
Philips Semiconductors
Dual 4-bit latch
Product specification
HEF4508B
MSI
AC CHARACTERISTICS
VSS = 0 V; Tamb = 25 °C; CL = 50 pF; input transition times ≤ 20 ns; see also waveforms Fig.4.
VDD
V
SYMBOL MIN. TYP. MAX.
TYPICAL EXTRAPOLATION
FORMULA
Propagation delays
ST → On
HIGH to LOW
LOW to HIGH
Dn → On
HIGH to LOW
LOW to HIGH
MR → On
HIGH to LOW
Output transition times
HIGH to LOW
LOW to HIGH
3-state propagation
delays
Output enable times
EO → On
HIGH
LOW
Output disable times
EO → On
HIGH
LOW
5
10
tPHL
15
5
10
tPLH
15
5
10
tPHL
15
5
10
tPLH
15
5
10
tPHL
15
5
10
tTHL
15
5
10
tTLH
15
5
10
tPZH
15
5
10
tPZL
15
5
10
tPHZ
15
5
10
tPLZ
15
115 230 ns
50 100 ns
35 70 ns
115 230 ns
50 100 ns
35 70 ns
95 190 ns
40 80 ns
30 60 ns
95 190 ns
40 80 ns
30 60 ns
100 200 ns
40 80 ns
30 60 ns
60 120 ns
30 60 ns
20 40 ns
60 120 ns
30 60 ns
20 40 ns
88 ns + (0,55 ns/pF) CL
39 ns + (0,23 ns/pF) CL
27 ns + (0,16 ns/pF) CL
88 ns + (0,55 ns/pF) CL
39 ns + (0,23 ns/pF) CL
27 ns + (0,16 ns/pF) CL
68 ns + (0,55 ns/pF) CL
29 ns + (0,23 ns/pF) CL
22 ns + (0,16 ns/pF) CL
68 ns + (0,55 ns/pF) CL
29 ns + (0,23 ns/pF) CL
22 ns + (0,16 ns/pF) CL
73 ns + (0,55 ns/pF) CL
29 ns + (0,23 ns/pF) CL
22 ns + (0,16 ns/pF) CL
10 ns + (1,0 ns/pF) CL
9 ns + (0,42 ns/pF) CL
6 ns + (0,28 ns/pF) CL
10 ns + (1,0 ns/pF) CL
9 ns + (0,42 ns/pF) CL
6 ns + (0,28 ns/pF) CL
45 90 ns
20 40 ns
18 36 ns
45 90 ns
20 40 ns
18 36 ns
35 70 ns
20 40 ns
18 36 ns
45 90 ns
20 40 ns
18 36 ns
January 1995
5