5-1

FAST AND LS TTL DATA

DECADE COUNTER;

4-BIT BINARY COUNTER

The SN54 / 74LS290 and SN54 / 74LS293 are high-speed 4-bit ripple type

counters partitioned into two sections. Each counter has a divide-by-two sec-

tion and either a divide-by-five (LS290) or divide-by-eight (LS293) section

which are triggered by a HIGH-to-LOW transition on the clock inputs. Each

section can be used separately or tied together (Q to CP)to form BCD,

Bi-quinary, or Modulo-16 counters. Both of the counters have a 2-input gated

Master Reset (Clear), and the LS290 also has a 2-input gated Master Set

(Preset 9).

14

13

12

11

10

9

12

3456

8

7

VCC

MR

MR

CP1

CP0

Q0

Q3

MS

NC

MS

Q2

Q1

NC

GND

CONNECTION DIAGRAM DIP (TOP VIEW)

LS290

LS293

NOTE:

The Flatpak version

has the same pinouts

(Connection Diagram) as

the Dual In-Line Package.

14

13

12

11

10

9

1234

56

8

7

VCC

MR

MR

CP1

CP0

Q0

Q3

NC

NC

NC

Q2

Q1

NC

GND

PIN NAMES

LOADING (Note a)

HIGH

LOW

CP0

Clock (Active LOW going edge) Input to

÷2 Section.

0.05 U.L.

1.5 U.L.

CP1

Clock (Active LOW going edge) Input to

÷5 Section (LS290).

0.05 U.L.

2.0 U.L.

CP1

Clock (Active LOW going edge) Input to

÷8 Section (LS293).

0.05 U.L.

1.0 U.L.

MR1, MR2

Master Reset (Clear) Inputs

0.5 U.L.

0.25 U.L.

MS1, MS2

Master Set (Preset-9, LS290) Inputs

0.5 U.L.

0.25 U.L.

Q0

Output from

÷2 Section (Notes b & c)

10 U.L.

5 (2.5) U.L.

Q1, Q2, Q3

Outputs from

÷5 & ÷8 Sections (Note b)

10 U.L.

5 (2.5) U.L.

NOTES:

a) 1 TTL Unit Load (U.L.) = 40

µA HIGH/1.6 mA LOW.

b) The Output LOW drive factor is 2.5 U.L. for Military (54) and 5 U.L. for Commercial (74) Temperature Ranges.

c) The Q0 Outputs are guaranteed to drive the full fan-out plus the CP1 Input of the device.

SN54/74LS290

SN54/74LS293

DECADE COUNTER;

4-BIT BINARY COUNTER

LOW POWER SCHOTTKY

ORDERING INFORMATION

SN54LSXXXJ

Ceramic

SN74LSXXXN

Plastic

SN74LSXXXD

SOIC

J SUFFIX

CERAMIC

CASE 632-08

N SUFFIX

PLASTIC

CASE 646-06

14

1

14

1

14

1

D SUFFIX

SOIC

CASE 751A-02