
Philips Semiconductors
Dual precision monostable multivibrator
Product specification
HEF4538B
MSI
AC CHARACTERISTICS
VSS = 0 V; Tamb = 25 °C; CL = 50 pF; input transition times ≤ 20 ns
VDD
V
SYMBOL MIN. TYP. MAX.
Propagation delays
I0, I1 → O
HIGH to LOW
I0, I1 → O
LOW to HIGH
CD → O
HIGH to LOW
CD → O
LOW to HIGH
Recovery times
CD → I0, I1
Retrigger times
O, O → I0, I1
Minimum I0
pulse width; LOW
Minimum I1
pulse width; HIGH
Minimum CD
pulse width; LOW
Output O or O
pulse width
Output O or O
pulse width
Output O or O
pulse width
5
10
tPHL
15
5
10
tPLH
15
5
10
tPHL
15
5
10
tPLH
15
5
10
tRCD
15
5
10
tRO
15
5
10
tWI0L
15
5
10
tWI1H
15
5
10
tWCDL
15
5
10
tWO
15
5
10
tWO
15
5
10
tWO
15
0
0
0
90
30
24
50
24
20
55
25
20
218
213
211
10,3
10,2
10,1
1,01
0,99
0,99
200
90
60
220
85
60
125
55
40
125
55
40
20
10
5
45
15
12
25
12
10
25
12
10
230
224
223
10,8
10,7
10,6
1,09
1,04
1,04
460 ns
180 ns
120 ns
440 ns
190 ns
120 ns
250 ns
110 ns
80 ns
250 ns
110 ns
80 ns
40 ns
20 ns
10 ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
242 µs
235 µs
234 µs
11,3 ms
11,2 ms
11,1 ms
1,11 s
1,09 s
1,09 s
TYPICAL EXTRAPOLATION
FORMULA
173 ns + (0,55 ns/pF) CL
79 ns + (0,23 ns/pF) CL
52 ns + (0,16 ns/pF) CL
193 ns + (0,55 ns/pF) CL
74 ns + (0,23 ns/pF) CL
52 ns + (0,16 ns/pF) CL
98 ns + (0,55 ns/pF) CL
44 ns + (0,23 ns/pF) CL
32 ns + (0,16 ns/pF) CL
98 ns + (0,55 ns/pF) CL
44 ns + (0,23 ns/pF) CL
32 ns + (0,16 ns/pF) CL
Rt = 100 kΩ
Ct = 0,002 µF
Rt = 100 kΩ
Ct = 0,1 µF
Rt = 100 kΩ
Ct = 10 µF
January 1995
5