An external, low cost, PNP provides the charging current to the battery and an external resistor sets the maximum charge current. A small external capacitor programs the maximum charge time. The controller includes an LED driver to indicate the battery charging status.
Safety features include charging stop mode for battery faults, output overshoot protection, and thermal shutdown. The ADP2291ACPZ-R7 also features automatic reverse isolation, which does not require an additional blocking diode.
The multistep charge cycle optimizes the battery charging time in a safe manner. It features a trickle charge mode for a deeply discharged cell and a fast charging mode with a maximum current of 1.5 A. The ADP2291ACPZ-R7 controls the end of charge with a 4.2 V output voltage that is 1% accurate over line and temp-erature. It automatically recharges the battery if the cell voltage drops. When the input supply is removed, the part enters a low current state and reduces the current drawn from the battery to below 1 µA.
The ADP2291ACPZ-R7 is available in both a small, 8-pin MSOP package and a 3 × 3 mm LFCSP package that is ideally suited for small, portable applications.
Feature
- Simple, Safe Linear Charger for Single Cell Lithium Battery
- 4.5 V to 12 V Input Voltage Range
- Adjustable Charging Current up to 1.5 A
- Low Cost PNP External Pass Element
- Automatic Reverse Isolation with No External Blocking Diode
- Output Overshoot Protection
- Deep Discharge Precharge Mode
- Thermal Shutdown
- Automatic Recharge
- Programmable Termination Timer
- LED Charging Status Indicator
- 4.2 V Output Voltage with ±1% Accuracy Over Line and Temperature.
(Picture: Pinout)
