What is the MAX16990ATCD/VY+T?
The MAX16990ATCD/VY+T is a current-mode PWM controller from Analog Devices designed for boost and SEPIC topologies in automotive systems. It is part of the Automotive, AEC-Q100 series, qualified for under-hood and cabin electronics where reliability over -40°C to +125°C junction temperature is required. The controller drives a single external N-channel MOSFET with a maximum duty cycle of 93%, switching from 220kHz up to 1MHz. Supply voltage range of 4.5V to 36V covers cold-crank and load-dump conditions common in 12V and 24V vehicle electrical systems.
Key features for the BOM decision
Clock sync input allows the switching frequency to be locked to an external clock, useful for avoiding beat frequencies in multi-rail power stages or sensitive RF sections. Control features include current limit, enable, frequency control, and power good. No synchronous rectifier means the controller uses an external diode — simpler but slightly lower efficiency than a sync-rectified design. The 12-TQFN-SW (3x3) package with wettable flank supports automated optical inspection (AOI) in production, a plus for automotive assembly lines.
Where it fits in the system
Typical applications include automotive LED lighting, infotainment supply rails, and sensor bias generators where a boosted or SEPIC-regulated voltage is needed from a battery bus. The 4.5V minimum supply lets it operate through engine start dips. The 125°C junction rating is sufficient for under-hood placement, though thermal pad layout and PCB copper area must be sized for the dissipation — the exposed pad is the primary heat path.