GENERAL DESCRIPTION

The ADP3804 is a complete Li-Ion battery charging IC. The device combines high output voltage accuracy with constant current control to simplify the implementation of Constant Current, Constant-Voltage (CCCV) chargers. The ADP3804 is available in two options. The ADP3804-12.6 guarantees the final battery voltage to 12.6 V ± 0.6, the ADP3804-12.5 guarantees 12.525 V ± 0.6 and the ADP3804 is adjustable using two external resistors to set the battery voltage. The current sense amplifier has rail-to-rail inputs to accurately operate under low drop out and short circuit conditions. The charge current is programmable with a DC voltage on ISET. A second differential amplifier senses the system current across an external sense resistor and outputs a linear voltage on the ISYS pin. The boosted synchronous driver allows the use of two NMOS transistors for lower system cost.

FEATURES

Li-Ion Battery Charger

Fixed 12,525 V, 12.600 V, or Adjustable Battery

Voltage

High End-of-Charge Voltage Accuracy

±0.4 @ +25°C

±0.6 @ 5°C to 55°C

±0.75 @ 0°C to 85°C

Programmable Charge Current with

Rail-to-Rail Sensing

System Current Sense with Reverse Input Protection

Softstart Charge Current

Undervoltage Lockout

Boosted Synchronous Drive For External NMOS

Programmable Oscillator Frequency

Oscillator SYNC Pin

Constant Current/Constant Voltage Flag

Trickle Charge

APPLICATIONS

Portable Computers

Fast Chargers