WPG World Peace Group launches automotive daytime running light LED driver reference design based on TI products

WPG Holdings announced that its subsidiary, World Peace, has launched an automotive daytime running light LED driver reference design based on TI products .

The reference design introduced by WPG is a dual-string LED light emitting diode ( LED ) driver that uses an operational amplifier ( op amp ) based circuit to balance the current in two LED strings. The op amp circuit senses the current in the reference string and uses the current in the mirror string to balance the current in the two LED strings.Feedback is used to bias the MOSFET which regulates the current between the strings .

This solution uses the TPS92692-Q1 multi-topology LED driver in a boost configuration to drive the LED . The TPS92692-Q1 features spread spectrum frequency modulation, analog current regulation, and internal pulse width modulation ( PWM ) dimming for electromagnetic interference ( EMI ) performance. This design includes an adjustable linear thermal foldback analog temperature sensor using the LMT87-Q1 as well as current limiting to prevent the mirror string from being unable to open the circuit. The design also has two brightness modes : one mode is full brightness mode and the other is a PWM dimming mode with reduced brightness.

Product Features

• Dual string current balancing using a single LED driver;

• Passed CISPR25 Class-5 conducted and radiated emissions test;

• PWM dimming in two brightness modes ;

• Current limiting;

• Operated by cold crank;

• No microcontroller unit ( MCU ) is required.

Figure 1-WPG World Peace launches vehicle daytime running light LED driver reference design system architecture diagram based on TI products

This module (EVM) helps designers evaluate the operation and performance of the TPS92692-Q1 and TPS92692 high-precision LED controllers designed for automotive and general lighting applications. The TPS92692EVM-880 uses the TPS92692-Q1 (AEC Q100) device; however, for general lighting and other non-automotive applications, the TPS92692 uses the same package and pin configuration with the same performance characteristics.

The TPS92692-Q1 device implements a fixed-frequency peak current mode control technique with programmable switching frequency, slope compensation, and startup timing. It integrates a low-offset rail-to-rail current sense amplifier that can directly measure the LED current over an output voltage range of 0V to 65V. Other features include a wide input voltage range (4.5V to 65V), spread spectrum frequency modulation, analog to PWM conversion circuitry, direct PWM dimming capability, analog dimming capability, adjustable switching frequency, input undervoltage protection, output overvoltage protection, and switch cycle-by-cycle current limiting. Based on the output LED stack voltage, the controller can be used to implement a range of LED driver topologies, including boost, buck-boost (boost to battery), SEPIC, and flyback.

Applications

• Car daytime running lights;

• Automobile front lighting;

• Car tail lights and brake lights.