INTEGRATED CIRCUITS
DATA SHEET
For a complete data sheet, please also download:
•
The IC04 LOCMOS HE4000B Logic
Family Specifications HEF, HEC
•
The IC04 LOCMOS HE4000B Logic
Package Outlines/Information HEF, HEC
HEF40244B
buffers
Octal buffers with 3-state outputs
Product specification
File under Integrated Circuits, IC04
January 1995
Philips Semiconductors
Product specification
Octal buffers with 3-state outputs
DESCRIPTION
The HEF40244B is an octal non-inverting buffer with
3-state outputs. It features output stages with high current
output capability suitable for driving highly capacitive
loads.
The 3-state outputs are controlled by the output enable
inputs EO
A
and EO
B
. A HIGH on EO causes the outputs to
assume a high impedance OFF-state. The device also
features hysteresis on all inputs to improve noise
immunity.
Schmitt-trigger action in the inputs makes the circuit highly
tolerant to slower input rise and fall times.
The HEF40244B is pin and functionally compatible with
the TTL ‘244’ device.
HEF40244B
buffers
Fig.2 Pinning diagram.
HEF40244BP(N): 20-lead DIL; plastic (SOT146-1)
HEF40244BD(F): 20-lead DIL; ceramic (cerdip) (SOT152)
HEF40244BT(D): 20-lead SO; plastic (SOT163-1)
( ): Package Designator North America
PINNING
I
A1
to I
A4
I
B1
to I
B4
O
A1
to O
A4
O
B1
to O
B4
EO
A
, EO
B
inputs
inputs
bus outputs
bus outputs
output enable inputs (active LOW)
FAMILY DATA, I
DD
LIMITS category buffers
See Family Specifications
Fig.1 Functional diagram.
January 1995
2
Philips Semiconductors
Product specification
Octal buffers with 3-state outputs
TRUTH TABLE
INPUTS
I
n
H
L
X
Notes
EO
L
L
H
HEF40244B
buffers
OUTPUT
O
n
H
L
Z
Fig.3 Logic diagram (one buffer).
1. H = HIGH state (the more positive voltage)
L = LOW state (the less positive voltage)
X = state is immaterial
Z = high impedance off state
RATINGS
Limiting values in accordance with the Absolute Maximum System (IEC 134).
See Family Specifications, except for:
D.C. current into any input
D.C. source or sink current into any output
D.C. current into the supply terminals
DC CHARACTERISTICS
V
SS
= 0 V
V
DD
V
V
OH
V
V
OL
V
SYMBOL
T
amb
(°C)
−40
MIN.
Output current
HIGH
Output current
HIGH
Output current
LOW
Hysteresis
voltage
(any input)
5
10
15
5
10
15
5
10
15
5
10
15
V
H
4,6
9,5
13,5
3,6
8,4
13,2
0,4
0,5 I
OL
1,5
−I
OH
−I
OH
0,75
1,85
14,5
9,3
14,4
19,5
2,9
9,5
30,0
TYP.
+25
MIN.
0,6
1,5
15
10
15
20
2,3
7,6
25
TYP.
1,2
3,0
50
24
46
62
5,4
17
45
220
250
320
+85
MIN.
0,45
1,1
15,5
10,7
15,0
19,8
1,75
5,50
19,0
TYP.
mA
mA
mA
mA
mA
mA
mA
mA
mA
mV
mV
mV
±
I
I
±
I
O
±
I
max.
max.
max.
10 mA
25 mA
100 mA
January 1995
3
Philips Semiconductors
Product specification
Octal buffers with 3-state outputs
HEF40244B
buffers
(1) P-channel MOS transistor conducting.
(2) P-channel MOS transistor and bipolar
n-p-n transistor conducting.
Fig.4 Typical output source current characteristic.
Fig.5 Schematic diagram of output stage.
AC CHARACTERISTICS
V
SS
= 0 V; T
amb
= 25
°C;
input transition times
≤
20 ns
ALL BUFFERS
SWITCHING
Dynamic power
dissipation per
package (P)
V
DD
V
5
10
15
TYPICAL FORMULA FOR P (µW)
4 250 f
i
+ ∑
(f
o
C
L
)
×
V
DD2
17 000 f
i
+ ∑
(f
o
C
L
)
×
V
DD2
46 000 f
i
+ ∑
(f
o
C
L
)
×
V
DD2
where
f
i
= input freq. (MHz)
f
o
= output freq. (MHz)
C
L
= load capacitance (pF)
∑
(f
o
C
L
) = sum of outputs
V
DD
= supply voltage (V)
January 1995
4
Philips Semiconductors
Product specification
Octal buffers with 3-state outputs
AC CHARACTERISTICS
V
SS
= 0 V; T
amb
= 25
°C;
C
L
= 50 pF; input transition times
≤
20 ns
V
DD
V
Propagation delays
I
An/Bn
→
O
An/Bn
HIGH to LOW
I
An/Bn
→
O
An/Bn
LOW to HIGH
Output transition
times
HIGH to LOW
LOW to HIGH
3-state propagation delays
Output disable times
EO
→
O
An/Bn
HIGH
5
10
15
5
LOW
Output enable times
EO
→
O
An/Bn
HIGH
5
10
15
5
LOW
10
15
t
PZL
t
PZH
80
35
30
90
40
30
160
70
60
180
80
60
ns
ns
ns
ns
ns
ns
10
15
t
PLZ
t
PHZ
70
35
30
75
40
30
140
70
60
150
80
60
ns
ns
ns
ns
ns
ns
5
10
15
5
10
15
5
10
15
5
10
15
t
TLH
t
THL
t
PLH
t
PHL
95
40
30
85
40
30
40
20
15
30
20
15
190
80
60
170
80
60
80
40
30
60
40
30
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
SYMBOL
MIN.
TYP.
MAX.
HEF40244B
buffers
TYPICAL EXTRAPOLATION
FORMULA
83 ns
+
(0,24 ns/pF) C
L
35 ns
+
(0,10 ns/pF) C
L
26 ns
+
(0,07 ns/pF) C
L
82 ns
+
(0,06 ns/pF) C
L
38 ns
+
(0,03 ns/pF) C
L
29 ns
+
(0,02 ns/pF) C
L
see Fig.6
January 1995
5
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