SI9121 Datasheet (Vishay Siliconix) - High-Voltage/ Non-Isolated Buck-Boost Converter for ISDN Digital Phones

SI9121, High-Voltage/ Non-Isolated Buck-Boost Converter for ISDN Digital Phones

The Si9121 simplifies the *48-V to +5-V or +3.3-V converter design for ISDN application by integrating the floating feedback error amplifier providing direct output voltage regulation.

This approach eliminates the need for an external shunt regulator.

The Si9121 also integrates a high voltag

SI9121 Features

* D Fixed +5-V or +3.3-V Output D Integrated Floating Feedback Amplifier D On-Chip 70-V, 1.5-W N-Channel MOSFET Switch D Integrated High Voltage Start-Up Circuit, with VCC Regulator D D D D D

* 10-V to

* 60-V Input Voltage Range 95-kHz PWM Operation Integrated Soft-Start and Oscillator H