BQ2004SN

The BQ2004SN is a switch-mode NiCd/NiMH Battery Charger with dt/dt termination. This fast-charge IC provides comprehensive 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 system integrated chargers for batteries of one or more cells. Switch-activated discharge-before charge allows BQ2004-based chargers to support battery conditioning and capacity determination. High-efficiency power conversion is accomplished using this charger as a hysteretic PWM controller for switch-mode regulation of the charging current. The BQ2004 may alternatively be used to gate as an externally regulated charging current. Fast charge may begin on application of the charging supply, replacement of the battery, or switch depression.