Fairchild MM74HC240 service manual
MM74HC240
Inverting Octa l 3-STATE Buffer
MM74HC240 Inverting Octal 3-STATE Buffer
September 1983
Revised May 2005
General Description
The MM74HC240 3-STATE buffer utilizes advanced silicon-gate CMOS techno logy. It possesses high drive current outputs which enable high speed operation even when
driving large bus capacitances. These circuits achieve
speeds comparable to low po wer Schottky devices, while
retaining the advantage of CMOS circuit ry, i.e., high noise
immunity and low power consumption. It has a fanout of 15
LS-TTL equivalent inputs.
The MM74HC240 is an inve rting b uffer and ha s two a ctive
LOW enables (1G
controls 4 buffers.
All inputs are protected from damage due to static discharge by diodes to V
and 2G). Each enable independently
and ground.
CC
Features
■ Typical propagation delay: 12 ns
■ 3-STATE outputs for connection to system buses
■ Wide power supply range: 2–6V
■ Low quiescent supply current: 80
■ Output current: 6 mA
P
A (74 Series)
Ordering Code:
Order Number Package Number Package Description
MM74HC240WM M20B 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300" Wide
MM74HC240SJ M20D 20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
MM74HC240MTC MTC20 20-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide
MM74HC240N N20A 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300" Wide
Devices also availab l e in Tape and Reel. Specify by appending the suffix let t er “X” to the ordering code.
Connection Diagram
Truth Table
1G 1A 1Y 2G 2A 2Y
LLHLLH
LHLLHL
HLZHLZ
HHZHHZ
H HIGH Level
L
LOW Level
HIGH Impedance
Z
Top View
© 2005 Fairchild Semiconductor Corporation DS005020 www.fairchildsemi.com
Logic Diagram
MM74HC240
www.fairchildsemi.com 2
Absolute Maximum Ratings(Note 1)
(Note 2)
Supply Voltage (VCC)
DC Input Voltage (V
DC Output Voltage (V
Clamp Diode Current (I
DC Output Current, per pin (I
DC V
or GND Current, per pin (ICC)
CC
Storage Temperature Range (T
Power Dissipation (P
)
IN
)
OUT
, IOK)
IK
)
OUT
STG
)
D
(Note 3) 600 mW
S.O. Package only 500 mW
Lead Temperature (T
)
L
(Soldering 10 seconds) 260
0.5 to 7.0V
1.5 to V
CC
0.5 to V
CC
r
r
r
)65qC to 150qC
20 mA
35 mA
70 mA
Recommended Operating
Conditions
1.5V
Supply Voltage (V
0.5V
DC Input or Output Voltage 0 V
, V
(V
IN
OUT
)26V
CC
)
Operating Temperature Range (T
Input Rise or Fall Times
, tf) V
(t
r
V
CC
V
CC
Note 1: Absolute Maximum Ratings are those values beyond which damage to the device may occur.
Note 2: unless otherwis e specified all voltages are referenced to ground.
q
C
Note 3: Power Dissipatio n temp er ature derat ing — plastic “N” package:
12 mW/qC from 65qC to 85qC.
2.0V 1000 ns
CC
4.5V 500 ns
6.0V 400 ns
Min Max Units
)4085
A
CC
DC Electrical Characteristics (Note 4)
TA
Symbol Parameter Conditions
V
V
V
V
I
I
I
Minimum HIGH Level 2.0V 1.5 1.5 1.5 V
IH
Input Voltage 4.5V 3.15 3.15 3.15 V
Maximum LOW Level 2.0V 0.5 0.5 0.5 V
IL
Input Voltage 4.5V 1.35 1.35 1.35 V
Minimum HIGH Level V
OH
Output Voltage |I
Maximum LOW Level V
OL
Output Voltage |I
Maximum Input Current V
IN
Maximum 3-STATE V
OZ
Output Leakage V
Current G VIH, G V
Maximum Quiescent V
CC
Supply Current I
Note 4: For a power supply of 5V r10% the worst case output voltages (VOH, and VOL) occur for HC at 4.5V. Thus the 4.5V val ues shou ld be us ed w hen
designing with this supply. Worst case V
, ICC, and IOZ) occur for CMOS at the higher voltage and so t he 6.0V values shoul d be used.
rent (I
IN
VIH or V
I N
OUT
V
IN
|I
OUT
|I
OUT
IN
OUT
V
IN
|I
OUT
|I
OUT
IN
IN
OUT
IN
OUT
and VIL occur at V
IH
IL
| d 20 PA 2.0V 2.0 1.9 1.9 1.9 V
VIH or V
IL
| d 6.0 mA 4.5V 4.2 3.98 3.84 3.7 V
| d 7.8 mA 6.0V 5.7 5.48 5.34 5.2 V
VIH or V
IL
| d 20 PA 2.0V 0 0.1 0.1 0.1 V
VIH or V
IL
| d 6.0 mA 4.5V 0.2 0.26 0.33 0.4 V
| d 7.8 mA 6.0V 0.2 0.26 0.33 0.4 V
VCC or GND 6.0V
VIH or V
IL
VCC or GND 6.0V
IL
VCC or GND
0 PA
CC
V
CC
6.0V 4.2 4.2 4.2 V
6.0V 1.8 1.8 1.8 V
4.5V 4.5 4.4 4.4 4.4 V
6.0V 6.0 5.9 5.9 5.9 V
4.5V 0 0.1 0.1 0.1 V
6.0V 0 0.1 0.1 0.1 V
6.0V 8.0 80 160
5.5V and 4.5V respectively. (The VIH value at 5.5V is 3.85V.) The worst case leakage cur-
25qCTA
Typ Guaranteed Limits
r
0.1
r
0.5
40 to 85qCTA
r
1.0
r
5
55 to 125qC
r
1.0
r
10
V
q
C
Units
P
P
P
A
A
A
MM74HC240
3 www.fairchildsemi.com
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