Demonstration circuit 2044A is a 55V buck-boost multi-chemistry battery charger featuring the LTC4020. The board will accept an input voltage between 15V and 55V. The float voltage of the battery output (BAT) is 25.2V, with 3.3A maximum charge current. The converter out-put (VOUT) has a voltage range of 21V to 28V, with 3A maximum load current. The LTC4020 contains a high efficiency synchronous buck-boost DC/DC controller and uses a proprietary average current mode architecture.
The LTC4020 battery charger can provide a constant-current/constant-voltage charge algorithm (CC/CV, with MODE pin grounded), constant-current charging (CC, with MODE pin floated), or charging with an optimized 4-step, 3-stage lead-acid battery charge profile (connect MODE pin to INTVCC, with a 0Ω jumper at the optional R29 position).
The LTC4020 data sheet gives a complete description of the IC operation and application information. The data sheet must be read in conjunction with the quick start guide.