BQ2004 Overview
The bq2004 Fast Charge IC provides prehensive fast charge control functions together with high-speed switching power control circuitry on a monolithic CMOS device. Integration of closed-loop current control circuitry allows the bq2004 to be the basis of a cost-effective solution for stand-alone and systemintegrated chargers for batteries of one or more cells. Switch-activated discharge-beforecharge allows bq2004-based chargers to support battery conditioning and capacity determination. High-efficiency power conversion is acplished using the bq2004 as a hysteretic PWM controller for switch-mode regulation of the charging current. The bq2004 may alternatively be used to gate an externally regulated charging current. Fast charge may begin on application of the charging supply, replace- ment of the battery, or switch depression. For safety, fast charge is inhibited unless/until the battery...
BQ2004 Key Features
- Fast charge and conditioning of nickel cadmium or nickel-metal hydride batteries
- Hysteretic PWM switch-mode current regulation or gated control of an external regulator
- Easily integrated into systems or used as a stand-alone charger
- Pre-charge qualification of temperature and voltage
- Configurable, direct LED outputs display battery and charge status
- Fast-charge termination by ∆ temperature/∆ time, peak volume detection, -∆V, maximum voltage, maximum temperature, and m
- Optional top-off charge and pulsed current maintenance charging
- Logic-level controlled low-power mode (< 5µA standby current)