This reference design uses UCD3138064A as a digital controller to control two-phase two-rail inverting buck-boost. This non-isolated converter is used for wireless radio power. The input voltage is from -35 V to -60 V. There are two outputs. The default output voltage of rail 1 is 32 V and max current is 8.5 A; the default output voltage of rail 2 is 48 V and max current is 5.5 A. The output voltage is adjustable from 30 V to 56 V. With some component changes and firmware changes, the hardware can be used for current mode control or transition mode control to increase power and improve load transient. Test results of three controls are provided respectively.
- Inverting buck boost for -48-V to 48-V system
- Transient response with less than +/- 3% overshoot/undershoot voltage