Boost controller for automotive LED strings
The BD18353MUF-ME2 is a DC DC controller configured as a step-up (boost) LED driver, designed to drive external N-channel MOSFETs for high-current LED strings in automotive lighting systems. PWM dimming input allows brightness control directly from the body controller or a local MCU PWM timer, without an external DAC.
Switching frequency and inductor selection
The oscillator runs from 200 kHz to 2.5 MHz, letting the designer trade inductor size against switching losses — a 400 kHz design uses a larger inductor but keeps FET gate-drive losses low; 2 MHz shrinks the magnetics but demands a faster external MOSFET and careful layout. Because the controller lacks an integrated switch, the external FET and inductor are sized to the actual LED current, not limited by a die-attach bond wire.
Temperature grade and automotive qualification
The VQFN20QV3535 package includes a wettable flank for automated optical inspection (AOI) of solder joints, a requirement for zero-defect automotive assembly lines. ROHS3 compliant per — no exemptions for lead or phthalates, which simplifies compliance declarations for Tier-1 automotive suppliers.