MAX8546EUB+

The MAX8546EUB+ is a voltage-mode pulse-width-modulated (PWM) step-down DC-DC controller designed for cost-sensitive applications. It operates with an input voltage range of 2.7V to 28V and can supply output voltages as low as 0.8V. This controller drives low-cost n-channel MOSFETs and does not require an external current-sense resistor, simplifying the design and reducing component count.

Key features include lossless overcurrent and short-circuit protection by monitoring the Rds(on) of the low-side MOSFET, with a current-limit threshold of 165mV for the MAX8546. It also offers foldback-current capability to minimize power dissipation under short-circuit conditions. The device operates at a switching frequency of 300kHz and is compatible with low-cost aluminum electrolytic capacitors. Input undervoltage lockout and internal soft-start are included to prevent overheating and reduce inrush current, respectively.

The MAX8546EUB+ is housed in a space-saving 10-pin µMAX package, suitable for surface mount applications. Its design supports an all n-channel MOSFET configuration and adaptive gate drivers to eliminate shoot-through. This controller is pin-compatible with the MAX1967, offering a potential upgrade path for existing designs.