AN3114 datasheet(8/43 Pages) STMICROELECTRONICS

8 / 43 page

LCD solution

AN3114

8/43

Doc ID 16829 Rev 3

Figure 2.

Equivalent electrical schematic of a segment line

1.3

Selecting an LCD glass

To select the LCD glass best suited for your application among the wide range of products

available on the market, the following criteria must be taken into account:

The information to display on the LCD glass. It is a combination of alphanumeric

symbols and various useful predefined symbols such as digits, bells, low-battery

symbol, arrows, antenna, and progress bar.

The typical electrooptical characteristics required for the LCD to operate: operating

temperature, storage temperature, and operating voltage, which affect the LCD

contrast.

The number of pixels required to achieve the desired display on the LCD.

When the multiplex of the LCD panel increases (quadruplex, octaplex...), the

discrimination ratio and the contrast decrease (please refer to the discrimination ratio

calculation for each backplane LCD). So, to provide a better contrast and a greater

separation between Von(RMS) and Voff(RMS), the LCD voltages must be increased.

1.4

Typical applications

The LCD controller can be used in many embedded applications. They can be classified as

follows:

Home appliances: refrigerator, microwave oven, coffee maker, washing machine,

thermostat, battery management, security system, baby alarm, and clock radio, etc.

Medical: spirometer, glucose meter, pressure meter, temperature reader, nurse call

system, medical pump, and pulse oximeter, etc.

Automotive: dashboard, audio system, tire pressure sensor, battery vehicle display,

iPod adapter, etc.

Industrial: data acquisition, pressure meter, portable instruments, gasoline pumps, air

conditioner, payment systems, gas detection, etc.

COM

ai17082

AN3114 Datasheet(PDF) 8 Page - STMicroelectronics