The rightmost trimpot has a finger-friendly dial, with the non-staggered pins located at the front of the package. The next trimpot is a multiturn that can be mounted vertically or laid flat. The next trimpot is more compact, but more expensive. The leftmost trimpot is the least expense and doesn’t tend to twist off the board due to the staggered pins. The most common trimpots have 0.1-inch spaced leads, but the leads are attached in slightly different places with respect to the component body. Small potentiometers (often called trimmers or trimpots) are also available in a variety of packages. Universal layout for three-pin linear voltage regulators Choice of Trimmer Potentiometers That covers all 6 permutations (3 factorial = 3! = 6) of pins.Īnd, if you make sure all of the holes are 0.040 inch diameter, then you have covered both TO-220 and TO-92 packages. +UN, +5, GND (installed backwards in bottom three holes).+5, GND, +UN (installed backwards in middle three holes).GND, +UN, +5 (installed backwards in top three holes).
With a little bit of forethought, you can design your circuit board to accept a variety of regulators.Īdding a fourth and fifth hole (in this case duplicating the input and output pins) permits the following pinouts: Sometime after the board has been made, you may find that the circuit needs a bit more current, a higher input voltage, a lower dropout voltage, or maybe you just ran out of stock of a particular voltage regulator. In the picture below, notice that none of the pinouts match. The order of the leads and the type of package (TO-220 or TO-92) varies from part to part. Regulated voltage output (5V, 3.3V, etc).Linear voltage regulators are popular for their simplicity. To see the examples presented in the article, click on the file and save it.ĭownload Copper Connection, the PCB layout software.