LT1769 1769fa Constant-Current/ Constant-Voltage 2A Battery Charger with Input Current Limiting
The LT1769 provides a simple, efficient solution for charging NiCd, NiMH, lead‑acid and lithium rechargeable batteries. Charge current is set by external resistors or a DAC on the PROG pin, and the device includes an input‑current‑limit loop to protect the wall adapter.
The IC operates as a current‑mode PWM buck regulator with a 200 kHz switching frequency, offering up to 2 A continuous charge current (3 A peak). It features an adjustable undervoltage lockout, automatic shutdown when the adapter is removed, and a very low reverse‑battery‑drain current of 3 µA.
| Maximum Charge Current | 2 A (peak 3 A) |
|---|---|
| Input Voltage Range | 1 V to 20 V |
| Undervoltage Lockout Threshold | 6.7 V |
| Switching Frequency | 180 kHz to 230 kHz |
| No‑Load Shutdown Current | 3 µA |
It can charge NiCd, NiMH, lead‑acid, and lithium rechargeable batteries.
The UV pin is the undervoltage lockout input; it trips when the voltage falls below about 6.7 V.