The LT3932EUFDPBF , featuring the Silent Switcher®architectureto minimize EMI/EMC emissions, utilizes fixed-frequency,peak current control and provides PWM dimming for astring of LEDs. The LED current is programmed by an analogvoltage or the duty cycle of pulses at the CTRL pin. Anoutput voltage limit can be set with a resistor divider tothe 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 signal isnot available. The LT3932-1 permits higher dimming ratios.
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.
Feature
- ±1.5% LED Current Regulation
- ±1.2% Output Voltage Regulation
- 5000:1/10000+:1 PWM Dimming at 100Hz (LT3932/LT3932-1)
- 128:1 Internal PWM Dimming
- Spread-Spectrum Frequency Modulation
- Silent Switcher® Architecture for Low EMI
- 3.6V to 36V Input Voltage Range
- 0V to 36V LED String Voltage
- 200kHz to 2MHz with SYNC Function
- 99.9% Maximum Duty Cycle
- 20:1 Analog or Duty Cycle LED Current Control
- Open/Short LED Protection and Fault Indication
- Accurate LED Current Sense with Monitor Output
- Programmable UVLO
- Thermally Enhanced 28-Pin (4mm × 5mm) QFN
Applications
- Automotive Lighting
- Industrial and General Purpose Lighting
- Machine Vision Systems
