SL4518B

System Logic

Semiconductor

SLS

Dual Up-Counter

High-Voltage Silicon-Gate CMOS

The SL4518B Dual BCD Up-Counter consists two identical,

internally synchronous 4-stage counters. The counter stages are D-

type flip-flops having interchangeable CLOCK and ENABLE lines for

incrementing on either the positive-going or negative-going transition.

For single-unit operation the ENABLE input is maintained high and the

counter advances on each positive-going transition of the CLOCK. The

counters are cleared by high levels on their RESET lines.

The counter can be cascaded in the ripple mode by connecting Q4

to the enable input of the subsequent counter while the CLOCK input

of the latter is held low.

• Operating Voltage Range: 3.0 to 18 V

• Maximum input current of 1 µA at 18 V over full package-

temperature range; 100 nA at 18 V and 25

°C

• Noise margin (over full package temperature range):

1.0 V min @ 5.0 V supply

2.0 V min @ 10.0 V supply

2.5 V min @ 15.0 V supply

ORDERING INFORMATION

SL4518BN Plastic

SL4518BD SOIC

° to 125° C for all packages

PIN ASSIGNMENT

LOGIC DIAGRAM

PIN 8= GND

FUNCTION TABLE

Inputs

Outputs

CLOCK

ENABLE

RESET

Mode

H

L

Increment Counter

L

L

Increment Counter

X

L

No Change

X

L

No Change

L

L

No Change

H

L

No Change

X

X

H

Q1 thru Q4=L

X = don’t care