TREA

HIGH VOLTAGE GATE DRIVER IC WITH RAMP DRIVER

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Information

  • Patent Application
  • 20080054984
  • Publication Number
    20080054984
  • Date Filed
    July 20, 2007
    18 years ago
  • Date Published
    March 06, 2008
    17 years ago
Information
Abstract
A High Voltage Gate Driver IC (HVIC) having an internal ramp drive function for controlling a high power switch to produce ramp output voltage waveforms. The HVIC including a sensor for sensing a voltage across the power switch; a reference generator for generating a reference voltage signal in accordance with an external setting; and a feedback circuit to provide a feedback gain to control a gate of the power switch, the feedback circuit making voltage across the power switch follow to reference and stable, wherein the HVIC generates the ramp drive function with minimized circuit components external to the HVIC.
Description

BRIEF DESCRIPTION OF THE DRAWINGS


FIG. 1 is a diagram of a conventional HVIC using external ramp generating circuits for driving the power switch;



FIG. 2 is a diagram of application of the HVIC of FIG. 1 in a conventional PDP ramp driver including additional external ramp generating circuitry required for smooth operations in a functioning system;



FIG. 3 is a diagram of an HVIC of an embodiment of the present invention; and



FIG. 4 is a diagram of an exemplary application of the HVIC of FIG. 1 in a PDP ramp driver using an internal ramp drive function.





DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

The present invention provides an HVIC having a stable ramp driver function for the power switch 16 using internal sensing and feedback function of the HVIC with minimized external circuits. The inventive HVIC circuit 22 having an internal ramp driver function is illustrated in FIG. 3. The HVIC circuit 22 includes a sensing circuit 24 that senses output voltage Vds; a reference generator 26 to generate a reference signal from external reference settings; a feedback logic system 30 and an output buffer 28 to control the gate of the switch 16. The HVIC circuit 22 provides a stable ramp waveform. Through the use of the fast feedback system 30, the HVIC circuit 22 can provide a stable ramp output regardless of disturbances.


One exemplary embodiment of the HVIC circuit 22 of the present invention that provides an internal ramp driver function is illustrated in FIG. 4. As shown, the HVIC circuit 22 further includes external resistors R1 and R2 that are parallel connected to the power switch 16. The sensing circuit 24 senses divided output voltage changes over switch. This is achieved by measuring a voltage signal Vds at a node between R1 and R2.


Further, the HVIC circuit 22 includes an operational error amplifier 32 that receives the voltage signal Vds at its positive terminal and a reference constant voltage signal VREF at its negative terminal. The reference constant voltage signal VREF is generated by the reference generator circuit 26 from an externally set reference. The output of the operational error amplifier 32 provides a feedback gain for controlling the gate of the switch 16.


Thus, the HVIC circuit 22 provides stable ramp output while eliminating external auxiliary circuits. Therefore, application of the HVIC circuit 22 in PDP reset ramp drivers can save system cost and space and improve performance.


Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred, therefore, that the present invention not be limited by the specific disclosure herein.

Claims
  • 1. A High Voltage Gate Driver IC (HVIC) having an internal ramp drive function for controlling a high power switch to produce ramp output voltage waveforms, the HVIC comprising: a sensor for sensing a voltage across the power switch;a reference generator for generating a reference current signal in accordance with an external setting; anda feedback circuit to provide a feedback gain to control a gate of the power switch, the feedback circuit making voltage across the power switch follow to reference and stable, wherein the HVIC generates the ramp drive function with minimized circuit components external to the HVIC.
  • 2. The HVIC of claim 1, further comprising a pair of resistors parallel coupled to the high power switch, and wherein the voltage comprises a first divided output voltage changes over switch, the first voltage signal being monitored at a node coupled to the high power switch and the pair of resistors.
  • 3. The HVIC of claim 2, wherein the feedback system comprises an operational error amplifier that receives the first voltage signal at its positive terminal and the reference voltage signal at its negative terminal and produces a stable ramp output.
  • 4. The HVIC of claim 3, wherein the stable ramp output is produced regardless of disturbances.
  • 5. The HVIC of claim 4, wherein the power switch is controlled to implement the ramp output voltage waveforms to allow slow and stepwise turn-ON of the high power switch.
  • 6. The HVIC of claim 5, wherein the ramp output voltage waveforms have a slow and stepwise dV/dt characteristic of several V/us.
  • 7. The HVIC of claim 6, wherein the HVIC is used for resetting Plasma Display Panels (PDP).
  • 8. The HVIC of claim 1, wherein the HVIC is provided on the same integrated circuit with the high power switch.
CROSS-REFERENCE TO RELATED APPLICATION

This application is based on and claims priority to U.S. Provisional Patent Application Ser. No. 60/824,183, filed on Aug. 31, 2006 and entitled HIGH VOLTAGE GATE DRIVER IC (HVIC) WITH RAMP DRIVER, the entire disclosure of which is hereby incorporated by reference.

Provisional Applications (1)
Number Date Country
60824183 Aug 2006 US