What this controller is and where it fits
The LTC3783EDHD#PBF from Linear Technology is a DC DC controller designed to drive external N-channel MOSFETs for LED lighting applications. It supports multiple topologies — Flyback, SEPIC, Step-Down (Buck), and Step-Up (Boost) — making it a single-solution fit for a wide range of LED drive architectures, from automotive headlamps to industrial panel lighting. The controller operates from a 3V to 36V supply rail, covering 12V and 24V automotive buses and standard industrial supplies, and delivers a switching frequency adjustable from 20kHz to 1MHz so you can optimize inductor size against efficiency and EMI. With both analog and PWM dimming on board, it handles continuous current adjustment and high-frequency brightness control without an external PWM generator.
Temperature range and environment
Rated for -40°C to 125°C junction temperature. The 16-DFN (5x4) exposed-pad package helps pull heat into the PCB ground plane.
Switching frequency and external component selection
The 20kHz to 1MHz programmable oscillator lets you pick the sweet spot for your inductor and output capacitor. Running at the low end (20kHz) keeps switching losses down and suits high-current boost stages; pushing toward 1MHz shrinks magnetics for space-constrained boards but demands careful layout to keep the switch node from radiating into the LED return path. Because the controller has no internal switch, you select the external MOSFET and sense resistor to match the LED string current — the controller's gate drive is sized for moderate-capacitance FETs; a high-current, high-frequency design may need a gate-driver buffer.
Lifecycle and sourcing posture
The LTC3783EDHD#PBF carries an Active lifecycle status and is ROHS3 compliant. No end-of-life notice or last-time-buy window is in effect, so it remains qualified for new designs and ongoing production BOMs.