Time delay reduction for improving transient response of digital controlled POL using DSP

The point of load (POL) is a power supply, supplies a “low voltage and large current” power to a digital processor application. Digital load current changes very quickly, therefore, a fast transient response is required for POL. In case of the digital controlled POL, “conversion time delay” on the ADC and “internal calculation time” deteriorates its performance. As a result, the output voltage of the Digital controlled POL has a large deviation with the rapid load transient. This is not acceptable for digital processor load. This paper clarifies the delay of the ADC which embedded in the DSP, and the calculation time. We introduce a technique for calculation process improvement, and for shortening the detection delay on the ADC to achieve the high-speed response. The proposed algorithm is verified by using 1/8 brick size of 10 W POL adopting the latest high performance DSP (TMS320F2808: TI), which is newly developed as a commercial product.