NCP1117-3V3 - RG2

The NCP1117-3V3 is a 3.3 V regulator marked as RG2 on the revision 2 Raspberry Pi computer board. This 1-ampere low-dropout voltage regulator establishes a 3.3 V rail for all the electronic circuitry on the board. It is the primary voltage regulator, which feeds RG1 and RG3. It has an absolute maximum input rating of 20 V, and the junction temperature can go as high as +125 °C. It has current limiting and thermal shutdown features to protect it against short circuits.

NCP1117-3V3 Pinout

The Raspberry Pi implementation of this regulator is in the DPAK case 369C, where pin 1 is ground, pin 2 is output, and pin 3 input. Therefore, when troubleshooting, expect 3.3 V at the output pin 2. The input pin 3 will have the same voltage that the adapter feeds.

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