Automotive-grade LED driver with wide input range
The Maxim Integrated MAX16838ATP+ is a 2-channel DC-DC regulator LED driver designed for automotive and backlight applications. It integrates internal switches and supports SEPIC, step-down (buck), and step-up (boost) topologies, giving the board designer flexibility to drive LED strings from a 4.55V to 40V supply rail. Each channel delivers up to 150 mA, and dimming is controlled via PWM. The part is rated for junction temperatures from -40°C to 125°C, which aligns with AEC-Q100 Grade 1 qualification for under-hood and cabin electronics.
Switching frequency and topology selection
The switching frequency is programmable from 200 kHz to 2 MHz, allowing the designer to trade off inductor size against efficiency and EMI. The SEPIC topology is particularly useful when the input voltage can be above or below the LED forward voltage — common in automotive cold-crank and load-dump scenarios. The buck and boost modes cover the more straightforward step-down or step-up cases.
Package and thermal considerations
Housed in a 20-WFQFN with exposed pad (20-TQFN, 4x4 mm), the MAX16838ATP+ requires a thermal via array under the pad to keep the junction within the -40°C to 125°C range at full load. The exposed pad is the primary heat path — without proper soldering to a copper plane, the 150 mA per channel output may be thermally limited. Surface-mount assembly per standard QFN guidelines applies.
Lifecycle and sourcing
The part is ROHS3 compliant.