Simple, high performance step-down LED driver solution

The IRS2980S utilized the control and high voltage technologies of International Rectifier Corporation to achieve a simple, high-performance step-down LED driver solution. The solution is based on hysteresis output current regulation and typically operates in the range of 25 kHz to 120 kHz. Frequency and duty cycle vary with line and load to maintain a tightly regulated average output current. The output current ripple will depend on the choice of inductance, as well as input and output voltages and the choice of output current and components.

The unique floating high-side differential current sensing and level shift scheme adopted by the IRS2980S allowed low-side switching mosFets to optimize hysteresis operation for size and cost. In addition, the IRS2980S included a high voltage regulator that could operate up to 450V, eliminating the need for an external VCC power supply. Also included is a PWM dimming interface that can be controlled from 0 to 2V analog or 3.3 or 5V logic control signals, capable of operating up to 1kHz, providing 0 to 100% brightness control. Programmable board PWM oscillator and DC dimming control.

Lead Assignments

Typical connection diagram

Block Diagram

Features

● Dimming LED drive controller

● Hysteresis current regulation

● Closed loop LED current dimming control

● Analog /PWM dimming input

● Internal high pressure regulator

● Internal 15.6V Zener clamp diode on Vcc

● Micro power start (250µA)

● Latch immunity and ESD protection