128-key keyboard scanning circuit

Programmable Package SG-8018CA(SG7050C) 0.67M~170M

Photocoupler

Keyboard scanning circuit

In the above example, the keyboard is small, with only 0-9 keys. If the keyboard is large in size, it would be uneconomical to implement the encoding with a combination of components such as a priority encoder. For this purpose, a keyboard scanning circuit has been designed. Figure 4-6-2 shows a 128-key scan encoder.