EC4304B – PWM Control 1.2A Step-Down Converter

General description

The EC4304B is a continuous mode inductive step-down converter, designed for driving

single or multiple series connected LEDs efficiently from a voltage source higher than

the LED voltage. The device operates from an input supply between 7V and 36V and

provides an externally adjustable output current of up to 1.2A. Depending upon supply

voltage and external components, this can provide up to 42 watts of output power. The

EC4304B includes the output switch and a high- side output current sensing circuit, which uses an external resistor to set the nominal average output current. Output current can be adjusted above, or below the set value, by applying an external control signal to the ‘ADJ’ pin. The ADJ pin will accept either a DC voltage or a PWM waveform.Depending upon the    control frequency, this will provide either a continuous or a gated output current.ThePWM filter components are contained within the chip. The EC4304B is available in SOT-23,SOT-89 Lead-free package.


Wide Input Voltage Range: 7V to 36V

LED Output Current Up to 1.2A


Single pin on/off and brightness control using

DC voltage or PWM

High efficiency (up to 97%)

Up to 1MHz switching frequency

Typical 5% output current accuracy

SOT-23, SOT-89 Lead-free Package .


◆LED/Display Back Light Driver


◆Portable Communication Devices

◆Handheld Electronics

Pin Configurations

Ordering info

Typical Applications circuit