ISL9220_10 [INTERSIL]
Switching Charger for 1-Cell and 2-Cell Li-ion Batteries; 开关充电器,1节和第2节锂离子电池型号: | ISL9220_10 |
厂家: | Intersil |
描述: | Switching Charger for 1-Cell and 2-Cell Li-ion Batteries |
文件: | 总15页 (文件大小:544K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
Switching Charger for 1-Cell and 2-Cell Li-ion
Batteries
ISL9220, ISL9220A
Features
• Highly Integrated Battery Charger IC
• Charges 1- and 2-Cell Li-ion or Li-Polymer Batteries
• Up to 2A Charge Current
The ISL9220, ISL9220A is a cost-effective and versatile
battery charger for 1-cell and 2-cell Li-ion and Li-Polymer
based portable applications.
The device features synchronous PWM technology,
maximizing power efficiency, thus minimizing charge
time and heat. The 1.2MHz switching frequency allows
use of small external inductors and capacitors.
• Synchronous Buck Topology with Integrated Power
FETs
• 1.2MHz Switching Frequency
• 0.5% Charge Voltage Accuracy
A simple charge current programming method is
provided. External resistors program the fast charge and
end-of-charge currents.
• Programmable Input Current Limit with One External
Resistor
The two status outputs can be used to drive LEDs, or can
be connected to host processor.
• Thermistor Interface for Battery Detection and
Temperature Qualified Charging
A programmable charge timer provides the ability to
detect defective batteries, and provides a secondary
method of detecting charge termination.
• Two Status Outputs
• Programmable Charge Safety Timer
• Short-Circuit and Thermal Protection
• Small 4mmx4mm TQFN Package
• -40°C to +85°C Operating Temperature Range
A thermistor interface is provided for battery presence
detection, and for temperature qualified charging
conditions.
Additional features include preconditioning of an
over-discharged battery, automatic recharge, and
thermally enhanced QFN package.
Related Literature
• Technical Brief TB363 “Guidelines for Handling and
Processing Moisture Sensitive Surface Mount Devices
(SMDs)”
Applications
• PDAs and Smart Phones
• MP3 and Portable Media Players
• Handheld GPS Devices
• Technical Brief TB379 “Thermal Characterization of
Packaged Semiconductor Devices”
• Technical Brief TB389 “PCB Land Pattern Design and
Surface Mount Guidelines for QFN Packages”
• Digital Still Cameras
• Industrial Handheld Scanners
Pin Configuration
ISL9220, ISL9220A
(20 LD TQFN)
TOP VIEW
STAT2
EN
PGND
SW
1
2
3
4
5
15
14
13
12
11
AGND
ISET1
ISET2
SW
EPAD
(AGND)
VHI
VIN
July 2, 2010
FN6936.1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright Intersil Americas Inc. 2010. All Rights Reserved
1
All other trademarks mentioned are the property of their respective owners.
ISL9220, ISL9220A
Pin Descriptions
PIN
SYMBOL
DESCRIPTION
1
STAT2
Open-drain indication pin. In conjunction with STAT1 this pin provides a unique indication for each
charging state of the cycle. This pin is capable to sink 10mA minimum current to drive an LED.
2
EN
IC enable input. Drive this pin to logic LO to enable the charger. Drive this pin to logic HI to disable
the charger. Do not leave this pin floating.
3
4
AGND
ISET1
Analog ground.
Charge current programing pin. Connect a resistor between this pin and the GND pin to set the
charge current.
5
6
7
ISET2
VBAT
ISNS
End-of-charge current programing pin. Connect a resistor between this pin and the GND pin to set
the end-of-charge current.
Battery connection pin. Connect this pin to the battery. A 10μF or larger X5R ceramic capacitor is
recommended for decoupling and stability purposes.
Output current sense pin. Connect a current sense resistor from this pin to V
capacitor is needed at this pin.
. No decoupling
BAT
8
9
CISP
CISN
VIN
Input current sense positive connection pin. Connector a sense resistor from this pin the CISN.
Input current sense negative connection pin. Connector a sense resistor from this pin the CISP.
Input supply voltage. Connect a 4.7μF ceramic capacitor from VIN to PGND.
10, 11
12
VHI
High side NMOS FET gate drive supply pin. Connect a Schottky diode from VBIAS to this pin, and a
0.1mF capacitor to AGND, as shown in the Typical Application Circuits.
13, 14
15, 16
17
SW
PGND
VBIAS
RTH
Switch node and inductor connection pin.
Power ground.
Internal 5V regulator output. Connect a 1μF ceramic capacitor from this pin to AGND.
Input for an external NTC thermistor for battery temperature monitoring.
18
19
TIME
The TIME pin sets the oscillation period by connecting a timing capacitor between this pin and GND.
The oscillator also provides a time reference for the charger. The timer function can be disabled by
connecting the TIME pin to GND. If the timer is disabled, there will be no timeout function for any
operation mode including trickle charge and fast charge modes.
20
STAT1
EPAD
Open-drain indication pin. In conjunction with STAT2 this pin provides a unique indication for each
charging state of the cycle. This pin is capable to sink 10mA minimum current to drive an LED.
Exposed pad. Connect to GND electrically. Thermally, connect as much as possible copper to this pad
either on the component layer or other layers through thermal vias to enhance the thermal
performance.
Ordering Information
PACKAGE
Tape & Reel
(Pb-free)
PART NUMBER
TEMP. RANGE
(°C)
PKG.
DWG. #
(Notes 1, 2, 3)
PART MARKING
ISL9220IRTZ-T
92 20IRTZ
-40 to +85
-40 to +85
20 Ld 4x4 TQFN
20 Ld 4x4 TQFN
L20.4x4E
L20.4x4E
ISL9220AIRTZ-T
ISL9220EVAL1Z
ISL9220AEVAL1Z
NOTES:
922 0AIRTZ
Evaluation Board
Evaluation Board
1. Please refer to TB347 for details on reel specifications.
2. These Intersil Pb-free plastic packaged products employ special Pb-free material sets, molding compounds/die attach
materials, and 100% matte tin plate plus anneal (e3 termination finish, which is RoHS compliant and compatible with both
SnPb and Pb-free soldering operations). Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that
meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020.
3. For Moisture Sensitivity Level (MSL), please see device information page for ISL9220, ISL9220A. For more information on MSL
please see techbrief TB363.
FN6936.1
July 2, 2010
2
ISL9220, ISL9220A
Absolute Maximum Ratings
Thermal Information
VIN, CISP, CISN. . . . . . . . . . . . . . . . . . . . . . . -0.3V to 18V
SW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.7V to 18V
VHI. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 24V
VBAT, ISNS . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 10V
ISET1, ISET2, RTH, VBIAS, STAT1, STAT2, EN. -0.3V to 5.5V
TIME. . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 2.75V
Input Current (VIN) . . . . . . . . . . . . . . . . . . . . . . . . . .2.0A
Output Current (SW) . . . . . . . . . . . . . . . . . . . . . . . . .2.2A
ESD Rating
Human Body Model (Tested per JESD22-A114F) . . . 2500V
Machine Model (Tested per EIA/JESD22-A115-A) . . . 175V
Charged Device Model (Tested per JES22-C101D). . 1500V
Latch-Up
Thermal Resistance (Typical)
θ
JA (°C/W) θJC (°C/W)
40 4.3
4x4 QFN Package (Notes 4, 5) . .
Maximum Junction Temperature (Plastic Package) . . +150°C
Maximum Storage Temperature Range . . . -65°C to +150°C
Pb-Free Reflow Profile . . . . . . . . . . . . . . . . . .see link below
http://www.intersil.com/pbfree/Pb-FreeReflow.asp
Recommended Operating Conditions
Ambient Temperature Range . . . . . . . . . . . -40°C to +85°C
Supply Voltage, VIN
ISL9220 . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5V to 14V
ISL9220A . . . . . . . . . . . . . . . . . . . . . . . . . . . 9V to 14V
Programmable Charge Current . . . . . . . . . . . . 200mA to 2A
Programmable Trickle Current . . . . . . . . . . 20mA to 200mA
(Tested per JESD-78B; Class 2 (+85°C), Level A) . . 100mA
CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely impact
product reliability and result in failures not covered by warranty.
NOTES:
4. θ is measured in free air with the component mounted on a high effective thermal conductivity test board with “direct attach”
JA
features. See Tech Brief TB379.
5. θ , “case temperature” location is at the center of the exposed metal pad on the package underside.
JC
Electrical Specifications Typical specifications are measured at the following conditions: T = +25°C; For ISL9220,
A
V
= 5V; For ISL9220A, V = 12V.
IN
IN
PARAMETER
POWER-ON RESET
Rising V Threshold
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNITS
V
3.4
2.2
3.6
2.4
3.8
2.6
V
V
IN
Falling V Threshold
POR_R
V
IN
POR_F
V
- V
OFFSET VOLTAGE
BAT
IN
Rising Offset Threshold
V
ISL9220
ISL9220A
ISL9220
ISL9220A
mV
mV
mV
mV
OS_R
-
95
170
65
150
-
300
Falling Offset Threshold
V
OS_F
10
20
-
-
130
SUPPLY CURRENT
VIN Pin Supply Current
PGOOD = TRUE, EN = L (Note 6)
I
10
-
15
mA
mA
CC(VIN)
PGOOD = TRUE, EN= (Note 6)
0.5
H
-
-
V
= 5V to 12V
IN
Battery Discharge Current
(Total of currents flowing into VBAT,
ISNS, SW pins)
I
VIN < V
EN =
2
5
μA
POR OR
2V < V < 11V
BAT
H
DIS
OVERVOLTAGE PROTECTION
Input OVP Rising Threshold
Input OVP Falling Threshold
OUTPUT CURRENT
V
14.5
14.0
15.0
14.5
15.5
15.0
V
V
IN_OVPR
V
IN_OVPF
Fast Charge Current Accuracy
I
RSNS = 0.039Ω
RISET1 = 49.9kΩ (Nominal
= 1000mA)
-10
-35
-
-
10
35
%
%
CHG
I
OUT
Charge Termination Current Accuracy
I
RSNS = 0.039Ω
RISET2 = 300kΩ (Nominal
MIN
I
= 100mA)
MIN
FN6936.1
July 2, 2010
3
ISL9220, ISL9220A
Electrical Specifications Typical specifications are measured at the following conditions: T = +25°C; For ISL9220,
A
V
= 5V; For ISL9220A, V = 12V. (Continued)
IN
IN
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNITS
Charge Termination Detection Deglitch
Time
-
12
-
ms
Level 1 Pre-Charge Current Range
(Linear mode)
I
I
V
< V
PCHG1
25
-
50
90
-
mA
%
PCHG1
BAT
Level 2 Pre-Charge Current Accuracy
RSNS = 0.039Ω
RISET2 = 300kΩ (Nominal
±20
PCHG2
I
= 140mA)
PCHG
Level 1 Pre-Charge Threshold Voltage
Level 2 Pre-Charge Threshold Voltage
V
V
ISL9220
ISL9220A
ISL9220
ISL9220A
2.42
4.8
2.5
5.0
3.0
6.0
2.56
5.3
V
V
V
V
PCHG1
2.9
3.1
PCHG2
5.75
6.25
RECHARGE THRESHOLD
Recharge Voltage Threshold
V
ISL9220
3.85
7.75
4.0
8.0
4.1
V
V
RECHG
ISL9220A
8.25
TEMPERATURE MONITORING
High Battery Temperature Threshold
Low Battery Temperature Threshold
Battery Removal Threshold
V
Specified as % of V
Specified as % of V
Specified as % of V
30
70
90
-
35
75
40
80
-
%
%
TMIN
BIAS
BIAS
BIAS
V
TMAX
V
95
%
RMV
Thermistor Disable Threshold
V
250
180
-
mV
mV
T_DIS
Temperature Threshold Hysteresis
-
V
-
-
T,HYS
Temperature Detection Deglitch Time
THERMAL PROTECTION
Thermal Shutdown Threshold
Thermal Hysteresis
12
-
ms
T
-
-
140
30
-
-
°C
°C
FD
T
HYS
VBIAS OUTPUT
Output Voltage
V
5.3 < V < 15V, I
IN
= 5mA
4.70
-
5.0
-
5.25
5
V
BIAS
VBIAS
Output Current
I
5.3 < V < 15V
IN
mA
BIAS
OSCILLATOR
Oscillation Period
t
C
= 15nF
-
3.0
-
ms
OSC
TIME
SWITCHING CHARGER AC CHARACTERISTICS
Switching Frequency
F
1.02
1.2
96
0
1.38
MHz
%
OSC
Maximum Duty Cycle
Minimum Duty Cycle
D
-
-
-
-
-
-
MAX
D
%
MIN
LIM
Cycle-By-Cycle Current Limit
I
3.0
A
SWITCHING CHARGER DC CHARACTERISTICS
High-Side MOSFET ON-Resistance
r
,
,
-
-
112
224
-
mΩ
mΩ
DS(ON)
HS1
Combined High Side ON-Resistance
(Note 7)
r
Measured between V and SW
IN
pins
450
DS(ON)
HS2
Low-Side MOSFET ON-Resistance
r
, L
-
-
72
180
5.0
mΩ
μA
DS(ON)
High-Side Path Reverse Leakage Current
I
V
= 0V, VSW = 15V
IN
1.0
REV
FN6936.1
July 2, 2010
4
ISL9220, ISL9220A
Electrical Specifications Typical specifications are measured at the following conditions: T = +25°C; For ISL9220,
A
V
= 5V; For ISL9220A, V = 12V. (Continued)
IN
IN
TEST CONDITIONS
ISL9220, I = 100mA,
PARAMETER
SYMBOL
MIN
TYP
MAX
UNITS
Charger Output Voltage
V
4.179
4.2
4.221
V
CHG
OUT
T = +25°C
A
ISL9220A, I
= 100mA,
8.358
8.4
8.442
V
OUT
T = +25°C
A
ISL9220, I
OUT
= 100mA
= 100mA
4.158
8.316
4.2
8.4
4.242
8.484
V
V
ISL9220A, I
OUT
INPUT CURRENT SENSE AMPLIFIER
Input Bias Current at CSIP and CSIN, Pin
(Charger Enabled)
I
EN =
-
100
100
200
112
μA
L
ISIP_ON
Input Current Limit Threshold
I
CSIP-CSIN
88
mV
IN_LIM
OUTPUT CURRENT SENSE AMPLIFIER
Input Bias Current at ISNS Pin,
(Charger Enabled)
I
EN =
EN =
EN =
EN =
-
-
-
-
100
-
200
1
μA
μA
μA
μA
L
ISNS_ON
Input Bias Current at ISNS Pin,
(Charger Disabled)
I
H
L
ISNS_OFF
Input Bias Current at VBAT Pin,
(Charger Enabled)
I
75
-
100
1
VBAT_ON
Input Bias Current at VBAT Pin,
(Charger Disabled)
I
H
VBAT_OFF
LOGIC INPUT AND OUTPUTS
EN Pin Logic High
1.3
-
-
-
-
-
-
0.4
-
V
V
EN Pin Logic Low
STAT1, STAT2 Sink Current When ON
Pin Voltage = 0.4V
Pin Voltage = 4.2V
10
-
mA
μA
STAT1, STAT2 Leakage Current When
OFF
1
NOTES:
6. PGOOD is defined as when V and V
IN
meet all these conditions: V > VPOR, V - V
IN IN
> VOS, V < V
IN
.
IN(OVP)
BAT
BAT
7. Limits should be considered typical and are not production tested.
FN6936.1
July 2, 2010
5
ISL9220, ISL9220A
Typical Applications Diagrams
1-Cell Application
2-Cell Application
FN6936.1
July 2, 2010
6
ISL9220, ISL9220A
Block Diagram
FN6936.1
July 2, 2010
7
ISL9220, ISL9220A
Typical Operating Conditions
CH4 = INDUCTOR CURRENT (500mA/DIV)
CH4 = INDUCTOR CURRENT (500mA/DIV)
CH1 = SW(5V/DIV)
CH1 = SW(5V/DIV)
FIGURE 2. PWM WAVEFORM IN TRICKLE MODE
FIGURE 1. PWM WAVEFORM IN CC MODE
95
95
V
= 8.2V
V
= 3.6V
BAT
BAT
90
85
80
75
70
90
85
80
75
70
V
= 4V
V
= 7V
BAT
BAT
V
= 6V
V
= 3V
BAT
BAT
0
0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2
CHARGE CURRENT (A)
0
0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
CHARGE CURRENT (A)
FIGURE 3. EFFICIENCY vs LOAD 1-CELL (V
= 5V,
FIGURE 4. EFFICIENCY vs LOAD 2-CELL (V =12V,
IN
IN
L = 10μH)
L = 10μH
FN6936.1
July 2, 2010
8
ISL9220, ISL9220A
Theory of Operation
The ISL9220, ISL9220A is an integrated charger
optimized for charging 1-cell and 2-cell Li-ion or
Li-polymer batteries. It charges a battery with constant
current (CC) and constant voltage (CV) profile. The
typical charge profile is illustrated in Figure 5.
FIGURE 6. THERMISTER INTERNAL CIRCUIT
FIGURE 5. TYPICAL CHARGE PROFILE
POR and Power-Good
The ISL9220, ISL9220A resets itself when V undergoes
IN
transition from below V
POR
to above V threshold.
POR
The ISL9220, ISL9220A has an internal PGOOD signal.
Charging is prohibited if PGOODstatement is not true.
See Note 6 in the “Electrical Specifications” table for
definition of PGOOD.
Valid Charge Temperatures
An external NTC thermistor can be used to provide
temperature-qualified charging. The VBIAS supply is
used as reference for the internal comparators. Thus, it is
FIGURE 7. THRESHOLD VOLTAGES FOR 0°C to +50°C
WINDOW (V
= 5.0V)
BIAS
Battery Detection
important that the V
supply also be used to bias the
BIAS
external voltage divider comprised of one or more fixed
resistors and the thermistor. This scheme allows the use
of a wide variety of thermistors. The RTH comparator
block monitors the RTH pin voltage to determine if the
battery temperature is within safe charging limits.
The presence or absence of the external thermistor is
used to detect a battery.
When V
RTH
is greater than V , i.e. when RTH pin
RTH,PRES
is not connected to ground, battery detection is provided
by the RTH comparator block, as shown in Figure 6. With
no battery connected, the RTH pin is pulled to VBIAS by
The ISL9220, ISL9220A uses two comparators (CP2 and
CP3) to form a window comparator, as shown in
Figure 6. When the NTC pin voltage is “out of the
R , and thus V
will exceed the V threshold.
U
RTH
RTH,NOBAT
The internal battery presence signal is deglitched with a
12ms deglitcher, to avoid false indication of battery
insertion or removal due to contact bounce or other
noises.
window,” determined by the V
and V , the
TMIN
TMAX
ISL9220, ISL9220A stops charging and indicate a
suspend condition. When the temperature returns to
the set range, the charger resumes charging. The two
MOSFETs, Q1 and Q2, produce hysteresis for both upper
and lower thresholds. The temperature window is
shown in Figure 7 for a 0°C to +50°C typical application
using an industry standard type 103AT thermistor.
Battery Precharge
When the charger is first enabled and no fault conditions
are detected, If the battery connecting to the charger is
deeply discharged, the charger will charge the battery in
a reduced current for the battery to recover.
The temperature qualification function can be disabled by
connecting the RTH pin to ground.
If battery voltage is less than the level 1 pre-charge
voltage (V
), the charger operates in LDO mode,
PCHG1
with an output current fixed at 50mA typical. In this
mode the output voltage can go to 0V. This provides the
ability to recover a battery that has entered a
safety-circuit undervoltage fault mode.
FN6936.1
July 2, 2010
9
ISL9220, ISL9220A
For best accuracy, select R
value that provides
between 40mV to 80mV differential voltage across R
SNS
(EQ. 1)
I
= 50mA
SNS
PCHG1
at the desired maximum peak current (DC plus ripple).
If battery voltage is between the level 1 pre-charge
voltage (V ) and level 2 pre-charge voltage
Charge Termination
PCHG1
), the charger operates in trickle mode, and uses
(V
Charge current is continuously monitored. When the
current falls below the taper current threshold, charging
will stop, and BATFUL is asserted to indicate a successful
charge completion. This taper current threshold is
programmed by a single external resistor between ISET2
and ground as calculated in Equation 7.
PCHG2
the precharge current limit. This precharge current is
programmed by the resistor between the ISET2 pin and
ground. Note that this resistor also programs the
end-of-charge taper current threshold.
1638
(EQ. 2)
I
= ------------------------------------------
(mA)
PCHG2
(EQ. 7)
1170
= ------------------------------------------
R
× R
SNS
I
(mA)
ISET2
EOC
R
× R
SNS
ISET2
Where R
is in kΩ and R is in Ω.
SNS
ISET2
Where R
is in kΩ and RSNS is in Ω.
ISET2
When the battery voltage exceeds the level 2 pre-charge
voltage threshold (V ), fast charging will
commence. If this threshold is not reached within the
precharge timer period, a TIME-OUT-FAULT condition is
asserted, and the charger is disabled.
A secondary charge termination method is provided via
the safety timer. The timeout period of this timer is
programmable via a single external capacitor between
the TIME pin and ground.
PCHG2
To disable the charge safety timer, short the TIME pin to
ground.
Charge Safety Timer
An internal oscillator establishes a timing reference. The
oscillation period is programmable with an external
Charge Current Sensing
capacitor at the TIME pin, C
, as shown in “Typical
Time
Charge current is sensed with an external current sense
resistor. A low-inductance, precision resistor should be
used for accurate charge current.
Applications Diagrams” on page 6. The oscillator charges
the timing capacitor to 1.5V and then discharges it to
0.5V in one period, both with 10μA current. The period
t
is calculated in Equation 3:
Input Current Sensing
OSC
6
(EQ. 3)
Input current is sensed with an external sense resistor. A
low-inductance, precision resistor should be used for
accurate input current limit.
t
= 0.2 × 10 × C
(Sec)
OSC
Time
Where C
Time
is in F.
The ISL9220, ISL9220A limits the battery charge current
when the input current limit threshold is exceeded. This
allows the most efficient use of AC-adapter power
without overloading the adapter output.
A 1nF capacitor provides 0.2ms oscillation period. The
allowable range of C value is 100pF to 1μF, providing
a programmable charge safety-timeout range of about
1.4 minutes to almost 10 days.
Time
An internal amplifier compares the voltage between CSIP
and CSIN, and reduces the output current when this
differential voltage exceeds the threshold voltage. The
effective input current limit threshold is thus set by the
Total charge time, excluding any time required for
precharge, is limited to a length of TIMEOUT. This can be
calculated as Equation 4:
value of the R
resistor as calculated by Equation 8.
(EQ. 4)
ICS
22
TIMEOUT = 2 × t
(Sec)
OSC
0.1
(EQ. 8)
I
= -------------
(A)
IN(LIM)
R
ICS
Total charge time for battery precharge is limited to a
length of 1/8 TIMEOUT. This can be calculated as
Equation 5:
Where R
ICS
is in Ω.
A low pass filter is suggested to eliminate the switching
noise, as shown in “Typical Applications Diagrams” on
page 6.
(EQ. 5)
19
TIMEOUT(PCHG) = 2 × t
(Sec)
OSC
The TIME pin can be grounded to disable the safety timer
functions if not needed.
Status Outputs
TABLE 1. STAT1 AND STAT2 TRUE TABLE
Fast Charge
The fast charge current is programmed by the resistor
between the ISET1 pin and ground, and by the value of
STAT1
STAT2
CHARGING CONDITION
Precharge, or fast charge in progress
Charge Complete
L
L
L
H
L
the R
resistor (see Equation 6).
SNS
H
H
Fault
1946
(EQ. 6)
I
= ------------------------------------------
(mA)
CHG
R
× R
H
Suspend
ISET1
SNS
Where R
is in kΩ and R
is in Ω.
ISET1
SNS
FN6936.1
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10
ISL9220, ISL9220A
STAT1 and STAT2 are configured to indicate various
charging conditions as given in Table 1.
Recharge
After a charge cycle completes at a timeout event,
charging is prohibited until the recharge condition
A fault status is triggered under one of these conditions:
(V
< VRECHG) is met, then the charging restarts with
BAT
1. V
> VOUT_OVP threshold
BAT
the timer reset to zero.
2. Timeout occurs before the EOC current has been
reached
Inductor and Output Capacitor Selection
To achieve better steady state and transient response,
ISL9220, ISL9220A typically uses a 10μH inductor. The
peak-to-peak inductor current ripple can be expressed in
Equation 9:
To exit the fault mode, the input power has to be
recycled, or the EN pin is toggled to HI and back to LO.
Applications Information
Power-On Reset (POR)
The ISL9220, ISL9220A resets itself as the input voltage
rises above the POR rising threshold. The internal
oscillator starts to oscillate, the internal timer is reset,
and the charger begins to charge the battery. The
STAT1/2 pins will indicate the operating condition
according to Table 1.
V
⎛
⎞
⎟
⎠
BAT
V
• 1 – --------------
⎜
BAT
(EQ. 9)
V
⎝
IN
ΔI = --------------------------------------------------
L • f
S
In Equation 9, usually the typical values can be used but
to have a more conservative estimation, the inductance
should consider the value with worst case tolerance; and
for switching frequency f , the minimum f from the
S
S
Trickle Charge
“Electrical Specifications” table on page 3 can be used. A
worst case for charge current ripple is when battery
voltage is half of the input voltage.
If the battery voltage is below the trickle charge
threshold, the ISL9220, ISL9220A delivers a small
current to charge the battery until the battery voltage
reaches the fast charge threshold value. There are two
To select the inductor, its saturation current rating should
be at least higher than the sum of the maximum output
current and half of the delta calculated from Equation 9.
Another more conservative approach is to select the
inductor with the current rating higher than the peak
current limit.
trickle charge thresholds. The first threshold, V
, is
PCHG1
to pre-charge a deeply discharged battery or short
circuit. The second threshold, V is for batteries
PCHG2
discharged to a voltage range from 2.5V to 3V. When
is below V the ISL9220, ISL9220A operates
V
BAT
PCHG1,
as a linear regulator, providing a 50mA constant current
to output. When V reaches V the ISL9220,
Another consideration is the inductor DC resistance since
it directly affects the efficiency of the converter. Ideally,
the inductor with the lower DC resistance should be
considered to achieve higher efficiency.
BAT PCHG2,
ISL9220A starts to operate as a switching charger. The
trickle charge current is programmable by RISET2.
Inductor specifications could be different from different
manufacturers so please check with each manufacturer if
additional information is needed.
Charge Cycle
A charge cycle consists of three charge modes: trickle
mode, constant current (CC) mode, and constant voltage
(CV) mode. The charge cycle always starts with the
trickle mode until the battery voltage stays above V
(3.0V typical). If the battery voltage stays below V
the charger stays in the trickle mode. The charger
For the output capacitor, a ceramic capacitor can be used
because of the low ESR values, which helps to minimize
the output voltage ripple. A typical value of 10μF/10V
ceramic capacitor should be enough for most of the
applications and the capacitor should be X5R or X7R.
MIN
MIN
,
operates in CC mode after the battery voltage is above
. As the battery-pack terminal voltage rises to the
V
MIN
Board Layout Recommendations
final charge voltage, the CV mode operation begins.
Since the battery terminal voltage is regulated at the
constant output voltage in the CV mode, the charge
current begins to drop. After the charge current drops
below the end-of-charge level, which is programmed by
RISET2. The ISL9220, ISL9220A indicates the
end-of-charge (EOC) with STAT1 and STAT2 and
terminates the charge. The following events initiate a
new charge cycle:
The ISL9220, ISL9220A is a high frequency switching
charger and hence the PCB layout is a very important
design practice to ensure a satisfactory performance.
The power loop is composed of the output inductor L, the
output capacitor C
, the SW pin and the PGND pin. It
OUT
is important to make the power loop as small as possible
and the connecting traces among them should be direct,
short and wide; the same practice should be applied to
• POR
the connection of the VIN pin, the input capacitor C
and PGND.
IN
• A new battery being inserted (detected by RTH pin)
• Recovery from an battery over-temperature fault
• The EN pin is toggled from HI-to-LO
The switching node of the converter, the SW pin, and the
traces connected to this node are very noisy, so keep the
voltage feedback trace and other noise sensitive traces
away from these noisy traces.
FN6936.1
July 2, 2010
11
ISL9220, ISL9220A
The input capacitor should be placed as close as possible
Charging Flow Chart
to the VIN pin. The ground of the input and output
capacitors should be connected as close as possible as
well. In addition, a solid ground plane is helpful for a
good EMI performance.
The charging flow chart is shown in Figure 9 The
charging starts with the trickle mode, the ISL9220,
ISL9220A charges the battery in a trickle current. If V
BAT
reaches V
before the trickle charge timeout
PCHG2
interval, the operation will change to CC mode. When the
output voltage reaches the 4.2V final voltage, the
operation will change to CV mode, where the battery is
charged at a constant voltage. If the end-of-charge
current is reached before the timeout interval is elapsed,
the operation will come to charge complete state. The
charging is terminated. After the termination, if the
output voltage drops below the recharge threshold, a
recharge starts and the timer is reset to zero.
The ISL9220, ISL9220A employs a thermal enhanced
QFN package with an exposed pad. In order to maximize
the current capability, it is very important that the
exposed pad under the package is properly soldered to
the board and is connected to other layers through
thermal vias. More thermal vias and more copper
attached to the exposed pad usually results in better
thermal performance. The exposed pad is big enough for
5 vias as shown in Figure 8.
In the event that the timeout condition is reached before
EOC, the fault mode is entered. The fault mode can also
be triggered by a V
OVP event. To exit the fault mode,
BAT
the input power has to be removed and re-applied, or the
EN pin is toggled to HI and back to LO, then a new cycle
starts.
FIGURE 8. EXPOSED PAD
FN6936.1
July 2, 2010
12
ISL9220, ISL9220A
FIGURE 9. CHARGING FLOW CHART
FN6936.1
July 2, 2010
13
ISL9220, ISL9220A
Revision History
The revision history provided is for informational purposes only and is believed to be accurate, but not warranted. Please go to
web to make sure you have the latest Rev.
DATE REVISION
CHANGE
7/1/10
FN6936.1 Changed minimum limit for “IPCHG1” on page 4 from 30 to 25mA.
On page 4, changed "Minimum On-Time" with typical 20ns to “Minimum Duty Cycle” with typical of 0%.
Changed minimum limit for “VPCHG1” on page 4 from 4.85 to 4.80V for only the "A option"
Changed maximum limit for “VPCHG1” on page 4 from 5.25 to 5.3V for only the "A option"
Changed minimum limit for “VPCHG2” on page 4 from 5.80V to 5.75V for only the "A option"
Changed maximum limit for “VPCHG2” on page 4 from 6.2V to 6.25V for only the "A option"
Changed minimum limit for “VRECHG” on page 4 from 7.80V to 7.75V for only the "A option"
Changed maximum limit for “VRECHG” on page 4 from 8.20 to 8.25V for only the "A option"
6/30/10 FN6936.0 Initial Release.
Products
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Company's products address some of the industry's fastest growing markets, such as, flat panel displays, cell phones,
handheld products, and notebooks. Intersil's product families address power management and analog signal
processing functions. Go to www.intersil.com/products for a complete list of Intersil product families.
*For a complete listing of Applications, Related Documentation and Related Parts, please see the respective device
information page on intersil.com: ISL9220, ISL9220A
To report errors or suggestions for this datasheet, please go to www.intersil.com/askourstaff
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Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications
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FN6936.1
July 2, 2010
14
ISL9220, ISL9220A
Package Outline Drawing
L20.4x4E
20 LEAD THIN QUAD FLAT NO-LEAD PLASTIC PACKAGE
Rev 0, 4/10
4X 2.00
0.50
4.00
16X
A
6
B
PIN #1
INDEX AREA
16
20
6
PIN 1
INDEX AREA
1
15
11
2 . 60
5
(4X)
0.15
6
10
0.10M C A B
TOP VIEW
20X 0 . 40 ±0.10
4
0.23 +0.07/- 0.05
BOTTOM VIEW
SEE DETAIL "X"
0.10 C
C
0.75
BASE PLANE
SEATING PLANE
0.08 C
SIDE VIEW
( 16X 0 . 50 )
(3.8 TYP)
(
2 . 60 )
5
C
0 . 2 REF
( 20X 0 . 23 )
( 20 X 0 . 60 )
0 . 00 MIN.
0 . 05 MAX.
TYPICAL RECOMMENDED LAND PATTERN
DETAIL "X"
NOTES:
1. Dimensions are in millimeters.
Dimensions in ( ) for Reference Only.
2. Dimensioning and tolerancing conform to ASME Y14.5m-1994.
3.
Unless otherwise specified, tolerance : Decimal ± 0.05
4. Dimension applies to the metallized terminal and is measured
between 0.15mm and 0.30mm from the terminal tip.
Tiebar shown (if present) is a non-functional feature.
5.
6.
The configuration of the pin #1 identifier is optional, but must be
located within the zone indicated. The pin #1 identifier may be
either a mold or mark feature.
JEDEC reference drawing: MO-229.
7.
FN6936.1
July 2, 2010
15
相关型号:
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