The Microcontroller Idea Book - Jan Axelson's Lakeview Research

Chapter 8
Figure 8-6. A 4543B driver can control a 7-segment LCD. A 555 timer
controls the drive voltage.
As in Figure 8-4, you control the display by writing to inputs A-D. If the display contains
other types of segments, such as ± or a leading 1, you can control these as well. For example,
for a leading 1, connect digit 1’s two segments to pins 10 and 11 on the 4543. When you
write 1 to the data inputs, the appropriate segments will light.
Multi-digit driver. As with the LEDs, there are driver chips for multi-digit LCD modules.
Figure 8-7 shows Telcom Semiconductor’s (formerly Teldyne) TC7211A, which will drive
four 7-segment LCDs, and includes an on-chip oscillator and backplane driver.
To display a number using Figure 8-7’s circuit, follow these steps:
136 The Microcontroller Idea Book