Datasheet

Stand-Alone Switch-Mode
Lithium-Ion Battery-Charger Controller
Table 1. Charging State Conditions
From initial power on
or
From done state if battery voltage <
recharge voltage threshold
or
V
DCIN
- V
BATT
< 100mV or V
BATT
> bat-
tery overvoltage threshold
Timers reset, charging current = 0,
FASTCHG = high, FULLCHG = high,
FAULT = high
Reset
Fault
From prequalification state if prequalifi-
cation timer expires
or
From fast-charge state if fast-charge
timer expires
Charging current = 0,
FASTCHG = high, FULLCHG = high,
FAULT = low
Over/Under Temperature
From fast-charge state or full-charge
state if battery temperature is outside of
limits
Charge current = 0, timers suspended,
FASTCHG = no change, FULLCHG = no change,
FAULT = no change
Done From top-off state if top-off timer expires
Recharge voltage threshold ≤ battery voltage ≤ battery
regulation voltage, charging current = 0, FASTCHG =
high, FULLCHG = high, FAULT = high
Top-Off
(Constant Voltage)
From full-charge state if full-charge timer
expires or charging current ≤ 10% of
current limit
Battery voltage = battery regulation voltage, charging
current ≤ 10% of current limit, timeout = 45min typ
(C
TIMER1
= 1nF), FASTCHG = high, FULLCHG = high,
FAULT = high
Full Charge
(Constant Voltage)
From fast-charge state if battery
voltage = battery regulation voltage
Battery voltage = battery regulation voltage, charging
current ≤ current limit,
timeout = 90min typ (C
TIMER1
= 1nF),
FASTCHG = high, FULLCHG = low, FAULT = high
ENTRY CONDITIONS STATE CONDITIONS
Prequalification
From reset state if input power,
reference, and internal bias are within
limits
Battery voltage ≤ undervoltage threshold, charging
current = C/20, timeout = 7.5min typ (C
TIMER1
= 1nF),
FASTCHG = low, FULLCHG = high, FAULT = high
Fast Charge
(Constant Current)
From prequalification state if battery
voltage > undervoltage threshold
Undervoltage threshold ≤ battery voltage ≤ battery regu-
lation voltage, charging current = current limit,
timeout = 90min typ (C
TIMER2
= 1nF),
FASTCHG = low, FULLCHG = high, FAULT = high
STATE
Maxim Integrated
13
MAX1737