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STw4102
User Manual
34 pgs537.03 Kb0
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ST STw4102 User Manual

Dual USB/wall adapter Li-ion battery charger with gas gauge
Features
■ Constant current constant voltage (CCCV)
linear charger
■ Common or separate USB/wall adapter inputs
adapter and up to 500 mA for USB
■ Support for currents higher than 1 A using
external components
■ Programmable charge voltage (4.1 V, 4.2 V,
4.3 V, 4.35 V) with 1% accuracy
■ Thermal regulation
■ Trickle charge mode at low battery voltage
■ Wall adapter voltage up to 16 V
■ Battery overvoltage protection at 4.7 V
■ Gas gauge with 13-bit AD converter
■ Battery voltage monitor with 7-12 bit AD
converter
2
■ I
C interface for device monitoring and control
■ Charge status output pin
■ Power detection output pin
■ Programmable watchdog security timer
■ 4.7 V LDO regulator (with external power
MOSFET)
Applications
■ Cellular phones (GSM, CDMA, WCDMA),
PDA, MP3 players, cordless phones
■ Digital camera, USB appliances, bluetooth
devices, portable navigation devices
STw4102
QFN 24
(Plastic micropackage)
Pin connections
(top view)
BATT
SENSE
EOCHG
BATTSENSE
PWRDETECTN
TEST
24 23 22 21 20 19
MAIN VOUT
USBPWR DRIVER LDODRV LDOFB
1 2 3 4 5 6
789101112
ISET
CVREF
The STw4102 offers dual charging capability using separate inputs for USB cable and wall adapter, or a single input that accepts both.
The STw4102 also offers programmable fast charge current using an ext ernal resistor. A thermal regulation circuit limits the charge current against the die high power dissipation or high ambient temperature. An e nd of charge output pin indicates the charge termination when the fast charge current drops below 10% of the programmed current value.
GND
ICG+
CVIS
18
VIO
17
SCL
16
SDA
15
RESETN
14
STDBY
13
C32KHZ
ICG-
Description
The STw4102 includes an accurate gas gauge
based on a 13-bit AD converter. An external The STw4102 is a standalone constant current constant voltage (CCCV) linear charger specifically designed for Li-ion batteries.
March 2008 Rev 2 1/34
resistor is used between battery and ground to
sense a charge/discharge current. With a typical
30 mΩ resistor, current can be up to 2.5 A.
www.st.com
34
Contents STw4102
Contents
1 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2 Pin assignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3 Absolute maximum ratings and operating conditions . . . . . . . . . . . . . 6
4 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Typical performance curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
5 Application schematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5.1 Charge from USB or wall adapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5.2 Charge currents higher than 1 Amp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.3 Using LDO regulator to supply telephone from wall adapter . . . . . . . . . . 16
6 Battery charger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
6.1 Charge cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
6.2 Trickle charge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
6.3 Charging from a wall adapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
6.4 Charging from a USB port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
6.5 Charging using external power devices . . . . . . . . . . . . . . . . . . . . . . . . . . 19
6.6 Charge mode summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
6.7 Watchdog timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
6.8 Thermal regulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
7 Low drop-out regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
8 Battery monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
8.1 Gas gauge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
8.2 Battery voltage monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
9 Factory OTP options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
2
10 I
2/34
C interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
10.1 Read and write operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
STw4102 Contents
10.2 Register mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
11 Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
12 Ordering information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
13 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
3/34
Block diagram STw4102

1 Block diagram

Figure 1. Internal block diagram
DRIVER
MAIN
USBPWR
PWRDETECTN
EOCHG
CVREF
Main adapter Detect
USB
Detect
Main Power Device (max 1A)
USB Power Device (max 500mA)
Driver
Thermal regulation
Voltage Current
Regulation
CC/CV
Trickle threshold Trickle current
Charge Voltage
Charge current
Vref
Current Sense
Voltage Sense
CC/CV
configuration
Current defined by external resistor
VOUT
SENSE
Sense ressitor
BATT
BATTSENSE
ISET
LDO
LDODRV
LDOFB
Main supply
LDO driver 4.7V
Charge Control
Registers
VIO
24 bit accumulator
Control registers
SCL SDA
RESETN
I2C interface
Control
Registers
4/34
Supply
Battery Monitoring
Power On Reset
AD converter
7-12 bits
GND
Internal
AD converter
12 bits + sign bit
CVIS
STDBY
C32KHZ
ICG+
ICG-
Battery voltage
TEST
STw4102 Pin assignment

2 Pin assignment

P
Table 1. Pin descriptions
Pin # Pin name Type Function
1 MAIN Supply Main power input from wall adapter or USB charger 2 VOUT O_A Power path output 3 USBPWR Supply Power supply from USB cable 4 DRIVER O_A Driver for external power switch (PMOS or PNP) 5 LDODRV O_A LDO power PMOS driver 6 LDOFB I_A LDO feedback regulation 7 ISET O_A Resistor to program the main charge current 8 CVREF I_A Bypass capacitor for internal voltage reference
9 GND Ground Analog and digital ground 10 CVIS I_A Bypass capacitor for internal supply 11 ICG+ I_A Gas gauge sense resistor 12 ICG- I_A Gas gauge sense resistor 13 C32KHZ I_D External 32kHz clock input 14 STDBY I_D Gas gauge standby input (active low) 15 RESETN I_D Digital register reset (active low)
2
16 SD A IO_D I 17 SCL I_D I 18 VIO Supply Supply for I/O 19 SENSE I_A Sense resistor input to regulate the charge current 20 BATT Supply Battery power voltage 21 BATTSENSE I_A Battery sense voltage
22 EOCHG OD
23 TEST I_D
24 PWRDETECTN OD
C serial data.
2
C serial clock.
End of charge output status. Pulled low when the fast charge current is above 10% of its programmed maximum value.
Reserved pin for factory test. To be connected to ground.
Main or USB plug-in detection. Pulled low when power is detected, open when no power is detected.
In this table, the following conventions are used:
I: Input O: Output I/O: Bidirectional OD: Open Drain A: Analog D: Digital
5/34
Absolute maximum ratings and operating conditions STw4102

3 Absolute maximum ratings and operating conditions

Table 2. Absolute maximum ratings (AMR)
Symbol Parameter Value Unit
V
MAIN
V
CC
V
USB
V
batt
V
V
DD
P
I
sense
T
stg
T
R
thja
ESD Electrostatic discha rg e (HBM human body model)
1. Package's exposed pad is soldered to a copper pad on the PCB with multiple vias to the ground plane.
2. Human body model: 100pF discharged through a 1.5 kΩ resistor between two pins of the device, done for all couples of pin combinations with other pins floating.
Table 3. Operating conditions
Maximum supply voltage on MAIN input 20 V Voltage on EOCHG, LDODRV, DRIVER pins -0.3 to V Maximum supply voltage on USBPWR input 7 V Maximum voltage on BATT, BATTSENSE, PWRDETECTN 7 V Maximum supply voltage on VIO pin 7 V
IO
Voltage on I/O pins (SCL, SDA, RESETN, C32KHZ, STDBY)
Pow er dissipation self-limited
d
-0.3 to V
Maximum current from SENSE to BATT 1 A Storage temperature -55 to 150 ° C Maximum junction temperature 150 ° C
j
Thermal resistance junction-ambient
(1)
(2)
MAIN
IO
V
V
45 ° C/W
2kV
Symbol Parameter Value Unit
V
V
T
V
V
V
V
main
CC
USB
batt
out
oper
Operating supply voltage on MAIN 4.25 to 16 V Maximum voltage on EOCHG 16 V Operating supply voltage on USBPWR 4.25 to 5.5 V Operating supply voltage on VIO 1.45 to 3.0 V
IO
Max voltage on BATT, BATTSENSE, PWRDETECTN 5.0 V Max voltage on VOUT BATT +0.7 V Operating free air temperature range -30 to 85 ° C
6/34
STw4102 Electrical characteristics

4 Electrical characteristics

Table 4. CC/CV charger - V
oper
=5V, V
=3.6V, T
batt
= -30°C to 85° C (unless otherwise
amb
specified)
Symbol Parameter Conditions Min Typ Max Unit
Supply (V
I
charger
I
STBY
I
batt_sense
I
batt
POR_IS+ Power ON reset threshold+ CVIS internal supply 2.2 2.3 2.4 V POR_IS- Po wer ON reset threshold- CVIS internal supply 2.1 2.2 2.3 V
Voltage regu lation
V
charge_acc
R
power
Battery Battery
Current regulation
I
trickle
V
trickle
V
trickle_hyst
I
charge
I
charge_acc
I
USB
EOCHG EOCHG T
regulation
T
softstart
from MAIN or USB)
oper
Main or USB input operating current 2 mA USBPWR input standby current Charge off 40 µA BSENSE input current No charge 1 µA BATT input current No charge 25 µA
Output voltage accuracy T Power path resistance MAIN to BATT 0.6 Ω
ovv ovv_hyst
Static battery overvoltage detection 4.55 4.7 4.8 V Static battery overvoltage hysteresis 100 mV
Trickle charge current
Trickle to fast charge threshold Standard configuration 2.8 2.9 3.0 V Trickle to fast charge threshold hysteresis 100 mV Main charge current range Internal path 100 1000 mA Main charge current accuracy I
USB charge current
ith ith_hys
End of charge threshold % of current setting 10 % End of charge threshold hysteresis % of current setting 5 % Regulated junction temperature 125 ° C Soft start from trickle to fast charge 100 µs
= 0°C to 85° C-1 +1%
amb
V
batt<Vtrickle
Standard configuration Factory OTP option
> 500mA -15 +15 %
charge
306060
120
100 180mAmA
REG_CHG0[7..6]: 00 01 10 11
30 60
200 400
100 500
0
mA mA mA mA
7/34
Electrical characteristics STw4102
Table 4. CC/CV charger - V
oper
=5V, V
=3.6V, T
batt
= -30°C to 85° C (unless otherwise
amb
specified) (continued)
Symbol Parameter Conditions Min Typ Max Unit
Watchdog
REG_WDOG[2,1]: 00
t
watchdog
Watchdog duration
01 10 11
Input/output pins
V
charger_det
V
charger_det_hys
V
USB_det
V
USB_det_hys
Vol
powerdetect
Vol
EOCHG
I
drv_sink
Table 5. LDO - V
Main charger supply voltage detection 2.4 2.5 2.6 V Main charger supply voltage detection
hysterisis USB supply voltage detection 2.4 2.5 2.6 V USB supply voltage detection hysteresis 100 mV POWERDETECTN output capability I
EOCHG output capability
= 10mA 0.45 V
sink
= 10mA
I
sink
= 20mA
I
sink
Driver sink current (If option enabled) 60 mA
main
=6V, T
= -30°C to 85° C (unless otherwise specified)
amb
Symbol Parameter Conditions Min Typ Max Unit
0.5
1
7.5
15
15
30
30
60
100 mV
1.5
22.5 45 90
0.5
1.1
min min min min
V V
LDO
LDO LDO LDO
V
power_th power_th_hys PSRR
Including line and load
LDO regulated output voltage
regulation (up to 1A), V
>6V
main
4.47 4.7 4.93 V
LDO power turn off threshold 6.8 7.2 7.5 V LDO power turn off threshold hysterisis 0.7 V LDO power supply rejection ratio Up to 20kHz 50 dB
8/34
STw4102 Electrical characteristics
Table 6. Battery monitor - V
=3.6V, T
batt
= -30°C to 85° C (unless otherwise specified)
amb
Symbol Parameter Conditions Min Typ Max Unit
POR_IS2+ Power ON reset threshold+ CVIS internal supply 2.6 2.7 2.8 V POR_IS2- Power ON reset threshold- CVIS internal supply 2.5 2.6 2.7 V
Gas gauge A/D converter
V
os_gg
V
in_gg
I
dd_gg
I
pdn_gg
I
in
LSB
Acc
gg
Tamb_gg
Input offset voltage 40 µV Input voltage range -80 +80 mV Current consumption CG_ENA=1 90 µA Current consumption in off mode CG_ENA=0 1 µA Input current for ICG+ and ICG- 500 nA AD converter granularity (LSB value) 12 bits + 1 sign bit 23.5 µV
Accuracy at ambient temperature
External resistor at 1% No calibration
3%
Battery voltage A/D converter
V
in_mon
I
dd_mon
I
pdn_mon
LSB
mon
Acc
Tamb_m on
Input voltage range BATT voltage 1 5 V Current consumption ADPOWERON=1 190 µA Current consumption in off mode ADPOWERON=0 1 µA
AD converter granularity (LSB value)
7 bits 12 bits
45.4
1.42
Accuracy at ambient temperature No calibration 3 %
Digital I/O pins (SCL, SDA, STDBY, C32KHZ, RESETN)
mV mV
V
il
V
ih
V
ol
Input pin low voltage 0 0.3 x V Input pin high voltage 0.7 x V SDA output pin low voltage I
= 3mA 0.2 x V
sink
IO
V
IO
V
IO
V V
IO
9/34
Electrical characteristics STw4102
Table 7. I
Symbol Parameter Conditions Min Typ Max Unit
2
C timing - VIO= 2.8V, T
= -30°C to 85° C (unless otherwise specified)
amb
F
scl
t
hd,sta
t
low
t
high
t
su,dat
t
hd,dat
t
r
t
f
t
su,sto
C
b
SCL clock frequency 400 kHz Hold time (repeated) START condition 0.6 µs LOW period of the SCL clock 1.3 µs HIGH period of the SCL clock 0.6 µs Setup time for repeated START condition 0.6 µs Data hold time 0 0.9 us
Rise time of both SDA and SCL signals
Fall time of both SDA and SCL signals
Setup time for STOP condition 0.6 µs Capacitive load for each bus line 400 pF
Figure 2. I2C timing diagram
t
f
ih
il
t
hd,sta
SDA
V
V
20+
0.1C 20+
0.1C
b
b
300 ns
300 ns
SCL
t
low
t
hd,dat
t
su,dat
t
high
t
su,sta
t
r
10/34
STw4102 Electrical characteristics

Typical performance curves

Figure 3. Charger voltage vs. charge current
(Main charge, 4.2V and 1A settings)
4.5
4.0
3.5
3.0
2.5
2.0
Vba tt (V)
1.5
1.0
0.5
0.0 0 200 400 600 800 1000 1200
Icharge (mA)
Figure 5. Charge current vs. tempe rat u r e
(charge from MAIN, 1A setting)
1.2
1.0
0.8
0.6
Icharge (A)
0.4
Figure 4. Charger voltage vs. charge current
(USB charge, 4.2V setting)
4.5
4.0
3.5
3.0
2.5
2.0
Vba tt (V)
1.5
1.0
0.5
0.0 0 100 200 300 400 500
Iusb (mA)
Ich=400mAIch=200mA
Figure 6. Charge current vs. temperature
(charge from USBPWR)
500
400
300
200
Iusb (mA)
Ich=400mA
Ich=200mA
0.2
0.0
-50-250 255075100125
Temp (°C)
Figure 7. Charge voltage vs. temperature
(4.2V nominal setting)
4.24
4.23
4.22
4.21
4.20
4.19
Vcharge (V)
4.18
4.17
4.16
-50 -25 0 25 50 75 100 125
Temp (°C)
100
0
-50 -25 0 25 50 75 100 125
Temp (°C)
11/34
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