Why negative voltage on old character LCDs?
-
- Posts: 18
- Joined: Wed Sep 12, 2018 6:17 pm
Why negative voltage on old character LCDs?
Why did the old character LCDs have a negative voltage?
Re: Why negative voltage on old character LCDs?
Older character, segment and monochrome graphic displays required a negative voltage to deal with temperature swings. More power is required to drive a monochrome display as the temperature drops.
Newer character displays have a built in circuit with a charge pump (bump circuit) the increases the output voltage necessary to keep the display active.
Newer character displays have a built in circuit with a charge pump (bump circuit) the increases the output voltage necessary to keep the display active.