High-Efficiency Switching Regulators with LM78xx Pinouts

Murata Power Solutions
Part Number Information
Part #: Price/Availability:
78 SR-C Buy Now
78 SRH-C Buy Now

Murata Power Solutions’ 7805SR-C (5V output), 7812SR-C (12V output) and 7803SR-C (3.3V output) step-down switching regulators are modern drop-in replacements for older, inefficient, LM7805 and LM7812 linear regulators. The 78XXSR's are pin- and size-compatible with industry-standard TO-220 SIP packages. A 260kHz switching frequency provides for efficiencies as high as 95%. Full-load (up to 0.5A) operation from 9V, 12V, 24V, or 36V supplies at ambient temperatures up to +70°C requires no heat sinks, no temperature derating, no forced-air cooling, and no external capacitors.

78SR switching regulators provide many significant improvements over their linear counterparts: lower quiescent current (3mA vs. 5 mA), higher input voltage (40V vs. 32V), and better output accuracy (±2% vs. ±5%). All these features combine to make 78SR regulators ideal for new or existing LM7805 & LM7812 applications requiring full-load operation at elevated voltages.


  • 3.3V/0.5A, 5V/0.5A or 12V/0.4A outputs; Pin and size-compatible with LM7805 & LM7812 regulators
  • Up to 95% efficiency – no heat sinks or thermal derating required
  • Two SIP-packages fit existing TO-220 footprints:
    • Vertical-pin models occupy less than 0.1 square in.
    • Optional horizontal pins provide 0.350 in. installed height
  • +7.5-36Vdc operating input range; Low 3mA quiescent current
  • Built-in filter capacitors – no external components required
  • –40 to +70°C operation at full load; Short-circuit protection
  • Excellent load (±0.2%) and line (±0.3%) regulation
  • Ideal for powering instrumentation from 9V/12V/24V/28V supplies or batteries
  • Can be used with unregulated dc supplies protection