Hybrid on-chip regulator for limited output high voltage
AssigneeOmniVision Technologies, Inc.
InventorsYun-Hak Koh, Charles Qingle Wu
Life of this patent
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Abstract
A driver circuit provides fast settling times, slew rate control, and power efficiency, while reducing the need for large external capacitors. A voltage reference circuit generates a voltage reference signal. A comparator compares the voltage reference signal and a driver output signal and generates an output high voltage control signal. An output driver includes a first and a second switch that are coupled together. The first and second switches are further coupled to generate the driver output signal in response to coupling the output high voltage control signal to the control terminal of the first switch and coupling an input signal to the control terminal of the second switch.
Claims20
A driver circuit, comprising:
- a voltage reference circuit that is coupled to generate a voltage reference signal;
- a comparator that is coupled to compare the voltage reference signal and a driver output signal to generate an output high voltage control signal;
- and
- an output driver comprising a first switch coupled to a second switch to generate the driver output signal, wherein the driver output signal is generated in response to the output high voltage control signal and an input signal,
- wherein the output driver further includes a native mode transistor coupled to the first and second switches, wherein the native mode transistor is an NMOS transistor having a gate that is coupled to the voltage reference circuit.
A method, comprising:
- generating a reference voltage;
- comparing a driver output signal to the reference voltage to generate an output high voltage control signal;
- generating the driver output signal, by using a first switch coupled to a second switch in, response to a received input signal and the output high voltage control signal;
- and
- arranging a native-mode NMOS transistor to the first and second switches, the native-mode NMOS transistor having a gate coupled to the reference voltage, and whereby a slew rate of the driver output signal is further limited.
An apparatus, comprising:
- a comparator that is coupled to compare a voltage reference signal and a driver output signal to generate an output high voltage control signal;
- and
- an output driver comprising a first switch coupled to a second switch to generate the driver output signal at an output node of the output driver in response to the output high voltage control signal and further in response to an input signal, wherein the output driver is arranged to decouple the output node from a power supply in response to the input signal,
- wherein the output driver further includes a third switch coupled between the output node and the first switch, wherein a gate of the third switch is coupled to receive the voltage reference signal.
Dependencies are inferred from the claim text.