Analog Devices LT3932

Description

The LT®3932 is a monolithic, synchronous, step-downDC/DC converter that utilizes fixed-frequency, peak currentcontrol and provides PWM dimming for a string of LEDs.The LED current is programmed by an analog voltage orthe duty cycle of pulses at the CTRL pin. An output voltagelimit can be set with a resistor divider to the FB pin.The switching frequency is programmable from 200kHz to2MHz by an external resistor at the RT pin or by an externalclock at the SYNC/SPRD pin. With the optional spreadspectrum frequency modulation enabled, the frequencyvaries from 100% to 125% to reduce EMI. The LT3932also includes a driver for an external, high side PMOS forPWM dimming and an internal PWM signal generator foranalog control of PWM dimming when an external signalis not available.Additional features include an LED current monitor, anaccurate EN/UVLO pin threshold, open-drain fault reportingfor open-circuit and short-circuit load conditions, andthermal shutdown.

Features

nn ±1.5% LED Current Regulationnn ±1.2% Output Voltage Regulationnn 5000:1 PWM Dimming at 100Hznn 128:1 Internal PWM Dimmingnn Spread-Spectrum Frequency Modulationnn Silent Switcher® Architecture for Low EMInn 3.6V to 36V Input Voltage Rangenn 0V to 36V LED String Voltagenn 2A, 36V Internal Switchesnn 200kHz to 2MHz with SYNC Functionnn 99.9% Maximum Duty Cyclenn Analog or Duty Cycle LED Current Controlnn Open/Short LED Protection and Fault Indicationnn Accurate LED Current Sense with Monitor Outputnn Programmable UVLOnn Thermally Enhanced 28-Pin (4mm × 5mm) QFN

Typical applications

• Automotive Lighting
• Industrial and General Purpose Lighting

More information

• Datasheet
• IC product information