Reference Designs
Universal uP Controlled Battery Charger 24Vin 10 Aout max, 5/12V 2A & 5V 4A, 2 USB Ports Ref Design
Texas Instruments
BQ24745 is a host controlled synchronous buck battery charger capable of charging batteries at up to 19.2V and up to 8 A normally, extended to 10 A with use of 8 mOhm battery sense resistor. The power train is capable of 8 A with convection only cooling and 10 A with moderate fan cooling (~200 LFM). The Test Report includes Thermal images for both cases. While the design shows a 28 pin MSP430 as the host, any processor with SMBus capability will work. A 5/12V 2A auxiliary converter using TPS54335, and 5V 4A with TPS40170 with 2x CSD18504 are provided. For the two USB ports, the design provides TPS2561A for power switching and TPS2513A for control. A linear TPS70933 provides the 3.3V for the MSP430 and interface signals. A rich Test Interface allows full testing of hardware in the absence of software and then provides multiple interface choices for software development.
Features
- Host controlled 10 A charger off 24 Vin
- MSP430 controller shown, but can work off other processors with SMBus capability
- Power train can be verified without processor
- 5/12 V 2A and 5V 4A with two USB ports & 3.3V uP power provided
- All parts on top side for ease of testing / battery discharge switch provided
- Schematic, BOM, layout and Test Report focusing on Battery charger