STARTUP CLAMP CIRCUIT FOR NON-COMPLIMENTARY DIFFERENTIAL PAIR IN DCDC CONVERTER SYSTEM

摘要

A DCDC converter includes a transconductance amplifier, a comparator, a current driving component, an output impedance, a switch, a clamp resistor and a p-channel FET. The transconductance amplifier outputs a transconductance current and a switch control signal. The comparator has a two n-channel FET inputs forming a differential pair and outputs a compared signal. The current driving component generates an output current based on the compared signal. The output impedance component generates an output DC voltage based on the output current. The switch is between the two n-channel FETs and can open and close based on the switch control signal. The clamp resistor is arranged in series with the switch. The p-channel FET is in series with the clamp resistor and is controlled by the output DC voltage.

主权项

1. A DCDC converter operable to receive an input DC voltage and to generate an output DC voltage based on the received input DC voltage, said DCDC converter comprising:
a transconductance amplifier operable to output a transconductance current and a switch control signal, the transconductance current being based on a comparison of a portion of the output DC voltage and a predetermined reference voltage; a comparator having a first n-channel field effect transistor input and a second n-channel field effect transistor input, said first n-channel field effect transistor input and said second n-channel field effect transistor input forming a differential pair, said comparator being operable to output a compared signal based on a first input voltage received at said first n-channel field effect transistor input and a second input voltage received at said second n-channel field effect transistor input; a current driving component operable to generate an output current based on the compared signal; an output impedance component arranged to generate the output DC voltage based on the output current; a switch arranged between said first n-channel field effect transistor input and said second n-channel field effect transistor input, said switch being operable to open and close based on the switch control signal; and a clamp resistor arranged in series with said switch and arranged between said first n-channel field effect transistor input and said second n-channel field effect transistor input; and a p-channel field effect transistor arranged in series with said clamp resistor and arranged between said first n-channel field effect transistor input and said second n-channel field effect transistor input, said p-channel field effect transistor being controlled by the output DC voltage.