MIC4605 Half Bridge MOSFET Drivers

The Microchip MIC4605 is an 85 V Half-Bridge MOSFET driver that features Adaptive-Dead-Time and Shoot-Through protection. The Adaptive-Dead-Time circuitry actively monitors the Half Bridge to minimize the time between high- and low-side MOSFET transitions, which maximize power efficiency. Anti-Shoot-Through circuitry prevents erroneous inputs and noise from turning both MOSFETs on at the same time. The MIC4605 also offers a wide 5.5 V to 16 V operating supply range to maximize system efficiency. The low 5.5 V operating voltage allows longer run times in battery-powered applications. These features make the MIC4605 an ideal solution for the industry’s most demanding battery-operated motor applications including power tools and power DC/AC inverters.

The Adaptive-Dead-Time (ADT) circuitry actively monitors the MOSFETs in the Half-Bridge switch circuit allowing only one MOSFET to be active at a time, thus assuring no cross conduction condition that can permanently destroy the Half-Bridge circuit. The ADT circuitry also keeps the transitions between the high and low-side MOSFET as short possible to minimize power losses due to long dead times that degrade the power efficiency. The ADT 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. In addition, the 85 V operating voltage offers plenty of margin as protection against voltage spikes which are present in motor drive and power supply applications. This makes the MIC4605 an ideal solution for low- and high-voltage applications.

The MIC4605 features fast 30 ns propagation delay times and 35 ns driver rise/fall times for a 1 nF capacitive load. For MIC4605-1, TTL inputs provide independent control of the low- and high-side gate drivers. The MIC4605-2 has a single PWM input for both low- and high-side gate drivers. The outputs do not overlap in either 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 tiny 10-pin 2.5 mm × 2.5 mm TDFN package. Both packages have an operating junction temperature range of –40°C to +125°C. 

Features

• Adaptive-Dead-Time circuitry automatically adjusts the dead time between high- and low-side MOSFETs
• Dead time under 20 ns; best in the industry
• 85 V operation protects against voltage spikes caused by the motor's back electromagnetic force (EMF)
• Anti-Shoot-Through protects against cross conduction
• Wide gate-drive range: 5.5 V to 16 V
• Low 4.9 V under-voltage lockout allows longer run time
• 2.5 mm x 2.5 mm TDFN package option
• 8-pin SOIC is also available in an industry-standard pinout