Automotive mini buck converter consumes very low quiescent power

September 17, 2013 // By Graham Prophet
Maxim's lowest-quiescent-current automotive buck converter can replace an always-on LDO

MAX16956 is a small, synchronous buck converter with integrated high-side and low-side switches, that Maxim designed to deliver up to 300mA with input voltages from 3.5V to 36V with 42-V tolerance, while using only 1.1 µA quiescent current at no load (fixed-output versions). Voltage quality can be monitored by observing the active-low RESET signal. The device can operate near dropout by running at 97% duty cycle, making it suitable for automotive applications under cold-crank.

The device offers fixed-output voltages of 5V and 3.3V, as well as an adjustable version. The adjustable version allows the user to program the output voltage between 1V and 10V by using a resistor-divider. Frequency is fixed at 2.1 MHz, which allows for small external components, reduced output ripple, and minimised AM radio interference. The device offers both forced-PWM and skip modes of operation, with ultra-low quiescent current of 1.1 µA in skip mode. The device can be supplied with spread-spectrum frequency modulation designed to minimise EMI-radiated emissions due to the switching frequency. MAX16956 is available in a 3 × 3mm 10-pin µMAX package, operates across the full automotive temperature range of -40°C to +125°C and is AEC-Q100 qualified.

Maxim Integrated; www.maximintegrated.com/datasheet/index.mvp/id/8166