Alpha Omega Semiconductor Inc.

Dialog Semiconductor Gmbh

Iwatt Inc.

Yu Cheng Chang

Yang Li

John William Kesterson

Xiaoyan Wang

Xuecheng Jin

Maofeng Lan

Chenghung Pan

Sung-Shan Tai

YongZhong Hu

An adaptive switch mode LED driver provides an intelligent approach to driving multiple strings of LEDs. The LED driver determines an optimal current level for each LED channel from a limited set of allowed currents. The LDO driver then determines a PWM duty cycle for driving the LEDs in each LED channel to provide precise brightness control over the LED channels. Beneficially, the LED driver minimizes the power dissipation in the LDO circuits driving each LED string, while also ensuring that the currents in each LED string are maintained within a limited range. A sample and hold LDO allows PWM control over extreme duty cycles with very fast dynamic response. Furthermore, fault protection circuitry ensures fault-free startup and operation of the LED driver.

Adaptive switch mode LED driver

A voltage/current control apparatus and method are disclosed. The apparatus includes a low-side field effect transistor (FET) having a source, a gate and a drain, a high-side field effect transistor (FET) having a source, a gate and a drain, a gate driver integrated circuit (IC), a sample and hold circuit, and a comparator configured to produce a trigger signal at the output when a sum of the first and second input signals is equal to a sum of the third and fourth input signals, wherein the trigger signal is configured to trigger a beginning of a new cycle by turning the gate of the high-side FET 'on' and the gate of the low-side FET 'off'.

Voltage/current control apparatus and method

A method of performing a programming, testing and trimming operation is disclosed in this invention. The method includes a step of applying a programming circuit for programming an OTP memory for probing and sensing one of three different states of the OTP memory for carrying out a trimming operation using one of the three states of the OTP memory whereby a higher utilization of OTP memory cells is achieved. Selecting and programming two conductive circuits of the OTP into two different operational characteristics thus enables the storing and sensing one of the three different states of the OTP memory. These two conductive circuits may include two different transistors for programming into a linear resistor and a nonlinear resistor with different current conducting characteristics. The programming processes include application of a high voltage and different programming currents thus generating different operational characteristics of these two transistors.

One-time programmable (OTP) memory cell

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Cupertino, CA, United States of America

Yu Cheng Chang