Adaptive-Dead-Time circuitry maximises MOSFET power efficiency

8th January 2014

Micrel, Inc.

Nat Bowers

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Datasheet

Featuring Adaptive-Dead-Time and Shoot-Through protection, the MIC4605 is an 85V Half Bridge MOSFET driver from Micrel. By actively monitoring the Half Bridge, the Adaptive-Dead-Time circuitry can minimise the time between high and low side MOSFET transitions to increase the power efficiency, while the Anti-Shoot-Through circuitry prevents erroneous inputs and noise from turning both MOSFETs on at the same time.

Offering an operating supply range of 5.5-16V, the MIC4605 enables longer run times in the industry's most demanding battery powered motor applications including power tools and power DC/AC inverters. Operating over a temperature range from -40 to +125°C, the MOSFET driver features fast 30ns propagation delay times and 35ns driver rise/fall times for a 1nF capacitive load. It is currently offered in two variants: the MIC4605 -1 has TTL inputs to provide independent control of the low-side and high-side gate drivers; and the MIC4605-2 has a single PWM input for both low-side and high-side gate drivers.

By only allowing only one MOSFET to be active at a time, the Adaptive-Dead-Time circuitry ensures that no cross conduction condition can permanently destroy the Half Bride circuit. Additionally, this circuitry eliminates the need to design in dead-time margin and time delay between HI and LI inputs to protect against cross conduction reducing the headroom requirements of the microcontroller

Brian Hedayati, Vice President of Marketing, high-performance Linear and Power Solutions, Micrel, comments: "The demand for higher efficiency is increasing via new government regulations. Since electrical motors are one of the largest consumers of electrical power, motor driver designers are in need of a more efficient and reliable solution. The MIC4605 is one of the industry's most robust and power efficient Half Bridge MOSFET drivers designed to address a wide variety of applications including motor drives, UPS and DC/AC inverters."

Supplied in an 8-pin SOIC package or a 10-pin 2.5x2.5mm TDFN package, the MIC4605 is available in volume production now with prices starting from $0.55 (USD) in 1,00 unit quantities.