Features
±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
AEC-Q100 Qualified for Automotive Applications
The LT3932, featuring the Silent Switcher® architecture to minimize EMI/EMC emissions, utilizes fixed-frequency, peak current control and provides PWM dimming for a string of LEDs. The LED current is programmed by an analog voltage or the duty cycle of pulses at the CTRL pin. An output voltage limit can be set with a resistor divider to the FB pin.
The switching frequency is programmable from 200kHz to 2MHz by an external resistor at the RT pin or by an external clock at the SYNC/SPRD pin. With the optional spread spectrum frequency modulation enabled, the frequency varies from 100% to 125% to reduce EMI. The LT3932 also includes a driver for an external, high side PMOS for PWM dimming and an internal PWM signal generator for analog control of PWM dimming when an external signal is not available. The LT3932-1 permits higher dimming ratios.
Additional features include an LED current monitor, an accurate EN/UVLO pin threshold, open-drain fault reporting for open-circuit and short-circuit load conditions, and thermal shutdown.
APPLICATIONS
Automotive Lighting
Industrial and General Purpose Lighting
Machine Vision Systems
