In Figure 1, the 5V linear regulator (U1) delivers as much as 150mA of load current when operating by itself. Operating with the external pass transistor shown (Q1), the circuit maintains 5V ...

Low dropout linear regulators are useful where a low-noise power source is needed, and where the regulator must maintain regulation with small differences between the input supply voltage and output ...

[Kevin Darrah] wanted to make a simple 3.3V regulator without using an integrated circuit. He wound up using two common NPN transistors and 4 1K resistors. The circuit isn’t going to beat out a cheap ...

This Design Idea is a two-wire current regulator that strikes a good balance between performance and parts count. Employing three transistors, three resistors, and one LED, it achieves good regulation ...