Intersil ISL9203CRZ-T Li-ion/li polymer battery charger Datasheet

ISL9203
®
Data Sheet
February 3, 2005
Li-ion/Li Polymer Battery Charger
Features
The ISL9203 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.
• Pb-Free Available (RoHS Compliant)
FN6106.0
• Complete Charger for Single-Cell Li-ion Batteries
• Very Low Thermal Dissipation
• Integrated Pass Element and Current Sensor
The ISL9203 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 ISL9203 can also work with a current-limited
adapter to minimize the thermal dissipation, in which case
the ISL9203 combines the benefits of both a linear charger
and a pulse charger.
• No External Blocking Diode Required
• 1% Voltage Accuracy
• Programmable Current Limit up to 1.5A
• Charge Current Thermal Foldback
• Accepts Multiple Types of Adapters
• Guaranteed to Operate at 2.65V After Start Up
• Ambient Temperature Range: -20°C to 70°C
The ISL9203 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,
automatic recharge, and thermally enhanced DFN package.
• Thermally-Enhanced DFN Packages
Ordering Information
• Portable Instruments, MP3 Players
PART # (NOTE)
ISL9203CRZ
TEMP.
RANGE (°C)
-20 to 70
ISL9203CRZ-T
PACKAGE
PKG. DWG.
#
10 Ld 3x3 DFN L10.3x3
10 Ld 3x3 DFN Tape and Reel
Applications
• Handheld Devices including Medical Handhelds
• PDAs, Cell Phones and Smart Phones
• Self-Charging Battery Packs
• Stand-Alone Chargers
• USB Bus-Powered Chargers
Related Literature
NOTE: "Z" Suffix: Intersil Pb-free 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.
• Technical Brief TB363 “Guidelines for Handling and
Processing Moisture Sensitive Surface Mount Devices
(SMDs)”
Typical Application Circuit
Pinout
5V
Input
VIN
C1
ISL9203 (3x3 DFN)
TOP VIEW
C2
VIN
VSEN
STATUS
Floating
to Enable
V2P8
EN
TIME
• Technical Brief TB389 “PCB Land Pattern Design and
Surface Mount Guidelines for QFN Packages”
VBAT
ISL9203
FAULT
• Technical Brief TB379 “Thermal Characterization of
Packaged Semiconductor Devices”
IREF
1
10 VBAT
FAULT 2
9
VSEN
STATUS 3
8
IREF
TIME
4
7
V2P8
GND
5
6
EN
C3
GND
CTIME
RIREF
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 321-724-7143 | Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright © Intersil Americas Inc. 2005. All Rights Reserved.
All other trademarks mentioned are the property of their respective owners.
ISL9203
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, FAULT) . . . . . . . . . . . . . . . -0.3 to 7V
Charge Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.6A
ESD Rating
Human Body Model (Per MIL-STD-883 Method 3015.7) . . .1500V
Machine Model (Per EIAJ ED-4701 Method C-111) . . . . . . .150V
Thermal Resistance
θJA (°C/W)
θJC (°C/W)
3x3 DFN Package (Notes 1, 2) . . . . . .
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. 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
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
FN6106.0
February 3, 2005
ISL9203
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
85
100
115
°C
Current Foldback Gain (Note 4)
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/FAULT Logic Low Sink Current
Pin Voltage = 0.8V
5
-
-
mA
STATUS/FAULT Leakage Current
VVIN = VSTATUS = VFAULT = 5V,
-
-
1
µA
EN Input Logic High (Note 4)
2.0
-
3.3
V
EN Input Logic Low (Note 4)
-
0.8
V
EN Pin Current When Driven Low (Note 4)
-
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 design, not a tested parameter.
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
4.201
CHARGE CURRENT = 50mA
4.204
4.2
VBAT (V)
VBAT (V)
4.206
RIREF = 40kΩ
4.2005
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 (oC)
FIGURE 2. CHARGER OUTPUT VOLTAGE vs TEMPERATURE
FN6106.0
February 3, 2005
ISL9203
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
4.3
1.8
CHARGE CURRENT = 50mA
CHARGE CURRENT (A)
4.25
VBAT (V)
2A
1.6
4.2
4.15
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
3.0
6.3
3.2
3.4
3.6
VIN (V)
FIGURE 3. CHARGER OUTPUT VOLTAGE vs INPUT
VOLTAGE CHARGE CURRENT IS 50mA
4.0
FIGURE 4. CHARGE CURRENT vs OUTPUT VOLTAGE
1.6
2.0
1.8
1.4
1.5A
1.6
1.2
CHARGE CURRENT (A)
CHARGE CURRENT (A)
3.8
VVBAT (V)
1.0
1.0A
0.8
0.6
0.5A
0.4
0.2
1.4
1.5
1.2
1.0
1A
0.8
0.6
0.4
0.5A
0.2
0.0
4.3
0.0
0
20
40
60
80
100
120
4.5 4.7
4.9 5.1 5.3 5.5
TEMPERATURE (oC)
5.7 5.9 6.1 6.3 6.5
VIN (V)
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
2.9
2.85
2.8
2.922
2.75
2.92
3.5
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
FN6106.0
February 3, 2005
ISL9203
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
380
550
r DS(ON) (mΩ)
r DS(ON) (mΩ)
500mA CHARGE
CURRENT, RIREF=40kΩ
400
600
500
450
400
350
360
340
320
300
300
280
250
260
3.0
200
0
20
40
60
80
100
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
0.0
20
40
60
80
100
EN = GND
35
30
25
20
15
10
5
120
0
20
TEMPERATURE (oC)
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 (oC)
FIGURE 11. REVERSE CURRENT vs TEMPERATURE
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
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
FN6106.0
February 3, 2005
ISL9203
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/FAULT 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)
FAULT (Pin 2)
FAULT is an open-drain output indicating fault status. This
pin is pulled to LOW under any fault conditions. Any time a
FAULT condition happens, it will reset the counter of the
charger.
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)
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.
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.
GND (Pin 5)
GND is the connection to system ground.
6
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)
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.
VBAT (Pin 10)
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.
FN6106.0
February 3, 2005
ISL9203
Typical Applications
5V WALL
ADAPTER
VIN
C1
10µF
R1
1kΩ
R2
1kΩ
D1
D2
VBAT
C2
10µF
BATTERY
PACK
ISL9203
VSEN
FAULT
STATUS
V2P8
EN
TIME
CTIME
15nF
7
IREF
GND
C3
1µF
RIREF
80kΩ
FN6106.0
February 3, 2005
ISL9203
Block Diagram
QMAIN
VIN
VMIN
100000:1
Current
Mirror
ISEN
Input_OK
VRECHRG
IT
REFERENCES
QSEN
VCH
TEMPERATURE
MONITORING
VPOR
C1
VBAT
+
CA
-
R IREF
+
-
CHRG
CURRENT
REFERENCES
IMIN = IR /10
VPOR
-
IR
VSEN
VIN
+
-
IREF
V2P8
+
100mV
+
VA VCH
+
Trickle/Fast
ISEN
-
Minbat
VMIN
+
-
MIN_I
+
Recharge
Input_OK
LOGIC
VRECHR G
VIN
ESDDiode
STATUS
STATUS
EN
VIN
OSC
TIME
COUNTER
FAULT
GND
FAULT
FIGURE 16. BLOCK DIAGRAM
8
FN6106.0
February 3, 2005
ISL9203
Charging Flow Chart
Power Up
VIN>VPOR ?
N
Y
POR
Initialization
Reset counter
CC Charge
CV Charge
Trickle
Charge
VSEN>=VCH?
VSEN>VMIN?
Ich < IMIN ?
Y
Y
Y
N
N
N
N
N
N
1/8 TIMEOUT?
Trickle
Charge
TIMEOUT?
Constant
Current
Charge
Y
set FAULT low
latch up charger
Y
TIMEOUT?
Constant
Voltage
Charge
Y
charger inhibited
reset counter
EOC indication:
set STATUS high
keepNFAULT high
N
TIMEOUT?
N
VSEN
<
VRECHRG?
Y
EN toggled ?
Y
N
Y
N
Start recharge
EOC or FAULT
Inhibit
FIGURE 17. CHARGING FLOW CHART
9
FN6106.0
February 3, 2005
ISL9203
Theory of Operation
The ISL9203 is an integrated charger for single-cell Li-ion or
Li-polymer batteries. The ISL9203 functions as a traditional
linear charger when powered with a voltage-source 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 ISL9203 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.
The charger offers a safety timer for setting the fast charge
time (TIMEOUT) limit to prevent charging a dead battery for
an extensively long time. The trickle mode is limited to 1/8 of
TIMEOUT.
The charger automatically re-charges the battery when the
battery voltage drops below a recharge threshold. When the
wall adapter is not present, the ISL9203 draws less than 1µA
current from the battery.
Trickle
Mode
VIN
VCH
Constant Current
Mode
Constant Voltage
Mode
Three 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 the 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 open-drain logic output that turns
LOW at the beginning of a charge cycle until the end-ofcharge (EOC) condition is qualified. The EOC condition is:
the battery voltage rises above the recharge threshold and
the charge current falls below a user-programmable EOC
current threshold. Once the EOC condition is qualified, the
STATUS output rises to HIGH and is latched. The latch is
released at the beginning of a charge or re-charge cycle.
The open-drain FAULT pin turns low when a charge time
fault occurs or when the IREF pin is pulled below 0.35V or
above 1.4V.
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
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.
Trickle
Mode
Inhibit
Input Voltage
Battery Voltage
(EQ. 1)
VIN
VCH
VMIN
VMIN
IREF
IREF
ILIM
Constant Current
Mode
Constant Voltage
Mode
Inhibit
Input Voltage
Battery Voltage
Charge Current
Charge Current
IREF/10
IREF/10
P1
P2
P3
Power Dissipation
TIMEOUT
FIGURE 18. TYPICAL CHARGE CURVES USING A
CONSTANT-VOLTAGE ADAPTER
10
P1
P2
Power Dissipation
TIMEOUT
FIGURE 19. TYPICAL CHARGE CURVES USING A CURRENTLIMITED ADAPTER
FN6106.0
February 3, 2005
ISL9203
When using a current-limited adapter, the thermal situation in
the ISL9203 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.
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)
LOW and a HIGH logic signal respectively. Figure 20
illustrates the start up of the charger between t0 to t2.
The ISL9203 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 current-limited 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. As 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 is expected to
decline. After the charge current drops below IMIN (1/10 of
IREF, see End-of-Charge Current for more detail), the
ISL9203 indicates the end-of-charge (EOC) with the
STATUS pin. The charging actually does not terminate until
the internal timer completes its length of TIMEOUT in order
to bring the battery to its full capacity. Signals in a charge
cycle are illustrated in Figure 20 between points t2 to t5.
The following events initiate a new charge cycle:
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 (EQ. 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
ISL9203. See the Application Information section of the
ISL6292 data sheet (www.intersil.com) for more information.
• POR,
• the battery voltage drops below a recharge threshold
after completing a charge cycle,
• or, the EN pin is toggled from GND to floating.
VIN
POR Threshold
V2P8
STATUS
15 Cycles to
1/8 TIMEOUT
FAULT
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 ISL9203 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 two indication pins, STATUS and FAULT, indicate a
11
Charge Cycle
Charge Cycle
VRECHRG
VBAT
15 Cycles
2.8V VMIN
IMIN
ICHARGE
t0
t1 t2 t3
t4
t5
t8
t6 t7
FIGURE 20. OPERATION WAVEFORMS
Further description of these events are given later in this
data sheet.
FN6106.0
February 3, 2005
ISL9203
Recharge
After a charge cycle completes, charging is prohibited until
the battery voltage drops to a recharge threshold, VRECHRG
(see Electrical Specifications). Then a new charge cycle
starts at point t6 and ends at point t8, as shown in Figure 20.
The safety timer is reset at t6.
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 )
(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.
Total Charge Time
The total charge time for the CC mode and CV mode is
limited to a length of TIMEOUT. A 22-stage binary counter
increments each oscillation period of the internal oscillator to
set the TIMEOUT. The TIMEOUT can be calculated as:
TIMEOUT = 2
22
⋅ T OSC
5
0.8V
I REF = ----------------- × 10 ( A )
R IREF
( minutes )
(EQ. 5)
A 1nF capacitor leads to 14 minutes of TIMEOUT. For
example, a 15nF capacitor sets the TIMEOUT to be 3.5
hours. The charger has to reach the end-of-charge condition
before the TIMEOUT, otherwise, a TIMEOUT fault is issued.
The TIMEOUT fault latches up the charger. There are two
ways to release such a latch-up: either to recycle the input
power, or toggle the EN pin to disable the charger and then
enable it again.
The trickle mode charge has a time limit of 1/8 TIMEOUT. If
the battery voltage does not reach VMIN within this limit, a
TIMEOUT fault is issued and the charger latches up. The
charger stays in trickle mode for at least 15 cycles of the
internal oscillator and, at most, 1/8 of TIMEOUT, as shown in
Figure 20.
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
12
(EQ. 6)
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. Use this guidance
only for mass production tests in customer’s products.
TABLE 1. CHARGE CURRENT vs RIREF VALUES.
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
TABLE 2. TRICKLE CHARGE CURRENT vs RIREF VALUES.
TRICKLE CHARGE CURRENT (mA)
(EQ. 4)
or
C TIME
TIMEOUT = 14 ⋅ -----------------1nF
current mode is 100,000 times that of the current in the
RIREF resistor. Hence, the charge current is,
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
TABLE 3. EOC CURRENT vs RIREF VALUES.
EOC CURRENT (mA)
RIREF (kΩ)
MIN
TYP
MAX
267
15
30
60
160
20
50
80
100
40
80
120
88.9
45
90
135
80
70
100
150
The ISL9203 is designed to be safe when the IREF pin is
accidentally short-circuited to an external source or to
ground. If the IREF pin is driven by an external source to
below 0.38V or above 1.5V for any reason, the charger is
disabled and the FAULT pin turns to LOW to indicate a fault
FN6106.0
February 3, 2005
ISL9203
condition. The charger will resume charging after the fault
condition is removed. When the IREF is driven by a voltage
between 0.38V to 0.5V (typical value), the charge current is
limited to 100mA; or when driven to a voltage between 1.2V
to 1.5V, the charge current is limited to 500mA. For any
voltage between 0.5V to 1.2V, the charge current will drop to
a very low value. This feature can protect the charger from a
large charging current when IREF is accidentally shorted to
ground or to a high voltage. Figure 21 shows the charge
current when the IREF pin voltage is driven from 0V to 3V.
End-of-Charge (EOC) Current
IR
IT
I SEN
100O C
FIGURE 22. CURRENT SIGNALS AT THE AMPLIFIER CA
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 until the end of the TIMEOUT, as
described in the Total Charge Time section. In the ISL9203,
the EOC current is internally set to 1/10 of the CC charge
current, that is,
1
I MIN = ------ ⋅ I REF
10
(EQ. 7)
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. This
guidance is offered only for mass production tests in
customer’s products.
Charge Current Thermal Foldback
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.
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 ISL9203 frees users from
the over-heating concern.
2.8V Bias Voltage
Figure 22 shows the current signals at the summing node of
the current error amplifier CA in the Block Diagram. IR is the
Indications
GND
TEMPERATURE
STATUS
5V/Div
IREF Pin Voltage
500mV/Div
The ISL9203 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.
The ISL9203 has three indications: the input presence, the
charge status, and the fault indication. The input presence is
indicated by the V2P8 pin while the other two indications are
presented by the STATUS pin and FAULT pin respectively.
Figure 23 shows the V2P8 pin voltage vs. the input voltage.
Table 2 summarizes the other two pins.
Time Scale
40s/Div
Charge Current
200mA/Div
GND
GND
FIGURE 21. CHARGE CURRENT WHEN IREF PIN IS DRIVEN
BY AN EXTERNAL VOLTAGE SOURCE
13
FN6106.0
February 3, 2005
ISL9203
VIN
VCC
ESD Diode
3.4V
2.4V
EN
VIN or
V2P8
Control
2.8V
VIN
STATUS
RLKG
R1
VIN
Q1
FAULT
GND
V2P8
FIGURE 23. THE V2P8 PIN OUTPUT vs THE INPUT VOLTAGE
AT THE VIN PIN. VERTICAL: 1V/DIV,
HORIZONTAL: 100ms/DIV
Note:
RLKG is approximately 240kΩ when EN is floating and is
approximately 140kΩ when the EN is grounded.
FIGURE 24. PULL-UP CIRCUIT TO AVOID BATTERY LEAKAGE
CURRENT IN THE ESD DIODES.
TABLE 4. STATUS INDICATIONS
FAULT STATUS
INDICATION
High
High
Charge completed with no fault (Inhibit) or
Standby
High
Low
Charging in one of the three modes
Low
High
Fault
NOTE: Both outputs are pulled up with external resistors.
FAULT and STATUS Pull-Up Resistors
Both FAULT and STATUS pins are open-drain outputs that
need an external pull-up resistor. It is recommended that
both pins be pulled up to the input voltage or the 2.8V from
the V2P8 pin. If the indication pins have 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 24 shows the implementation. If the FAULT pin is
directly pulled up to the VCC voltage (not shown in Figure
24), a current will flow from the VCC to the FAULT 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 FAULT pin. The
gate of Q1 is connected to VIN or the V2P8 pin. When the
FAULT pin outputs a logic low signal, Q1 is turned on and its
drain outputs a low signal as well. When FAULT 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.
14
Shutdown
The ISL9203 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.
Input and Output Capacitor Selection
Typically any type of capacitors can be used for the input
and the output. Use of a 0.47µF 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 0.1µF. 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 ISL9203 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 ISL9203 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
FN6106.0
February 3, 2005
ISL9203
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.
15
FN6106.0
February 3, 2005
ISL9203
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
D
1.95
E
SIDE VIEW
C
SEATING
PLANE
A3
1
e
1.60
-
0.50 BSC
-
k
0.25
-
-
L
0.30
0.35
0.40
N
10
Nd
5
3. Nd refers to the number of terminals on D.
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
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
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)
0.08 C
-
3.00 BSC
E2
0.10 C
0.23
3.00 BSC
D2
A
NOTES
A
A3
B
MAX
A1
b
TOP VIEW
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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Intersil Corporation’s quality certifications can be viewed at www.intersil.com/design/quality
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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16
FN6106.0
February 3, 2005