Self-oscillating half-bridge driver targets cars

International Rectifier introduces an automotive-qualified control IC for low-, mid- and high-voltage automotive drive applications. The AUIR2085S suits DC/DC converters, hybrid electric vehicle auxiliary converters and battery management converters.

A self-oscillating half-bridge 100V driver IC with 50 per cent duty cycle, the AUIR2085S features an integrated soft-start capacitor that gradually increases duty cycle from zero to 50 per cent for 5msec to limit in-rush current during start up, and maintains equal pulse widths for the high- and low-side MOSFETs throughout the start-up sequence.

The low- and high-side pulses for the half-bridge are matched to within ±25nsec to prevent transformer imbalances during operation. Other features include ±1A gate drive current optimised for low charge MOSFETs and adjustable deadtime from 50nsec to 200nsec to protect against shoot-through current.

"The AUIR2085S with its smart protection features and small footprint is specifically designed for harsh automotive drive applications, addressing the emerging needs for efficient DC/DC converters and fast switching robust power management solutions in modern cars," said Henning Hauenstein, VP and general manager of IR's automotive products business unit.

The AUIR2085S which is qualified to AEC-Q100 standards provides programmable switching frequency up to 500kHz for design flexibility. Higher switching frequency decreases output voltage ripple and allows use of smaller, lower loss magnetic components. Switching frequency and deadtime can be controlled independently with just two external components to customise circuits for a particular application. The device also features a floating channel designed for bootstrap operation up to +100Vdc and Vcc supply, under-voltage lockout and adjustable over-current protection.

Offered in an 8-pin SOIC package, pricing for the AUIR2085S begins at Rs.83.13 ($1.71) each in 100,000-unit quantities. Production orders are available immediately. The device is qualified according to AEC-Q100 standards, features an environmentally friendly, lead-free and RoHS compliant bill of materials, and is part of IR's automotive quality initiative targeting zero defects.

For application notes and technical articles on half-bridge drivers, visit Embedded Design India.