NR891D PDF – Step-down Switching Mode Regulator

What is NR891D?

This is a synchronous chopper regulator IC with built-in power MOSFET. The current control method allows for ultra-low ESR capacitors such as ceramic capacitors. It has protective functions such as overcurrent protection (OCP), undervoltage lockout (UVLO), and thermal shutdown (TSD). It has a soft start function to prevent inrush current at startup. Soft start time can be set by connecting a capacitor.

Function: Separate Excitation Step-down Switching Mode Regulator IC

Package: DIP 8 Pin type

Manufacturer: Sanken

1 page
NR891D image


This is Full-Mold, Separate Excitation Step-down Switching Mode Regulator IC.

A Separate Excitation Step-down Switching Mode Regulator IC is an integrated circuit that regulates the voltage and current of a power supply in a step-down mode using a switching mechanism. The term “separate excitation” refers to the fact that the input voltage and output voltage are isolated from each other. This type of regulator is commonly used in electronic devices that require a stable and efficient power supply, such as computers, consumer electronics, and industrial equipment.


• DIP 8 pin package
• Input voltage range (VIN): VO + 3 to 18 V
• Synchronous rectifier mode
• High efficiency: 90%
• Introduction of current mode control method
• A ceramic capacitor can be used for output
• Built-in phase correction component
• Output current: 2 A
• Reference voltage and accuracy of 0.8 V ± 2%
• Oscillation frequency: 500 kHz
• Output ON/OFF available
• Undervoltage lockout
• Soft start function


• Power supply for LCDTV and PDP
• Power supply for DVD, BD, and STB
• On-board local power supply
• Power supply for switches

2 page

NR891D PDF Datasheet