
International Rectifier
Description
The IR2085S is a self-oscillating half-bridge driver IC with 50% duty cycle ideally suited for 36V – 75V half bridge DC-bus converters.
This product is also suitable for push-pull converters without restriction on input voltage.
Each channel frequency is equal to fOSC, which can be set by selecting RT & CT, where fOSC = 1/(2*RT.CT).
Dead-time can be controlled through proper selection of CT and can range from 50ns to 200ns. Internal soft-start increases the pulse width during power up and maintains pulse width matching for the high and low outputs throughout the start up cycle. The IR2085S initiates a soft start at power up and after every overcurrent condition. Undervoltage lockout prevents operation if VCC is less than 7.5V.
FEATUREs
• Simple primary side control solution to enable half-bridge DC-Bus
Converters for 48V distributed systems with reduced component
count and board space
• Integrated 50% duty cycle oscillator & half-bridge driver
IC in a single SO-8 package
• Programmable switching frequency with up to 500kHz max per channel
• +/- 1A drive current capability optimized for low charge MOSFETs
• Adjustable dead-time 50ns – 200ns
• Floating channel designed for bootstrap operation up to +100Vdc
• High and low side pulse width matching to +/- 25ns
• Adjustable overcurrent protection
• Undervoltage lockout and internal soft start
• Also available Leadfree