74F794PC

© 2004 Fairchild Semiconductor Corporation DS010652 www.fairchildsemi.com
March 1990
Revised February 2004
74F794 8-Bit Register with Readback
74F794
8-Bit Register with Readback
General Description
The 74F794 is an 8-bit register with readback capability
designed to store data as well as read the register informa-
tion back onto the data bus. The I/O bus (D bus) has
3-STATE outputs. Current sinking capability is 64 mA on
both the D and Q busses.
Data is loaded into the registers on the LOW-to-HIGH tran-
sition of the clock (CP). The output enable (OE
) is used to
enable data on D
0
–D
7
. When OE is LOW, the output of the
registers is enabled on D
0
–D
7
, enabling D as an output
bus. When OE is HIGH, D
0
–D
7
are inputs to the registers
configuring D as an input bus.
Features
3-STATE outputs on the I/O port
D and Q output sink capability of 64 mA
Functionally and pin equivalent to the 74LS794
Ordering Code:
Logic Symbol Connection Diagram
Order Number Package Number Package Description
74F794PC N20A 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300" Wide
www.fairchildsemi.com 2
74F794
Input Loading/Fan-Out
Truth Table
Note 1: In this case the output of the register is clocked to the inputs and
the overall Q output is unchanged at Q
n
.
Logic Diagram
Pin Names Description
HIGH/LOW
(U.L.) Current
OE
Output Enable Input 1.0/1.0 20 µA/0.6 mA
CP Clock Pulse Inputs 1.0/1.0 20
µA/0.6 mA
D
0
D
7
D Bus Inputs/ 3.5/1.083 70 µA/650 µA
3-STATE Outputs 750/106.6
15 mA/64 mA
Q
0
Q
7
Q Bus Outputs 750/106.6 15 mA/64 mA
Inputs Outputs
CP OE
QD
L or H or
LQ
n
Output, Q
L or H or
HQ
n
Input
LQ
n
Output, Q (Note 1)
HDInput
3 www.fairchildsemi.com
74F794
Absolute Maximum Ratings(Note 2) Recommended Operating
Conditions
Note 2: Absolute maximum ratings are values beyond which the device
may be damaged or have its useful life impaired. Functional operation
under these conditions is not implied.
Note 3: In this case the output of the register is clocked to the inputs and
the overall Q output is unchanged at Q
n
.
Note 4: Either voltage limit or current limit is sufficient to protect inputs.
DC Electrical Characteristics over Operating Temperature Range unless otherwise specified
Storage Temperature
65°C to + 150°C
Ambient Temperature under Bias
55° to +125°C
Junction Temperature under Bias
55°C to +150°C
V
CC
Pin Potential to Ground Pin 0.5V to +7.0V
Input Voltage (Note 3)
0.5V to +7.0V
Input Current (Note 3)
30 mA to +5.0 mA
ESD Last Passing Voltage (Min) 4000V
Voltage Applied to Output
In HIGH State (with V
CC
= 0V)
Standard Output
0.5V to V
CC
3-STATE Output 0.5V to +5.5V
Current Applied to Output
in LOW State (Max) Twice the Rated I
OL
(mA)
Free Air Ambient Temperature 0
°C to 70°C
Supply Voltage
+4.5V to +5.5V
Symbol Parameter Min Typ Max Units
V
CC
Conditions
V
IH
Input HIGH Voltage 2.0 V Recognized as a HIGH Signal
V
IL
Input LOW Voltage 0.8 V Recognized as a LOW Signal
V
CD
Input Clamp
1.2 V Min I
IN
= 18 mA
Diode Voltage
V
OH
Output HIGH 2.4 2.8
VMin
I
OH
= 3 mA
Voltage 2.0 2.44 I
OH
= 15 mA
V
OL
Output LOW
0.45 0.55 V Min I
OL
= 64 mA
Voltage
I
IH
Input HIGH
5.0 µAMaxV
IN
= 2.7V
Current
I
BVI
Input HIGH Current
7.0 µAMaxV
IN
= 7.0V (OE, CP)
Breakdown Test
I
BVIT
Input HIGH Current
0.5 mA Max V
IN
= 5.5V (D
n
)
Breakdown (I/O)
I
CEX
Output HIGH
50 µAMaxV
OUT
= V
CC
Leakage Current
V
ID
Input Leakage
4.75 V 0.0
I
ID
= 1.9 µA
Test All Other Pins Grounded
I
OD
Output Leakage
3.75 µA0.0
V
IOD
= 150 mV
Circuit Current All Other Pins Grounded
I
IL
Input LOW
0.6 mA Max
V
IN
= 0.5V
Current (OE, CP)
I
OS
Output Short-
100 225 mA Max V
OUT
= 0V
Circuit Current
I
IH
+ Output Leakage 70 µAMaxV
OUT
= 2.7V
I
OZH
Current (Dn)
I
IL
+ Output Leakage
650 µAMax
V
OUT
= 0.5V
I
OZL
Current (Dn)
V
ID
Input Leakage
4.75 V 0.0
I
ID
= 1.9 µA
Test All Other Pins Grounded
I
OD
Output Circuit
3.75 µA0.0
V
IOD
= 150 mV
Leakage Current All Other Pins Grounded
I
ZZ
Bus Drainage Test 100 µA0.0V
OUT
= 5.25V
I
CCH
Power Supply Current 65 mA Max V
O
= HIGH
I
CCL
Power Supply Current 80 mA Max V
O
= LOW
I
CCZ
Power Supply Current 80 mA Max V
O
= HIGH Z

74F794PC

Mfr. #:
Manufacturer:
ON Semiconductor / Fairchild
Description:
Flip Flops 8-Bit Register
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
T/T Paypal Visa MoneyGram Western Union

Products related to this Datasheet