Design of wide power supply, high performance voltage regulator with BCD process

This paper analyzes a voltage regulator with widely range of power supply which is essential module in switching mode power supply. It is composed of Pre-charging Circuit, Bandgap Reference Circuit, Current Reference Circuit, Thermal Protect Circuit and Low-dropout (LDO) regulator. A frequency compensation method with buffer stage isolation is utilized, that conduces to the improvements of transient response and PSR performance of the LDO. This regulator is fabricated with BCD technology, has a wide range of power supply from 5.2 to 25 V and functions of current limiting and thermal protection. Simulation results show that, the output voltage and current are 5V and 80mA. While the overshoot and undershoot of the output voltages are less than 45mV and 80mV, respectively, when the load current changes at a rate of 50 mA/μs. The PSR is more than 95.2dB@DC. Also, an internal 1.22V bandgap reference voltage, proportional to absolute temperature (PTAT) current reference and zero temperature coefficient (TC) current reference are produced.

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