The Intersil ICL7673 is a monolithic CMOS battery backup circuit that offers unique performance advantages over conventional means of switching to a backup supply. The ICL7673 is intended as a low-cost solution for the switching of systems between two power supplies; main and battery backup. The main application is keep-alive-battery power switching for use in volatile CMOS RAM memory systems and real time clocks. In many applications this circuit will represent a low insertion voltage loss between the supplies and load. This circuit features low current consumption, wide operating voltage range, and exceptionally low leakage between inputs. Logic outputs are provided that can be used to indicate which supply is connected and can also be used to increase the power switching capability of the circuit by driving external PNP transistors.


  • Automatically Connects Output to the Greater of Either Input Supply Voltage
  • If Main Power to External Equipment is Lost, Circuit Will Automatically Connect Battery Backup
  • Reconnects Main Power When Restored
  • Logic Indicator Signaling Status of Main Power
  • Low Impedance Connection Switches
  • Low Internal Power Consumption
  • Wide Supply Range: 2.5V to 15V
  • Low Leakage Between Inputs
  • External Transistors May Be Added if Very Large Currents Need to Be Switched
  • Pb-Free Plus Anneal Available (RoHS Compliant)


  • On Board Battery Backup for Real-Time Clocks, Timers, or Volatile RAMs
  • Over/Under Voltage Detector
  • Peak Voltage Detector
  • Other Uses: Portable Instruments, Portable Telephones, Line Operated Equipment


Title language Type Format File Size Date
star ICL7673 Datasheet Datasheet PDF 420 KB
AN1681: Grounding Techniques Application Note PDF 509 KB
AN1684: Nonideality of Ground Application Note PDF 397 KB
PIN19028 - Q3 Cy 19 Price Increase Notice Price Increase Notice PDF 208 KB
PCN12085 - 8l, 14l, 16l SOIC w/ Gold Bond Wire @ ATP as Alternate Assembly Site Product Change Notice PDF 152 KB
PCN12086 - Alternate Manufacturing Site for Assembly of the Listed Intersil PDIP Packaged Products -Amkor Technology, Philippines (ATP) Product Change Notice PDF 86 KB
Five Easy Steps to Create a Multi-Load Power Solution White Paper PDF 846 KB