1/11
July 2001s
HIGH SPEED:
t PD = 16ns (TYP .) at V CC = 6V s
LOW POWER DISSIPATION:I CC = 4μA(MAX.) at T A =25°C s HIGH NOISE IMMUNITY:
V NIH = V NIL = 28 % V CC (MIN.)
s
SYMMETRICAL OUTPUT IMPEDANCE:|I OH | = I OL = 4mA (MIN)
s
BALANCED PROPAGATION DELAYS:t PLH ? t PHL
s
WIDE OPERATING VOLTAGE RANGE:V CC (OPR) = 2V to 6V
s
PIN AND FUNCTION COMPATIBLE WITH 74 SERIES 237
DESCRIPTION
The M74HC237 is an high speed CMOS 3 TO 8LINE DECODER fabricated with silicon gate C 2MOS technology.
When GL goes from low to high, the address present at the select inputs (A, B, C) is stored in the latches. As long as GL remains high no address changes will be recognized. Output enable controls, G1 and G2 control the state of the outputs independently of the select or
latch-enable inputs. All of the outputs are low unless G1 is high and G2 is low. The M74HC237is ideally suited for the implementation of glitch-free decoders in stored-address applications in bus oriented systems.
All inputs are equipped with protection circuits against static discharge and transient excess voltage.
M74HC237
3 TO 8 LINE DECODER LATCH
PIN CONNECTION AND IEC LOGIC SYMBOLS
ORDER CODES
PACKAGE TUBE T & R
DIP M74HC237B1R SOP M74HC237M1R
M74HC237RM13TR TSSOP
M74HC237TTR
P r o d u c t (s ) - O b s o l e t e P r o d u c t (s ) b s o l e t e P r o d u c t (s ) - O b s o l e t e P r o d
O
b s o l e t e P r o d u
c t (s ) - O b s o l e t e P r o
d u c t (s ) M74HC237
2/11
INPUT AND OUTPUT EQUIVALENT CIRCUIT
PIN DESCRIPTION
TRUTH TABLE
X : Don’t Care
PIN No SYMBOL NAME AND FUNCTION 1, 2, 3A, B, C Data Inputs
4GL Latch Enable Input
5G2Data Enable Input (Active LOW)
6G1Data Enable Input (Active HIGH)
15, 14, 13, 12, 11, 10, 9,
7Y0 to Y7
Decoder Outputs
8GND
Ground (0V)
16
V CC
Positive Supply Voltage
INPUTS
OUTPUTS
ENABLE SELECT
GL G2G1C B
A Y0Y1Y2Y3Y4Y5Y6Y7X X L X X X L L L L L L L L X H X X X X L L L L L L L L L L H L L L H L L L L L L L L L H L L H L H L L L L L L L L H L H L L L H L L L L L L L H L H H L L L H L L L L L L H H L L L L L L H L L L L L H H L H L L L L L H L L L L H H H L L L L L L L H L L L H H H H L
L L L L L L
H
H
L
H
X
X X Outputs corresponding to stored address H: all others L
O b s o l e t e P r o d u c t (s ) - O b s o l e t e P r o d u c t (s )
O
b s o l e t e P r o d u
c t (s ) - O b s o l e t e P
M74HC237
3/11
LOGIC DIAGRAM
ABSOLUTE MAXIMUM RATINGS
Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these conditions is not implied
(*) 500mW at 65 °C; derate to 300mW by 10mW/°C from 65°C to 85°C
RECOMMENDED OPERATING CONDITIONS
Symbol Parameter Value Unit V CC Supply Voltage -0.5 to +7
V V I DC Input Voltage
-0.5 to V CC + 0.5V V O DC Output Voltage
-0.5 to V CC + 0.5
V
I IK DC Input Diode Current ± 20mA I OK
DC Output Diode Current
± 20mA I O
DC Output Current
± 25
mA
I CC or I GND DC V CC or Ground Current
± 50mA P D Power Dissipation
500(*)mW T stg Storage Temperature
-65 to +150
°C
T L
Lead Temperature (10 sec)
300
°C
Symbol Parameter
Value Unit V CC Supply Voltage 2 to 6
V V I Input Voltage 0 to V CC V V O Output Voltage
0 to V CC V T op Operating Temperature -55 to 125
°C t r , t f
Input Rise and Fall Time
V CC = 2.0V 0 to 1000ns V CC = 4.5V 0 to 500ns V CC = 6.0V
0 to 400
ns O b s o l e t e P r o d u c t (s ) - O b
O
b s o l e t e P r o d u
c t (s ) - O b s o l e t e P r o
d u c t (s ) M74HC237
4/11
DC SPECIFICATIONS
Symbol
Parameter
Test Condition
Value Unit
V CC (V)T A = 25°C -40 to 85°C -55 to 125°C Min.Typ.
Max.
Min.Max.
Min.Max.
V IH
High Level Input Voltage
2.0 1.5 1.5 1.5V 4.5
3.15 3.15 3.156.0
4.2
4.2
4.2
V IL
Low Level Input Voltage
2.00.50.50.5V
4.5 1.35 1.35 1.356.0 1.8
1.8 1.8V OH
High Level Output Voltage
2.0
I O =-20 μA 1.9 2.0 1.9 1.9V
4.5I O =-20 μA 4.4 4.5 4.4 4.46.0I O =-20 μA
5.9
6.0
5.9
5.9
4.5
I O =-4.0 mA 4.18 4.31 4.13 4.106.0
I O =-5.2 mA 5.68
5.8 5.63
5.60
V OL
Low Level Output
Voltage
2.0
I O =20 μA 0.00.10.10.1V
4.5I O =20 μA 0.00.10.10.16.0I O =20 μA
0.0
0.1
0.1
0.1
4.5
I O =4.0 mA 0.170.260.330.406.0
I O =5.2 mA
0.18
0.26
0.330.40I I Input Leakage Current
6.0V I = V CC or GND ± 0.1± 1± 1μA
I CC
Quiescent Supply Current
6.0
V I = V CC or GND
4
40
80
μA
O b s o l e t e P r o d u c t (s ) - O b s o l e t e P r o d u c t (s )
O
b s o l e t e P r o d u
c t (s ) - O b s o l e t e P r o
d u c t (s ) M74HC237
5/11
AC ELECTRICAL CHARACTERISTICS (C L = 50 pF, Input t r = t f = 6ns)
CAPACITIVE CHARACTERISTICS
1) C PD is defined as the value of the IC’s internal equivalent capacitance which is calculated from the operating current consumption without load.
Symbol
Parameter
Test Condition
Value Unit
V CC (V)T A = 25°C -40 to 85°C -55 to 125°C Min.
Typ.Max.Min.
Max.Min.
Max.t TLH t THL Output Transition
Time 2.0307595110ns 4.581519226.07131619t PLH t PHL Propagation Delay
Time (A, B, C - Y) 2.060180225270ns
4.5193645546.016313846t PLH t PHL Propagation Delay
Time (G1 - Y) 2.0451********ns
4.5152835426.013243036t PLH t PHL Propagation Delay
Time (G2 - Y) 2.0451********ns
4.5152835426.013243036t PLH t PHL Propagation Delay
Time (GL - Y) 2.065190240285ns
4.5213848576.018324148t W(L)
Minimum Pulse Width (GL)
2.010*******ns
4.561519226.06131619t s
Minimum Set-up
Time (A, B, C - GL) 2.012506575ns
4.531013156.02
91113t h
Minimum Hold Time (A, B, C - GL)
2.0253040ns
4.55686.0
5
5
7
Symbol Parameter
Test Condition Value
Unit
V CC (V)T A = 25°C -40 to 85°C -55 to 125°C Min.Typ.Max.Min.Max.Min.
Max.C IN
Input Capacitance 5.0
5
10
10
10
pF
C PD
Power Dissipation Capacitance (note 1)
5.052pF
O b s o l e t e P r o d u c t (s ) - O b s o l e t e P r o d u c t (s )
O
b s o l e t e P r o d u
c t (s ) - O b s o l e t e P r o
d u c t M74HC237
6/11
TEST CIRCUIT
L R T = Z OUT of pulse generator (typically 50?)
WAVEFORM 1: PROPAGATION DELAY TIME (f=1MHz; 50% duty cycle)
O b s o l e t e P r o d u c t (s ) - O b s o l e t e
O b s o
l e t
e P
r o d
u c
t(s
)-
O b
s o
l e t
e P
r o d
u c
t(s
)
M74HC237
7/11
WAVEFORM 2: SETUP AND HOLD TIME, MINIMUM PULSE WIDTH (GL)(f=1MHz; 50% duty cycle)
O b s o
l e t
e P
r o d
u c
t(s
)-
O b
s o
l e t
e P
r o d
u c
t(s
)
分销商库存信息:
STM
M74HC237RM13TR M74HC237B1R