5

circuit 2) having a greater load resistance (5 k

Ω).

Input

monitor

Vo

Ω

51

Ω

PS2601

Test Circuit 2

Graph 2

Up

: Input

0.2 V/DIV

DOWN : Output

2 V/DIV

(50

µs/DIV)

As shown in Graph 2, the turn-off time for load resistance of 5 k

Ω is about 100 µs. Similarly, the turn-off time for load resistance

of 100 k

Ω is 1 to 2 ms. This is also true when the load resistance is connected to the collector of the phototransistor.

having collector load resistance (5 k

Ω) with the emitter grounded.

Input

monitor

Vo

Ω

51

Ω

PS2601

Test Circuit 3

Input

monitor

Vo

Graph 3

Up

: Input

0.2 V/DIV

DOWN : Output

2 V/DIV

(50

µs/DIV)

Input

monitor

Vo