5-597
FAST AND LS TTL DATA
4 x 4 REGISTER FILE
WITH 3-STATE OUTPUTS
The TTL/MSI SN54/74LS670 is a high-speed, low-power 4 x 4 Register
File organized as four words by four bits. Separate read and write inputs, both
address and enable, allow simultaneous read and write operation.
The 3-state outputs make it possible to connect up to 128 outputs to in-
crease the word capacity up to 512 words. Any number of these devices can
be operated in parallel to generate an n-bit length.
The SN54/74LS170 provides a similar function to this device but it features
open-collector outputs.
• Simultaneous Read/Write Operation
• Expandable to 512 Words by n-Bits
• Typical Access Time to 20 ns
• 3-State Outputs for Expansion
• Typical Power Dissipation of 125 mW
CONNECTION DIAGRAM DIP (TOP VIEW)
NOTE:
The Flatpak version
has the same pinouts
(Connection Diagram) as
the Dual In-Line Package.
PIN NAMES LOADING (Note a)
HIGH
LOW
D
1
– D
4
Data Inputs 0.5 U.L. 0.25 U.L.
W
A
, W
B
Write Address Inputs 0.5 U.L. 0.25 U.L.
E
W
Write Enable (Active LOW) Input 1.0 U.L. 0.5 U.L.
R
A
, R
B
Read Address Inputs 0.5 U.L. 0.25 U.L.
E
R
Read Enable (Active LOW) Input 1.5 U.L. 0.75 U.L.
Q
1
– Q
4
Outputs (Note b) 65 (25) U.L. 15 (7.5) U.L.
NOTES:
a) 1 TTL Unit Load (U.L.) = 40 µA HIGH/1.6 mA LOW.
b) The Output LOW drive factor is 7.5 U.L. for Military (54) and 15 U.L. for Commercial
(74) Temperature Ranges. The Output HIGH drive factor is 25 U.L. for Military and
65 U.L. for Commercial Temperature Ranges.
SN54/74LS670
4 x 4 REGISTER FILE
WITH 3-STATE OUTPUTS
LOW POWER SCHOTTKY
ORDERING INFORMATION
SN54LSXXXJ Ceramic
SN74LSXXXN Plastic
SN74LSXXXD SOIC
J SUFFIX
CERAMIC
CASE 620-09
N SUFFIX
PLASTIC
CASE 648-08
16
1
16
1
16
1
D SUFFIX
SOIC
CASE 751B-03
LOGIC SYMBOL
