DESCRIPTION
Si9122 is a dedicated half-bridge IC ideally suited to fixed telecom applications where efficiency is required at low output voltages (e.g. < 3.3 V). Designed to operate within the fixed telecom voltage range of 33 to 72 V, the IC is capable of controlling and driving both the low and high-side switching devices of a half bridge circuit and also controlling the switching devices on the secondary side of the bridge.

FEATURES
• 12 V to 72 V input voltage range
• Integrated half-bridge primary drivers (1 A drive capability)
• Secondary synchronous signals with programmable deadtime delay
• Voltage mode control
• Voltage feedforward compensation
• High voltage pre-regulator operates during start-up
• Current sensing on low-side primary device
• Frequency foldback eliminates constant current tail
• Advanced maximum current control during start-up and shorted load
• Low input voltage detection
• Programmable soft-start function
• Over temperature protections

APPLICATIONS
• Network cards
• Power supply modules