MP2617A [MPS]
3A Switching Charger with NVDC Power Path Management For Single Cell Li Battery;型号: | MP2617A |
厂家: | MONOLITHIC POWER SYSTEMS |
描述: | 3A Switching Charger with NVDC Power Path Management For Single Cell Li Battery 电池 |
文件: | 总32页 (文件大小:1824K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
MP2617A, MP2617B
3A Switching Charger with NVDC
Power Path Management
For Single Cell Li+ Battery
DESCRIPTION
FEATURES
The MP2617A / MP2617B is a monolithic
switch mode battery charger with power path
management for single-cell Li-ion batteries in a
wide range of tablet and other portable devices.
It integrates a synchronous BUCK regulator to
provide regulated voltage for powering the
system output and at the same time charging
the battery. This device supports both USB and
high power DC adapter input. In USB mode, the
input current limit can be programmed to
450mA or 825mA via the logic pins to cover the
USB2.0 and USB3.0 specifications. When the
adapter input is present, the input current can
also be limited in order to avoid overloading of
the DC adapter. Input current limit can be
programmed up to 3A.
4V to 10V Operating Input Voltage
Smart Power Path Management
Five Control Loops: Input Current Limit,
Input Voltage Limit, Constant Charge
Current, Terminal Battery Control and
Thermal Fold-Back.
1.6MHz Switching Frequency
Programmable Input Current Limit
Programmable Charge Current
Single Input for USB and AC adapter
Cover
Specification
Fully Integrated Power Switches
USB2.0
and
USB3.0
Input
No External Blocking Diode and Sense
Resistor Required
Charging Operation Indicator
Built-in Programmable Charging Timer
Thermal Limiting Regulation on Chip
Battery Temperature Monitor
The smart power path management allows
MP2617A and MP2617B to regulate the system
voltage for powering an external load and
charging the battery independently and
simultaneously. This allows immediate system
operation even under missing or deeply
discharged battery. When the input current limit
is reached, the system load is satisfied in
priority, then the charger will take the remaining
current to charge the battery. Additionally, the
smart power path control allows an internal
connection from battery to the system in order
to supplement additional power to the load in
the event the system power demand increases
over the input limited power or the input is
removed.
Tiny Package Features Small Size.
APPLICATIONS
Smart Phone
E-Book
GPS
Portable Media Player
Portable Hand-held Solution
Tablet PC
All MPS parts are lead-free, halogen free, and adhere to the RoHS
directive. For MPS green status, please visit MPS website under Quality
Assurance.
“MPS” and “The Future of Analog IC Technology” are Registered
Trademarks of Monolithic Power Systems, Inc.
The MP2617A / MP2617B features high
integration with all the power switches integrate
inside. No external MOSFET, blocking diodes,
or current sense resistor is required.
Two status monitor output pins are provided to
indicate the battery charge status and power
source status. Other features include trickle
charge, battery temperature monitoring, timer
and thermal limiting regulation on chip.
The MP2617A / MP2617B is available in QFN
3mmx4mm package.
MP2617A, MP2617B Rev. 1.23
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© 2018 MPS. All Rights Reserved.
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1
MP2617A, MP2617B – SINGLE CELL SWITCHING CHARGER WITH POWER PATH
TYPICAL APPLICATION
ON
OFF
AC adapter
/USB input
VILIM
M0
M1
EN
L
SYS Load
SW
IN
R3
R4
C1
C3
CSYS
CHGOK
BST
SYS
ACOK
VCC
R1
SYSFB
PGND
RT1
CIN
C2
NTC
R2
ICHG
BATT
vBATT
TMR
AGND
RT2
CBATT
CTMR
RNTC
ISET
ILIM
MP2617A/B
RISET
RILIM
0
MP2617A
MP2617B
MP2617 Family Table
Features
Battery Charge Full Voltage
MP2617A
4.35V
MP2617B
4.2V
MP2617A, MP2617B Rev. 1.23
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MP2617A, MP2617B – SINGLE CELL SWITCHING CHARGER WITH POWER PATH
ORDERING INFORMATION
Part Number
MP2617AGL*
MP2617BGL
Package
QFN-20 (3mmx4mm)
QFN-20 (3mmx4mm)
Top Marking
MP2617A
MP2617B
* For Tape & Reel, add suffix –Z (e.g. MP2617AGL–Z);
PACKAGE REFERENCE
TOP VIEW
20 19 18 17
1
2
3
4
5
6
16
BST
NTC
15 ISET
SW
IN
14 BATT
13
SW
PGND
SYS
SYSFB
12
11
AGND
EN
7
8
9
10
MP2617A, MP2617B Rev. 1.23
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MP2617A, MP2617B – SINGLE CELL SWITCHING CHARGER WITH POWER PATH
PIN FUNCTIONS
Package
Pin #
Name Description
Bootstrap. A capacitor is connected between SW and BST pin to form a floating supply
across the power switch driver to drive the power switch’s gate above the supply voltage.
1
BST
3
2,4
5
IN
Power input of the IC from adapter or USB.
SW
Switch output.
PGND Power ground.
_____
Function logic control pin of the IC. Logic low to enable the part and logic high to disable the
part.
6
EN
7
8
M0
M1
Mode Select Input Pin, in combination with M1 pin, setting the input current limit mode.
Mode Select Input Pin, in combination with M0 pin, setting the input current limit mode.
_____________
Open drain output. It is pulled low during charging. And it is pulled high through an external
resistor to VCC to indicate charge completed.
9
CHGOK
Open drain output. It is pulled low to indicate the presence of a valid input power supply.
Otherwise, it is pulled high through an external resistor to VCC to indicate invalid input or
removed input.
__________
10
ACOK
11
12
AGND Analog ground.
SYS voltage program pin. Connect a resistor divider from the pin to SYS and AGND to
SYSFB
program the system output voltage. Leave the pin float to disable the function.
13
14
SYS DC-DC regulator output to power the system load and charge the battery.
BATT Positive battery terminal.
Charge current program pin. A resistor from the pin to AGND can program the charge
current during CC charge. Float the pin will disable the charge function.
15
16
17
ISET
Thermistor input. Connect a resistor from this pin to VCC and the thermistor from this pin to
ground. The thermistor is usually inside the battery pack.
NTC
Input current limit program pin. A resistor from the pin to AGND can program the input
current limit with adapter input.
ILIM
18
19
20
TMR Set timer out period. Connect TMR pin to AGND to disable the internal timer.
VLIM Input voltage clamp program pin.
VCC Supply voltage of the IC.
MP2617A, MP2617B Rev. 1.23
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MP2617A, MP2617B – SINGLE CELL SWITCHING CHARGER WITH POWER PATH
ABSOLUTE MAXIMUM RATINGS (1)
IN, SW ........................................ -0.3V to +20V
BATT, SYS .................................... -0.3V to +6V
BST ............................................. -0.3V to +26V
All Other Pins................................. -0.3V to +6V
Thermal Resistance (4)
QFN-20 (3mmx4mm) ............. 48...... 11... C/W
θJA θJC
Notes:
1) Exceeding these ratings may damage the device.
2) The maximum allowable power dissipation is a function of the
maximum junction temperature TJ (MAX), the junction-to-
ambient thermal resistance θJA, and the ambient temperature
TA. The maximum allowable continuous power dissipation at
any ambient temperature is calculated by PD (MAX) = (TJ
(MAX)-TA)/θJA. Exceeding the maximum allowable power
dissipation will cause excessive die temperature, and the
regulator will go into thermal shutdown. Internal thermal
shutdown circuitry protects the device from permanent
damage.
(2)
Continuous Power Dissipation (TA = +25°C)
QFN20 3mmx4mm ....................................2.6W
Junction Temperature..............................150C
Lead Temperature ...................................260C
Storage Temperature.................–65°C to 150°C
Recommended Operating Conditions (3)
Supply Voltage VIN .......................... 4.0V to 10V
Operating Junction Temp. (TJ)....-40°C to +125°C
3) The device is not guaranteed to function outside of its
operating conditions.
4) Measured on JESD51-7, 4-layer PCB.
MP2617A, MP2617B Rev. 1.23
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MP2617A, MP2617B – SINGLE CELL SWITCHING CHARGER WITH POWER PATH
ELECTRICAL CHARACTERISTICS
VIN = 5.0V, TA = 25C, unless otherwise noted.
Parameters
Symbol Condition
Min
Typ
Max Units
Input Power (IN)
IN Operating Range
VIN
4.0
3.65
3.35
240
40
10
V
V
Rising
Falling
Rising
Falling
3.8
3.5
280
70
3.95
3.65
320
120
IN Under Voltage Lockout
Threshold
V
mV
mV
IN vs. BATT Threshold
Rising
VBST-VSW
2.55
2.9
150
1.6
3.25
V
BST Voltage Threshold
Switching Frequency
Hysteresis
mV
MHz
1.4
1.8
USB2.0 Mode
400
750
450
825
500
900
mA
mA
USB3.0 Mode
Default Mode
1840 2000 2160 mA
Programmable Mode, RILIM=23k
(MP2617B)
1840 2000 2160 mA
Input Current Limit
IIN
Programmable Mode, RILIM=22.47k
(MP2617A)
1840 2000 2160 mA
Programmable Mode,
RILIM=48k (MP2617A)
900
1.1
950
1000 mA
Input Current Limit Reference
Voltage
VILIM
1.14
1.18
V
High-side NMOS On Resistance RH_DS(ON) Include the BLOCK FET
Low-side NMOS On Resistance RL_DS(ON)
120
80
130
100
mΩ
mΩ
High-side NMOS Peak Current
limit
3.8
4.8
5.8
A
Input Voltage Clamp Threshold
VVLIM
Voltage on VLIM
1.49
1.52
2.4
2.8
3.8
1.55
V
Charger Enabled, USB2.0 Mode
Charger Enabled, USB3.0 Mode
Charger Enable, Programmable Mode
5
5
5
mA
mA
mA
Input Quiescent Current
IIN
Charger Enabled, Default Mode
Disabled, EN=0V
3.8
3
5
5
mA
uA
SYS to IN reverse current
blocking
SYS=SW=4.5V,VIN=0V, monitor VIN
leakage
0.01
0.2
uA
SYS Output (MP2617A)
Minimum
Voltage
SYS
Regulation
SYS voltage @ VBATT≤3.4V, SYSFB
float
VSYS
3.45
3.6
3.75
V
V
3.4V<VBATT≤4.2V, SYSFB float
BATT Float
VBATT
0.2V
+
3.5
4.63
4.63
SYS Regulation Voltage
SYS Reference Voltage
VSYS
User Programmed by SYSFB
4.22
V
V
VSYS_REF
1.135 1.152 1.170
MP2617A, MP2617B Rev. 1.23
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MP2617A, MP2617B – SINGLE CELL SWITCHING CHARGER WITH POWER PATH
ELECTRICAL CHARACTERISTICS (continued)
VIN = 5.0V, TA = 25C, unless otherwise noted.
Parameters
Symbol Condition
Min
Typ
Max Units
SYS Output (MP2617B)
SYS voltage @ VBATT≤3.4V,
SYSFB float
Minimum SYS Regulation Voltage
SYS Regulation Voltage
VSYS
3.45
3.6
3.75
V
V
3.4V<VBATT≤4.2V, SYSFB float
BATT Float
VBATT
0.2V
+
3.5
4.5
4.4
VSYS
User Programmed by SYSFB
4.08
V
V
SYS Reference Voltage
Battery Discharge
VSYS_REF
1.135 1.152 1.170
BATT to SYS Resistance
VIN=0V, ISYS=200mA, VBATT=4.2V
VSYS>VBATT–800mV, VBATT=4.2V
SYS short
40
5
50
6
mΩ
A
4
BATT to SYS Current Limit
230
mA
Battery Charger Voltage Spec (MP2617A)
VBATT>VRECH, ICHG≤IBF, SYSFB float 4.328 4.35 4.372
V
V
VSYS
-
Terminal Battery Voltage
VBATT
VSYS<4.2V Programmed by
SYSFB Pin
0.04 x
IBF
SYSFB Float
4.04
3.99
4.14
4.09
85
4.24
4.19
V
V
Recharge Threshold at VBATT
VRECH
SYSFB programmed
Recharge Hysteresis
mV
V
Trickle Charge Threshold
Trickle Charger Hysteresis
3.01
3.11
200
3.21
mV
Battery Charger Voltage Spec (MP2617B)
VBATT>VRECH, ICHG≤IBF, SYSFB float 4.179
4.2
4.221
V
V
VSYS
0.04 x
IBF
-
Terminal Battery Voltage
VBATT
VSYS<4.2V Programmed by
SYSFB Pin
SYSFB Float
3.9
4.0
3.95
85
4.1
V
V
Recharge Threshold at VBATT
VRECH
SYSFB programmed
3.85
4.05
Recharge Hysteresis
mV
V
Trickle Charge Threshold
Trickle Charger Hysteresis
Battery Charger Current Spec
Trickle Charge Current
2.9
5%
3
3.1
200
mV
ITRICKLE
IBF
10%
10%
ICC
ICC
Termination Charger Current
15%
200
IBF Maximum Limit
150
mA
3.02
5
RISET=760
2.475 2.75
1.26 1.4
A
Constant Current Mode Charge
Current
ICC
RISET=1.53k
RISET=4.6k
1.54
A
A
0.405 0.450 0.495
MP2617A, MP2617B Rev. 1.23
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MP2617A, MP2617B – SINGLE CELL SWITCHING CHARGER WITH POWER PATH
ELECTRICAL CHARACTERISTICS (continued)
VIN = 5.0V, TA = 25C, unless otherwise noted.
Parameters
Symbol Condition
Min
Typ
Max
Units
ISET Reference Voltage
1.1
2.4
2.2
1.15
2.6
1.2
2.8
2.6
V
V
V
Rising
Falling
Battery UVLO
2.4
VBATT
65mV
-
Idea Diode Regulation Voltage
BATT Leakage Current
VSYS
IBATT
Supplement Mode
mV
µA
VBATT=4.2V, SYS float,
VIN=PGND
20
30
__________ _____________
ACOK, CHGOK
__________ _____________
ACOK, CHGOK Pin Output
Low Voltage
__________ _____________
Sinking 5mA
270
0.1
350
0.5
mV
ACOK,CHGOKPin Leakage
Current
Connected to 3.3V
μA
Timer
Trickle Charge Time
Total Charge Time
CTMR=0.1µF, ICHG=1A
CTMR=0.1µF, ICHG=1A
45
Min
6.5
Hour
Negative Temperature Coefficient (NTC) Control
NTC Low Temp Rising
Threshold
VTHL
RNTC=NCP18XH103F 0°C
63
32
65
35
67
35
%VCC
mV
Hysteresis on Low Temp
Threshold
NTC High Temp Falling
Threshold
VTHH
RNTC=NCP18XH103F, 50°C
33.5
70
%VCC
mV
Hysteresis on High Temp
Threshold
VCC Supply
Rising
3.15
2.8
3.35
3
3.55
3.2
V
V
VCC UVLO
Falling
VCC Output Voltage
0mA<IVCC<25mA, VIN=6V
4.3
4.5
40
4.6
V
VCC Output Current Limit
mA
Logic
0.4
8
V
V
ENInput Low Voltage
ENInput High Voltage
1.5
4
EN=4V
μA
ENInput Current
M0, M1
-0.5
1.5
-0.1
EN=0V
Logic High
Logic Low
V
V
0.4
MP2617A, MP2617B Rev. 1.23
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MP2617A, MP2617B – SINGLE CELL SWITCHING CHARGER WITH POWER PATH
ELECTRICAL CHARACTERISTICS (continued)
VIN = 5.0V, TA = 25C, unless otherwise noted.
Parameters
Symbol Condition
Min
Typ
Max
Units
Protection
Thermal Limit Temperature
Thermal Shutdown
120
150
°C
°C
MP2617A, MP2617B Rev. 1.23
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MP2617A, MP2617B – SINGLE CELL SWITCHING CHARGER WITH POWER PATH
TYPICAL PERFORMANCE CHARACTERISTICS
VIN = 5.0V, VBATT = Full Range, Default Mode, IIN Limit=2A, VSYS=4.4V, R6 and R7 are float, ICHG=2A,
VIN Clamp=4.5V, L = 1.2 µH, TA = +25ºC, Test in MP2617B, unless otherwise noted.
MP2617A, MP2617B Rev. 1.23
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MP2617A, MP2617B – SINGLE CELL SWITCHING CHARGER WITH POWER PATH
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
VIN = 5.0V, VBATT = Full Range, Default Mode, IIN Limit=2A, VSYS=4.4V, R6 and R7 are float, ICHG=2A,
VIN Clamp=4.5V, L = 1.2 µH, TA = +25ºC, Test in MP2617B, unless otherwise noted.
MP2617A, MP2617B Rev. 1.23
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MP2617A, MP2617B – SINGLE CELL SWITCHING CHARGER WITH POWER PATH
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
VIN = 5.0V, VBATT = Full Range, Default Mode, IIN Limit=2A, VSYS=4.4V, R6 and R7 are float, ICHG=2A,
L = 1.2 µH, TA = +25ºC, Test in MP2617B, unless otherwise noted.
MP2617A, MP2617B Rev. 1.23
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MP2617A, MP2617B – SINGLE CELL SWITCHING CHARGER WITH POWER PATH
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
VIN = 5.0V, VBATT = Full Range, Default Mode, IIN Limit=2A, VSYS=4.4V, R6 and R7 are float, ICHG=2A,
L = 1.2 µH, TA = +25ºC, Test in MP2617B, unless otherwise noted.
MP2617A, MP2617B Rev. 1.23
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MP2617A, MP2617B – SINGLE CELL SWITCHING CHARGER WITH POWER PATH
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
VIN = 5.0V, VBATT = Full Range, Default Mode, IIN Limit=2A, VSYS=4.4V, R6 and R7 are float, ICHG=2A,
L = 1.2 µH, TA = +25ºC, Test in MP2617B, unless otherwise noted.
MP2617A, MP2617B Rev. 1.23
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MP2617A, MP2617B – SINGLE CELL SWITCHING CHARGER WITH POWER PATH
OPERATION
BST
IN
HSG
SYSFB1
EAO
EA
EA
3.6V
L
Converter
control
Max(A,B)
SW
SYS
VBATT+200mV
Driver
1
0
M
Input current
limit reference
selector
C
LSG
Iref
M
EAO
SYSFB
VBG
VREF
SYSFB
SYS
SYSFB
EA
ILIM
SYSFB1
VLIM
1.5V
mO
4 0
VBATx 2
Charge
Pump
VIN
Ideal diode
regulation
VTH
SYS
Battery switch
current limit
BATT
BATT
EN
3.5 V coarse
LDO &
EN
3.0 V UVLO
CC/ CV linear
charger
BATTFB
BATTFB
VBG
VREF_CC
VCC
Bandgap
& Bias
VBG
EN
4.5 V LDO
Charger Control & Chip Logic
UVLO
.
V UVLO
3 8
VIN
ISET
CHGOK
ACOK
TMR
NTC
GND
Figure 1—Function Block Diagram
MP2617A, MP2617B Rev. 1.23
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MP2617A, MP2617B – SINGLE CELL SWITCHING CHARGER WITH POWER PATH
the combination of the system load and battery
charger. The regulator contains input current
Introduction
The MP2617A and MP2617B is a switching
charger IC, with integrated smart power path
management for powering the system and
charging a single cell battery simultaneously and
independently.
measurement and control scheme to ensure the
average input current remains below the level
programmed via ILIM pin or logic inputs M0&M1.
This meets the adapter capacity limit or stays in
compliance with USB specification.
The MP2617A and MP2617B includes input DC-
DC step down converter for wide range of DC
sources and USB inputs. It has precision average
input current limit to make maximum use of the
allowable input power. This feature allows fast
charging when powering from an USB port, and
ensures the input current never exceeds the
input power specification especially when the
input power comes from a USB port. Additionally,
the input current limit threshold can be
programmed by logic inputs or a resistor to
ground from the ILIM pin.
When the input voltage is higher than UVLO and
280mV higher than the battery voltage, input
——————
voltage OK signal is active (ACOK turns low) and
the DC-DC converter soft-starts. If the input
power is sufficient to supply the combination of
the system load and battery charger, and the
input current limit loop is not triggered. The
converter output voltage VSYS will be regulated:
1) If BATT>3.4V, VSYS is approximately 0.2V
above the battery voltage to minimize the power
loss of the battery charger during fast charging.
The MP2617A and MP2617B implements an on-
chip 40mΩ MOSFET which works as a full-
featured linear charger with trickle charge, high
accuracy constant current and constant voltage
charge, charge termination, auto recharge, NTC
monitor, built-in timer control, charge status
indication, and thermal protection. The charge
current can be programmed by an external
resistor connected from the ISET pin to AGND.
The IC limits the charge current when the die
temperature exceeds 120°C.
2) If BATT<3.4V, VSYS is fixed at 3.6V to power
the system immediately even when a drained
battery is inserted to be charged. Figure 2 shows
the relationship of VSYS vs. VBATT.
System voltage can also be regulated to any
value between 4.08V to 4.4V in MP2617B (4.22V
to 4.63V in MP2617A) by using a resistor divider
on the SYSFB pin. This is shown as R6 and R7
in Figure 10. If the SYSFB is left floating, the
system program is invalid, and VSYS is regulated
as Figure 2.
The 40mΩ MOSFET works as an ideal diode to
connecting the battery to the system load when
the input power is not enough to power the
system load. When the input is removed, the
40mΩ MOSFET is turned on allowing the battery
to power up the system.
The converter adopts fixed off-time control to
extend the duty cycle (close to 100%) when the
input of the converter is close to VSYS.
4.4V
4.2V
With smart power path management, the system
load is satisfied in priority then the remaining
current is used to charge the battery. The
MP2617A and MP2617B will reduce charging
current or even use power from the battery to
satisfy the system load when its demand is over
the input power capacity.
VSYS
200mV
3.6V
VBATT
Figure 1 shows the function block diagram of the
MP2617A and MP2617B.
DC-DC Step Down Converter
3.4V
4.2V
The DC-DC converter is a 1.6MHz step-down
switching regulator to provide the input power to
Figure 2 — MP 2617B SYS Regulation
Output
the
SYS,
which
drives
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MP2617A, MP2617B – SINGLE CELL SWITCHING CHARGER WITH POWER PATH
Close to 100% duty operation, BST refresh
to control the operation duty. In this mode, the
input voltage will be clamped according to the
value set by the resistor divider. The control to
the system voltage and charge current is the
same as the one explained in the input current
limit. Charge current drops down to satisfy the
system current request first. This feature
provides a second protection to the input power
and ensures the safe operation of the input
adapter. Even if a wrong adapter is inserted, the
MP2617A and MP2617B can continue operation,
providing the maximum power to its load. User
can program the input voltage limit value through
the resistor divider from IN to VLIM to AGND.
operation makes sure the driver voltage of the
HS will be charged by turning on the LS until
negative IL hit a threshold. If the input power is
insufficient to supply the combination of the
system load and battery charger, the DC-DC
converter will limit the total power requirement by
restricting the input voltage, input current and the
peak current through the MOSFET. The power
path management will reduce the charge current
to satisfy the external system load in priority.
According to this feature, the USB specification is
always satisfied first. Even if the charge current is
set larger than the USB input current limit, the
real charge current will be reduced as needed.
Peak Current Limit: The peak current of the high
side switch of the DC-DC converter is sensed
during every cycle, it is compared to the
reference 4.8A. If the peak current hits the
threshold, the peak current limit mode is
triggered. The control of the charge current is the
same with the above two limits.
Input Limit State
If the input power is insufficient to supply the
combination of the system load and battery
charger,
the
MP2617A
and
MP2617B
implements three input limit control loops to
reduce the charge current and satisfy the
external system load in priority. The input in this
case might be limited as follows: input current
limit, input voltage limit and DC-DC peak current
limit.
Input Current Limit Setting
The current at ILIM is a precise fraction of the
adapter input current. When a programming
resistor is connected from ILIM to AGND, the
voltage on ILIM represents the average input
current of the PWM converter. And the input
current approaches the programmed limit, ILIM
voltage reaches 1.14V.
Input Current Limit: When the input current is
higher than the programmed input current limit
the input current limit loop takes the control of the
converter and regulates the input current at
constant value. When the battery voltage is over
3.4V, the output voltage (VSYS) will drop down
according to the increase of the system current,
and the charge current drops down after the
BATT-to-SYS switch (40mΩ MOSFET) is fully on
according to VSYS dropping down. During this
process, the system voltage is slightly higher
than VBATT. When the battery voltage is lower
than 3.4V, to maintain the minimum system
voltage and ensure the system operation, the
input current limit control will pull down the
charge current directly to reduce the load of the
converter so that the system current is satisfied
in priority.
The average input current limit can be set
through the resistor connecting from ILIM to
AGND according to the following expression:
40000
IIN_LIM=1.14
(mA)
RILIM(kΩ)
When USB input, the input current limit is set
internally and the programmed value is invalid.
The MP2617A and MP2617B provides typical of
450mA input current limit for USB2.0
specification and a typical of 825mA for USB3.0
specification respectively.
Input Voltage Limit: A resistor divider from IN pin
to VLIM pin to AGND is used for the input voltage
limit control. When the voltage on VLIM pin hits
the reference voltage of 1.52V, the output of the
input voltage limit error amplifier will drop in
The user can choose to set the input current limit
through the two logic pins M0 and M1 as shown
in Table 2 according to its input specification.
MP2617A, MP2617B Rev. 1.23
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MP2617A, MP2617B – SINGLE CELL SWITCHING CHARGER WITH POWER PATH
When both M0 and M1 pins are float, they are
pulled to the logic high, under this condition, the
input current is limited to a default value of 2A.
satisfied first over the battery charge current. If
the system load requirement is low, the battery
can be charged at full constant current.
Table 2―Input Current Limit Setting
When the battery voltage reaches the battery full
threshold, the charger enters the “constant
voltage mode” operation.
M0
Low
Low
M1
Low
High
Mode
USB2.0 Mode
USB3.0 Mode
End of Charge (EOC) and Indication
High
Low
Programmable Mode
In constant voltage charge mode, the battery
voltage is regulated at 4.2V (MP2617B) and
4.35V (MP2617A) (when SYSFB is float or SYS
is programmed higher than battery full threshold)
and the charge current decreases naturally.
Once the charge current hits the battery full
threshold IBF (1/10 programmed charge current),
the battery is fully charged and charge cycle is
terminated.
High/Float High/Float Default Mode
Input Voltage Limit Setting
The input voltage can be limited at a value set by
a resistor divider from IN pin to VLIM pin to
AGND according to the following expression
(Typical Application Circuit):
R1+R2
VIN_LIM=1.52
(V)
If the charge current drops below IBF because of
any limit condition, the MP2617A and MP2617B
will come out of CV mode, and the charge full
detection is invalid.
R2
When the voltage on VLIM pin drops and hits the
reference voltage 1.52V, the input voltage will be
clamped to the setting value.
A safe timer starts at the beginning of each new
charge cycle and it monitors if the whole charge
period is within the programmed time limit. After
each charge cycle, when the battery is indicated
as full, the timer counter will be reset. If the time
is expired while the charging is still on going, the
Battery Charger
The MP2617A and MP2617B completes charge
operation consist of trickle charge, automatic
charge termination, charge status indication,
timer control, NTC indication, automatic recharge,
and thermal limiting.
timer will force the MP2617A and MP2617B to
_____________
terminate charging CHGOK is blinking to indicate
the fault condition.
When the PWM converter is out of soft start, the
battery charge cycle begins, the MP2617A and
MP2617B first determines if the battery is deeply
discharged. If the battery voltage is lower than
the trick charge threshold (typical 3.0V), the
battery charger starts in “trickle charge mode”.
The trickle charge current is limited to 10% of the
programmed charge current until the battery
voltage reaches 3.0V. If the charge stays in the
“trickle charging mode” for longer than ”trickle
If system voltage is programmed lower than 4.2V
(MP2617B) and 4.35V (MP2617A) by the resistor
divider at the SYSFB pin, the battery will be
charged most close to VSYS until the charge
current reaches the IBF threshold.
Automatic Recharge
Once the battery charge cycle is completed, the
MP2617A and MP2617B turns off indicating the
battery full status. During this process, the
battery power may be consumed by the system
load or self discharge. If the input power is
always on, to ensure the battery not to be
exhausted, the new charge cycle will
automatically begin when the battery voltage falls
below the auto-recharge threshold VRCHG when
the SYSFB is float, and 50mV lower if the SYSFB
is connected to a resistor divider. The timer will
re-start when the auto-recharge cycle begins.
charge timer period”, the “timer out” condition is
_____________
triggered, the charge is terminated and CHGOK
will start blinking to indicate that the battery is
unresponsive. When the battery voltage is above
3.0V, the charger is operating at “constant
current mode.” The current delivered to the
battery will try to reach the value programmed by
the ISET pin. Depending on the available input
power and system load conditions, the battery
charger may or may not be able to charge at the
full programmed rate. The system load is always
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MP2617A, MP2617B – SINGLE CELL SWITCHING CHARGER WITH POWER PATH
During the charge off state when the battery is
VBATT-40mV
Enable Ideal Diode Mode
Disable Ideal Diode Mode
fully charged, if the input power is recycled, or
the EN signal is refreshed, the charge cycle will
re-start and the timer will refresh even if the
battery voltage is above the auto-recharge
threshold.
VSYS
VBATT+40mV
Charge Current Setting
The charge current of the MP2617A and
MP2617B is programmed using a single resistor
from ISET pin to ground. The program resistor
and charge current are calculated using the
following equations:
Figure 3— Ideal Diode Mode Enable/Disable
Logic Control
The MP2617A and MP2617B have two separate
enable control pins.
_____
1800
ICHG 1.15
(mA)
EN is a logic control pin that controls the
RSET(k)
_____
operation of the whole IC. When EN is low, the
At either constant current mode or constant
voltage mode, the voltage at the ISET pin is
proportional to the actual charge current
delivered to the battery, IBATT. The charge current
can be calculated by monitoring the ISET pin
voltage with the following formula:
IC is enabled and the PWM converter output
_____
powers the system and the charger. When EN is
high, both the PWM converter and the charger
are disabled. The BATT to SYS switch turns fully
on to connect the battery to power the system.
The ISET pin can be also used to control the
operation of the charger. Setting ISET pin floating
will disable the charger function while the output
of PWM converter will continue supply power to
system. On the other hand, a resistor from ISET
to AGND will enable the charging at the
programmed charge current.
V
IBATT
=
ISET ×ICHG
1.15
Additionally, the actual battery charge current
may be lower than the programmed current due
to limited input power available and prioritization
of the system load.
The logic control of the ISET pin of the MP2617A
and MP2617B can be realized as Figure 4. In this
way, the user can choose logic low to be “off”
signal or logic high to be ”on” signal with a N-
MOSFET.
Battery charge full current threshold IBF is set
internally at 10% of the programmed charge
current. However, IBF has a 150mA maximum
limit which can not be exceeded.
Ideal Diode Mode
If the system current requirement increases over
the preset limit of the PWM converter, the
additional current will be drawn from the battery
via the BATT-to-SYS switch. To avoid very large
currents being drawn from the battery which
might affect the reliability of the device, the
MP2625B controls the charge switch to work at
ISET
OFF ON
RISET
Figure 4— ISET Logic Control
__________
the ideal diode mode regulating VSYS to VBATT
-
Input Power Status Indication (ACOK)
65mV when VSYS is 40mV lower than VBATT is
detected. Only when VSYS is 40mV higher than
VBATT, the charger switch exits the ideal diode
mode, and the charge cycle softly restarts.
An internal under voltage lockout circuit monitors
the input voltage and keeps the IC in off state
until the input rises over the rising threshold
(3.8V). When the input voltage decreases below
threshold (3.5V), the IC will turn off, and the
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MP2617A, MP2617B – SINGLE CELL SWITCHING CHARGER WITH POWER PATH
Table 2―Charger Status Indication
system load will be powered by the battery
__________
Charger Status
ACOK
low
CHGOK
automatically. ACOK is an open-drain, active-low
In charging, supplement
mode
End of charge, ISET
disable charger only.
output that indicates the status of input power.
The input is considered valid when the input
voltage is over the UVLO rising threshold, and
310mV higher than the battery voltage to ensure
both the converter and the charger can operate
low
low
low
high
blinking at
6Hz
NTC fault, timer out
normally. If the input voltage from an adapter or
__________
VIN absent, EN disable,
thermal shutdown
high
high
from a USB port is indicated OK, ACOK will turn
low.
_____
Timer Setting
During EN off or thermal shutdown conditions,
__________
The MP2617A and MP2617B uses an internal
timer to terminate charge if the timer times out.
The timer duration is programmed by an external
capacitor at the TMR pin and related to the real
charge current.
the ACOK turns high to indicate no power is
__________
provided by the input to the system. The ACOK
signal indicates if input supplies power to the
system load or not. Any other condition can not
__________
affect the ACOK indication as long as the input
power is present.
The trickle mode charge time is:
CTMR
tTrickle _ TMR 45
(min) (ICHG 1A)
_____________
0.1μF
Charge Status Indication (CHGOK)
_____________
The total charge time is:
CHGOK is an open-drain, active-low output that
_____________
indicates the status of charge. CHGOK will be
low during normal charging operation, turn high
after charge full, and blink if a fault condition
happens including NTC fault (battery temperature
invalid) and timer out (bad battery).
CTMR
tTotal_TMR 6.5
0.1μF
(hr) (ICHG 1A)
The above equations are based on 1A charge
current. As a result of power path management
control, charge current might vary during normal
operation, under this condition, the MP2617A
and MP2617B automatically takes into account
this variation and adjust the timer period
accordingly.
_____________
In the event of a fault condition, CHGOK
switches at 6Hz with the 50% duty cycle and
enter “blinking” mode. The user should check the
application circuit to find out the root cause of the
fault condition if the “blinking” signal is asserted.
_____________
When the charge current is set larger than 1A,
the safe timer period is reduced accordingly with
the same TMR capacitor. If the charge current is
reduced because of insufficient input power, the
timer period is increased proportionally by the
same rate at which the charge current is reduced.
If charge is stopped due to high system load, the
timer is temporarily suspended.
For no battery condition, CHGOK is blinking
according to the transition between charging and
charge full. The blinking frequency is determined
by the cycle of charge and discharge of the
output capacitor.
When the charge current to the battery is low or
in the event the battery is in supplement mode
_____________
caused by the insufficient input power, CHGOK
keeps low to avoid providing false charge full
indication.
This feature avoids indicating a false trigger
indication for bad battery indication when there is
little charge current delivered to the battery as a
result of the insufficient input power. When the
timer out condition occurs, the MP2617A and
__________
_____________
Table 2 shows the ACOK and CHGOK status
under different charge conditions.
MP2617B terminates the charge at once and
_____________
CHGOK blinks to indicate the fault status. If one
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MP2617A, MP2617B – SINGLE CELL SWITCHING CHARGER WITH POWER PATH
150oC as the IC enters thermal shutdown
protection.
of the following events happens, the timer is
refreshed and the MP2617A and MP2617B re-
starts the charge cycle.
Battery Discharge Protection
When the input power is removed or invalid, the
system load will draw power from the battery via
the battery switch. Under this condition, the
battery switch is fully on to minimize the power
loss. The MP2617A and MP2617B integrates
battery discharge protection. If the battery
discharge current is larger than the discharge
current limit threshold IDIS (5A), the current will be
regulated at the preset limited value. And if the
current increases further, the SYS voltage starts
to decrease. When VSYS drops to about 800mV
lower than VBATT, SYS short condition is detected.
Under this condition, the discharge current is
limited at 230mA. In the event of a short from
system to GND the discharge current from the
battery to the system is also limited to 230mA.
Furthermore, battery voltage UVLO is always
monitored. If the battery voltage is lower than the
battery UVLO threshold, the battery switch is
turned off immediately. This feature makes sure
the battery from over-discharged.
Input re-startup
_____
Refresh EN /ISET signal
Auto-Recharge
NTC Thermistor
The NTC pin allows MP2617A and MP2617B to
sense the battery temperature using the Negative
Thermal Coefficient (NTC) thermistor usually
available in the battery pack to ensure safe
operating environment of the battery. A resistor
with appropriate value should be connected from
VCC to NTC and the NTC resistor is from NTC
pin to AGND. The voltage on NTC pin is
determined by the resistor divider whose divide
ratio as the different resistance of the NTC
thermistor depends on the ambient temperature
of the battery.
The MP2617A and MP2617B has an internal
NTC voltage comparator to set the upper and
lower limit of the divide ratio. If NTC pin voltage
falls out of this range it means the temperature is
outside the safe operating range,
Dynamic Power Path Management (DPPM)
In the presence of a valid input source, the PWM
converter will supply the current to both the
system and the battery charger.
As a result, the MP2617A and MP2617B will stop
charging and report it on indication pins.
Charging will automatically resume after the
temperature falls back into the safe range.
The voltage VSYS is regulated based on the value
of the battery voltage. When VBATT is higher than
3.4V, VSYS is regulated 200mv above VBATT to
charge the battery. When VBATT is lower than
3.4V, to ensure the system can still be powered
up even with a drained battery connected, VSYS is
regulated at constant 3.6V.
Thermal Protection
The MP2617A and MP2617B implements
thermal protection to prevent the thermal damage
to the IC or surrounding components. An internal
thermal sense and feedback loop will
automatically decrease the charge current when
the die-temperature rises to about 120oC. This
function is referred as charge current thermal
fold-back. This feature protects the MP2617A
and MP2617B from excessive temperature due
to high power operation or high ambient thermal
conditions. Another benefit of this feature is
charge current can be set according to the
requirement rather than worst-case conditions for
a given application with the assurance of safe
operation. The MP2617A and MP2617B will stop
charging if the junction temperature rises above
When the input source is overloaded, either the
current exceeds the input current limit or the
voltage falls below the input voltage limit, the
MP2617A and MP2617B then reduces the
charge current until the input current falls below
the input current limit and the input voltage rises
above the input voltage limit. If the system
current increases beyond the power allowed by
the input source, additional power will be drawn
from the battery via an on-chip 40mΩ MOSFET
working as an ideal diode.
Additionally, if the input source is removed, the
MP2617A and MP2617B will turn on the 40mΩ
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MP2617A, MP2617B – SINGLE CELL SWITCHING CHARGER WITH POWER PATH
Taking the MP2617B for example, Figure 5
shows the operation flow chart of the MP2617B
while Figure 6 shows the operation process.
MOSFET allowing the battery to power the
system load to keep the operation of the portable
device.
Operation Flow Chart
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MP2617A, MP2617B – SINGLE CELL SWITCHING CHARGER WITH POWER PATH
Yes
Clamp DC-DC
EAOto regulate
the part
Any Limit condition
triggered?
at the limit state
No
VBATT<3.4V?
VBATT>3.0V?
Yes
No
Yes
No
Trickle Charge
ICHG=10%ICC
VSYS drops down,
Charge switch
is fully on
Decrease ICHG
Keep VSYS=3.6V
,
CC/CV Charge
Yes
No
Satisfy System current
Charge the battery with
remaining current
No
Limit condition
Removed?
ICHG=IBF
?
No
Yes
Disable
Ideal Diode Mode
Charge in
CV mode and
ICHG<IBF?
No
No
Charge Full, EOC=1
TMR off,
Yes
ICHG=0?
Yes
clear the counter
DC-DC keeps work
Yes
No
No
VSYS>VBATT+40mV?
VSYS<VBATT-40mV?
Yes
VSYS<VBATT-40mV?
No
Yes
Yes
VBATT>VBATT_UVLO
?
No
Yes
VBATT<VRCHG
?
Ideal Diode Mode:
VSYS=VBATT-65mV,
Enable discharge
current limit
Battery switch shuts down,
DC-DC in over load
condition,
VSYS drops down
Figure 5— MP2617B Operation Flow Chart under No Fault Condition
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MP2617A, MP2617B – SINGLE CELL SWITCHING CHARGER WITH POWER PATH
Normal
operation
voltage
UVLO
Threshold-Hys
UVLO
Thresohold
VIN
0
Power Path Management
Battery
Supplement
Mode
ISYS
0
CV Charge
CC Charge
Trickle Charge
Battery
Full
IBATT
0
ISYS -IIN_LIM
Input Power
Current Limit
IIN_LIM
IIN_AVE
0
Supplement
Mode-
Discharging
Auto-
Recharging
Self-
discharging
Power off-
discharging
Charging
Charging
V
BATT=4.0V
VSYS
VBATT
VBATT=3.4V
V
BATT=3.0V
0
Figure 6— MP2617B Operation Process under No Fault Condition
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MP2617A, MP2617B – SINGLE CELL SWITCHING CHARGER WITH POWER PATH
For example, if the typical ICHG is designed as
APPLICATION INFORMATION
COMPONENT SELECTION
Setting the Input Current Limit
2A, then the RSET is calculated at 1.05kΩ. The
tolerance of the ICHG setting is ±10%. If the
minimum or maximum charge current is
required, first the typical value should be
calculated according to the tolerance. After that,
calculate the resistor according to formula (2).
1% accuracy resistor is used for this setting.
First the input current limit can be set by the M0
and M1 pins refer to the Table 1, the exact
current value in minimum, typical and maximum
is listed in the EC table.
For a given setting resistor, the charge current
can be calculated by the same way did in the
input current limit setting. Usually in USB mode,
the charge current is always set over the USB
input limit specification. Then the MP2625
regulates the input current constant at the
limitation value. Thus the real CC charge
current is not the setting value, it varies with
different input and battery voltages.
Under program mode, connect a resistor from
the ILIM pin to AGND to program the input
current limit for different input ports. The
relationship between the input current limit and
setting resistor is as Equation (1) which is
shown in following again:
40000
(1)
IIN_LIM=1.14
(mA)
RILIM(kΩ)
For MP2617A/B, IILIM is not over 3A.
The tolerance is ±8% of the input current limit
setting.
The maximum CC charge value can be
calculated as:
V IILIM
IN
ICC _ MAX
(A)
(3)
So for a required minimum input current limit
value, just calculate its typical value first, then
calculate the setting resistor based on Equation
(1). Also the maximum value can be calculated
VTC
Where VTC is trickle charge threshold (3V) and η
is the current charge efficiency. Assume
VIN=5.5V, IILIM=1A, suppose η=83%, thus
ICC_MAX=1.52A.
Figure 7 shows a calculating charge current
curve by limiting the input current limit.
according to the tolerance.
1% accuracy
resistor is used for this setting. Also, for a given
resistor of RILIM, the input current limit can be
calculated. Following table is an example:
Table 3: Example of RILIM setting
I
l
i
m
=
1
.
4
2A
1A
4
RILIM
(kΩ)
54.9
IIN_LIM
(mA)
A
Resistor
8%
-8%
I
l
i
m
=
1
A
Typ.
Min.
Max.
830.601 897.049 764.153
I
l
i
m
54.351 838.991 906.11 771.872
55.449 822.377 888.168 756.587
=
0
.
8
2
5
A
Therefore, if customer selected a 54.9k in 1%
accuracy resistor for the input current limit
setting, then the typical input current limit value
is 830.6mA, the minimum is 756.6mA and the
maximum is 906mA.
3V
4.2V
Battery Voltage
Figure 3—ICHG Variation with Different Input
Current Limit
Setting the Charge Current
Setting the Input Voltage Limit
RISET connecting from the ISET pin to AGND
sets the charge current (ICHG). The relationship
between the charge current and setting resistor
is as Equation (2) which is shown in following
again:
The input clamp voltage is set using a resistive
voltage divider from the input voltage to VLIM
pin. The voltage divider divides the input
voltage down to the limit voltage by the ratio:
R2
1800
(4)
(2)
VVLIM = V
×
(V)
ICHG 1.15
(mA)
IN_LIM
R1+R2
RSET(k)
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MP2617A, MP2617B – SINGLE CELL SWITCHING CHARGER WITH POWER PATH
Thus the input voltage is:
Selecting the Inductor
Inductor selection trades off among cost, size,
and efficiency. A lower inductance value
corresponds to a smaller size, but results in
higher ripple currents, higher magnetic
R1+R2
R2
V
IN_LIM = VVLIM
×
(V)
(5)
The voltage clamp reference voltage VVLIM is
1.52V, and a typical value for R2 can be 10kΩ.
With this value, R1 can be determined by:
hysteretic
losses,
and
higher
output
capacitances. From a practical standpoint, the
inductor ripple current does not exceed 30% of
the maximum load current under worst cases
conditions. For example, if the ICHG is setting to
3A in MP2617B, then, ΔIL is general set at 0.9A.
V
IN_LIM - V
R1=R2×
VLIM (V)
(6)
VVLIM
For example, for a 4.65V input limit voltage, R2
is 10kΩ, and R1 is 20.6kΩ.
However, for the light load condition, the
inductor ripple current will be very small which
may cause unstable operation due to the peak
current mode control of the IC. For stable
operation, the experienced minimum limit value
for inductor current ripple is 0.5A. Therefore, the
inductor current ripple is the maximum one of
30% times ICHG and 0.5A.
The minimum value and the maximum value of
the input voltage limit can be calculated
according to the accuracy of the resistor and
the tolerance of VVLIM. 1% accuracy resistors
are used for R1 and R2.
Setting the System Voltage
The system voltage can be regulated to any
value between 4.08V to 4.4V (MP2617B) by the
resistor divider on SYSFB pin as R6 and R7 in
Figure 10.
And the inductance can be calculated according
to Equation (9):
R6 R7
VSYS VSYS_REF
(7)
V VSYS
IL _MAX V fS (MHz)
The peak current of the inductor is calculated
as Equation (10):
VSYS
IN
R7
L
(H)
(9)
Where VSYS_REF is 1.152V, the reference voltage
of SYS. With a typical value for R7, 10kΩ, R6
can be determined by:
IN
VSYS V
%ripple
R6 R7
SYS_REF (V)
(8)
IPEAK ILOAD(MAX) (1
)
(mA)
(10)
2
VSYS_REF
Where VIN, VSYS, and fS are the typical input
voltage, the output voltage, and the switching
frequency, respectively.
For example, for a 4.2V system voltage, R7 is
10kΩ, and R6 is 26.5kΩ. 1% resistors are
selected for the R5 and R6.
Following Table 4 provides the selection guide
of the inductance based on different input
voltage.
Be noted that, the minimum VSYS is limited to be
higher than the maximum value of the auto-
recharge threshold which is 4.05V.
Table 4: Inductance Selection Guide under different Input Voltage
Inductance Selection
SPEC
VIN
LMIN
(μH)
LMAX
L
Saturation
DCR
V VSYS
VSYS
IN
Package
(μH) (μH) Current (A)(5) (mΩ)
L
IL
V fS (MHz)
IN
Application
Required
5V
9V
0.367 1.25
1.0
2.2
>3.95
>3.95
<50
<50
ΔIL=max (0.3*ICHG,0.5A)
ΔILMIN=0.5A
Application
Required
1.5 2.8
ΔILMAX=0.9A
NOTE:
5) Saturation Current of the inductor should be higher than the IPEAK, add 0.5A margin here.
MP2617A, MP2617B Rev. 1.23
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MP2617A, MP2617B – SINGLE CELL SWITCHING CHARGER WITH POWER PATH
Selecting the Input Capacitor
the system load to ensure it properly absorbs
the ripple current.
The input capacitor C1 from the typical
application circuit absorbs the maximum ripple
current from the PWM converter, which is given
by
Use a ceramic capacitor because it has lower
ESR and smaller size that allows us to ignore
the ESR of the output capacitor. Thus, the
output voltage ripple is given by:
VTC (V
VTC)
IN_MAX
(A) (11)
IRMS _MAX ICC _MAX
V
VSYS
IN_MAX
1
VSYS
VSYS
V
IN
For ICC_MAX=2A, VTC=3V, VIN_MAX=10V, the
maximum ripple current is 1A. Select the input
capacitors so that the temperature rise due to
the ripple current does not exceed 10°C. Use
ceramic capacitors with X5R or X7R dielectrics
because of their low ESR and small
temperature coefficients.
(12)
r
%
2
8C2 fS L
In order to guarantee the ±0.5% system voltage
accuracy, the maximum output voltage ripple
must not exceed 0.5% (e.g. 0.1%). The
maximum output voltage ripple occurs at the
minimum system voltage and the maximum
input voltage.
For most applications, use a 10µF capacitor.
Besides, usually a small cap with at least 1uF
(C1) from IN to GND is required to be put as
much close as possible to the IC. For the input
voltage is high to 10V, consider the spike when
input insert, select the input capacitors (both the
22uF and 1uF) in 25V rating.
The output capacitor can be calculated with
Equation (13):
VSYS _MIN
1
V
IN
(13)
CSYS
2
8 fS L r
When SYSFB pin is floating, output voltage
ripple is the main concern to select the output
capacitor (CSYS), refer to Table 5 for detail
selection guide about the SYS capacitance
selection under typical inputs.
Selecting the Output Capacitor
The output capacitor CSYS from the typical
application circuit is in parallel with the SYS
load. CSYS absorbs the high-frequency switching
ripple current and smoothes the output voltage.
Its impedance must be much less than that of
Table 5: SYS Capacitance Selection Guide
SPEC
VIN
SYS Capacitance (CSYS) Selection
CSYS_MIN (μF) 6)
When SYSFB is
Floating
CSYS_MIN (μF) 6)
When SYSFB
is Programmed
VSYS
Temperature
Characteristic
1
Package
V
IN
CSYS
2
8 fS L r
Application
Required
5V
9V
13.6
20
X5R;X7R
X5R;X7R
Δr=0.1%
L=1μH @VIN=5V
L=2.2μH @VIN=9V
Application
Required
13.3
20
NOTE:
6) For different voltage rating, capacitance will have different DC bias characteristic. Suppose a general condition, capacitance drops
40% under VSYS=4.4V under 10V rating, and 50% at 6.3V rating.
MP2617A, MP2617B Rev. 1.23
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MP2617A, MP2617B – SINGLE CELL SWITCHING CHARGER WITH POWER PATH
When SYSFB is programmed using external
it has the following electrical characteristic:
At 0°C, RNTC_Cold = 27.445kΩ;
resistors, the control loop function is changed.
A zero point is added around the cross over
frequency of the DC gain, and this may result in
the phase margin varied a lot, which may cause
the unstable operation. To avoid this condition,
a minimum capacitance requirement should be
satisfied to make the pole point to compensate
the zero point. This minimum capacitance is
20uF for a general application.
At 50°C, RNTC_Hot = 4.1601kΩ.
The following equations are derived assuming
that the NTC window is between 0°C and 50°C.
According to the above equations to calculate
RT1=7.15kΩ and RT2=25.5kΩ.
So, for the SYSFB programmed condition, the
CSYS should be selected as max (CSYS_MIN
,
20uF), CSYS_MIN is calculated from the formula of
equation (13), as shown in Table 5. For better
stability margin, select
a
47uF ceramic
capacitor with 6.3V and above voltage rating as
the output capacitor in this case.
Resistor Choose for NTC Sensor
Figure 8 shows an internal resistor divider
reference circuit to limit the low temperature
threshold and high temperature threshold at
65%·VCC and 33.5%·VCC, respectively. For a
given NTC thermistor, select appropriate RT1
and RT2 to set the NTC window:
Figure 4—NTC Function Block
PCB Layout Guideline
It is important to pay special attention to the
PCB layout to meet specified noise, efficiency
and stability requirements. The following design
considerations can improve circuit performance:
RT2//RNTC_Cold
RT1 RT2//RNTC_Cold VCC
RT2//RNTC_Hot
RT1 RT2//RNTC_Hot VCC
VTHL
(14)
65%
1) Route the power stage adjacent to their
grounds. Aim to minimize the high-side
switching node (SW, inductor), trace lengths in
the high-current paths and the current sense
resistor trace.
VTHH
(15)
33.5%
RNTC_Hot is the value of the NTC resistor at high
temperature of the required temperature
operation range, and RNTC_Cold is the value of
the NTC resistor at low temperature.
Keep the switching node short and away from
all small control signals, especially the feedback
network.
The two resistors, RT1 and RT2, allow the high
temperature limit and low temperature limit to
be programmed independently. With this
feature, the MP2625B can fit most type of NTC
resistor and different temperature operation
range requirements.
Place the input capacitor as close as possible
to the IN and PGND pins.
Place the output inductor close to the IC and
connect the output capacitor between the
inductor and PGND of the IC.
RT1 and RT2 values depend on the type of the
NTC resistor:
2) For high-current applications, the balls for the
power pads (IN, SW, SYS, BATT and PGND)
should be connected to as much copper in the
board as possible. This improves thermal
performance because the board conducts heat
away from the IC.
0.3 RNTC_Cold RNTC_Hot
(16)
RT2
0.1225RNTC_Cold - 0.4225RNTC_Hot
0.3RNTC_Hot RNTC_Cold
(17)
RT1
0.2275(RNTC_Cold RNTC_Hot
)
For example, for the thermistor NCP18XH103,
MP2617A, MP2617B Rev. 1.23
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MP2617A, MP2617B – SINGLE CELL SWITCHING CHARGER WITH POWER PATH
3) The PCB should have a ground plane
connected directly to the return of all
components through vias (two vias per
capacitor for power-stage capacitors, one via
per capacitor for small-signal components). It is
also recommended to put vias inside the PGND
pads for the IC, if possible. A star ground
design approach is typically used to keep circuit
block currents isolated (high-power/low-power
small-signal) which reduces noise-coupling and
ground-bounce issues. A single ground plane
for this design gives good results. With this
small layout and a single ground plane, there is
no ground-bounce issue, and having the
components segregated minimizes coupling
between signals.
MP2617A, MP2617B Rev. 1.23
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www.MonolithicPower.com
29
MP2617A, MP2617B – SINGLE CELL SWITCHING CHARGER WITH POWER PATH
TYPICAL APPLICATION CIRCUITS
ON
OFF
VILIM
M0
M1
EN
5V Input
L
SYS Load
SW
IN
1.0uH
2k
2k
R3
R4
C1
1uF
C3
100nF
CHGOK
CSYS
BST
SYS
R1
21k
ACOK
VCC
22uF
MP2617B
SYSFB
PGND
RT1
CIN
10k
NTC
10uF
C2
R2
ICHG
10k
BATT
RT2
10k
1uF
vBATT
TMR
AGND
CBATT
CTMR
100nF
ISET
ILIM
22uF
RISET
1.05k
RILIM
30.9k
0
Figure 9: Typical Charge Application Circuit for 5V input with NTC Resistor Fixed
Table 6: The Key BOM of Figure 9.
Qty
Ref
Value
Description
Package Manufacture
Ceramic Capacitor;10V;
X5R or X7R
1
CIN
10μF
1206
0603
Any
Any
Ceramic Capacitor;10V;
X5R or X7R
1
1
C1
C2
1μF
Ceramic Capacitor;6.3V;
X5R or X7R
1μF
0603
Any
Ceramic Capacitor;16V;
X5R or X7R
Ceramic Capacitor;6.3V;
X5R or X7R
1
1
C3
100nF
100nF
0603
0603
Any
Any
CTMR
Ceramic Capacitor;10V;
X5R or X7R
2
2
1
CSYS,CBATT
RT1,RT2
L1
22μF
10k
1206
0603
SMD
Any
Any
Any
Film Resistor;1%
Inductor;1.0uH;Low
DCR;ISAT>2.8A
1.0μH
MP2617A, MP2617B Rev. 1.23
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MP2617A, MP2617B – SINGLE CELL SWITCHING CHARGER WITH POWER PATH
TYPICAL APPLICATION CIRCUITS
ON
OFF
R5 100k
VILIM
M0
M1
EN
9V Input
L
SYS Load
SW
IN
2.2uH
C3
2k
2k
R3
R4
C1
1uF
BST
SYS
CHGOK
CSYS
100nF
R1
21k
ACOK
VCC
22uF
C4
R6
26.5k
R7
4.7uF
MP2617B
SYSFB
PGND
RT1
CIN
10k
10k
NTC
22uF
C2
R2
ICHG
10k
BATT
RT2
10k
1uF
vBATT
TMR
AGND
CBATT
22uF
CTMR
100nF
ISET
ILIM
RISET
1.05k
RILIM
30.9k
0
Figure 10: Typical Charge Application Circuit for 9V Input and 1.5A Input Current Limit
Table 7: The Key BOM of Figure 10.
Qty
Ref
Value
Description
Package Manufacture
Ceramic Capacitor;16V;
X5R or X7R
1
CIN
22μF
1206
0603
Any
Any
Ceramic Capacitor;16V;
X5R or X7R
1
1
C1
C2
1μF
Ceramic Capacitor;
6.3V; X5R or X7R
1μF
0603
Any
Ceramic Capacitor;25V;
X5R or X7R
1
1
1
2
C3
C4
100nF
4.7μF
100nF
22μF
0603
0603
0603
1206
Any
Any
Any
Any
Ceramic Capacitor;
10V; X5R or X7R
Ceramic Capacitor;
6.3V;X5R or X7R
Ceramic Capacitor;10V;
X5R or X7R
CTMR
CSYS,CBATT
1
3
R6
26.5k
10k
Film Resistor;1%
Film Resistor;1%
0603
0603
Any
Any
RT1,RT2,R7
Inductor;2.2μH;Low
DCR;ISAT>6A
1
L1
2.2μH
SMD
Any
MP2617A, MP2617B Rev. 1.23
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MP2617A, MP2617B – SINGLE CELL SWITCHING CHARGER WITH POWER PATH
PACKAGE INFORMATION
QFN-20 (3mmX4mm)
PIN 1 ID
MARKING
PIN 1 ID
0.10 X 45?TYP
PIN 1 ID
INDEX AREA
TOP VIEW
BOTTOM VIEW
SIDE VIEW
0.10 X 45?
NOTE:
1) ALL DIMENSIONS ARE IN MILLIMETERS.
2) EXPOSED PADDLE SIZE DOES NOT INCLUDE
MOLD FLASH.
3) LEAD COPLANARITY SHALL BE0.10
MILLIMETERS MAX.
4) JEDEC REFERENCE IS MO-220.
5) DRAWING IS NOT TO SCALE.
RECOMMENDED LAND PATTERN
NOTICE: The information in this document is subject to change without notice. Users should warrant and guarantee that third
party Intellectual Property rights are not infringed upon when integrating MPS products into any application. MPS will not
assume any legal responsibility for any said applications.
MP2617A, MP2617B Rev. 1.23
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