H21L Datasheet, PDF (7/8 Pages) Fairchild Semiconductor – OPTOLOGIC OPTICAL INTERRUPTER SWITCH

Figure 9. Switching Speed Test Circuit
C2
R2
Pulse
Generator
VO = 5V
f = 10 KHz
d.c. = 50%
5V
R1
.1 uf
bypass
C1
GND
R1 = 300Ω
R2 = 180Ω
C1 = 15pF
C2 = 20pF
C1 and C2 include probe and
stray wire capacitance
Figure 10. Typical Operating Circuit
VCC
RIN
+
V- IN
RL
.1 uf
VO _bypass
GND
Figure 11. Switching Times Definition for Buffer
50%
0 mA
t_PLH
V_OH
Output
V_O
t _PHL
90%
10%
50%
V_OL
t_r
10%
90%
t_f
Figure 12. Switching Times Definitions for Inverters
50%
0 mA
t_PHL
V_OH
Output
V_O
10%
t _PLH
90%
V_OL
t_f
90%
10%
t_r
©2004 Fairchild Semiconductor Corporation
H21L Series Rev. 1.1.0
7
www.fairchildsemi.com