MC14489B 查看數據表（PDF） - Motorola => Freescale

零件编号

产品描述 (功能)

生产厂家

MC14489B

Multy-Character LED Display/Lamp Driver

Motorola => Freescale 

Table 2. Register Access for Two or More Cascaded Devices

Configuration Register Access

Display Register Access

Criteria*

Total Number of Bytes

Number of Leading

“Don’t Care” Bytes

Total Number of Bytes

Number of Leading

“Don’t Care” Bytes

If 3N is a Multiple of 4

3N

2

3N + 2

2

If 3N – 1 is a Multiple of 4

3N – 1

1

3N + 1

1

If 3N – 2 is a Multiple of 4

3N – 2

0

3N

0

If 3N – 3 is a Multiple of 4

3N – 2

0

3N

0

* N = number of devices that are cascaded. For example, to drive 10 digits, 2 devices are cascaded; therefore, N = 2. To drive 35 digits, seven

devices are cascaded; therefore N = 7.

+5V

CMOS

MCU/MPU

LED DISPLAY

8

5

VDD

Rx

MC14489B

VSS

+5V

R1

R2

NOTE: R1 limits the maximum current to avoid damaging the display and/or the MC14489B

due to overheating. See the Thermal Considerations section. An 1/8 watt resistor

may be used for R1. R2 is a 1 kΩ or 5 kΩ potentiometer (≥ 1/8 watt). R2 may be a

light–sensitive resistor.

Figure 15. Common–Cathode LED Display with Dial–Adjusted Brightness

MC14489B

16

MOTOROLA

Share Link: