CT-161-CD Fujitsu Semiconductor America Inc, CT-161-CD Datasheet - Page 46

• Manufacturer Part Number: CT-161-CD
• Description: KIT 16LX FOR MB90F387
• Manufacturer: Fujitsu Semiconductor America Inc
• Series: F²MC-16LXr
• Type: MCUr

Specifications of CT-161-CD

• Contents: Board, Cable, CD
• For Use With/related Products: MB90F387S
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 865-1103

2 “Let's try to turn on the LED!”
LEDs appear everywhere in our everyday lives -- for example, the LEDs indicating the power-on
status of a laptop personal computer, digital camera, washing machine, air conditioner, or rice
cooker, the LEDs display indicating train departure times at a railroad station, and in traffic signals
using LEDs, which have now become widespread. This chapter explains how to control the port
output of the microcomputer to turn on an LED on the board.
2.1
A light-emitting diode (LED) is a semiconductor device that emits light when an electric
current passes through it. The LED is represented by the symbol as shown in Figure 2.1.
An LED has two electrodes: anode and cathode. When a voltage is applied across the LED
so that the anode is at a positive potential with respect to the cathode, a current flows and the
LED emits light. In the circuit shown in Figure 2.1, the LED goes on (emits light) when the
switch (SW) is turned on and goes off when the switch is turned off. The brightness of the
LED is controlled through the adjustment of flowing current by changing the resistance. As
the current becomes larger, the emitted light becomes brighter. An LED can emit light in red,
orange, yellow, green, or blue. Since the three primary colors (blue, green, and red) of light
can be produced by combinations of the five colors, a full-color can be displayed by LEDs.
Compared with an incandescent lamp, the LED has lower power consumption, longer
operating life, and shorter response time.
backlight for liquid-crystal display monitor, traffic signals, tail lamps of cars, and displays.
The board has red of LED3 and green of LEDs1, 2, 4, and 5 as shown in Figure 2.2.
What is an LED?
SW
Figure 2.1
-
40
-
So, the LED is used in lighting equipment,
LED
Cathode
LED
Anode
© Fujitsu