Circuit Enhancement Enables Digital Setting of Voltage Reference (.PDF Download)

Adjustable voltage references offer great flexibility to circuit designers because the reference isn’t limited to the manufacturer’s preset values. The adjustable output is typically configured with a voltage divider from the output to the feedback pin (Fig. 1). To regulate the output, the circuit compares the voltage at the feedback pin to an internal reference (shown in this article as V_{REF_INT}), typically 1.2 V. The device adjusts the output until V_FB<