CM9112 Datasheet, PDF (6/18 Pages) California Micro Devices Corp – Dual Inputs Dual Outputs High Accurate Fast Charger

PRELIMINARY
CM9112
Specifications (cont’d)
FET, Q2. When this condition occurs, the battery will provide extra current to keep VSYS constant at Vbatt-Vfwd. This lasts
until the power dissipated in LDO1 triggers the OTP. As a result, there will be no input current to supply either charging or
LDO1. Current will still be available from battery to supply VSYS, through the external Q2. To resume charging (after the
chip temperature drop bellow 120°C), the VAD/USB inputs must be toggled.
Note 7: This feature can be disabled by connecting the THERM pin to GND.
Note 8: This function requires that Battery Thermistor should be connected between the THERM pin and GND. Another resistor
connected between THERM pin and VIN is required, its value should equal the Thermistor Hot Value (at 50°C). In order to
catch both the 0°C and 50°C thresholds (typical range for Li-ion battery) use Thermistors following 7/1 ratio (Thermistor
COLD/Thermistor HOT=7).
Note 9: If the battery HOT/COLD detection identifies a condition outside the thresholds, the IC stops charging the battery and waits
for the temperature to return to the normal value. During this event, VSYS will continue to be supplied with the required cur­
rent.
Functional Block Diagram
GAD
USB
VIN
VAD
ISET2
GND
Qb
OVP &
ADOK
0.03
Adapter
Current
Limit
OCP
OTP
Over-Temp
Limit
LDO1
450mA
S/D
LDO2
2mA
4.2V
Qc / 1000
Qc Current
Mirror
CT
Timer
CM9112
STAT2STAT1
Charger
Control
VSYS
VREF
VOUT
BSEN
ENA
ISET1
THERM
© 2006 California Micro Devices Corp. All rights reserved.
6 490 N. McCarthy Blvd., Milpitas, CA 95035-5112 lTel: [phone] lFax: [phone] lwww.cmd.com
07/06/06