Seiko Instruments LTP F Series 用户手册

Table 3-14  Paper Detector Input/Output Conditions

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



∗

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

74HC04

0.1 

µF