SUPPLY VOLTAGE CIRCUIT

Modules require +5V at 1 to 10 milliamps. Extended temperature and some high contrast modules require higher voltage, also at low current. Inexpensive ICs convert +5V to -5V efficiently. If the display has backlighting, required power must also be budgeted. The power supply does not have to "lock-on" +5V but it must not "spike" beyond the module's absolute maximums.

A module's logic circuits have 3 connections to the power supply: VDD (+5VDC); VSS (Ground); and VO (viewing angle adjustment), sometimes called contrast or bias control. The diagrams below show typical connections.

Contrast can also be controlled digitally with a digital potentiometer or DAC.

Circuit