Re: [EE] looking for negative 5V regulator or circuit
Isaac Marino Bavaresco <[email protected]>
| Newsgroups | gmane.comp.hardware.microcontrollers.pic |
|---|---|
| Message-ID | <[email protected]> |
The TL431 is a shunt regulator, so it will keep the voltage regulated against a pull-down resistor (in the case of a negative voltage output). This pull-down resistor must have low enough resistance so it can sink the maximum current that the circuit can consume and still keep the correct voltage drop ( 12 V - 5 V = 7 V ). In short, your circuit will always consume this maximum current all the time. When the circuit consumes less, the TL431 will increase its consumption so the voltage drop keeps the same. One possible solution would be using a larger pull-down resistor and a PNP emitter-follower after the TL431. Cheers, Isaac Em 11/06/2025 13:40, Jason White escreveu: > see [1] for how you might do it with a low current version of the tl431 > > [1] > https://electronics.stackexchange.com/questions/723624/can-a-tl431-be-configured-to-output-a-negative-reference-voltage -- O software antivírus Avast realizou uma checagem de vírus neste e-mail. www.avast.com -- http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at https://mailman.mit.edu/mailman/listinfo/piclist