HD74HC620/HD74HC623
Octal Bus Transceivers (with inverted 3-state outputs)
Octal Bus Transceivers (with 3-state outputs)
Description
This octal bus transceiver is designed for asynchronous two-way communication between data bus. The control fuction implementation allows for maximum flexibility in timing.
This device allows data transmission from the A bus to the B bus or from the B bus to the A bus depending upon the logic levels at the enable inputs (GBA and GAB).
The enable inputs can be ud to disable the device so that the bus are effectively isolated.
The dual-enable configuration gives the devices the capability to store data by simultaneous enabling of GBA and GAB. Each output reinforces its input in this transceiver configuration. Thus, when both control inputs are enabled and all other data sources to the two ts of bus lines are at high impedance, both ts of bus lines (16 in all) will remain at their last states. The 8-bit codes appearing on the two ts of bus will be identical for the HD74HC623 or coplementary for the HD74HC620.
Features
• High Speed Operation: t pd (Bus to Bus) = 12 ns typ (C L = 50 pF)
• High Output Current: Fanout of 15 LSTTL Loads
• Wide Operating Voltage: V CC = 2 to 6 V
• Low Input Current: 1 µA max
• Low Quiescent Supply Current: I CC (static) = 4 µA max (Ta = 25°C)
Function Table
Enable Inputs Operation
broken mirrorGBA GAB HD74HC620HD74HC623
L L B data to A bus B data to A bus
cet6听力
H H A data to B bus A data to B bus
H L Isolation Isolation
L H B data to A bus, A data to B bus B data to A bus, A data to B bus
HD74HC620/HD74HC623
2
Pin Arrangement
英国巨石阵石料来源之谜被揭开Absolute Maximum Ratings
Item
Symbol Rating Unit Supply voltage range V CC –0.5 to +7.0V Input voltage V IN –0.5 to V CC + 0.5V Output voltage V OUT –0.5 to V CC + 0.5V Output current
I OUT ±35mA DC current drain per V CC GND I CC , I GND ±75mA DC input diode current I IK ±20mA DC output diode current I OK ±20mA Power Dissipation per package P T 500mW Storage temperature
Tstg
–65 to +150
°C
banzhuHD74HC620/HD74HC623 Block Diagram
remained
HD74HC620
3
HD74HC620/HD74HC623 HD74HC623
4
HD74HC620/HD74HC623
5
DC Characteristics
Ta = 25°C
Ta = –40 to +85°C
Item Symbol V CC (V)Min Typ Max Min
Max Unit Test Conditions
Input voltage
V IH
2.0 1.5—— 1.5—V
4.5 3.15—— 3.15—6.0
4.2—— 4.2—V IL
2.0——0.5—0.5V 4.5—— 1.35—
1.356.0
风靡世界的意思—
—
1.8
— 1.8Output voltage
V OH
2.0 1.9 2.0— 1.9—V
Vin = V IH or V IL I OH = –20 µA
4.5 4.4 4.5— 4.4—6.0
5.9
6.0— 5.9—4.5 4.18—— 4.13—I OH = –6 mA 6.0
5.68——
5.63—I OH = –7.8 mA
V OL
2.0—0.00.1—0.1V
Vin = V IH or V IL I OL = 20 µA
4.5—0.00.1—0.16.0—0.00.1—
0.14.5——0.26—0.33I OL = 6 mA 6.0
——0.26—0.33I OL = 7.8 mA
Off-state output current I OZ 6.0——±0.5—±5.0µA Vin = V IH or V IL ,Vout = V CC or GND Input current Iin 6.0——±0.1—±1.0µA Vin = V CC or GND
Quiescent supply current
I CC
6.0
—
—
4.0
—
40
µA
Vin = V CC or GND, Iout = 0 µA
HD74HC620/HD74HC623
6
AC Characteristics (C L = 50 pF, Input t r = t f = 6 ns)
Ta = 25°C
adverTa = –40 to +85°C
Item Symbol V CC (V)Min Typ Max Min
practi是什么意思wu ha free frMax Unit Test Conditions
Propagation delay t PLH
2.0——100—125ns
time
t PHL 4.5—1220—256.0——17—21Output enable t ZH 2.0——150—
190ns time
t ZL 4.5—1230—386.0——26—33Output disable t HZ 2.0——150—
190ns time
t LZ 4.5—1630—386.0——26—33Output ri/fall t TLH 2.0——60—75ns time
t THL 4.5—412—156.0——10—13Input capacitance会计职称有哪些
Cin
—
—
5
10
—
10
pF
