Automotive High-Side Dimming Rear Light
Created: Feb 24, 2016
No description available.
The car lights are significant parts of a car system. The reference design is an automotive high-side dimming rear light. The board is composed of the main component TPS1H100-Q1, high-side power switch with an integrated NMOS power field-effect transistor (FET) and charge pump. The TPS92630-Q1 and TPS92638-Q1, is a three-channel linear and eight-channel linear LED driver, respectively. The reference design also comes with a TPS7B6950, which is a high voltage LDO regulator. The TLC555-Q1 is timer that generates the PWM input for the high-side driver. This reference design uses a body control module (BCM) to supply the rear light system.
The circuit starts to operate when the TLC555-Q1 generates the desired PWM for the TPS1H100-Q1 high-side driver. The TPS1H100-Q1 then sends signal to TPS7B6950 and TPS92638-Q1, which drives the string of LEDs. Each LED string has a 100mA available current but only 40mA is being consumed by each string when a stoplight is implemented and 8mA/string at taillight. The system incorporates a switch, which can allow the TPS1H100-Q1 to provide a 20% duty cycle with a frequency of 200Hz PWM supply and a 100% duty cycle supply. The 20% duty cycle output can be utilized, as taillight and a 100% duty cycle can be a full stop sign. The reference design also has the function of one-fail-all-fail function that shuts down both TPS92638-Q1 and TPS7B6950 when a short or open fault is detected in the LEDs string. The TPS1H100-Q1 has an internally high current sense function, which is utilized for more efficient real-time monitoring for output current and more accurate diagnostics without requiring further calibration. It also implements a current limit function that protects the power supply during short circuit or power up.
The TPS1H100-Q1 also passes the short-to-ground test, which is performed 1 million times according to AEC-Q100 or also known as the Automotive Electronics Council. The TPS1H100-Q1 can function in different applications such as a high-side power switch for sub-module, low-wattage lamp power switch, PLC digital output power switch, or a High-Side Relay/Solenoids.