Configuration
Maxim Integrated
17
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
USB POWER
MANAGEMENT
BUS_A
BUS_B
SYS_A
SYS_B
TO
SYSTEM
LOAD
V
BUS_
Li+ BATTERY
CHARGER AND
SYS LOAD SWITCH
OUT OF
RANGE
VALID
UOK
INPUT
CURRENT LIMIT
V
BUS_
ISET
I
I
SYS_
LIM
I
I
-
SYS
LIM
CHARGER
CURRENT
VOLTAGE
CONTROL
I
CHG
IC
R
SET INPUT
CURRENT LIMIT
ISET
THERMAL
REGULATION
I
CHG_MAX
BAT_A
BAT_B
I
LIM
BAT+
USB ADAPTER
TYPE DETECTION
AND
ENUMERATION
BAT-
NTC
MAX8895W
V
BUS
THM
THERMISTOR
MONITOR
D+
D-
D+
D-
R
THM
3.3V FOR USB
TRANSCEIVER
INT_3V3
GND
C
INT_3V3
SUS_EN
ENU_EN
KB_TM
STDBY
AUTOMATIC SUSPEND ENABLED
AUTOMATIC SUSPEND DISABLED
CHARGE
TERMINATION
AND
USB INTERFACE
LOGIC
IDN
AUTOMATIC SUSPEND ENABLED
AUTOMATIC SUSPEND DISABLED
MONITOR
R
IDN
KEYBOARD TEST MODE ENABLED
KEYBOARD TEST MODE DISABLED
FORCED STANDBY MODE
AUTOMATIC STANDBY MODE
DET_DONE
CHG_TYPE
IBUS_DEF
ADAPTER DETECTION IN PROGRESS
ADAPTER DETECTION COMPLETE
FLT
CT
NO FAULT
FAULT
R500mA INPUT CURRENT LIMIT
100mA MAX. INPUT CURRENT LIMIT
CHARGE
TIMER
C
TIMER
INPUT CURRENT LIMIT SET TO 500mA
INPUT CURRENT LIMIT SET TO 100mA
CEN
CHARGER DISABLED
CHARGER ENABLED
POR
INT_3V3
DGND
AGND
Figure 3. MAX8895W Block Diagram
18
Maxim Integrated
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
MICRO
USB-B
BUS_A
BUS_B
SYS_A
SYS_B
V
BUS
C
BUS
C
SYS
BAT
BAT_A
BAT_B
R
D+
D+
D-
D+
C
1-CELL Li+
MAX8895V
MAX8895X
R
D-
D-
GND
THM
R
R
R
R
TB
TP
TS
RWU
SUS_EN
ENU_EN
KB_TM
STDBY
CEN
INT_3V3
C
INT_3V3
T
ISET
IDN
R
R
ISET
IDN
CHG
PREQ
UOK
FLT
CT
C
CT
DGND AGND
Figure 4. MAX8895V/MAX8895X Typical Application Circuit
NAME
VALUE
FUNCTION
C
10FF, 16V
10FF, 6.3V
10FF, 6.3V
Decoupling of input supply.
Decoupling of system rail.
Decoupling of battery rail.
BUS
C
C
SYS
BAT
R
User dependent Thermistor for thermal sensing. See the Thermistor Input (THM) section for details.
User dependent Bias resistors for thermal sensing. See the Thermistor Input (THM) section for details.
T
R
, R , R
TB TP TS
C
0.1FF, 6.3V
Decoupling of internal 3.3V rail.
INT_3V3
Capacitor to set charge timer, optional. See the Fault Output (FLT) and Charge Timer (CT) section
for details.
C
CT
1000pF to 0.2FF
R
1.875kIto 30kI Resistor to set maximum charging current, optional.
15kIto 240kI Resistor to set termination current for charger, optional.
ISET
R
IDN
R , R
D+ D-
33I
D+/D- serial impedance.
Maxim Integrated
19
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
MICRO
USB-B
BUS_A
BUS_B
SYS_A
SYS_B
V
BUS
C
BUS
C
SYS
MAX8895Y
BAT_A
BAT_B
R
D+
D+
D-
D+
D-
C
BAT
1-CELL Li+
R
D-
GND
THM
RWU
KB_TM
STDBY
CEN
R
R
TP
R
R
TB
TS
T
INT_3V3
C
INT_3V3
XIN
ISET
C
XTAL_IN
XTAL
R
ISET
XOUT
C
XTAL_OUT
IDN
CHG
PREQ
UOK
FLT
R
IDN
CT
C
CT
DGND AGND
Figure 5. MAX8895Y Typical Application Circuit
NAME
VALUE
FUNCTION
C
10FF, 16V
10FF, 6.3V
10FF, 6.3V
Decoupling of input supply.
Decoupling of system rail.
Decoupling of battery rail.
BUS
C
C
SYS
BAT
R
User dependent Thermistor for thermal sensing. See the Thermistor Input (THM) section for details.
User dependent Bias resistors for thermal sensing. See the Thermistor Input (THM) section for details.
T
R
, R , R
TB TP TS
C
0.1FF, 6.3V
Decoupling of internal 3.3V rail.
INT_3V3
XTAL
12MHz 2500ppm MAX8895Y only, clock source for full-speed mode, requires a 2500ppm or better accuracy.
MAX8895Y only, crystal load capacitor, only required for full-speed operation. See the External
Crystal/Ceramic Resonator section for details.
C
User dependent
XTAL_IN
C
User dependent MAX8895Y only, crystal load capacitor, only required for full-speed operation.
XTAL_OUT
Capacitor to set charge timer, optional. See the Fault Output (FLT) and Charge Timer (CT) section
for details.
C
CT
1000pF to 0.2FF
R
1.875kIto 30kI Resistor to set maximum charging current, optional.
15kIto 240kI Resistor to set termination current for charger, optional.
ISET
R
IDN
R , R
D+ D-
33I
D+/D- serial impedance.
20
Maxim Integrated
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
MICRO
USB-B
BUS_A
BUS_B
SYS_A
SYS_B
V
BUS
C
BUS
C
C
SYS
BAT
MAX8895W
BAT_A
BAT_B
R
D+
D+
D-
D+
D-
1-CELL Li+
R
D-
GND
THM
DET_DONE
SUS_EN
ENU_EN
KB_TM
R
R
R
TB
TP
TS
INT_3V3
R
THM
C
INT_3V3
STDBY
CEN
ISET
IDN
CHG_TYPE
IBUS_DEF
R
R
ISET
IDN
UOK
FLT
CT
C
CT
DGND AGND
Figure 6. MAX8895W Typical Application Circuit
NAME
VALUE
FUNCTION
C
10FF, 16V
10FF, 6.3V
10FF, 6.3V
Decoupling of input supply.
Decoupling of system rail.
Decoupling of battery rail.
BUS
C
C
SYS
BAT
THM
R
User dependent Thermistor for thermal sensing. See the Thermistor Input (THM) section for details.
User dependent Bias resistors for thermal sensing. See the Thermistor Input (THM) section for details.
R
, R , R
TB TP TS
C
0.1FF, 6.3V
Decoupling of internal 3.3V rail.
INT_3V3
Capacitor to set charge timer, optional. See the Fault Output (FLT) and Charge Timer (CT) section
for details.
C
CT
1000pF to 0.2FF
R
1.875kIto 30kI Resistor to set maximum charging current, optional.
15kIto 240kI Resistor to set termination current for charger, optional.
ISET
R
IDN
R , R
D+ D-
33I
D+/D- serial impedance.
Maxim Integrated
21
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
USB Timing
Detailed Description
The MAX8895_ is an integrated 1-cell Li+ charger with
t
t
FALL
RISE
USB enumeration capability. All power switches for
charging and switching the load between battery and
external power are internal. No external MOSFETS are
required.
90%
10%
The MAX8895_ makes it possible to negotiate more
than 100mA of charging current from a USB host or hub
without processor intervention. The MAX8895_ also auto-
matically detects a dedicated charger or USB charger
and set the input current limit accordingly. The battery
charge current can be set up to 1.85A. Input power not
used by the system charges the battery.
Figure 7. USB Rise and Fall Timing
TEST POINT
3.3Ω
D+ OR D-
MAX8895V
MAX8895W
MAX8895X
MAX8895Y
C = 50pF
15kI
L
USB Interface
An integrated USB peripheral controller provides auto-
enumeration for full-speed (MAX8895Y) and low-speed
(MAX8895V/MAX8895W/MAX8895X) modes.
Figure 8. Load for D+/D- AC Measurements
D+ and D-
The internal USB full speed (MAX8895Y)/low-speed
(MAX8895V/MAX8895W/MAX8895X) transceiver is
brought out to the bidirectional data pins D+ and D-.
These pins are ESD protected up to Q8kV (HBM).
Connect these pins to a USB “B” custom connector
through external 33I series resistors. The MAX8895V/
MAX8895X provide an automatic switchable 1.5kI pul-
lup resistor for D-, while the MAX8895Y provides an auto-
matic switchable 1.5kI pullup resistor for D+.
The USB controller executes the adapter detection
sequence, which consists of detecting the type of
adapter that is externally connected and setting the input
current limit accordingly.
If attached to a USB charger (host or hub) or a USB 2.0
(host or hub), it enumerates as an HID device and nego-
tiates the maximum charging current level (from V
).
BUS_
The MAX8895V/MAX8895W/MAX8895X operate in low-
speed mode, using an internal 6MHz oscillator, and does
not require an external crystal to be USB compliant. The
MAX8895Y operates in full-speed mode and requires an
external 12MHz crystal.
Adapter Detection
When an adapter is present on V , the MAX8895_
BUS_
examines the external device to identify the type of
adapter connected.
According to the USB 2.0 specification, a low-speed
device is not allowed to use a standard USB “B” con-
nector. This is why MAX8895_ is available in both a
low- and full-speed version. This makes it possible to
use a custom or captive cable for low-speed mode
using the MAX8895V/MAX8895W/MAX8895X and still be
USB compliant. Operating in full-speed mode, using the
MAX8895Y allows use of a standard USB “B” connector.
The possible adapter types are:
U Dedicated charger
U USB charger (host or hub)
U USB 2.0 (host or hub) low power
U USB 2.0 (host or hub) high power
Each of these different devices has different current
capability as shown in Table 1.
Table 1. Adapter Types
ADAPTER TYPE
OUTPUT VOLTAGE
OUTPUT CURRENT
4.75V to 5.25V at I
2.0V to 5.25V for I
< 500mA
R500mA
LOAD
Dedicated charger
500mA to 1.85A
LOAD
4.75V to 5.25V at I
< 500mA
R500mA
500mA to 900mA for low speed, full speed
500mA to 1.5A for low speed and full speed
LOAD
USB charger
0 to 5.25V for I
LOAD
USB 2.0 low power
USB 2.0 high power
4.25V to 5.25V
4.75V to 5.25V
100mA (max)
500mA (max)
22
Maxim Integrated
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
When an adapter is connected to the MAX8895_, a
series of tests is performed to identify the type of device
connected. The sequence is done according to the flow
charts in Figures 7 and 8. Figures 9, 10, and 11 show the
adapter-type detection timing.
USB_OK = LOW
USB_OK = LOW
FROM ANY CONDITION
FROM ANY CONDITION
DISABLE V
DP_SRC
DISABLE V
DP_SRC
DISABLE V
DISABLE V
DM_SINK
DM_SINK
DISABLE DM_PU
DISABLE DM_PU
DISABLE I
DISABLE I
_DM_PD
_DM_PD
DISABLE DP_CD_PU
DISABLE DP_CD_PU
USB_OK = HIGH
NO
USB_OK = HIGH
NO
YES
YES
DEBOUNCE
DEBOUNCE
t
t
USB_DB
USB_DB
YES
YES
DISABLE V
DP_SRC
DISABLE V
DP_SRC
STDBY = HIGH
FROM ANY
CONDITION,
DISABLE V
DISABLE DM_PU
STDBY = HIGH
FROM ANY
CONDITION,
DISABLE V
DISABLE DM_PU
DM_SINK
DM_SINK
STDBY = HIGH
STDBY = HIGH
DISABLE I
DISABLE I
_DM_PD
_DM_PD
YES
YES
USB_OK = _HIGH
DISABLE DP_CD_PU
USB_OK = _HIGH
DISABLE DP_CD_PU
I
= I
I
= I
LIM SUS
LIM SUS
NO
NO
I
= I
LIM USB_LP
I
= I
LIM USB_LP
ENU_EN = HIGH
ENU_EN = HIGH
YES
YES
NO
NO
ENABLE V
DP_SRC
ENABLE V
DP_SRC
ENABLE V
ENABLE V
DM_SINK
DM_SINK
DELAY t
DELAY t
DP_SRC_ON
DP_SRC_ON
YES
NO
YES
NO
V
P V
< V
DM DM_IH
V
P V
< V
DM DM_IH
DAT_REF
DAT_REF
DISABLE V
DISABLE V
DP_SRC
DISABLE V
DISABLE V
DP_SRC
DP_SRC
DP_SRC
DISABLE V
ENABLE I
DISABLE V
DISABLE V
ENABLE I
DISABLE V
DM_SINK
DM_SINK
DM_SINK
DM_SINK
I
= I
LIM ENU
I
= I
LIM ENU
_DM_PD
_DM_PD
ENABLE DP_CD_PU
DELAY t
ENABLE DP_CD_PU
DELAY t
DP_SRC_HC
DP_SRC_HC
DELAY t
ENABLE DM_PU
DELAY t
ENABLE DM_PU
DP_SRC_HC
DP_SRC_HC
DISABLE DM_PU
DISABLE DM_PU
NO
NO
YES
NO
NO
YES
ENUMERATION
SUCCEEDED
ENUMERATION
SUCCEEDED
DM > V
DM_IH
DM > V
DM_IH
I
= I
I
= I
LIM SUS
DELAY t
LIM SUS
DELAY t
FAULT
FAULT
DISABLE I
_DP_PD
DISABLE
DISABLE I
_DP_PD
DISABLE
YES
YES
I
= I
I
= I
LIM DCHG
LIM DCHG
DP_CD_PU
ENABLE DM_PU
DP_CD_PU
ENABLE DM_PU
ILIM = USB_LP
OR USB_HP
ILIM = USB_LP
OR USB_HP
I
= I
I
= I
LIM USS_CHG
LIM USS_CHG
DISABLE DP_PU
DISABLE DP_PU
NO
NO
ENUMERATION
SUCCEEDED
ENUMERATION
SUCCEEDED
I
= I
NO
NO
USB
I
= I
USB
SUSPEND?
LIM SUS
DELAY t
LIM SUS
DELAY t
SUSPEND?
FAULT
FAULT
YES
YES
YES
YES
I
= I
LIM USB_CHG
I
= I
LIM USB_CHG
YES
YES
SUS_EN = LOW
NO
SUS_EN = LOW
NO
I
= I
I
= I
LIM SUS
LIM SUS
USB HOST
D- HIGH TO LOW
TRANSITION
USB HOST
D- HIGH TO LOW
TRANSITION
YES
YES
NO
NO
YES
NO
YES
CHARGE
DONE
CHARGE
DONE
DELAY t
INITIATE
RESUME
DELAY t
INITIATE
RESUME
RWU
RWU
NO
NO
RWU
SUPPORTED
BY HOST
YES
RWU = LOW
YES
NO
RWU
SUPPORTED
BY HOST
NO
YES
RWU = LOW
YES
NO
DELAY t
RE_ENUM
DELAY t
RE_ENUM
Figure 9. MAX8895X Flow Chart for Adapter Type Detection
Figure 10. MAX8895V Flow Chart for Adapter Type Detection
23
Maxim Integrated
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
USB_OK = LOW
FROM ANY CONDITION
DISABLE V
DP_SRC
DISABLE V
DM_SINK
DISABLE DP_PU
DISABLE I
_DM_PD
DISABLE DP_CD_PU
USB_OK = HIGH
NO
YES
DEBOUNCE
t
USB_DB
YES
DISABLE V
DP_SRC
DISABLE V
DISABLE DP_PU
STDBY = HIGH
FROM ANY
CONDITION,
DM_SINK
STDBY = HIGH
DISABLE I
_DM_PD
DISABLE DP_CD_PU
= I
YES
USB_OK = _HIGH
I
LIM SUS
NO
I
= I
LIM USB_LP
ENU_EN = HIGH
YES
NO
ENABLE V
DP_SRC
DM_SINK
ENABLE V
DELAY t
DP_SRC_ON
YES
NO
V
P V < V
DM
DAT_REF
DM_IH
DISABLE V
DISABLE V
ENABLE I
DISABLE V
DP_SRC
DP_SRC
DM_SINK
_DM_PD
DISABLE V
DM_SINK
I
= I
LIM ENU
ENABLE DP_CDC_PU
DELAY t
DELAY t
ENABLE DP_PU
DP_SRC_HC
DP_SRC_HC
DISABLE DP_PU
NO
NO
YES
ENUMERATION
SUCCEEDED
DM > V
I
= I
DM_IH
LIM SUS
DELAY t
FAULT
DISABLE I
DISABLE
_DP_PD
YES
I
= I
LIM DCHQ
DP_CD_PU
ENABLE DP_PU
ILIM = USB_LP
OR USB_HP
I
= I
LIM USS_CHG
DISABLE DP_PU
NO
ENUMERATION
SUCCEEDED
I
= I
LIM SUS
DELAY t
NO
USB
FAULT
SUSPEND?
YES
YES
I
= I
LIM USB_CHG
YES
SUS_EN = LOW
NO
I
= I
LIM SUS
USB HOST
D+ HIGH TO LOW
TRANSITION
YES
NO
YES
CHARGE
DONE
NO
RWU
SUPPORTED
BY HOST
DELAY t
RWU
INITIATE
RESUME
YES
NO
NO
RWU = LOW
YES
DELAY t
RE_ENUM
Figure 11. MAX8895Y Flow Chart for Adapter Type Detection
24
Maxim Integrated
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
USB_OK = LOW
FROM ANY CONDITION
DISABLE V
DP_SRC
DISABLE V
DM_SINK
DISABLE DM_PU
DISABLE I
_DM_PD
DISABLE DP_CD_PU
NO
USB_OK = HIGH
YES
DEBOUNCE
t
USB_DB
YES
DISABLE V
DP_SRC
DISABLE V
DISABLE DP_PU
DM_SINK
STDBY = HIGH
FROM ANY
CONDITION,
DISABLE I
STDBY = HIGH
NO
_DM_PD
YES
DISABLE DP_CD_PU
USB_OK = _HIGH
I
= I
LIM SUS
DET DONE = 1
ENABLE V
DP_SRC
ENABLE V
DM_SINK
DELAY t
DP_SRC_ON
YES
NO
DM = V
DAT_REF
DISABLE V
DISABLE V
DISABLE V
DP_SRC
DP_SRC
DM_SINK
DISABLE V
DM_SINK
ENABLE I
I
= I
LIM ENU
_DM_PD
ENABLE DP_CDC_PU
DELAY t
ENABLE DP_PU
DP_SRC_HC
DELAY t
DP_SRC_HC
NO
ENU_EN =
LOW
NO
YES
I
= V
IBUS_DEF
LIM
DM > V
DM_IH
YES
DISABLE I
I
= I
_DP_PD
LIM DCHG
DISABLE DP_CD_PU
DET_DONE = 0
ENABLE DM_PU
IBUS_DEF = 1
DISABLE DM_PU
NO
ENUMERATION
SUCCEEDED
I
= I
LIM USB_CHG
I
= I
LIM SUS
DELAY t
DET_DONE = 0
IBUS_DEF = 1
FAULT
YES
DET_DONE = 0
DISABLE DM_PU
NO
ENUMERATION
SUCCEEDED
I
= I
LIM SUS
DELAY t
FAULT
ILIM = USB_LP
or USB_HP
YES
I
= I
LIM USB_CHG
NO
USB
SUSPEND?
YES
YES
SUS_EN = LOW
NO
I
= I
LIM SUS
DET_DONE = 0
USB HOST
D+ HIGH TO LOW
TRANSITION
YES
NO
YES
CHARGE
DONE
NO
RWU
SUPPORTED
BY HOST?
DELAY t
INITIATE
RESUME
RWU
YES
Figure 12. MAX8895W Flow Chart for Adapter Type Detection
Maxim Integrated
25
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
MAX8895Y. In this mode, the D+ and D- lines become
high impedance. When STDBY is high, V
is regulated
SYS_
ENUMERATION INITIATED
to 50mV (typ) below V
.
BAT_
I
= 500mA
LIM
USB Suspend
SEND CONNECT
According to the USB rev 2.0 specification, when a USB
host stops sending traffic for at least 10ms to a peripher-
al (MAX8895_), the peripheral must enter a power-down
state called SUSPEND. Once suspended, the peripheral
must have enough of its internal logic active to recognize
when the host resumes signaling, or if enabled, for gen-
erating remote wake-up.
YES
NO
IC IS IN
CONFIGURED
STATUS
NO
t < t
ENUM
YES
YES
DISABLE
DM_PU (MAX8895V/MAX8895W/
MAX8895X)
ENUM_500mA
The MAX8895_ enters SUSPEND state in two ways:
DP_PU (MAX8895Y)
U MAX8895V/MAX8895W/MAX8895X: When no activi-
ty is present on D+/D- for 10ms (max), the MAX8895V/
MAX8895W/MAX8895X automatically enters sus-
pend mode to be compliant with USB specification.
The MAX8895V/MAX8895W/MAX8895X only enters
suspend mode if SUS_EN is pulled high. When
entering suspend mode the MAX8895V/MAX8895W/
DELAY t
ENU_FAULT
I
= 100mA ENABLE
LIM
DM_PU (MAX8895V/MAX8895W/
MAX8895X)
DP_PU (MAX8895Y)
NO
MAX8895X disables the charger as well as V
SYS_
IC IS IN
CONFIGURED
STATUS
to reduce the input current drawn from V
. The
BUS_
t < t
ENUM
current drawn in this mode is less than 500FA for the
MAX8895V/MAX8895W/MAX8895X, ensuring that the
device is compliant with USB specification. In sus-
pend state the bus is IDLE: D+ is low and D- is kept
high by the MAX8895V/MAX8895W/MAX8895X pul-
YES
YES
DISABLE DM_PU
DELAY t
ENUM_100mA
ENU_FAULT
lup resistor. When in suspend mode, V
is pow-
SYS_
RETURN TO MAIN LOOP
ered from V
. When entering automatic suspend
BAT_
mode, the FLT output is pulled low as an indication
that the charger is disabled.
Figure 13. Flow Chart for Enumeration Process
U MAX8895Y: When no activity is present on D+/D- for
10ms (max), the MAX8895Y automatically enters
suspend mode to be compliant with USB specifica-
tion. When entering suspend mode, the MAX8895Y
Once the type of adapter is determined, the MAX8895_
determines the maximum input current limit, if the exter-
nal adapter is recognized as a USB charger or USB 2.0
device. The MAX8895_ then initiates enumeration and
determine the maximum input current limit according to
Figure 13.
disables the charger as well as V
to reduce the
SYS_
input current drawn from V . The current drawn in
BUS_
this mode is less than 2.5mA, ensuring that the device
is compliant with the USB specification.
Low-Power Mode
Driving STDBY high disables the charger as well as
In suspend state, the bus is IDLE: D- is low and D+ is
kept high by the MAX8895Y pullup resistor. When in
V
SYS_
, to reduce the input current drawn from V
.
BUS_
suspend mode, V
is powered from V . When
BAT_
SYS_
The current drawn in this mode is less than 500FA for the
MAX8895V/MAX8895W/MAX8895X and 2.5mA for the
entering automatic suspend mode, the FLT output is
pulled low as an indication that the charger is disabled.
26
Maxim Integrated
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
V
BUS_
DEDICATED CHARGER
USB CHARGER
1800mA
1500mA
0.5mA
INPUT CURRENT LIMIT
0mA
ON
t
DP_SRC_ON
V
DP_SRC
OFF
ON
CHARGER
(MAX8895V
MAX8895X)
I
DM_SINK
OFF
ON
DM_PU
OFF
LOGIC-HIGH
DEDICATED CHARGER
USB CHARGER
DEDICATED CHARGER
OR USB CHARGER
D-
LOGIC-LOW
t
DP_SRC_HC
LOGIC-HIGH
LOGIC-LOW
V
FLT
Figure 14a. Charger Detection Timing Diagram (MAX8895V/MAX8895X)
V
BUS_
USB 2.0 HIGH POWER
USB 2.0 LOW POWER
500mA
100mA
INPUT CURRENT LIMIT
0.5mA
0mA
ON
t
DP_SRC_ON
V
DP_SRC
OFF
ON
USB 2.0
(MAX8895V
MAX8895X)
I
DM_SINK
OFF
ON
DM_PU
OFF
LOGIC-HIGH
D-
LOGIC-LOW
LOGIC-HIGH
LOGIC-LOW
V
FLT
Figure 14b. USB Detection Timing Diagram (MAX8895V/MAX8895X)
Maxim Integrated
27
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
V
BUS_
DEDICATED CHARGER
USB CHARGER
1800mA
1500mA
0.5mA
INPUT CURRENT LIMIT
0mA
ON
t
DP_SRC_ON
V
DP_SRC
OFF
ON
CHARGER
(MAX8895Y)
I
DM_SINK
OFF
ON
DP_PU
OFF
LOGIC-HIGH
DEDICATED CHARGER
USB CHARGER
DEDICATED CHARGER
OR USB CHARGER
D-
LOGIC-LOW
t
DP_SRC_HC
LOGIC-HIGH
LOGIC-LOW
V
FLT
Figure 15a. Charger Detection Timing Diagram (MAX8895Y)
V
BUS_
USB 2.0 HIGH POWER
USB 2.0 LOW POWER
500mA
100mA
INPUT CURRENT LIMIT
0.5mA
0mA
ON
t
DP_SRC_ON
V
DP_SRC
OFF
ON
USB 2.0
(MAX8895Y)
I
DM_SINK
OFF
ON
DP_PU
OFF
LOGIC-HIGH
D-
LOGIC-LOW
LOGIC-HIGH
LOGIC-LOW
V
FLT
Figure 15b. USB Detection Timing Diagram (MAX8895Y)
28
Maxim Integrated
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
V
BUS
1800mA
1500mA
0.5mA
INPUT CURRENT LIMIT
0mA
ON
t
DP_SRC_ON
V
DP_SRC
OFF
ON
V
DM_SINK
DM_PU
OFF
ON
OFF
LOGIC-HIGH
D-
LOGIC-LOW
t
DP_SRC_CON
LOGIC-HIGH
LOGIC-LOW
DET_DONE
LOGIC-HIGH
LOGIC-LOW
IBUS_DEF
Figure 16a. Charger Detection Timing Diagram (MAX8895W)
V
BUS
USB 2.0 HIGH POWER
USB 2.0 LOW POWER
500mA
100mA
0.5mA
INPUT CURRENT LIMIT
0mA
ON
t
DP_SRC_ON
V
DP_SRC
OFF
ON
V
DM_SINK
DM_PU
OFF
ON
OFF
LOGIC-HIGH
D+
LOGIC-LOW
t
DP_SRC_CON
LOGIC-HIGH
LOGIC-LOW
DET_DONE
LOGIC-HIGH
LOGIC-LOW
IBUS_DEF
Figure 16b. USB Detection Timing Diagram (MAX8895W)
Maxim Integrated
29
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
Wake-Up and USB Resume
The MAX8895_ can wake up four ways while in suspend
mode:
Enumeration is started on the MAX8895V/MAX8895W/
MAX8895X only if ENU_EN is logic-low. If ENU_EN is
logic-high, the MAX8895V/MAX8895W/MAX8895X does
not connect a pullup resistor between D- and INT_3V3,
and the current limit is set to 100mA regardless of the
input type.
U Logic-high to logic-low transition of STDBY initiating
enumeration.
U MAX8895V/MAX8895W/MAX8895X: If STDBY is
logic-low and SUS_EN is logic-high, the MAX8895V/
MAX8895W/MAX8895X monitor the bus activity on
the D- line. If the host resumes bus activity, the
MAX8895V/MAX8895W/MAX8895X detects this as a
1 to 0 transition on D-. Once this occurs, the device
restarts the oscillator and waits for it to stabilize.
When the USB 2.0 host/hub or USB charger detects a
plugged-in peripheral (MAX8895_), it interrogates the
peripheral to learn about its capabilities and require-
ments; and if all is well, configures it to bring it on line.
This process is known as enumeration.
During enumeration the host sends multiple requests to the
device (MAX8895_) asking for descriptors (see Table 2)
that define the device operation.
U MAX8895Y: If STDBY is logic-low, the MAX8895Y
monitors the bus activity on the D+ line. If the host
resumes bus activity, the MAX8895Y detects this as a
1 to 0 transition on D+. Once this occurs, the device
restarts the oscillator and waits for it to stabilize.
All the enumeration tasks are self-managed by the
MAX8895_ serial interface engine (SIE) without any pro-
cessor intervention.
U Remote wake-up is supported by the MAX8895V/
MAX8895X/MAX8895Y, but the remote wake-up fea-
ture must be enabled by the host during the enu-
meration process. Once suspended, the MAX8895V/
MAX8895X/MAX8895Y look at the state of the battery
charger. If the charger is not in the done state, the
MAX8895V/MAX8895X/MAX8895Y initiate a remote
wake-up signal. If the charger is in the done state, a
remote wake-up is not initiated before the charger is
restarted due to a drop in battery voltage.
The SIE supports the following features:
U USB 2.0 low-speed (1.5Mbps): the MAX8895V/
MAX8895W/MAX8895X pulls D- high to indicate to the
host that it is a low-speed device
U Full-speed (12Mbps) operation: the MAX8895Y pulls
D+ high to indicate to the host that it is a full-speed
device
U Human interface device (HID) in the consumer page
(MAX8895_ does not require any custom drivers)
U 8 bytes end-point zero (control end point)
U 1 byte end-point one (INT-IN end point)
U USB suspend/resume support
U When the MAX8895V/MAX8895X/MAX8895Y initiate
a remote wake-up, they first restart the oscillator and
wait for the oscillator to stabilize, and then send the
remote wake-up event to signal to the host that it
needs to be driven out of the suspend status.
U Remote wake-up capability
At the end of enumeration (if successful), the device is
ready to transfer data (if needed) and enabled to sink the
U If RWU is connected to ground and the remote
wake-up feature has not been set by the host during
negotiated current from V
.
BUS_
enumeration, the IC waits t
after entering
RE_ENUM
suspend mode, then disconnects the pullup resistor
and reinitiates the charger type detection.
Figure 17 shows USB bus traffic as captured by a
CATC USB bus analyzer. The traces show a PC (host)
enumerating the peripheral (MAX8895V/MAX8895W/
MAX8895X). Notice that the LS field indicates the
low-speed (1.5Mbps) operation of the MAX8895V/
MAX8895W/MAX8895X.
Enumeration
USB bus enumeration is an activity that identifies and
assigns unique addresses to devices attached to the
bus. Once the MAX8895_ detects V
is valid for
BUS_
T
, the MAX8895_ initiates the detection process
1) The host uses the default CONTROL end-point EP0
(shown in the “ENDP” boxes) to send a request to the
device. The host initially sends requests to address
0 (shown in the ADDR boxes) to communicate with a
device to which it has not yet assigned a unique address.
USB_DB
to determine the type of device that it is connected to.
If the device type is a USB 2.0 host/hub or USB char-
ger, a 1.5kI pullup resistor is connected between D-
(MAX8895V/MAX8895W/MAX8895X) or D+ (MAX8895Y)
to INT_3V3.
30
Maxim Integrated
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
Figure 17. USB Bus Traffic: MAX8895V/MAX8895W/MAX8895X Enumeration
Maxim Integrated
31
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
Figure 18. USB Bus Traffic: MAX8895Y Enumeration
32
Maxim Integrated
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
2) The host begins by sending a Get_Descriptor_Device
request (Transfer 0 in Figure 16). It does this to deter-
mine the maxPacketSize of the device’s EP0 buffer
(for the MAX8895V/MAX8895X, it is 8 bytes). The host
then resets the device by issuing a bus reset (packet
69).
According to the USB 2.0 specification, a bus powered
device can be either low power (it may draw no more
than 100mA) or high power (it may draw no more than
500mA).
All devices must default to low power. The transition to
high power is under software control (running on the
host side). It is the responsibility of software to ensure
adequate power is available before allowing devices to
consume high-power.
3) In transfer 1, the host assigns a unique address to
the peripheral by using the Set_Address request.
The assigned address depends on how many other
USB devices are currently attached to the host.
In this case, the address assigned to our periph-
eral device (MAX8895V/MAX8895X) is 3. Thereafter,
the MAX8895V/MAX8895X respond only to requests
directed to address 3. This address remains in force
until the host does a bus reset or the device is dis-
connected. Notice that the peripheral address field
(ADDR) in the bus trace changes from 0 to 3 after
transfer 1.
The MAX8895_ initiates enumeration by asking for
500mA of current. If the MAX8895_ does not enter con-
figured status before the t
(10s, typ), it interprets
ENUM
this as an indication that the host is not able to support
the requested current. The MAX8895_ disconnects
the pullup resistor on D- (MAX8895V/MAX8895X)/D+
(MAX8895Y), wait for t
, and then retry to enu-
ENU_FAULT
merate, but now as a low current device (100mA). If the
MAX8895_ has still not reached the configured status
4) In transfers 2 to 11, the host asks for various descrip-
tors. The device FSM needs to determine from the
eight setup bytes which descriptor to send, use this
information to access one of several character arrays
(ROMs) representing the descriptor arrays.
after t
, the MAX8895_ assumes that either the host
ENUM
is nonresponsive or a wrong adapter type is detected.
In this case, the MAX8895_ disconnects the pullup
resistor on D- (MAX8895V/MAX8895W/MAX8895X)/D+
(MAX8895Y) and wait for t
+ t
before
ENU_FAULT
FAULT
starting the adapter detection process again.
5) In transfer 12, the host requests the device to use the
specified configuration (1) and the device enters the
configured state.
Figure 18 shows the USB traffic captured during the
MAX8895Y enumeration. Notice the field FS indicates the
full-speed (12Mbps) operation of the MAX8895Y.
Table 2. Device Descriptor
LENGTH OFFSET
FIELD
DECODED HEXVALUE
DESCRIPTION
(bits)
(bits)
bLength
bDescriptorType
bcdUSB
bDeviceClass
bDeviceSubClass
bDeviceProtocol
bMaxPacketSize0
idVendor*
8
8
16
8
8
8
0
8
0x12
0x01
0x0200
0x00
0x00
0x00
0x08
—
0x5346
0x1234
0x12
Descriptor size is 18 bytes
Device descriptor type
0x01
0x0200
0x00
0x00
0x00
0x08
—
0x5346
0x1234
16
32
40
48
56
64
80
96
Device compliant to the USB specification version 2.0
Each interface specifies its own class information
Each interface specifies its own subclass information
No protocols the device basis
Maximum packet size for end-point zero is 8
Vendor ID is 2922: Maxim Integrated Products
Product ID is 21318
8
16
16
16
idProduct*
bcdDevice
The device release number is 1.00
The device does not have the string descriptor
describing the manufacturer
iManufacturer
iProduct
8
8
8
8
112
120
128
136
0x00
0x01
0x00
0x01
0x00
0x01
0x00
0x01
The product stringed descriptor index is 1
The device does not have the string descriptor
describing the serial number
iSerialNumber
bNumConfigurations
The device has 1 possible configuration
Maxim Integrated
33
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
load current. If the system load continuously exceeds the
input current limit, then the battery does not charge, even
though external power is connected. This is not expected
to occur in most cases, since high loads usually occur
only in short peaks. During these peaks, battery energy is
used, but at all other times the battery charges.
Smart Power Selector
The Smart Power Selector seamlessly distributes power
between the external V
and the system load (V
input, the battery (V ),
BAT_
BUS_
). See Figure 19. The Smart
SYS_
Power Selector basic functions are:
U With both an external adapter and battery connected:
Input Limiter
The input limiter distributes power from the external
adapter to the system load and battery charger. In addi-
tion to the input limiter’s primary function of passing
power to the system and charger, it performs several
additional functions to optimize use of available power.
a. When the system load requirements are less than
the input current limit, the battery is charged with
residual power from the input.
b. When the system load requirements exceed the
input current limit, the battery supplies supplemental
current to the load.
U Input Voltage Limiting: If the V
input voltage
BUS_
U When the battery is connected and there is no external
is above the overvoltage threshold (V ), the
BUS_OVP
power input, the system is powered from the battery.
MAX8895_ enters overvoltage lockout (OVL). OVL
protects the MAX8895_ and downstream circuitry
U When an external power input is connected and there
is no battery, the system is powered from V
.
BUS_
from high-voltage stress up to 16V at V
. In OVL,
BUS_
V
remains on, the input switch that sees
If the junction temperature starts to get too hot (+110NC
typ), the charging rate is reduced. If this is not sufficient
to cool down the MAX8895_, the input current limit is
then reduced.
INT_3V3
overvoltage (Q1, Figure 19) opens, FLT is pulled low,
and UOK, CHG, DET_DONE, and PREQ become
high-impedance. In OVL, the charger turns off. The
V
BAT_
- V
switch (Q2, Figure 19) closes, allowing
SYS_
System Load Switch
the battery to power V
is less than V
threshold (V
age, V
. V
is also invalid if it
SYS_ BUS_
An internal 55mI (typ) MOSFET connects V
to
SYS_
, or less than the USB undervoltage
BAT_
V _ (Q2, Figure 19) when no voltage source is avail-
BAT
). With an invalid input volt-
BUS_UVLO_F
able at V
and V
is above the battery UVLO
BUS_
BAT_
connects to BAT_ through a 55mI (typ)
SYS_
threshold. When an external source is detected at
switch (Q2, Figure 19).
V
V
, this switch controls the charging of V
is powered from the valid input source through the
and
BUS_
SYS_
BAT_
U Input Overcurrent Protection: The current at V
BUS_
is limited to prevent input overload. This current limit is
automatically selected to match the capabilities of the
adapter source, whether it is a 100mA or 500mA USB
2.0 source, or 500mA to 1.8A for a dedicated adap-
tor or USB charger. When the load exceeds the input
input current limiter.
The V - V switch also prevents V from fall-
SYS_
SYS_
BAT_
ing below V
when the system load exceeds the input
BAT_
current limit. If that should happen, V
is allowed to
SYS_
drop to V
. At this point, the V
- V
switch
BAT_
SYS_
BAT_
current limit, V
drops to 50mV (typ) below V
SYS_
BAT_
turns on so that the battery supplies additional I
SYS_
and the battery supplies supplemental load current.
V
V
BUS_
SYS_
BAT_
CHARGE
CURRENT
LOAD
CURRENT
SYSTEM
LOAD
Q1
Q2 CHARGE
AND SYS LOAD
SWITCH
V
V
140mV
SYS_
3.4V (min)
V
1-CELL Li+
BAT_
MAX8895V
GND
MAX8895W
MAX8895X
MAX8895Y
TIME
Figure 20. V
Regulation
SYS_
Figure 19. Smart Power Selector Block Diagram
34
Maxim Integrated
*Contact factory for specific vendor ID and product ID.
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
V
BUS_
440mV (typ)
140mV (typ)
I
IILM
500mA
V
SYS_
BAT_
3.4V (min)
V
TIME
ADAPTER TYPE DETECTION
ADAPTIVE INPUT CURRENT-LIMIT REGULATION
Figure 21. Adaptive Input Current-Limit Regulation Loop
U Thermal Limiting: The MAX8895V/MAX8895X/
MAX8895Y reduce input current by 5%/NC when its
Input Current Limit
If the connected adapter is a USB 2.0 device the input
current limit is set by default to 100mA.
die temperature exceeds T
(+110NC typ). The
DIE_LIM
system load (V
) has priority over charger cur-
SYS_
If ENU_EN is connected to INT_3V3 or driven logic-high
for the MAX8895V/MAX8895X/MAX8895Y, the charger
input current limit remains at 100mA. If ENU_EN is set to
logic-high for the MAX8895W the charger’s input current
limit is determined by the logic state of IBUS_DEF.
rent, so the input current is first reduced by lowering
the charge current. If the junction temperature still
reaches T
+20NC in spite of charge current
DIE_LIM
reduction, no input V
current is drawn, the bat-
BUS_
tery supplies the entire system load, and V
is
SYS
When ENU_EN is connected to AGND, automatic enu-
meration is initiated. The MAX8895_ proceeds to deter-
mine if the external USB device is a low- or high-power
device and set the input current limit to 100mA or
500mA, respectively. For a dedicated charger or USB
charger, the current limit is determined by loading the
adapter. When the adapter’s output voltage starts to
collapse, it is an indication that the current limit of the
device is reached.
regulated at 50mV (typ) below V
.
BAT_
Note: The on-chip thermal limiting circuitry is not
related to, and operates independently from, the
thermistor input.
U Adaptive Battery Charging: While the system is
powered from V , the charger draws power from
BUS_
V
SYS_
to charge the battery. If the combined load
between the charger and system exceeds the input
current limit, an adaptive charger control loop reduces
The MAX8895_ set the input current limit to regulate
charge current to prevent the V
lapsing.
voltage from col-
SYS_
V
BUS
to V
+440mV (typ). This ensures that the power
SYS
dissipation in the MAX8895_ is kept to a minimum, and
at the same time, ensuring that the adapter’s current
capability is fully utilized. When a dedicated charger is
detected, the input current limited is limited by the adap-
tive input current limit. In this mode, it is up to the adapter
to limit the maximum current, which is 1.85A for a dedi-
cated charger and 1.5A for a USB charger, according to
the USB charging specification.
Regulation Threshold
The MAX8895_ always regulates V to 140mV (typ)
SYS_
above V
with a minimum voltage of 3.4V regardless
BAT_
of what device is connected. The 3.4V minimum voltage
regulation reduces the ripple on V _ during peak load
SYS
conditions where the input current limit is tripped.
Maxim Integrated
35
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
U The initial detection threshold allows all types of
If the adapter output (V
) starts to drop below V
SYS
BUS
adapters to be detected on V . Once the type
BUS_
- 440mV (typ), the input current limit function adap-
tively decreases the input current limit to ensure that the
adapter is not overloaded. When the input current limit
is reached, the first action taken by the MAX8895_ is to
reduce battery charge current. If, after the charge cur-
of adapter is determined, the UVLO threshold is
changed.
U For any USB 2.0 device the UVLO thresholds are set
to be compliant with USB specifications.
rent is reduced to 0mA, the load at I
still exceeds the
SYS
U For a dedicated charger, the UVLO (falling) threshold
input current limit, V
begins to fall. When V
drops
SYS
SYS
is lowered to V
+ 50mV (typ) to allow for support-
SYS_
to 50mV below V , the V
BAT
- V
switch turns on,
SYS
BAT
ing collapsing charger types, allowing the MAX8895_
to operate with lower power dissipation.
using battery power to support the system load during
the load peak. See Figure 21 for more information.
Note that since the V
UVLO threshold is changed
BUS_
Power Monitor Output (UOK)
UOK is an open-drain output that pulls low when the
after initial detection of the device type, there are condi-
tions where the MAX8895_ can toggle between V
BUS_
V
input has valid power.
BUS_
valid and not valid. This is an indication that the adapter
is not within the specified limits.
The UOK monitor has several different thresholds,
depending on what type of adapter detected. The differ-
ent thresholds are as follows:
See Table 3 for more information.
Table 3. UOK Monitor Thresholds
THRESHOLDS
UVLO
OVLO (V)
Initial V
detection
4.0V (typ), rising
3.9V (typ), falling
4.1V (typ), falling
BUS_
For USB 2.0 low power
6.9
For USB 2.0 high power
For dedicated charger to USB charger
V
+ 50mV (typ), falling
SYS_
V
CHG_REG
V
BAT_FCHG_R
I
FCHG
0.6 x I
FCHG
I
I
CHG_DONE
V
BAT_PCHG_R
PCHG
TIME
MAINTENANCE
CHARGE
CHARGE
DONE
PRECHARGE
t < t
FAST-CHARGE
TOP-OFF
t < t
t = t
MTCHG
PCHG
FCHG
Figure 22. Charging States
36
Maxim Integrated
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
Soft-Start
To prevent input transients that can cause instability in
NO VALID V
BUS
the USB power source, the rate of change of input cur-
rent and charge current is limited. When a valid USB 2.0
input is connected, the input current limit is ramped from
0 to 100mA in 50Fs. Once enumeration is ended, the cur-
rent can be ramped to 500mA or to the new input current
limit value in 50Fs.
V
V
> V
BUS_
OR
BUS_UVLO
< V
BUS_
UOK = HIGH-Z
(CHG = HIGH-Z)
FLT = HIGH-Z
BUS_OVP
FROM ANY STATE
I
= 0mA
CHG
V
< V
< V
BUS_ BUS_OVP
BUS_UVLO
CHARGER OFF
When the charger is enabled, the charge current ramps
from zero to the final value in 1.5ms (typ). Charge cur-
rent also ramps when transitioning to fast-charge from
prequalification and when changing the USB charge
current from 100mA to 500mA.
UOK = LOW
(CHG = HIGH-Z)
FLT = LOW
CEN = HIGH
FROM ANY STATE
I
= 0mA
CHG
CEN = LOW
RESET CHARGE TIMER
Note: There is no di/dt limiting if I
is changed sud-
ISET
PREQUAL
denly using a switch at R
.
ISET
t
t
>
CHG_TIMER
PCHG
UOK = LOW
PREQ = LOW
(CHG = LOW)
FLT = HIGH-Z
Battery Charger
The battery charger has five different states of operation
(see Figures 22 and 23):
I
= I
CHG PCHG
V
> V
BAT_PCHG_R
BAT_
V
< V
BAT_PCHG_F
BAT_
RESET CHARGE TIMER
RESET CHARGE
TIMER
U Precharge: When the battery voltage is below
V
. In this state, the battery is charged
BAT_PCHG_R
FAULT
FAST-CHARGE
t
t
>
CHG_TIMER
FCHG
at maximum I
precharging current is determined by the I
. If the I > I , then the
PCHG PCHG LIM
UOK = LOW
(CHG = HIGH-Z)
FLT = LOW
UOK = LOW
(CHG = LOW)
FLT = HIGH-Z
(input
LIM
I
= 0mA
CHG
current limit). Charging a Li+ battery at high charging
current when it is fully discharged can cause the bat-
tery to become unstable and potentially dangerous.
Charging at high charging rates on a fully discharged
battery can also reduce life cycles of the Li+ battery.
*I
= I
CHG FCHG
V
< V
BAT_FCHG_F
BAT_
V
> V
BAT_FCHG_R
BAT_
TOP-OFF
CHARGE
V
< V
BAT_ BAT_PCHG_F
RESET CHARGE TIMER
UOK = LOW
(CHG = LOW)
FLT = HIGH-Z
t
> t
CHG_TIMER FCHG
U Fast-charge: In fast-charge mode, the charging cur-
*CHARGE TIMER
SLOWED DOWN BY X2
rent is set to maximum I
current is determined by I
. The actual charging
FCHG
I = I /2
CHG FCHG
IF: I /2
< I
CHG FCHG
I
I
t
< I
AND
CHG CHG_DONE
- I
.
AND PAUSED IF:
< I /5
LIM SYS_
I
R I
< I
CHG CHG_DONE
RESET CHARGE
BUS LIM
I
CHG FCHG
< t
DIE DIE_LIM
U Top-off charge: In top-off mode, the battery voltage
has almost reached the set point (V ). The
TIMER
RESET CHARGE TIMER
BAT_FCHG_R
MAINTENANCE
CHARGE
(
) MAX8895V/MAX8895X/
MAX8895Y ONLY
charging current is reduced in this mode to prevent
overcharging the battery, and also to minimize the
power dissipation in the battery.
UOK = LOW
(CHG = HIGH-Z)
FLT = HIGH-Z
I
< I
CHG CHG_DONE
FROM ANY CHARGING STATE
T
< T
A
THM_COLD
< T
THM_HOT
U Maintenance charge: The charger enters this mode
t
> t
CHG_TIMER MTCHG
T
T
> T OR
THM_COLD
THM_HOT
A
when the charging current has dropped below the
< T
A
TEMPERATURE
SUSPENSE
I
threshold. The charger continues to
CHG_DONE
DONE
V > V
BAT_ BAT_RECHG
charge for t
time to ensure the battery is fully
MTCHG
UOK = LOW
(CHG = HIGH-Z)
FLT = HIGH-Z
RESET CHARGE
UOK = LOW
(CHG = HIGH-Z)
FLT = HIGH-Z
charged before the charger is disabled.
TIMER
I
= 0mA
CHG
CHARGE TIMER PAUSED
U Charge done: Charger is disabled and only en-
I
= 0mA
CHG
gages again if the battery voltage drops below the
V
threshold.
BAT_RECHG
Figure 23. Charger Flow Chart
Maxim Integrated
37
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
Charge Enable (CEN)
When CEN is logic-low, the battery charger is enabled.
When CEN is logic-high, the battery charger is disabled.
Monitoring Charge Current (ISET)
In addition to setting charge current, ISET can also be
used to monitor the actual current charging the battery.
The ISET output voltage is:
CEN does not affect V . In many systems, there is
SYS_
no need for the system controller (typically a micro-
processor) to disable the battery charger because the
MAX8895_ Smart Power Selector circuitry independently
manages charging and USB-battery power handover. In
these situations, CEN may be connected to ground.
V
ISET
I
=
× 2000
CHG
R
ISET
where:
is the actual battery charge current, R
resistor from ISET to ground.
A 1.5V output indicates the battery is being charged
at the maximum fast-charge current (I ). 0V indi-
cates no charging. The ISET voltage is also used by the
charger control circuitry to set and monitor the battery
current. Avoid adding more than 10pF of capacitance
directly to the ISET pin. If filtering of the charge current
monitor is necessary, add a resistor of 100kI or more
between ISET and the filter capacitor to preserve char-
ger stability.
I
is a
ISET
CHG
Setting Charge Current (ISET)
ISET adjusts the charge current to match the capacity of
the battery. The maximum charging current can be fixed
by connecting ISET to INT_3V3 or can be adjusted by
connecting ISET to ground through a resistor. When ISET
is connected to ground through a resistor the maximum
charging current is determined using the following for-
mula:
FCHG
3000
I
=
FCHG
R
ISET
If the maximum charge current (I
default value, the current monitor function is not available.
), is set to the
FCHG
where R
is a resistor from ISET to ground.
ISET
Determine the I
value by considering the charac-
FCHG
Charge Termination (IDN)
When the charge current falls to the termination thresh-
old and the charger is in voltage mode, charging is com-
plete. Charging continues for a time period defined by
teristics of the battery. It is not necessary to limit charge
current based on the capabilities of the expected adapt-
er input, the system load, or thermal limitations of the
PCB. The MAX8895_ automatically adjusts the charging
algorithm to accommodate these factors.
the t
and then enters the DONE state where
CHG_DONE
charging stops.
The IDN input adjusts the charge current termination
threshold. The termination threshold can be fixed by
connecting IDN to INT_3V3 or can be adjusted by con-
necting IDN to ground through a resistor. When IDN is
connected to ground through a resistor, the charge done
threshold is determined using the following formula:
V
ISET
(V)
MONITORING THE BATTERY CHARGE
CURRENT USING V
ISET
1.5V
2400
I
=
TERM
R
IDN
where R
is a resistor from IDN to ground.
IDN
Note that if charge current falls to I
the input or thermal limiter, the charger does not enter
the DONE state. For the charger to enter DONE, charge
as a result of
TERM
0V
BATTERY
CHARGE
CURRENT (A)
0A
DISCHARGE CHARGE
current must be less than I
, the charger must be
TERM
1.5V
=
x 2000
in voltage mode, and the input or thermal limiter must
not be reducing charge current. The charger exits the
DONE state and fast-charge resumes if the battery volt-
R
ISET
OR
= I
FCHG
age subsequently drops below V
or if CEN is
BAT_RECHG
cycled. Connecting IDN to INT_3V3 selects the default
termination current threshold.
Figure 24. Monitoring Charge Current with the ISET Voltage
38
Maxim Integrated
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
range or on-chip thermal limit conditions are not consid-
ered faults. When the MAX8895V/MAX8895X/MAX8895Y
are used in conjunction with a microprocessor, connect
a pullup resistor between FLT and the logic I/O voltage to
indicate fault status to the microprocessor. Alternatively,
FLT can sink up to 20mA for an LED indicator.
Charge Status Outputs
Charge Output (CHG) (MAX8895V/MAX8895X/
MAX8895Y Only)
CHG is an active-low, open-drain output that is driven
low during charging. CHG is logic-low when the battery
charger is in fast-charge and top-off states. When charge
current falls to the charge termination threshold and the
charger is in voltage mode CHG goes high impedance.
CHG holds its current state if the thermistor causes the
charger to enter temperature suspend mode. When
the MAX8895V/MAX8895X/MAX8895Y are used with a
microprocessor, connect a pullup resistor between CHG
and the logic I/O voltage to indicate charge status to the
microprocessor. Alternatively, CHG can sink up to 20mA
for an LED indicator.
CHG_TYPE Output (MAX8895W Only)
The output CHG_TYPE is used to indicate the type of
interface detected. If CHG_TYPE output is logic level
low the input current limit is set to 100mA or less. If
CHG_TYPE output is logic level high the input current
limit is set to 500mA or greater.
DET_DONE Output (MAX8895W Only)
DET_DONE is an active low, open-drain output that
is driven low once adapter detection is complete.
DET_DONE is high impedance in suspend mode.
Prequalification Output (PREQ)
(MAX8895V/MAX8895X/MAX8895Y Only)
IBUS_DEF Output (MAX8895W Only)
The IBUS_DEF input is only valid when ENU_EN is set
to logic-high activating the adapter type detection. If
the adapter type is detected as a USB 2.0 device, the
input current limit is set to the programmed value and
the MAX8895W does not initiate USB enumeration. If
IBUS_DEF is connected to ground or logic level low, the
input current limit is set to 100mA. If IBUS_DEF is con-
nected to INT_3V3 or logic level high, the input current
limit is set to 500mA.
PREQ is an active-low, open-drain output that is driven
low when the charger is in prequalification state. When
the MAX8895V/MAX8895X/MAX8895Y are used in con-
junction with a microprocessor, connect a pullup resis-
tor between PREQ and the logic I/O voltage to indicate
charge status to the microprocessor. Alternatively, PREQ
can sink up to 20mA for an LED indicator.
Fault Output (FLT) and Charge Timer (CT)
FLT is an active-low, open-drain output that is driven
low during a battery fault. The fault state occurs when
either the prequalification or fast-charge timer expires.
The prequalification and fast-charge fault timers are set
Thermistor Input (THM)
The THM input connects to an external negative tem-
perature coefficient (NTC) thermistor to monitor battery
or system temperature. Charging is suspended when
the thermistor temperature is out of range. The charge
timers are suspended and hold their state, but no fault is
indicated. When the thermistor comes back into range,
charging resumes and the charge timer continues from
where it was at previously. Connecting THM to AGND
disables the thermistor monitoring function.
by C
:
CT
C
CT
t
=16min×
PREQUAL
0.068FF
C
CT
t
=100min×
FCHG
0.068FF
While in fast-charge mode, a large system load or device
self-heating may cause the MAX8895_ to reduce charge
current. Under these circumstances, the fast-charge timer
adjusts to ensure that adequate charge time is still
allowed. Consequently, the fast-charge timer is slowed
by 2x if charge current is reduced below 50% of the pro-
grammed fast charge level. If charge current is reduced
to below 20% of the programmed level, the fast-charge
timer is paused. The fast-charge timer is not adjusted if the
charger is in voltage mode where charge current reduces
due to current tapering under normal charging.
Since the thermistor monitoring circuit employs an exter-
nal bias resistor from THM to V (R , Figure 25),
INT_3V3 TB
the thermistor is not limited only to 10kI(at T = +25NC).
A
Any resistance thermistor can be used as long as the
value of R is equivalent to the thermistor’s T = +25NC
TB
A
resistance. For example, with a 10kI at T = +25NC
A
thermistor, use 10kI at R , and with a 100kI at T
=
TB
A
+25NC thermistor, use 100kI.
For a typical 10kIat T = +25NC thermistor and a 10kI
A
R
TB
resistor, the charger enters a temperature suspend
state when the thermistor resistance falls below 3.97kI
(too hot) or rises above 28.7kI (too cold). These limits
To exit a fault state, toggle CEN or remove and recon-
nect the V
input source. Note: A thermistor out-of-
BUS_
Maxim Integrated
39
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
correspond to a 0NC to +50NC range when using a 10kI
NTC thermistor with a beta of 3500. The general relation
of thermistor resistance to temperature is defined by the
following equation:
R = The resistance (I) of the thermistor at temperature
T
T in NC.
R
25
= The resistance (I) of the thermistor at T = +25NC.
A
A = The material constant of the thermistor which typi-
cally ranges from 3000K to 5000K.
1
1
β
−
T+273 298
T = The temperature of the thermistor in NC.
R
= R × e
25
T
Table 4 shows the MAX8895_ THM temperature limits for
different thermistor material constants.
where:
Table 4. Fault Temperatures for Different Thermistors
THERMISTOR ß (K)
3000
3250
3500
10
3750
10
4250
10
R
TB
(kI) (Figure 22)
10
10
Resistance at +25NC (kI)
10
10
10
10
10
Resistance at +50NC (kI)
4.59
25.14
55
4.30
27.15
53
4.03
29.32
50
3.78
31.66
49
3316
36.91
46
Resistance at 0NC (kI)
Nominal hot trip temperature (NC)
Nominal cold trip temperature (NC)
-3
-1
0
2
4.5
CEN
MAX8895V
MAX8895X
MAX8895Y
0.74 x
R
TB
V
INT_3V3
THERMISTOR
CIRCUITRY
ALTERNATE THERMISTOR
CONNECTION
COLD
THM
0.28 x
V
INT_3V3
THM OUT OF
RANGE
R
TS
HOT
0.03 x
R
TP
R
T
V
INT_3V3
DISABLE
CHARGER
ENABLE THM
ALL COMPARATORS
60mV HYSTERESIS
R
T
AGND
Figure 25. Thermistor Monitor Circuitry
40
Maxim Integrated
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
Some designs may require other thermistor temperature
limits. The threshold adjustment can be accommodated
Note: Series resonance resistance is the resistance
observed when the resonator is in the series resonant
condition. This is a parameter often stated by quartz crys-
tal vendors and is called R1. When a resonator is used in
the parallel resonant mode with an external load capaci-
tance, as is the case with the MAX8895Y oscillator circuit,
the effective resistance is sometimes stated. The effective
resistance at the loaded frequency of oscillation is:
by changing R , connecting a resistor in series and/or
TB
in parallel with the thermistor, or using a thermistor with
different A. For example, a T = +45NC hot threshold
A
and T = 0NC cold threshold can be realized by using
A
a thermistor with a A of 4250 and connecting a 120kI
resistor in parallel. Since the thermistor resistance near
T
= 0NC is much higher than it is near T = +50NC, a
A
A
2
C
large parallel resistance lowers the cold threshold, while
only slightly lowering the hot threshold. Conversely, a
small-series resistance raises the cold threshold, while
O
R
= R1× 1+
EFF
C
LOAD
only slightly raising the hot threshold. Raising R low-
TB
where:
R1 = Series resonance resistance
ers both the hot and cold thresholds, while lowering R
raises both thresholds.
TB
C
O
= Crystal capacitor
Thermal Shutdown
Thermal shutdown limits total power dissipation in the
MAX8895_. When the junction temperature exceeds
+160NC (typ), the device turns off, allowing the MAX8895_
to cool. The MAX8895_ turn on and begin soft-start after
the junction temperature cools by 20NC (typ). This results
in a pulsed charge current during continuous thermal-
overload conditions.
C
= External load capacitance
LOAD
For typical C and C
tance can be greater than R1 by a factor of 2.
values, the effective resis-
O
LOAD
External Clock (MAX8895Y)
The MAX8895Y can also be driven from an external clock.
The MAX8895Y accepts an external clock input at XIN.
The external clock can either be a digital level square
wave or sinusoidal and this may be directly coupled to XIN
without the need for additional components. If the peaks of
the reference clock are above V
the clock signal must be driven through a DC-blocking
capacitor (approximately 33pF) connected to XIN.
External Clock (MAX8895Y)
The MAX8895Y includes full-speed USB 2.0 compat-
ibility. USB 2.0 full speed requires that the system clock
of the transceiver is within Q2500ppm, over temperature,
aging, etc. Therefore, the MAX8895Y requires an exter-
nal resonator or clock source to stay within this limit.
or below ground,
INT_3V3
The external clock source can either be enabled using
the UOK or INT_3V3 signals depending on if the clock
source is active-low or active-high enabled.
The MAX8895Y local oscillator and internal digital clocks
are derived from the reference clock at the XIN input.
If the INT_3V3 rail is used, ensure that no significant load
is taken from this output since this affects the perfor-
mance of the MAX8895Y.
External Crystal/Ceramic Resonator
(MAX8895Y)
XIN and XOUT are used to interface to an external
12MHz crystal or ceramic resonator. Connect a 33pF
load capacitor from both XIN/XOUT to ground.
Clock Timing Accuracy (MAX8895Y)
USB 2.0 specification requires the system clock to be within
Q2500ppm over temperature, aging, etc. It is recommended
to use a clock source with tighter initial accuracy to ensure
that over time the accuracy of Q2500ppm is still valid.
Requirements for the external resonator/crystal for
MAX8895Y:
Frequency: 12MHz Q0.25%
ESD Protection
possess extra protection against
C
LOAD
: 33pF Q20%
D+, D-, and V
BUS_
Drive level: 200FW
static electricity to protect the devices up to Q8kV (HBM).
The ESD structures withstand high ESD in all operating
modes: normal operation, suspend mode, and powered
Series resonance resistance: 60I (maximum), 30I
(typical)
down. V
requires 1FF ceramic capacitors connect-
BUS_
ed to ground as close as possible to the pins.
Maxim Integrated
41
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
ESD Test Conditions
ESD performance depends on a variety of conditions.
Contact Maxim for a reliability report that documents
test setup, test methodology, and test results. Figure 26
shows the Human Body Model, and Figure 27 shows
the current waveform generated when discharged into a
low impedance. This model consists of a 100pF capaci-
tor charged to the ESD voltage of interest, which then
discharges into the test device through a 1.5kI resistor.
and analog ground (AGND) copper areas, and connect
them together at the negative terminal of the battery.
The pins and/or external components for KB_TM, crystal
load capacitors, ISET, IDN, CT, thermistor, and INT_3V3
should connect to a quiet analog ground. All other
ground connections should connect to DGND.
Recommended PCB Layout
and Routing
Place all bypass capacitors for INT_3V3, V
, V
,
BUS_ BAT_
and V
as close as possible to the device. Connect
SYS_
Applications Information
the battery to BAT_A and BAT_B as close as possible to
the device to provide accurate battery voltage sensing.
Make all high-current traces short and wide to minimize
voltage drops.
Capacitor Selection
Ceramic X5R or X7R dielectric capacitors are recommend-
ed for best operation. When selecting ceramic capacitors
in the smallest available case size for a given value, ensure
that the capacitance does not degrade significantly with
DC bias. Generally, ceramic capacitors with high values
and very small case size have poor DC bias characteris-
tics. Evaluate capacitors carefully before using.
When using the MAX8895Y, place the external crystal and
load capacitors as close as possible to the MAX8895Y.
The crystal and load capacitors should be kept as far
away as possible from the D+/D- traces.
Refer to the MAX8895 Evaluation Kit for an exam-
ple layout. The MAX8895 Evaluation Kit supports the
MAX8895V/MAX8895X and MAX8895Y.
Ground Connections
Minimize trace lengths between the bypass capacitors
and ground. Use separate digital/power ground (DGND)
R
D
1.5kI
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
I
I 100%
90%
r
P
DISCHARGE
RESISTANCE
CHARGE-CURRENT
LIMIT RESISTOR
AMPERES
HIGH-
VOLTAGE
DC SOURCE
36.8%
DEVICE
UNDER
TEST
C
100pF
STORAGE
CAPACITOR
S
10%
0
TIME
t
0
t
RL
DL
CURRENT WAVEFORM
Figure 27. Human Body Model Current Waveform
Figure 26. Human Body Test Model
42
Maxim Integrated
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
Typical Operating Circuit
Chip Information
PROCESS: BiCMOS
V
BUS_ BUS_
SYS_
SYSTEM
LOAD
Ordering Information
CHARGE AND
SYSTEM LOAD
SWITCH
CONTROL
LOGIC
USB INTERFACE
PIN-PACKAGE
TYPE
PART
25 WLP
2.36mm x 2.36mm
25 WLP
2.36mm x 2.36mm
25 WLP
2.36mm x 2.36mm
25 WLP
2.36mm x 2.36mm
MAX8895VEWA+T
MAX8895WEWA+T**
MAX8895XEWA+T
MAX8895YEWA+T
Low speed
BAT_A/
BAT_B
D+
D-
USB
INTERFACE
Low speed
1-CELL
Li+
MAX8895V
MAX8895W
MAX8895X
MAX8895Y
Low speed
OSCILLATOR
Full speed
Note: All devices are specified over the -40°C to +85°C oper-
ating temperature range.
+Denotes a lead(Pb)-free/RoHS-compliant package.
T = Tape and reel.
**Contact factory for availability.
Maxim Integrated
43
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
Package Information
For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a
“+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the
drawing pertains to the package regardless of RoHS status.
PACKAGE TYPE
PACKAGE CODE
OUTLINE NO.
21-0453
LAND PATTERN NO.
25 WLP
W252D2+1
Refer to Applications Note 1891
PIN 1
INDICATOR
E
MARKING
COMMON DIMENSIONS
1
0.64
0.19
0.45
0.025
0.27
1.60
1.60
0.40
0.00
0.00
A
A1
A2
A3
b
0.05
0.03
A
A3
REF
D
BASIC
0.03
AAAA
A1
A2
A
0.05
S
D1
E1
e
S
TOP VIEW
See Note 7
SIDE VIEW
BASIC
BASIC
BASIC
SD
SE
E1
SE
e
E
D
E
B
DEPOPULATED
BUMPS
SD
MAX
2.36
2.16
2.44
2.44
MIN
2.25
2.02
2.32
2.41
MIN
2.25
2.02
2.22
2.41
MAX
PKG. CODE
D
C
B
D1
NONE
NONE
NONE
NONE
2.36
2.16
2.34
2.44
W252D2+1
W252F2+1
W252G2+1
A
1
42 53
W252H2+1
b
M
S
AB
A
0.05
BOTTOM VIEW
NOTES:
1. Terminal pitch is defined by terminal center to center value.
2. Outer dimension is defined by center lines between scribe lines.
3. All dimensions in millimeter.
4. Marking shown is for package orientation reference only.
5. Tolerance is ± 0.02 unless specified otherwise.
6. All dimensions apply to PbFree (+) package codes only.
7. Front - side finish can be either Black or Clear.
TITLE
PACKAGE OUTLINE
25 BUMPS, WLP PKG. 0.4mm PITCH
REV.
APPROVAL
DOCUMENT CONTROL NO.
1
- DRAWING NOT TO SCALE -
1
21-0453
D
44
Maxim Integrated
MAX8895V/MAX8895W/MAX8895X/MAX8895Y
Li-Ion Chargers with Smart Power Selector,
Adapter Type Detection, and USB Enumeration
Revision History
REVISION REVISION
PAGES
CHANGED
DESCRIPTION
NUMBER
DATE
0
1
2
3
4
7/10
Initial release
—
1–38
1
10/10
2/11
Added MAX8895W to data sheet
Added patent information
4/11
Added contact factory note for MAX8895W
Added MAX8895V to data sheet
1
9/12
1–42
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied.
Maxim reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical
Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
Maxim Integrated 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000
45
©
2012 Maxim Integrated
The Maxim logo and Maxim Integrated are trademarks of Maxim Integrated Products, Inc.
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