Many engineers assume a 20kHz PWM signal is fine for dimming. However, the LZC8650C’s DIM pin is optimized for 100Hz to 2kHz. Higher frequencies cause incomplete turn-on/off cycles and distorted brightness. The datasheet explicitly states the acceptable range.
In a typical application, the LZC8650C drives an external MOSFET in a flyback topology. The input AC voltage (often 85-300 VAC) is rectified, and the IC manages the switching to maintain a constant current output (e.g., 720mA or 750mA) for the LED string. Critical components like the and high-temperature electrolytic capacitors (e.g., 130°C rated) are commonly paired with this IC for robust industrial or commercial lighting solutions.
The is a high-performance, single-stage LED driver integrated circuit (IC) primarily used in offline AC/DC flyback power converters. It is designed for high-efficiency LED lighting applications, featuring active power factor correction (PFC) and primary-side regulation (PSR), which eliminates the need for secondary feedback components like optocouplers. 🛠️ Key Specifications & Ratings
Supports current compensation based on temperature using an external NTC resistor to protect the LEDs from overheating. Technical Specifications Based on typical datasheet parameters for the 8650 series:
Eliminates secondary feedback circuits, reducing total component count and cost.
: A unique four-stage temperature foldback function that can be programmed via a single external resistor to reduce current as temperature rises .