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Method and System for Generating a High Voltage from a Low Voltage Source using a MOSFET and a Commercial Off The Shelf (COTS) LED Driver Chip

IP.com Disclosure Number: IPCOM000238115D
Publication Date: 2014-Aug-01
Document File: 2 page(s) / 117K

Publishing Venue

The IP.com Prior Art Database

Abstract

A method and system is disclosed for generating a high voltage from a low voltage source using a Metal Oxide Semiconductor Field Effect Transistor (MOSFET) with a Commercial Off The Shelf (COTS) LED driver chip.

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Method and System for Generating a High Voltage from a Low Voltage Source using a MOSFET and a Commercial Off The Shelf (COTS) LED Driver Chip

As illustrated in figure 1, a Power Management Integrated Circuit (PMIC) contains a function that is designed to power a string of

white LEDs for LCD back light.

Figure 1

The PMIC generates its LED power output based on a current source, allowing the voltage to go as high as needed by the LEDs. There is a need for a method to use the PMIC LED circuit to charge up a bank of capacitors to a high voltage. However, this needs to be achieved with the minimal usage of energy, which avoids the usage of high level voltage sources.

Disclosed is a method and system for generating a high voltage charge from a low voltage source using a Metal Oxide Semiconductor Field-Effect Transistor (MOSFET) and a Commercial Off The Shelf (COTS) LED driver chip. The method and system utilize the MOSFET to generate a current of 5mA (milliamps) for the COTS LED driver sense input from a low value voltage source (3.3V). The high voltage output of the COTS LED driver chip is used to charge a bank of capacitors that can be used for a high energy application.

In accordance with the method and system, the MOSFET is used along with a voltage divider to generate the current that the COTS LED driver would see from the string of LEDs, as shown in figure 2.

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Figure 2

The usage of the MOSFET with the voltage divider enables control of the voltage...