Step-down controller, not a regulator — external FET required
The MAX1649CSA+ is a current-mode PWM buck controller from Analog Devices, not a complete regulator — it drives an external transistor switch to step down a DC voltage. Function is Step-Down, topology Buck, output type Transistor Driver, with no synchronous rectifier. Supply voltage (Vcc/Vdd) spans 3 V to 16 V, switching frequency runs up to 300 kHz, and max duty cycle hits 96.5% — useful for high step-down ratios where the on-time dominates the switching period.
Active, RoHS3, commercial temp — deployment check
The SOIC-8 footprint is standard and widely second-sourced across the industry.
Control features and output configuration
Single positive output with Enable control — the Enable pin allows the controller to be gated by an external signal, useful for power sequencing or shutdown in battery-powered gear. No clock sync capability; the switching frequency is set by an external RC and runs up to 300 kHz. One output phase, output configuration Positive.