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1-888-IN
ISL9203R5220
FN9242.1
Li-ion/Li Polymer Battery Charger
Features
The ISL9203R5220 is an integrated single-cell Li-ion or
Li-polymer battery charger capable of operating with an input
voltage as low as 2.4V. This charger is designed to work with
various types of AC adapters.
• Complete Charger for Single-Cell Li-ion Batteries
The ISL9203R5220 operates as a linear charger when the
AC adapter is a voltage source. The battery is charged in a
CC/CV (constant current/constant voltage) profile. The
charge current is programmable with an external resistor up
to 1.5A. The ISL9203R5220 can also work with a currentlimited adapter to minimize the thermal dissipation, in which
case the ISL9203R5220 combines the benefits of both a
linear charger and a pulse charger.
• No External Blocking Diode Required
The ISL9203R5220 features charge current thermal
foldback to guarantee safe operation when the printed circuit
board is space limited for thermal dissipation. Additional
features include preconditioning of an over-discharged
battery and thermally enhanced DFN package.
• Ambient Temperature Range: -20°C to 70°C
Typical Application Circuit
• Handheld Devices including Medical Handhelds
• Very Low Thermal Dissipation
• Integrated Pass Element and Current Sensor
• 1% Voltage Accuracy
• Programmable Current Limit up to 1.5A
• Charge Current Thermal Foldback
• Accepts Multiple Types of Adapters
• Guaranteed operation down to VIN = 2.65V after start up
• Thermally-Enhanced DFN Packages
• Pb-Free Plus Anneal Available (RoHS Compliant)
Applications
• PDAs, Cell Phones and Smart Phones
5V
Input
VIN
VBAT
• Portable Instruments, MP3 Players
ISL9203
C1
• Self-Charging Battery Packs
C2
• Stand-Alone Chargers
VSEN
• USB Bus-Powered Chargers
STATUS
Floating
to Enable
V2P8
EN
TIME
Related Literature
IREF
C3
• Technical Brief TB363 “Guidelines for Handling and
Processing Moisture Sensitive Surface Mount Devices
(SMDs)”
GND
CTIME
RIREF
• Technical Brief TB379 “Thermal Characterization of
Packaged Semiconductor Devices”
• Technical Brief TB389 “PCB Land Pattern Design and
Surface Mount Guidelines for QFN Packages”
Pinout
Ordering Information
PART NUMBER
(Note)
ISL9203CRZR5220
ISL9203CRZ-TR5220
PART
TEMP.
MARKING RANGE (°C)
03CZ
-20 to 70
PACKAGE
(Pb-free)
10 Ld 3x3 DFN L10.3x3
10 Ld 3x3 DFN Tape and Reel
NOTE: Intersil Pb-free plus anneal products employ special Pb-free material
sets; molding compounds/die attach materials and 100% matte tin plate
termination finish, which are 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.
1
ISL9203R5220
(3x3 DFN)
TOP VIEW
PKG
DWG. #
VIN
1
10 VBAT
NC
2
9
VSEN
STATUS
3
8
IREF
TIME
4
7
V2P8
GND
5
6
EN
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. 2005, 2006. All Rights Reserved.
All other trademarks mentioned are the property of their respective owners.
ISL9203R5220
Absolute Maximum Ratings
Thermal Information
Supply Voltage (VIN) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 to 7V
Output Pin Voltage (BAT, VSEN, V2P8). . . . . . . . . . . . . -0.3 to 5.5V
Signal Input Voltage (TIME, IREF). . . . . . . . . . . . . . . . . -0.3 to 3.2V
Output Pin Voltage (STATUS) . . . . . . . . . . . . . . . . . . . . . . -0.3 to 7V
Charge Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.6A
ESD Rating
Human Body Model (Per MIL-STD-883 Method 3015.7) . . .4500V
Machine Model (Per EIAJ ED-4701 Method C-111) . . . . . . . .200V
Thermal Resistance (Typical, Notes 1, 2) JA (°C/W) JC (°C/W)
3x3 DFN Package . . . . . . . . . . . . . . . .
46
4
Maximum Junction Temperature (Plastic Package) . . . . . . . . 150°C
Maximum Storage Temperature Range . . . . . . . . . . . -65°C to 150°C
Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . . 300°C
Recommended Operating Conditions
Ambient Temperature Range . . . . . . . . . . . . . . . . . . . .-20°C to 70°C
Supply Voltage, VIN . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3V to 6.5V
CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the
device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
NOTES:
1. JA is measured in free air with the component mounted on a high effective thermal conductivity test board with “direct attach” features. See
Tech Brief TB379.
2. JC, “case temperature” location is at the center of the exposed metal pad on the package underside. See Tech Brief TB379.
Electrical Specifications
Typical values are tested at VIN = 5V and 25°C Ambient Temperature, maximum and minimum values are
guaranteed over 0°C to 70°C Ambient Temperature with a supply voltage in the range of 4.3V to 6.5V, unless
otherwise noted.
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNITS
Rising VIN Threshold
3.0
3.4
4.0
V
Falling VIN Threshold
2.3
2.4
2.65
V
VIN floating or EN = LOW
-
-
3.0
A
POWER-ON RESET
STANDBY CURRENT
VBAT Pin Sink Current
ISTANDBY
VIN Pin Supply Current
IVIN
VBAT floating and EN pulled low
-
30
250
A
VIN Pin Supply Current
IVIN
VBAT floating and EN floating
-
1
2
mA
4.158
4.20
4.242
V
-
320
550
mV
VOLTAGE REGULATION
Output Voltage
VCH
Dropout Voltage
VBAT = 3.7V, Charge current = 1A
CHARGE CURRENT
Constant Charge Current (Note 3)
ICHARGE
RIREF = 80k, VBAT = 3.7V
0.9
1.0
1.1
A
Constant Charge Current
ICHARGE
RIREF = 1.21M, VBAT = 3.7V
33
66
100
mA
Trickle Charge Current
ITRICKLE
RIREF = 80k, VBAT = 2.0V
85
110
135
mA
Trickle Charge Current
ITRICKLE
RIREF = 1.21M, VBAT = 2.0V
2
7
15
mA
End-of-Charge Threshold
IMIN
RIREF = 80k
85
110
135
mA
End-of-Charge Threshold
IMIN
RIREF = 1.21M
2
-
30
mA
VRECHRG
3.85
4.00
4.10
V
VMIN
2.7
2.8
3.0
V
RECHARGE THRESHOLD
Recharge Voltage Threshold
TRICKLE CHARGE THRESHOLD
Trickle Charge Threshold Voltage
2
FN9242.1
January 3, 2006
ISL9203R5220
Electrical Specifications
Typical values are tested at VIN = 5V and 25°C Ambient Temperature, maximum and minimum values are
guaranteed over 0°C to 70°C Ambient Temperature with a supply voltage in the range of 4.3V to 6.5V, unless
otherwise noted. (Continued)
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNITS
VV2P8
2.7
2.9
3.1
V
Charge Current Foldback Threshold (Note 4)
TFOLD
-
100
-
°C
Current Foldback Gain (Note 5)
GFOLD
-
100
-
mA/°C
2.4
3.0
3.6
ms
V2P8 PIN VOLTAGE
V2P8 Pin Voltage
TEMPERATURE MONITORING
OSCILLATOR
Oscillation Period
CTIME = 15nF
TOSC
LOGIC OUTPUTS
STATUS Logic Low Sink Current
Pin Voltage = 0.8V
5
-
-
mA
STATUS Leakage Current
VVIN = VSTATUS = 5V
-
-
1
A
EN Input Logic High
2.0
-
3.3
V
EN Input Logic Low
-
-
0.8
V
EN Pin Current When Driven Low
-
-
100
A
NOTES:
3. The accuracy includes all errors except the programming resistance tolerance. The actual charge current may be affected by the thermal
foldback function if the thermal dissipation capability is not enough or by the on resistance of the power MOSFET if the charger input voltage is
too close to the output voltage.
4. Guaranteed by design and characterization to be typically 100°C ±15%
5. Guaranteed by design and characterization.
Typical Operating Performance The test conditions for the Typical Operating Performance are: VIN = 5V, TA = 25°C,
RIREF = RIMIN = 80k, VBAT = 3.7V, unless otherwise noted.
4.210
4.2015
4.208
4.201
4.206
RIREF = 40k
4.2005
VBAT (V)
4.2
VBAT (V)
CHARGE CURRENT = 50mA
4.204
4.1995
4.199
4.202
4.200
4.198
4.196
4.1985
4.194
4.198
4.192
4.190
4.1975
0
0.3
0.6
0.9
1.2
1.5
CHARGE CURRENT (A)
FIGURE 1. CHARGER OUTPUT VOLTAGE vs CHARGE
CURRENT
3
0
20
40
60
80
100
120
TEMPERATURE (°C)
FIGURE 2. CHARGER OUTPUT VOLTAGE vs TEMPERATURE
FN9242.1
January 3, 2006
ISL9203R5220
Typical Operating Performance The test conditions for the Typical Operating Performance are: VIN = 5V, TA = 25°C,
RIREF = RIMIN = 80k, VBAT = 3.7V, unless otherwise noted. (Continued)
2.0
4.3
1.8
CHARGE CURRENT = 50mA
CHARGE CURRENT (A)
VBAT (V)
4.25
4.2
4.15
2A
1.6
1.4
1.5A
1.2
1.0
1A
0.8
0.6
0.4
0.5A
0.2
4.1
4.2
4.5
4.8
5.1
5.4
5.7
6
0.0
6.3
3.0
VIN (V)
FIGURE 3. CHARGER OUTPUT VOLTAGE vs INPUT
VOLTAGE CHARGE CURRENT IS 50mA
3.6
VVBAT (V)
3.8
4.0
2.0
1.8
1.4
1.5A
CHARGE CURRENT (A)
CHARGE CURRENT (A)
3.4
FIGURE 4. CHARGE CURRENT vs OUTPUT VOLTAGE
1.6
1.2
1.0
1.0A
0.8
0.6
0.5A
0.4
1.6
1.4
1.5A
1.2
1.0
1A
0.8
0.6
0.4
0.5A
0.2
0.2
0.0
3.2
0.0
4.3 4.5 4.7 4.9 5.1 5.3 5.5 5.7 5.9 6.1 6.3 6.5
0
20
40
60
80
100
120
VIN (V)
TEMPERATURE (°C)
FIGURE 5. CHARGE CURRENT vs AMBIENT TEMPERATURE
FIGURE 6. CHARGE CURRENT vs INPUT VOLTAGE
3
2.93
2.95
V2P8 PIN LOADED WITH 2mA
V2P8 VOLTAGE (V)
V2P8 VOLTAGE (V)
2.928
2.926
2.924
2.922
2.92
3.5
2.9
2.85
2.8
2.75
4
4.5
5
5.5
6
VIN (V)
FIGURE 7. V2P8 OUTPUT vs INPUT VOLTAGE
4
6.5
2.7
0
2
4
6
8
10
V2P8 LOAD CURRENT (mA)
FIGURE 8. V2P8 OUTPUT vs ITS LOAD CURRENT
FN9242.1
January 3, 2006
ISL9203R5220
Typical Operating Performance The test conditions for the Typical Operating Performance are: VIN = 5V, TA = 25°C,
RIREF = RIMIN = 80k, VBAT = 3.7V, unless otherwise noted. (Continued)
700
420
THERMAL FOLDBACK STARTS
NEAR 100°C
650
600
380
rDS(ON) (m)
550
rDS(ON) (m)
500mA CHARGE
CURRENT, RIREF = 40K
400
500
450
400
350
360
340
320
300
300
280
250
260
3.0
200
0
20
40
60
80
100
120
3.2
3.4
TEMPERATURE (°C)
1.8
50
1.6
45
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
20
40
60
80
100
EN = GND
35
30
25
20
15
10
5
0
120
0
20
60
80
100
120
FIGURE 12. INPUT QUIESCENT CURRENT vs TEMPERATURE
32
1.10
EN = GND
VIN QUIESCENT CURRENT (mA)
VIN QUIESCENT CURRENT (A)
40
TEMPERATURE (°C)
FIGURE 11. REVERSE CURRENT vs TEMPERATURE
28
26
24
22
20
18
16
14
12
10
3.0
4.0
40
TEMPERATURE (°C)
30
3.8
FIGURE 10. rDS(ON) vs OUTPUT VOLTAGE USING CURRENT
LIMITED ADAPTERS
VIN QUIESCENT CURRENT (A)
VBAT LEAKAGE CURRENT (A)
FIGURE 9. rDS(ON) vs TEMPERATURE AT 3.7V OUTPUT
0.0
3.6
VBAT (V)
3.5
4.0
4.5
5.0
5.5
6.0
VIN (V)
FIGURE 13. INPUT QUIESCENT CURRENT vs INPUT
VOLTAGE WHEN SHUTDOWN
5
6.5
1.05
1.00
0.95
BOTH VBAT AND EN
PINS FLOATING
0.90
0.85
0.80
4.3
4.6
4.9
5.2
5.5
5.8
6.1
6.4
VIN (V)
FIGURE 14. INPUT QUIESCENT CURRENT vs INPUT
VOLTAGE WHEN NOT SHUTDOWN
FN9242.1
January 3, 2006
ISL9203R5220
Typical Operating Performance The test conditions for the Typical Operating Performance are: VIN = 5V, TA = 25°C,
RIREF = RIMIN = 80k, VBAT = 3.7V, unless otherwise noted. (Continued)
28
STATUS PIN CURRENT (mA)
24
20
16
12
8
4
0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
STATUS PIN VOLTAGE (V)
FIGURE 15. STATUS PIN VOLTAGE vs CURRENT WHEN THE OPEN-DRAIN MOSFET TURNS ON
Pin Descriptions
EN (Pin 6)
VIN (Pin1)
EN is the enable logic input. Connect the EN pin to LOW to
disable the charger or leave it floating to enable the charger.
VIN is the input power source. Connect to a wall adapter.
V2P8 (Pin 7)
NC (Pin 2)
No connection for this pin.
STATUS (Pin 3)
STATUS is an open-drain output indicating charging and
inhibit states. The STATUS pin is pulled LOW when the
charger is charging a battery. It will be forced to high
impedence when the charge current drops to IMIN. This high
impedence mode will be latched until a recharge cycle or a
new charge cycle starts.
This is a 2.8V reference voltage output. This pin outputs a
2.8V voltage source when the input voltage is above POR
threshold, otherwise it outputs zero. The V2P8 pin can be
used as an indication for adapter presence.
IREF (Pin 8)
This is the programming input for the constant charging
current. It maintains at 0.8V when the charger is in normal
operation.
VSEN (Pin 9)
TIME (Pin 4)
The TIME pin determines the oscillation period by
connecting a timing capacitor between this pin and GND.
The oscillator also provides a time reference for the charger.
VSEN is the remote voltage sense pin. Connect this pin as
close as possible to the battery pack positive connection. If
the VSEN pin is floating, its voltage drops to zero volt and
the charger operates in the trickle mode.
GND (Pin 5)
VBAT (Pin 10)
GND is the connection to system ground.
VBAT is the connection to the battery. Typically a 10F
Tantalum capacitor is needed for stability when there is no
battery attached. When a battery is attached, only a 0.1F
ceramic capacitor is required.
6
FN9242.1
January 3, 2006
ISL9203R5220
Typical Applications
5V WALL
ADAPTER
VIN
C1
10µF
VBAT
C2
R1
1k
10µF
ISL9203R5220
BATTERY
PACK
D1
VSEN
STATUS
V2P8
EN
IREF
TIME
C3
GND
1µF
RIREF
80k
CTIME
1nF
Block Diagram
QMAIN
VIN
ISEN
Input_OK
VMIN
IT
100000:1
Current
Mirror
+
CA
-
RIREF
+
-
CHRG
CURRENT
REFERENCES
IMIN = IR/10
VPOR
-
IR
VSEN
VIN
+
-
IREF
V2P8
VRECHRG
QSEN
VCH
REFERENCES
TEMPERATURE
MONITORING
VPOR
C1
VBAT
+
VA
-
+
100mV
VCH
+
Trickle/Fast
ISEN
-
Minbat
VMIN
+
-
+
MIN_I
Recharge
Input_OK
VRECHRG
-
LOGIC
VIN
EN
ESD Diode
STATUS
STATUS
OSC
TIME
COUNTER
GND
FIGURE 16. BLOCK DIAGRAM
7
FN9242.1
January 3, 2006
ISL9203R5220
Charging Flow Chart
Power Up
VIN>VPOR ?
N
Y
POR
Initialization
Reset STATUS
Reset counter
CC Charge
CV Charge
Trickle
Charge
VSEN>=VCH?
VSEN>VMIN
Y
Ich < IMIN ?
Y
N
Y
N
N
Constant
Current
Charge
Trickle
Charge
Constant
Voltage
Charge
EOC indication:
set STATUS high
N
VSEN
<
VRECHRG?
Y
N
EN toggled ?
N
Y
EOC
FIGURE 17. CHARGING STATE DIAGRAM
8
FN9242.1
January 3, 2006
ISL9203R5220
Theory of Operation
The ISL9203R5220 is an integrated charger for single-cell
Li-ion or Li-polymer batteries. The ISL9203R5220 functions
as a traditional linear charger when powered with a voltagesource adapter. When powered with a current-limited
adapter, the charger minimizes the thermal dissipation
commonly seen in traditional linear chargers.
As a linear charger, the ISL9203R5220 charges a battery in
the popular constant current (CC) and constant voltage (CV)
profile. The constant charge current IREF is programmable
up to 1.5A with an external resistor. The charge voltage VCH
has 1% accuracy over the entire recommended operating
condition range. The charger always preconditions the
battery with 10% of the programmed current at the beginning
of a charge cycle, until the battery voltage is verified to be
above the minimum fast charge voltage, VMIN. This lowcurrent preconditioning charge mode is named trickle mode.
The verification takes 15 cycles of an internal oscillator
whose period is programmable with the timing capacitor.
HIGH and is latched. The latch is released at the beginning
of a re-charge cycle, when the EN is toggled, or after the
chip is power cycled.
If the ISL9203R5220 has not been power cycled and has not
had the EN pin toggled, but the VSEN voltage drops below
the recharge level, then the device re-enters the charge
mode. In this condition, the charger indicates a re-charge
cycle by bringing the STATUS pin LOW.
When the wall adapter is not present, the ISL9203R5220
draws less than 1A of current from the battery.
Figure 18 shows the typical charge curves in a traditional
linear charger powered with a constant-voltage adapter.
From the top to bottom, the curves represent the constant
input voltage, the battery voltage, the charge current and the
power dissipation in the charger. The power dissipation PCH
is given by the following equation:
P CH =  V IN – V BAT   I CHARGE
(EQ. 1)
A thermal-foldback feature removes the thermal concern
typically seen in linear chargers. The charger reduces the
charge current automatically as the IC internal temperature
rises above 100°C to prevent further temperature rise. The
thermal-foldback feature guarantees safe operation when
the printed circuit board (PCB) is space limited for thermal
dissipation.
where ICHARGE is the charge current. The maximum power
dissipation occurs during the beginning of the CC mode. The
maximum power the IC is capable of dissipating is
dependent on the thermal impedance of the printed-circuit
board (PCB). Figure 18 shows, with dotted lines, two cases
that the charge currents are limited by the maximum power
dissipation capability due to the thermal foldback.
Two indication pins are available from the charger to indicate
the charge status. The V2P8 outputs a 2.8V DC voltage
when the input voltage is above the power-on reset (POR)
level and can be used as a power-present indication. This
pin is capable of sourcing a 2mA current, so it can also be
used to bias external circuits. The STATUS pin is an opendrain logic output that goes LOW at the beginning of a
charge cycle and stays LOW until the end-of-charge (EOC)
condition is qualified. The EOC condition is met when the
battery voltage rises above a recharge threshold and the
charge current falls below an EOC current threshold. Once
the EOC condition is qualified, the STATUS output goes
When using a current-limited adapter, the thermal situation in
the ISL9203R5220 is totally different. Figure 19 shows the
typical charge curves when a current-limited adapter is
employed. The operation requires the IREF to be programmed
higher than the limited current ILIM of the adapter, as shown in
Figure 19. The key difference of the charger operating under
such conditions occurs during the CC mode.
Trickle
Mode
VIN
VCH
Constant Current
Mode
Constant Voltage
Mode
Inhibit
Input Voltage
Battery Voltage
VMIN
IREF
Charge Current
IREF/10
P1
P2
P3
Power Dissipation
TIMEOUT
FIGURE 18. TYPICAL CHARGE CURVES USING A
CONSTANT-VOLTAGE ADAPTER
9
FN9242.1
January 3, 2006
ISL9203R5220
The Block Diagram, Figure 16, aids in understanding the
operation. The current loop consists of the current amplifier
CA and the sense MOSFET QSEN. The current reference IR
is programmed by the IREF pin. The current amplifier CA
regulates the gate of the sense MOSFET QSEN so that the
sensed current ISEN matches the reference current IR. The
main MOSFET QMAIN and the sense MOSFET QSEN form a
current mirror with a ratio of 100,000:1, that is, the output
charge current is 100,000 times IR.
In the CC mode, the current loop tries to increase the charge
current by enhancing the sense MOSFET QSEN, so that the
sensed current matches the reference current. On the other
hand, the adapter current is limited, the actual output current
will never meet what is required by the current reference. As
a result, the current error amplifier CA keeps enhancing the
QSEN as well as the main MOSFET QMAIN, until they are
fully turned on. Therefore, the main MOSFET becomes a
power switch instead of a linear regulation device. The
power dissipation in the CC mode becomes:
P CH = R DS  ON   I CHARGE
2
(EQ. 2)
where RDS(ON) is the resistance when the main MOSFET is
fully turned on. This power is typically much less than the
peak power in the traditional linear mode.
The worst power dissipation when using a current-limited
adapter typically occurs at the beginning of the CV mode, as
shown in Figure 19. The equation 1 applies during the CV
mode. When using a very small PCB whose thermal
impedance is relatively large, it is possible that the internal
temperature can still reach the thermal foldback threshold. In
that case, the IC is thermally protected by lowering the
charge current, as shown by the dotted lines in the charge
current and power curves. Appropriate design of the adapter
can further reduce the peak power dissipation of the
Trickle
Mode
VIN
VCH
Constant Current
Mode
Constant Voltage
Mode
EOC
Input Voltage
Battery Voltage
VMIN
IREF
ILIM
Charge Current
IREF/10
ISL9203R5220. See the Application Information section of
the ISL6292 data sheet (www.intersil.com) for more
information.
Figure 20 illustrates the typical signal waveforms for the
linear charger from the power-up to a recharge cycle. More
detailed Applications Information is given below.
Applications Information
Power on Reset (POR)
The ISL9203R5220 resets itself as the input voltage rises
above the POR rising threshold. The V2P8 pin outputs a
2.8V voltage, the internal oscillator starts to oscillate, the
internal timer is reset, and the charger begins to charge the
battery. The STATUS pin indicates a LOW logic signal.
Figure 20 illustrates the start up of the charger between t0 to
t2.
The ISL9203R5220 has a typical rising POR threshold of
3.4V and a falling POR threshold of 2.4V. The 2.4V falling
threshold guarantees charger operation with a currentlimited adapter to minimize the thermal dissipation.
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 VMIN (2.8V typical) for
15 consecutive cycles of the internal oscillator. If the battery
voltage drops below VMIN during the 15 cycles, the 15-cycle
counter is reset and the charger stays in the trickle mode.
The charger moves to the CC mode after verifying the
battery voltage is above VMIN.
When the battery-pack terminal voltage rises to the final
charge voltage VCH, the CV mode begins. The terminal
voltage is regulated at the constant VCH in the CV mode and
the charge current declines. After the charge current drops
below IMIN (1/10 of IREF, see Section “End-of-Charge (EOC)
Current” for more detail) the ISL9203R5220 indicates the
end-of-charge with the STATUS pin. The charging operation
does not terminate. Signals in a charge cycle are illustrated
in Figure 20 between points t2 to t5.
The end of charge indicator (STATUS) will not be set if the
charging current is below IMIN within the first 16 cycles after
VBAT exceeds the VRECHRG voltage. If the charge current is
still below IMIN after these 16 cycles, STATUS goes high to
indicate end of charge.
The following events initiate a new charge cycle:
• POR,
P1
P2
Power Dissipation
• the battery voltage drops below a recharge threshold,
• or, the EN pin is toggled from GND to floating.
FIGURE 19. TYPICAL CHARGE CURVES USING A CURRENTLIMITED ADAPTER
10
Further description of these events are given later in this
data sheet.
FN9242.1
January 3, 2006
ISL9203R5220
Recharge
After a charge cycle completes, the charger continues to
regulate the output at the constant voltage; but the STATUS
pin indicates that the charging is completed. The STATUS
pin stays high until the battery voltage drops to below the
recharge threshold, VRECHRG (see Electrical
Specifications). Then the STATUS pin goes low and a new
charge cycle starts at point t6. The charge cycle ends at
point t7 with the STATUS pin again going high, as shown in
Figure 20.
VIN
POR Threshold
V2P8
Charge Cycle
Charge Cycle
STATUS
Table 1 shows the charge current vs. selected RIREF values.
The typical trickle charge current is 10% of the programmed
constant charge current. Table 2 shows the trickle charge
current tolerance guidance at given RIREF values, when the
battery voltage is between 0V to 2.5V.
TABLE 1. CHARGE CURRENT vs RIREF VALUES.
CHARGE CURRENT (mA)
RIREF (k)
MIN
TYP
MAX
267 ~ 160
17% lower than
TYP Value
= IREF
in EQ. 5
17% higher than
TYP Value
160
450
500
550
100
720
800
880
88.9
810
900
990
80
900
1000
1100
TABLE 2. TRICKLE CHARGE CURRENT vs RIREF VALUES.
TRICKLE CHARGE CURRENT (mA)
At least 15
Cycles
VRECHRG
VBAT
2.8V VMIN
IMIN
ICHARGE
t0
t1 t2 t 3
t4
t5
t6
t7
FIGURE 20. OPERATION WAVEFORMS
The internal oscillator establishes a timing reference. The
oscillation period is programmable with an external timing
capacitor, CTIME, as shown in Typical Applications. The
oscillator charges the timing capacitor to 1.5V and then
discharges it to 0.5V in one period, both with 10A current.
The period TOSC is:
6
 sec onds 
(EQ. 3)
A 1nF capacitor results in a 0.2ms oscillation period.The
accuracy of the period is mainly dependent on the accuracy
of the capacitance and the internal current source.
Charge Current Programming
The charge current in the CC mode is programmed by the
IREF pin. The voltage of IREF is regulated to a 0.8V
reference voltage. The charging current during the constant
current mode is 100,000 times that of the current in the
RIREF resistor. Hence, the charge current is,
5
0.8V
I REF = -----------------  10  A 
R IREF
(EQ. 4)
11
MIN
TYP
MAX
267
15
30
60
160
30
50
80
100
40
80
120
88.9
45
90
135
80
70
100
150
NOTE: The values in table 2 and table 1 are not tested and are only
for guidance in selecting resistor values for mass production tests or
in customer’s products.
Internal Oscillator
T OSC = 0.2  10  C TIME
RIREF (k)
End-of-Charge (EOC) Current
The EOC current IMIN sets the level at which the charger
starts to indicate the end of the charge with the STATUS pin,
as shown in Figure 20. The charger actually does not
terminate charging. In the ISL9203R5220, the EOC current
is internally set to 1/10 of the CC charge current, that is,
1
I MIN = ------  I REF
10
(EQ. 5)
At the EOC, the STATUS signal rises to HIGH and is latched.
The latch is not reset until a recharge cycle or a new charge
cycle starts. The tolerance guidance for the EOC current at
selected RIREF values are given in Table 3.
TABLE 3. EOC CURRENT vs RIREF VALUES.
EOC CURRENT (mA)
RIREF (k)
MIN
TYP
MAX
267
15
30
60
160
30
50
80
100
40
80
120
88.9
45
90
135
FN9242.1
January 3, 2006
ISL9203R5220
TABLE 3. EOC CURRENT vs RIREF VALUES.
EOC CURRENT (mA)
RIREF (k)
MIN
TYP
MAX
80
70
100
150
IR
3.4V
2.4V
VIN
2.8V
IT
V2P8
I SEN
100O C
TEMPERATURE
FIGURE 21. CURRENT SIGNALS AT THE AMPLIFIER CA INPUT
NOTE: The values in table 3 are not tested and are only for guidance
in selecting resistor values for mass production tests or in customer’s
products.
Charge Current Thermal Foldback
Over-heating is always a concern in a linear charger. The
maximum power dissipation usually occurs at the beginning
of a charge cycle when the battery voltage is at its minimum
but the charge current is at its maximum. The charge current
thermal foldback function in the ISL9203R5220 frees users
from the over-heating concern.
Figure 21 shows the current signals at the summing node of
the current error amplifier CA in the Block Diagram. IR is the
reference. IT is the current from the Temperature Monitoring
block. The IT has no impact on the charge current until the
internal temperature reaches approximately 100°C; then IT
rises at a rate of 1A/°C. When IT rises, the current control
loop forces the sensed current ISEN to reduce at the same
rate. As a mirrored current, the charge current is 100,000
times that of the sensed current and reduces at a rate of
100mA/°C. For a charger with the constant charge current
set at 1A, the charge current is reduced to zero when the
internal temperature rises to 110°C. The actual charge
current settles between 100°C to 110°C.
Usually the charge current should not drop below IMIN
because of the thermal foldback. For some extreme cases if
that does happen, the charger does not indicate end-ofcharge unless the battery voltage is already above the
recharge threshold.
2.8V Bias Voltage
The ISL9203R5220 provides a 2.8V voltage for biasing the
internal control and logic circuit. This voltage is also
available for external circuits such as the NTC thermistor
circuit. The maximum allowed external load is 2mA.
12
FIGURE 22. THE V2P8 PIN OUTPUT vs THE INPUT VOLTAGE
AT THE VIN PIN. VERTICAL: 1V/DIV,
HORIZONTAL: 100ms/DIV
Indications
The ISL9203R5220 has two indications: the input presence
and the charge status. The input presence is indicated by
the V2P8 pin and the charge status is indicated by the
STATUS pin. Figure 22 shows the V2P8 pin voltage vs. the
input voltage.
STATUS Pull-Up Resistor
The STATUS pin is an open-drain output that need an
external pull-up resistor. It is recommended that this be
pulled up to the input voltage or the 2.8V from the V2P8 pin.
If the STSTUS pin has to be pulled up to other voltages, the
user needs to examine carefully whether or not the ESD
diodes will form a leakage current path to the battery when
the input power is removed. If the leakage path does exist,
an external transistor is required to break the path.
Figure 23 shows the implementation. If the STATUS pin is
directly pulled up to the VCC voltage (not shown in Figure 23),
a current will flow from the VCC to the STATUS pin, then
through the ESD diode to the VIN pin. Any leakage on the VIN
pin, caused by an external or internal current path, will result
in a current path from VCC to ground.
The N-channel MOSFET Q1 buffers the STATUS pin. The
gate of Q1 is connected to VIN or the V2P8 pin. When the
STATUS pin outputs a logic low signal, Q1 is turned on and
its drain outputs a low signal as well. When STATUS is high
impedance, R1 pulls the Q1 drain to high. When the input
power is removed, the Q1 gate voltage is also removed, thus
the Q1 drain stays high.
Shutdown
The ISL9203R5220 can be shutdown by pulling the EN pin
to ground. When shut down, the charger draws typically less
than 30A current from the input power and the 2.8V output
at the V2P8 pin is also turned off. The EN pin needs be
FN9242.1
January 3, 2006
ISL9203R5220
VIN
EN
on the 3x3 DFN package are on only two sides, as much top
layer copper as possible should be connected to the
exposed pad to minimize the thermal impedance. Refer to
the ISL6292 evaluation boards for layout examples.
VCC
RLKG
VIN or
V2P8
R1
Control
Q1
ESD Diode
STATUS
GND
Note:
RLKG is approximately 240k when EN is floating and is
approximately 140k when the EN is grounded.
FIGURE 23. PULL-UP CIRCUIT TO AVOID BATTERY
LEAKAGE CURRENT IN THE ESD DIODES
driven with an open-drain or open-collector logic output, so
that the EN pin is floating when the charger is enabled. If the
EN pin is driven by an external source, the POR threshold
voltage will be affected.
Input and Output Capacitor Selection
Typically any type of capacitors can be used for the input
and the output. Use of a 0.47F or higher value ceramic
capacitor for the input is recommended. When the battery is
attached to the charger, the output capacitor can be any
ceramic type with the value higher than 0.1F. However, if
there is a chance the charger will be used as an LDO linear
regulator, a 10F tantalum capacitor is recommended. Note
that the charger always steps through the 15-cycle VMIN
verification time before the charge current rises to the
constant charge current, as discussed earlier. Hence, when
using as an LDO, the system should make sure not to load
the charger heavily until the 15-cycle verification is
completed.
Working with Current-Limited Adapter
The ISL9203R5220 can work with a current-limited adapter
to significantly reduce the thermal dissipation during
charging. Refer to the ISL6292 data sheet, which can be
found at http://www.intersil.com, for more details.
Board Layout Recommendations
The ISL9203R5220 internal thermal foldback function limits
the charge current when the internal temperature reaches
approximately 100°C. 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 result in
better thermal performance. On the other hand, the number
of vias is limited by the size of the pad. The 3x3 DFN
package allows 8 vias be placed in two rows. Since the pins
13
FN9242.1
January 3, 2006
ISL9203R5220
Dual Flat No-Lead Plastic Package (DFN)
2X
0.15 C A
D
A
L10.3x3
10 LEAD DUAL FLAT NO-LEAD PLASTIC PACKAGE
MILLIMETERS
2X
0.15 C B
E
6
INDEX
AREA
SYMBOL
MIN
0.80
0.90
1.00
-
-
-
0.05
-
0.28
5,8
2.05
7,8
1.65
7,8
0.20 REF
0.18
0.23
D
1.95
SIDE VIEW
C
SEATING
PLANE
0.08 C
A3
3.00 BSC
e
-
0.50 BSC
-
k
0.25
-
-
-
L
0.30
0.35
0.40
8
N
10
Nd
5
4. All dimensions are in millimeters. Angles are in degrees.
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.
NX L
7. Dimensions D2 and E2 are for the exposed pads which provide
improved electrical and thermal performance.
NX b
5
(Nd-1)Xe
REF.
3. Nd refers to the number of terminals on D.
5. Dimension b applies to the metallized terminal and is measured
between 0.15mm and 0.30mm from the terminal tip.
E2/2
N-1
3
2. N is the number of terminals.
E2
e
2
1. Dimensioning and tolerancing conform to ASME Y14.5-1994.
NX k
8
1.60
NOTES:
D2/2
2
N
1.55
Rev. 3 6/04
D2
1
-
8
7
(DATUM B)
2.00
E
E2
0.10 C
-
3.00 BSC
D2
A
NOTES
A
A3
B
MAX
A1
b
TOP VIEW
6
INDEX
AREA
(DATUM A)
NOMINAL
0.10 M C A B
8. Nominal dimensions are provided to assist with PCB Land
Pattern Design efforts, see Intersil Technical Brief TB389.
BOTTOM VIEW
C
L
0.415
NX (b)
(A1)
0.200
5
L
NX L
e
SECTION "C-C"
C
NX b
C C
TERMINAL TIP
FOR ODD TERMINAL/SIDE
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in the quality certifications found at www.intersil.com/en/support/qualandreliability.html
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without notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be
accurate and reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third
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14
FN9242.1
January 3, 2006
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