Intersil ISL9203ACRZ Li-ion/li polymer battery charger Datasheet

ISL9203A
®
Data Sheet
February 14, 2007
FN6430.0
Li-ion/Li Polymer Battery Charger
Features
The ISL9203A 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 ISL9203A 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 ISL9203A can also work with a current-limited
adapter to minimize the thermal dissipation, in which case
the ISL9203A combines the benefits of both a linear charger
and a pulse charger.
• No External Blocking Diode Required
The ISL9203A 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
5V
INPUT
VIN
• 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
VBAT
• Portable Instruments, MP3 Players
C1
R1
• Self-Charging Battery Packs
C2
ISL9203A
• Stand-Alone Chargers
VSEN
• USB Bus-Powered Chargers
V2P8
Related Literature
STATUS
FLOATING
TO ENABLE
EN
TIME
IREF
• Technical Brief TB363 “Guidelines for Handling and
Processing Moisture Sensitive Surface Mount Devices
(SMDs)”
C3
GND
CTIME
R IREF
• 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
PART
(Note)
MARKING
ISL9203ACRZ
03ACZ
TEMP.
RANGE
(°C)
-20 to +70
PACKAGE
(Pb-free)
PKG
DWG. #
10 Ld 3x3 DFN L10.3x3
ISL9203ACRZ-T 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
ISL9203A
(10 LD 3x3 DFN)
TOP VIEW
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. 2007. All Rights Reserved.
All other trademarks mentioned are the property of their respective owners.
ISL9203A
Absolute Maximum Ratings
Thermal Information
Supply Voltage (VIN) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 to 7V
Output Pin Voltage (BAT, VSEN, V2P8). . . . . . . . . . . . -0.3V to 5.5V
Signal Input Voltage (TIME, IREF). . . . . . . . . . . . . . . . -0.3V to 3.2V
Output Pin Voltage (STATUS) . . . . . . . . . . . . . . . . . . . . . -0.3V 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) θJA (°C/W) θJC (°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.
+150°C max junction temperature is intended for short periods of time to prevent shortening the lifetime. Operation close to +150°C junction may trigger the shutdown of
the device even before +150°C, since this number is specified as typical.
NOTES:
1. θJA 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. θJC, “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
µA
POWER-ON RESET
STANDBY CURRENT
VBAT Pin Sink Current
ISTANDBY
VIN Pin Supply Current
IVIN
VBAT floating and EN pulled low
-
30
250
µA
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 = 80kΩ, VBAT = 3.7V
0.9
1.0
1.1
A
Constant Charge Current
ICHARGE
RIREF = 1.21MΩ, VBAT = 3.7V
33
66
100
mA
Trickle Charge Current
ITRICKLE
RIREF = 80kΩ, VBAT = 2.0V
85
110
135
mA
Trickle Charge Current
ITRICKLE
RIREF = 1.21MΩ, VBAT = 2.0V
2
7
15
mA
End-of-Charge Threshold
IMIN
RIREF = 80kΩ
85
110
135
mA
End-of-Charge Threshold
IMIN
RIREF = 1.21MΩ
2
-
30
mA
3.85
4.00
4.10
V
RECHARGE THRESHOLD
Recharge Voltage Threshold
VRECHRG
2
FN6430.0
February 14, 2007
ISL9203A
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
VMIN
2.1
2.3
2.5
V
VV2P8
2.7
2.9
3.1
V
Charge Current Foldback Threshold (Note 4)
TFOLD
-
100
-
°C
Current Foldback Gain (Note 4)
GFOLD
-
100
-
mA/°C
2.4
3.0
3.6
ms
TRICKLE CHARGE THRESHOLD
Trickle Charge Threshold Voltage
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
µA
EN Input Logic High
2.0
-
3.3
V
EN Input Logic Low
-
-
0.8
V
EN Pin Current When Driven Low
-
-
100
µA
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 characterization.
Typical Operating Performance
The test conditions for the Typical Operating Performance are: VIN = 5V, TA = +25°C,
RIREF = RIMIN = 80kΩ, VBAT = 3.7V, unless otherwise noted.
4.210
4.2015
4.208
4.2010
CHARGE CURRENT = 50mA
4.204
4.2000
VBAT (V)
VBAT (V)
4.206
RIREF = 40kΩ
4.2005
4.1995
4.1990
4.202
4.200
4.198
4.196
4.1985
4.194
4.1980
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
FN6430.0
February 14, 2007
ISL9203A
Typical Operating Performance
The test conditions for the Typical Operating Performance are: VIN = 5V, TA = +25°C,
RIREF = RIMIN = 80kΩ, VBAT = 3.7V, unless otherwise noted. (Continued)
2.0
4.30
1.8
CHARGE CURRENT = 50mA
CHARGE CURRENT (A)
VBAT (V)
4.25
4.20
4.15
2A
1.6
1.4
1.5A
1.2
1.0
1A
0.8
0.6
0.4
0.5A
0.2
4.10
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
3.4
3.6
VVBAT (V)
3.8
4.0
FIGURE 4. CHARGE CURRENT vs OUTPUT VOLTAGE
1.6
2.0
1.8
1.4
1.5A
CHARGE CURRENT (A)
CHARGE CURRENT (A)
3.2
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
4.3 4.5 4.7 4.9 5.1 5.3 5.5 5.7 5.9 6.1 6.3 6.5
0.0
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
3.00
2.930
2.95
V2P8 PIN LOADED WITH 2mA
V2P8 VOLTAGE (V)
V2P8 VOLTAGE (V)
2.928
2.926
2.924
2.922
2.90
2.85
2.80
2.75
2.920
3.5
4.0
4.5
5.0
5.5
6.0
VIN (V)
FIGURE 7. V2P8 OUTPUT vs INPUT VOLTAGE
4
6.5
2.70
0
2
4
6
8
10
V2P8 LOAD CURRENT (mA)
FIGURE 8. V2P8 OUTPUT vs ITS LOAD CURRENT
FN6430.0
February 14, 2007
ISL9203A
Typical Operating Performance
The test conditions for the Typical Operating Performance are: VIN = 5V, TA = +25°C,
RIREF = RIMIN = 80kΩ, VBAT = 3.7V, unless otherwise noted. (Continued)
700
420
THERMAL FOLDBACK STARTS
NEAR +100°C
650
600
380
rDS(ON) (mΩ)
550
rDS(ON) (mΩ)
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
20
40
60
80
100
EN = GND
35
30
25
20
15
10
5
120
0
20
FIGURE 11. REVERSE CURRENT vs TEMPERATURE
80
100
120
1.10
EN = GND
VIN QUIESCENT CURRENT (mA)
VIN QUIESCENT CURRENT (µA)
60
FIGURE 12. INPUT QUIESCENT CURRENT vs TEMPERATURE
32
28
26
24
22
20
18
16
14
12
10
3.0
40
TEMPERATURE (°C)
TEMPERATURE (°C)
30
4.0
40
0
0
3.8
FIGURE 10. rDS(ON) vs OUTPUT VOLTAGE USING CURRENT
LIMITED ADAPTERS
VIN QUIESCENT CURRENT (µA)
VBAT LEAKAGE CURRENT (µA)
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
FN6430.0
February 14, 2007
ISL9203A
Typical Operating Performance
The test conditions for the Typical Operating Performance are: VIN = 5V, TA = +25°C,
RIREF = RIMIN = 80kΩ, 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 10µF
Tantalum capacitor is needed for stability when there is no
battery attached. When a battery is attached, only a 0.1µF
ceramic capacitor is required.
6
FN6430.0
February 14, 2007
ISL9203A
Typical Applications
5V WALL
ADAPTER
VIN
C1
10µF
C2
R2
1kΩ
R1
1Ω
VBAT
10µF
BATTERY
PACK
ISL9203A
D1
VSEN
STATUS
V2P8
EN
IREF
TIME
C3
1µF
GND
RIREF
80kΩ
CTIME
1nF
Block Diagram
Q M A IN
V IN
VBAT
C1
REFERENCES
TEM PERATURE
M O N IT O R IN G
V 2P 8
VRECHRG
VCH
VPOR
1 0 0 0 0 0 :1
CURRENT
M IR R O R
R1
VMIN
Q SEN
IT
IS E N
IN P U T _ O K
+
CA
-
IR
V POR
+
-
IR E F
VSEN
V IN
+
+
100m V
-
R IR E F
CHRG
CURRENT
REFERENCES
I M IN
+
= I R /1 0
VA
V CH
+
T R IC K L E /F A S T
-
M IN B A T
V M IN
IS E N
+
-
V RECHRG
+
M IN _ I
RECHARGE
IN P U T _ O K
L O G IC
V IN
EN
E S D D IO D E
STATUS
STATUS
OSC
T IM E
CO UNTER
GND
FIGURE 16. BLOCK DIAGRAM
7
FN6430.0
February 14, 2007
ISL9203A
Charging Flow Chart
POWER
UP
VIN >VPOR ?
N
Y
POR
INITIALIZATION
RESET STATUS
RESET COUNTER
CC
CHARGE
CV
CHARGE
TRICKLE
CHARGE
VSEN> =V CH?
ICH < IMIN ?
Y
VSEN>VMIN
Y
Y
N
N
N
CONSTANT
CURRENT
CHARGE
TRICKLE
CHARGE
CONSTANT
VOLTAGE
CHARGE
EOC INDICATION:
SET STATUS
N HIGH
VSEN
<
VRECHRG?
Y
N
EN TOGGLED
?
N
Y
EOC
FIGURE 17. CHARGING STATE DIAGRAM
8
FN6430.0
February 14, 2007
ISL9203A
Theory of Operation
The ISL9203A is an integrated charger for single-cell Li-ion
or Li-polymer batteries. The ISL9203A 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 ISL9203A 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.
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.
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
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.
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)
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.
When using a current-limited adapter, the thermal situation in
the ISL9203A 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
CONSTANT CURRENT
MODE
CONSTANT VOLTAGE
MODE
INHIBIT
VIN
INPUT VOLTAGE
VCH
BATTERY VOLTAGE
VMIN
IREF
CHARGE CURRENT
IREF/10
P1
P2
P3
POWER DISSIPATION
FIGURE 18. TYPICAL CHARGE CURVES USING A
CONSTANT-VOLTAGE ADAPTER
If the ISL9203A 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 ISL9203A draws
less than 1µA 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
9
FN6430.0
February 14, 2007
ISL9203A
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
CONSTANT CURRENT
MODE
CONSTANT VOLTAGE
MODE
EOC
INPUT VOLTAGE
VCH
BATTERY VOLTAGE
VMIN
IREF
ILIM
CHARGE CURRENT
ISL9203A. 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 ISL9203A 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 ISL9203A 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 (2.3V 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” on page 11 for more detail) the ISL9203A
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,
IREF/10
• the battery voltage drops below a recharge threshold,
P1
POWER DISSIPATION
P2
• or, the EN pin is toggled from GND to floating.
Further description of these events are given later in this
data sheet.
FIGURE 19. TYPICAL CHARGE CURVES USING A CURRENT
LIMITED ADAPTER
10
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ISL9203A
Recharge
TABLE 1. CHARGE CURRENT vs RIREF VALUES
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.
CHARGE CURRENT (mA)
RIREF (kΩ)
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
VIN
POR THRESHOLD
TABLE 2. TRICKLE CHARGE CURRENT vs RIREF VALUES
V2P8
CHARGE CYCLE
CHARGE CYCLE
STATUS
AT LEAST 15
CYCLES
VRECHRG
2.8V VMIN
VBAT
TRICKLE CHARGE CURRENT (mA)
RIREF (kΩ)
MIN
TYP
MAX
267
15
30
60
160
30
50
80
100
40
80
120
88.9
45
90
135
80
70
100
150
IMIN
ICHARGE
t0
t1 t2 t3
t4
t5
t6
t7
FIGURE 20. OPERATION WAVEFORMS
End-of-Charge (EOC) Current
Internal Oscillator
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 10μA current.
The period TOSC is:
6
T OSC = 0.2 ⋅ 10 ⋅ C TIME
( sec onds )
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.
(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.
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 ISL9203A, 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
Charge Current Programming
EOC CURRENT (mA)
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)
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.
11
RIREF (kΩ)
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 3 are not tested and are only for guidance
in selecting resistor values for mass production tests or in customer’s
products.
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ISL9203A
IR
3.4V
IT
I SEN
2.4V
VIN
2.8V
+100°C TEMPERATURE
FIGURE 21. CURRENT SIGNALS AT THE AMPLIFIER CA INPUT
V2P8
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 ISL9203A 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 1µA/°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 ISL9203A 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.
Indications
The ISL9203A 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.
12
FIGURE 22. THE V2P8 PIN OUTPUT vs THE INPUT VOLTAGE
AT THE VIN PIN. VERTICAL: 1V/DIV,
HORIZONTAL: 100ms/DIV
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 ISL9203A can be shutdown by pulling the EN pin to
ground. When shut down, the charger draws typically less
than 30µA current from the input power and the 2.8V output
at the V2P8 pin is also turned off. The EN pin needs be
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.
FN6430.0
February 14, 2007
ISL9203A
Board Layout Recommendations
VIN
EN
VCC
RLKG
VIN or
V2P8
R1
CONTROL
Q1
ESD DIODE
STATUS
GND
Note:
RLKG is approximately 240kΩ when EN is floating and
is approximately 140kΩ when the EN is grounded.
The ISL9203A 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
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.
FIGURE 23. PULL-UP CIRCUIT TO AVOID BATTERY
LEAKAGE CURRENT IN THE ESD DIODES
Input and Output Capacitor Selection
Due to the inductance of the power leads of the wall adapter
or USB source, the input capacitor type must be properly
selected to prevent high voltage transient during a hot-plug
event. A tantalum capacitor is a good choice for its high
ESR, providing damping to the voltage transient. Multi-layer
ceramic capacitors, however, have a very low ESR and
hence when chosen as input capacitor, a 1Ω series resistor
must be used, as shown in the Typical Applications Section,
to provide adequate damping.
The output capacitor can be any ceramic type with the value
higher than 0.1µF. However, if there is a chance the charger
will be used as an LDO linear regulator, a 10µF 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 ISL9203A 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.
13
FN6430.0
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ISL9203A
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
SYMBOL
MIN
6
INDEX
AREA
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
D
1.95
E
0.10 C
0.08 C
SIDE VIEW
C
SEATING
PLANE
1
e
1.60
-
0.50 BSC
-
k
0.25
-
-
L
0.30
0.35
0.40
N
10
Nd
5
3
3. Nd refers to the number of terminals on D.
4. All dimensions are in millimeters. Angles are in degrees.
5. Dimension b applies to the metallized terminal and is measured
between 0.15mm and 0.30mm from the terminal tip.
E2/2
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
N-1
7. Dimensions D2 and E2 are for the exposed pads which provide
improved electrical and thermal performance.
NX b
5
(Nd-1)Xe
REF.
8
2
2. N is the number of terminals.
E2
e
-
1. Dimensioning and tolerancing conform to ASME Y14.5-1994.
NX k
8
1.55
NOTES:
D2/2
2
N
-
Rev. 3 6/04
D2
(DATUM B)
2.00
8
7
6
INDEX
AREA
(DATUM A)
A3
-
3.00 BSC
E2
A
0.23
3.00 BSC
D2
B
NOTES
A
b
TOP VIEW
MAX
A1
A3
E
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"
NX b
C
C C
TERMINAL TIP
FOR ODD TERMINAL/SIDE
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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 at any time 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 parties which may result
from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries.
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14
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February 14, 2007