28V, 1.2A Automotive Step-Down Converter with Low Operating Current

The MAX16975 is a 1.2A current-mode step-down converter with an integrated high-side switch. The device operates with input voltages from 3.5V to 28V while using only 45µA quiescent current at no load. The switching frequency is adjustable from 220kHz to 1.0MHz by using an external resistor and can be synchronized to an external clock. The device’s output voltage is pin-selectable to a fixed 5V or adjustable from 1V to 10V using external resistors. The wide input voltage range makes the device ideal for automotive and industrial applications.

The device operates in skip mode for reduced current consumption in light-load conditions. An adjustable reset threshold helps keep microcontrollers alive down to the lowest specified input voltage. Protection features include cycle-by-cycle current limit, soft-start, overvoltage, and thermal shutdown with automatic recovery. The device also features a power-good monitor to ease power-supply sequencing.

The device is available in 16-pin QSOP and thermally enhanced QSOP-EP packages. It operates over the -40°C to +125°C automotive temperature range. Applications

* Automotive * Industrial

* Wide 3.5V to 28V Input Voltage Range

* 42V Input Transient Tolerance

* 5V Fixed or 1V to 10V Adjustable Output Voltage

* Integrated 1.2A High-Side Switch

* 220kHz to 1.0MHz Adjustable Switching Frequency

* Frequency Synchronization Input

* Internal Boost Diode

* 45µA Skip-Mode Operating Current

* Less than 10µA Shutdown Current

* Adjustable Power-Good Output Level and Timing

* 3.3V Logic Level to 42V Compatible Enable Input

* Current-Limit, Thermal Shutdown, and Overvoltage Protection

* -40°C to +125°C Automotive Temperature Range