On July 22, 2014, Micrel Korea (CEO Young-June Oh, www.micrel.com), a leading industry provider of high-performance linear and power solutions as well as LAN, timing and communications solutions, announced the MIC4605, an 85V half bridge MOSFET driver with adaptive dead-time and shoot-through protection. The adaptive dead-time circuit actively monitors the half bridge to minimize the transition time of high and low-side MOSFETs, maximizing power efficiency. The shoot-through prevention circuit prevents false inputs and noise that occur when two MOSFETs are switched simultaneously. Additionally, the MIC4605 provides a wide supply voltage range from 5.5V to 16V to maximize system efficiency. The low operating voltage of 5.5V can extend runtime in battery-based applications. With these features, the MIC4605 is well-suited for the most demanding battery-powered motor applications in industrial fields such as power tools and power DC/AC inverters.

Brian Hedayati, Vice President of Marketing for Micrel's High-Performance Linear and Power Solutions division, stated, "The demand for higher efficiency is increasingly driven by new government regulations, and electric motors are among the products that consume the most electrical power, requiring motor designers to implement more efficient and reliable solutions." He added, "The MIC4605 is one of the most robust and power-efficient half bridge MOSFET drivers in the industry, designed to enable various applications including motor drives, UPS, and DC/AC inverters."

The adaptive dead-time circuit actively monitors MOSFETs in a half bridge switch circuit and ensures only one MOSFET is enabled at a time, preventing the cross-conduction condition that permanently damages the half bridge circuit. Additionally, the adaptive dead-time circuit processes at a short duration to minimize power loss because power efficiency degrades when the dead-time is long during the transition between high-side and low-side MOSFETs. This adaptive dead-time circuit eliminates the need to design delay time or dead-time margin between HI and LI inputs to protect against cross-conduction, and reduces microcontroller headroom requirements. The 85V operating voltage also provides significant margin by protecting against voltage spikes that appear in motor drive and power supply applications. Due to these characteristics, the MIC4605 is an ideal solution for both low-voltage and high-voltage applications.

The MIC4605 features a fast propagation delay of 30ns and driver rise/fall time of 35ns at a 1nF capacitive load. For the MIC4605-1, TTL inputs enable independent control of low-side and high-side gate drivers. The MIC4605-2 features a single PWM input for low-side and high-side gate drivers. The outputs do not overlap in any mode. An internal high-voltage Schottky diode charges the high-side gate-drive bootstrap (external) capacitor. The MIC4605 is available in an 8-pin SOIC package and a thin 10-pin 2.5mm × 2.5mm TDFN package. Both packages have an operating junction temperature range of –40°C to +125°C.