TC7107ACKW Ver la hoja de datos (PDF) - Microchip Technology

Número de pieza

componentes Descripción

Fabricante

TC7107ACKW

3-1/2 Digit Analog-to-Digital Converters

Microchip Technology 

In addition to limiting maximum power dissipation, the

resistor reduces the change in power dissipation as the

display changes. This effect is caused by the fact that,

as fewer segments are “ON,” each “ON” output drops

more voltage and current. For the best case of six

segments (a “111” display) to worst-case (a “1888”

display), the resistor will change about 230 mW, while

a circuit without the resistor will change about 470 mW.

Therefore, the resistor will reduce the effect of display

dissipation on reference voltage drift by about 50%.

The change in LED brightness caused by the resistor is

almost unnoticeable as more segments turn off. If

display brightness remaining steady is very important

to the designer, a diode may be used instead of the

resistor.

+5V

IN

-5V

+

–

24 kΩ

1 MΩ

150Ω

TP3

1 kΩ

100 pF

TP5

TP2

0.1

100

µF

kΩ

TP1

0.47

0.01

µF

µF 0.22

µF

47

kΩ

Display

40

30

TP

21

4

TC7107A

1

10

20

5.1Ω 1/4W

1N4001

Display

FIGURE 9-4:

Diode or Resistor Limits

Package Power Dissipation.

TC7106/A/TC7107/A

© 2008 Microchip Technology Inc.

DS21455D-page 19

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