G78xxHE - DC-DC converter module in a TO-220 footprint

Project Status: 
work in progress

G78 AP5100 Linear regulators from the 7800 series are often the choice for electronics hobbyists because of their ease of use, versatility, robustness and availability. G78xxHE is a very small DC-DC converter aimed to be a "drop in" replacement for the 7800 series regulators in TO-220 package. Thanks to its high efficiency the G78xxHE does not need to be connected to an heatsink even when delivering the maximum rated 7800 series current (1A) with large Vin-Vout deltas.

The 7800 series regulators allow input voltages as high as 35V (40V for 7820 and 7824). Designing a switching regulator that operates at optimal efficiency with such a wide Vin is not possible given the size and cost constraints.
Our approach was to segment the problem and develop different designs for different input voltage requirements and efficiency expectations.

Ver Regulator Fs Vin Vout Avg Eff Status
A Diodes Inc. AP5100 1.4MHz 4.75-24 0.81-15 86% Preliminary
B ST Microelectronics L5973 500KHz 4-36 1.2-35 83% Preliminary
C ON Semiconductor NCP3125 350KHz 4.5-13.2 0.8-6   Concept
D MPS MP2403/MP2307         Concept

G78 AP5100 top G7 AP5100 bottom G78 AP5100


G78xxHE-A00 Features

  • Based on Diodes Inc. AP5100
  • 1.4MHz switching frequency
  • Vin range: 4.75-24V
  • Vout range: 0.81-15V
  • Iout: 1.2A

AP5100 output voltage ripple

Design Files
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