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參數(shù)資料
| 型號： | PS2622 |
| 廠商： | NEC Corp. |
| 英文描述： | Optocoupler Applications |
| 中文描述： | 光耦應(yīng)用 |
| 文件頁數(shù)： | 25/38頁 |
| 文件大?。?/td> | 223K |
| 代理商： | PS2622 |
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24
C
C
Time (Hr)
Time (Hr)
Figure 6.
Figure 5.
CTR vs. T
A
Characteristics (T
A
: Ambient Temperature)
The CTR-Temperature characteristic is greatly affected by the total characteristics of light-emission efficiency of the LED and h
FE
of the phototransistor as the light-emission efficiency has a negative temperature coefficient and h
FE
has a positive temperature
coefficient. See Figure 7.
L
e
h
F
C
T
A
Figure 7. CTR vs. T
A
Characteristics
T
A
T
A
Current Transfer Ratio (CTR)
The current transfer ratio (CTR) of an optocoupler is the ratio of the value of output current I
C
to the value of input forward current
I
F
(I
C
/I
F
x 100%). The CTR is a parameter equivalent to the D.C. current amplification factor h
FE
of a transistor.
The CTR is one of the most significant characteristics of optocouplers, as well as isolation voltage. In circuit designing, CTR must
be considered first of all because the CTR:
1 varies as time goes by,
2 is affected by ambient temperature, and
3 is dependent upon forward current I
F
flowing through the LED.
Both PS2505 and PS2506 optocouplers (bidirectional input type) have two current transfer ratios (CTRs) because they have two
LEDs in the input. For further information, refer to Applications of Optocouplers for A.C. input.
Change of CTR over time
The current transfer ratio (CTR) of an optocoupler is determined by the light-emission efficiency of the LED (emitting infrared
light), efficiency of light transmission between the LED and the phototransistor, light sensitivity of the phototransistor, and h
FE
of
the transistor.
The change of a CTR over time is mainly caused by reduction of the light-emission efficiency of the LED. Generally, the CTR is
reduced to a greater extent as the forward current I
F
increases or as the operating temperature increases. Figure 5 and 6
respectively show estimated changes of CTRs of PS2501 and PS2505 optocouplers over time.
Estimated change of CTRs with time lapse (Standard values)
CHARACTERISTICS OF PS2501 AND PS2505 OPTOCOUPLERS
Standard value
Continuous supply of 20 mA (I
F
)
T
A
= 60
C T
A
= 25
C
1.2
1.0
0.8
0.6
0.4
0.2
0
10
10
10
10
10
2
3
4
5
6
1.2
1.0
0.8
0.6
0.4
0.2
0
10
10
10
10
2
3
4
5
Standard characteristics
I
F
= 5 mA
T
A
= 60
C
I
F
= 20 mA
T
A
= 25
C
I
F
= 5 mA
T
A
= 25
C
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PDF描述 |
|---|---|
| PS2622L | Optocoupler Applications |
| PS2653 | Optocoupler Applications |
| PS2653L2 | Optocoupler Applications |
| PS2654L2 | Optocoupler Applications |
| PS2625 | HIGH ISOLATION VOLTAGE AC INPUT LARGE FORWARD AC INPUT TYPE 6 PIN PHOTOCOUPLER |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| PS2622L | 制造商:NEC 制造商全稱:NEC 功能描述:Optocoupler Applications |
| PS2625 | 制造商:NEC 制造商全稱:NEC 功能描述:Optocoupler Applications |
| PS2625L | 制造商:NEC 制造商全稱:NEC 功能描述:Optocoupler Applications |
| PS2626 | 制造商:California Eastern Laboratories (CEL) 功能描述:6pin DIP,Single Tr, AC, High Input, Coupler 制造商:Renesas Electronics 功能描述:Optocoupl AC-IN 1-CH Trans DC-OUT 6-Pin PDIP Cut Tape |
| PS2626L | 制造商:NEC 制造商全稱:NEC 功能描述:Optocoupler Applications |
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