What Is the LM7905 (7905)? −5V Negative Regulator: Pinout and Uses
The LM7905 (7905) is a negative linear voltage regulator with a fixed −5 V output (the 79xx family, the negative counterpart of the 7805). It provides the negative rail for op-amp/analog circuits; usually a ±5 V symmetric supply is built with the 7805. ⚠️ Its pinout DIFFERS from the 7805: 1 GND, 2 INPUT, 3 OUTPUT.
The LM7905 (7905) is a negative linear voltage regulator with a fixed −5 V output. It is a member of the 79xx family and the negative counterpart of the positive 7805. For the concept, see what is a voltage regulator.
What is the LM7905 used for?
Providing the negative rail (−5 V) for op-amps and analog circuits; usually with the 7805 to build a ±5 V symmetric supply. It regulates a negative input to a clean −5 V.
LM7905 pinout (TO-220) — DIFFERENT from the 7805!
⚠️ A common mistake: the 79xx pinout differs from the 78xx.
| Pin | Function |
|---|---|
| 1 | GND |
| 2 | INPUT (−Vin) |
| 3 | OUTPUT (−5 V) |
(Compare: 7805 = INPUT / GND / OUTPUT. On the 7905 the order is different!)
Specifications
| Parameter | Value |
|---|---|
| Output | −5 V (fixed) |
| Input | ~−7 V … −35 V |
| Current | ~1 A (with heatsink) |
Equivalents
- LM7912: −12 V in the same family.
- LM337: an adjustable negative regulator.
- 7805: the positive +5 V counterpart.
Find it in our catalog
Use the 7905 search.