Seiko Instruments LTP F Series - Manual (Page 48)

3-30
Table 3-14 Paper Detector Input/Output Conditions
Item Symbol Conditions Min. Std. Max.
Forward voltage V
F
I
F
=10 mA 1.0 V 1.2 V 1.6 V LED (input)
Reverse current I
R
V
R
=5 V   10 µA
Photo-
transistor
(output) Dark current I
CEO
I
F
=0 mA, V
CE
=10 V   200 nA
Photoelectric current I
C
I
F
=10 mA, V
CE
=5 V 150 µA  600 µA
Leak current I
LEAK
I
F
=10 mA, V
CE
=5 V   1 µA
Collector saturation
voltage V
CE
(sat) I
F
=10 mA, I
C
=5 µA   0.5V
Response time
(at rise) tr  5 µs 
Transfer
characteristics
Response time
(at fall) tf
I
C
=1mA, V
CC
=5 V
R
L=
100 Ω  5 µs 
3.7.2 Sample External Circuit
∗
The PS signal is high when there is no paper.
Figure 3-15 Sample External Circuit of the Paper Detector
PS
VPS
GND
Photo-interrrupter
To CPU port
V
dd
(5 V) V
dd
(5 V)
47 k Ω 220 Ω
GND
LTP F Series
74HC04
0.1 µF