HD74LS148 Datasheet, PDF (3/6 Pages) Hitachi Semiconductor – 8-line-to-3-line Octal Priority Encoders

HD74LS148
Recommended Operating Conditions
Item
Supply voltage
Output current
Operating temperature
Symbol
V_CC
I_OH
I_OL
Topr
Min
4.75
—
—
–20
Typ
5.00
—
—
25
Max
5.25
–400
8
75
Unit
V
µA
mA
°C
Electrical Characteristics
(Ta = –20 to +75 °C)
Item
Symbol min.
typ.*
max.
Unit
Condition
Input voltage
V_IH
2.0
—
—
V
V_IL
—
—
0.8
V
Output voltage
V_OH
2.7
—
—
—
—
0.4
V_OL
—
—
0.5
V
V_CC = 4.75 V, V_IH = 2 V, V_IL = 0.8 V,
I_OH = –400 µA
V
I_OL = 4 mA V_CC = 4.75 V, V_IH = 2 V,
I_OL = 8 mA ^VIL ^{= 0.8 V}
1 to 7 Inputs
—
—
40
Other inputs
I_IH
—
—
20
µA
V_CC = 5.25 V, V_I = 2.7 V
Input 1 to 7 Inputs
—
—
–0.8
current _{Other inputs}
I_IL
—
—
–0.4
mA V_CC = 5.25 V, V_I = 0.4 V
1 to 7 Inputs
Other inputs
I_I
—
—
0.2
—
—
0.1
mA V_CC = 5.25 V, V_I = 7 V
Short-circuit output
current
I_OS
–20
—
–100
mA V_CC = 5.25 V
Supply current**
—
12
20
mA Condition 1
I_CC
—
10
17
mA
Condition 2 ^{VCC = 5.25 V}
Input clamp voltage
V_IK
—
—
–1.5
V
V_CC = 4.75 V, I_IN = –18 mA
Notes: * V_CC = 5 V, Ta = 25°C
** The condition 1 is measured with inputs 7 and EI grounded, other inputs and outputs open, the condition 2 is
measured with all inputs and outputs open.
Switching Characteristics
Item
Symbol min.
typ.
t_PLH
—
14
t_PHL
—
15
t_PLH
—
20
t_PHL
—
16
t_PLH
—
7
t_PHL
—
25
Propagation
t_PLH
—
35
delay time
t_PHL
—
9
t_PLH
—
16
t_PHL
—
12
t_PLH
—
12
t_PHL
—
14
t_PLH
—
12
t_PHL
—
23
max.
18
25
36
29
18
40
55
21
25
25
17
36
21
35
(V_CC = 5 V, Ta = 25°C)
Unit
Inputs Outputs
Output
Waveforms
Condition
ns
0 to 7
A₀, A₁
or A₂
In-phase
Output
ns
0 to 7
A₀, A₁
Out-of-phase
or A₂
Output
Out-of-phase
ns
0 to 7
EO
Output
ns
0 to 7
GS
In-phase
Output
C_L = 15 pF,
R_L = 2 kΩ
ns
EI
A₀, A₁
In-phase
or A₂
Output
In-phase
ns
EI
GS
Output
In-phase
ns
EI
EO
Output
Rev.2.00, Feb.18.2005, page 3 of 5