LTC4001 Datasheet, PDF (9/20 Pages) Linear Technology – 2A Synchronous Buck Li-Ion Charger

U
OPERATIO
Overvoltage, Chip Overtemperature and Short-Circuit
Current Protection
The LTC4001 includes overvoltage, chip overtemperature
and several varieties of short-circuit protection.
A comparator turns off both chargers (high rate and
trickle) if battery voltage exceeds the float voltage by
approximately 5%. This may occur in situations where the
battery is accidentally disconnected while battery charg-
ing is underway.
A comparator continuously monitors on-chip temperature
and will shut off the battery charger when chip temperature
LTC4001
exceeds approximately 160°C. Battery charging will be
enabled again when temperature drops to approximately
150°C.
Short-circuit protection is provided in several different
ways. First, a hard short on the battery terminals will
cause the charge to enter trickle charge mode, limiting
charge current to the trickle charge current (typically
50mA). Second, PWM charging is prevented if the high
rate charge current is programmed far above the 2A
maximum recommended charge current (via the PROG
pin). Third, an overcurrent comparator monitors the peak
inductor current.
4001f
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