LTC4010_15 Datasheet, PDF (9/24 Pages) Linear Technology – High Efficiency Standalone Nickel Battery Charger

Block Diagram
FAULT
1
CHRG
2
4 GND
CHEM
3
V_TEMP
5
V_CELL
6
THERMISTOR
INTERFACE
A/D
CONVERTER
BATTERY
DETECTOR
TIMER
8
7 ^VCDIV
CHARGE
TIMER
VOLTAGE
REFERENCE
CHARGER
STATE
CONTROL
LOGIC
LTC4010
UVLO AND
SHUTDOWN
PWM
READY
16
V_CC
15
TGATE
14
BGATE
12
PGND
13
SENSE
9
BAT
10
VOLTAGE
REGULATOR
INTV_DD
11
INTERNAL
VOLTAGE
REGULATOR
4010 BD
Operation (Refer to Figure 1)
NO DC ADAPTER
SHUTDOWN
DC ADAPTER PRESENT
NO BATTERY
OR
V_CC < 4.25V
TOP-OFF
CHARGE**
(C/10)
CHARGE
QUALIFICATION
V_CELL > 350mV, ADEQUATE V_CC,
CHARGER ENABLED AND
TEMPERATURE OK (OPTIONAL)
CHECK
BATTERY
V_CELL > 900mV
NiMH
∆T/∆t
FAST CHARGE**
(1C)
V_CELL < 900mV
VCELL ^{> 900mV}
PRECHARGE**
(C/5 FOR
t_MAX/12)
V_CELL < 900mV
V_CELL < 1.22V AT t_MAX*/12
OR TIME = t_MAX
FAULT
t_MAX/3
NiCd OR
NiMH – ∆V
AUTOMATIC
RECHARGE
V_CELL < 1.325V
V_CELL > 1.95V
OR PWM FAULTS
4010 F01
*t_MAX IS PROGRAMMED MAXIMUM FAST CHARGE DURATION
**OPTIONAL TEMPERATURE LIMITS APPLY
Figure 1. LTC4010 State Diagram
4010fb