BQ24205

Features:

Designed Specifically to Work With Current-Limited Wall Supplies
Ideal for Low Dropout Charger Design for Single-Cell Li-Ion Packs With Coke or Graphite Anodes
Integrated PowerFET for 500 mA
Integrated Voltage Regulation With 0.5% Accuracy
Battery Insertion and Removal Detection
Charge Termination by Minimum Current and Time
Pre-Charge Conditioning With Safety Timer
Sleep Mode for Low-Power Consumption
Charge Status Output for LED or Host Processor Interface Indicates Charge-in-Progress, Charge Completion, and Fault Conditions
Optional Temperature Monitoring Before and During Charge
Small, 8-Pin Power-Pad MSOP Package


Pinout




Specifications

Supply voltage (Vcc with respect to GND) . . . . . . . . . . . 16.5 V
Input voltage, IN, STAT, TS (all with respect to GND). . . 16.5 V
Input voltage, BAT, OUT (all with respect to GND) .. . . . . . . 7 V
Output sink/source current (STAT) . . . . . . . . . . . . . . . . . 15 mA
Storage temperature range, T_stg . . . . . . . . . . . 65 to 150
Junction temperature range, T_J   . . . . . . . . . . . 40  to 125
Lead temperature (soldering, 10sec) .. . . . . . . . . . . . . . . 300


Description

The bq2420x series are simple Li-Ion linear charge management devices targeted at low-cost and space limited charger applications. The bq2420x series offer integrated powerFET,high-accuracy voltage regulation, temperature monitoring, charge status, and charge termination, in a single monolithic device.

The bq2420x is designed to work with a current-limited wall-mount transformer and therefore does not provide any current regulation.However, these devices offer a fixed internal current limit to prevent damage to the internal powerFET. A time-limited pre-conditioning phase of BQ24205 is provided to condition deeply discharged cells.Once the battery reaches the charge voltage, the high accuracy voltage regulation loop takes over and completes the charge cycle. Charge of BQ24205 is terminated based on minimum current. An internal charge timer provides a backup safety for charge termination.