<p>An OLED (organic light-emitting diode) passive-matrix display (26) includes a display portion (10) and a driver portion (28). The display portion (10) includes a matrix of OLEDs (13) for displaying information. The driver portion (28) includes a monitor circuit (32) and a voltage adjusting circuit (34). The voltage adjusting circuit (34) has a power-up portion (36) that generates a supply voltage (VH) based on a reference voltage (VREF). In response to an indication to switch modes, the voltage adjusting circuit (34) switches to an operational mode wherein the supply voltage (VH) is generated based on the maximum voltage drop read across the OLEDs (13).</p>
