ICS651B

LOW SKEW 1 TO 4 CLOCK BUFFER

FAN OUT BUFFER

IDT™ / ICS™ LOW SKEW 1 TO 4 CLOCK BUFFER

2

ICS651B

REV B 112509

Pin Assignment

Pin Descriptions

External Components

A minimum number of external components are required for proper operation. A decoupling capacitor of 0.01

µF

should be connected between VDD on pin 7 and GND on pin 6, as close to the device as possible. A 33

Ω series

terminating resistor may be used on each clock output if the trace is longer than 1 inch.

To achieve the low output skew that the ICS651B is capable of, careful attention must be paid to board layout.

Essentially, all four outputs must have identical terminations, identical loads and identical trace geometries. If they

do not, the output skew will be degraded. For example, using a 30

Ω series termination on one output (with 33Ω on

the others) will cause at least 15 ps of skew.

1

2

3

4

5

6

7

8

ICLK

Q1

Q2

Q3

Q4

OE

VDD

GND

Pin

Number

Pin

Name

Pin

Type

Pin Description

1

ICLK

Input

Clock Input. 3.3 V tolerant input.

2

Q1

Output

Clock Output 1.

3

Q2

Output

Clock Output 2.

4

Q3

Output

Clock Output 3.

5

Q4

Output

Clock Output 4.

6

GND

Power

Connect to ground.

7

VDD

Power

Connect to +1.5 V or +2.5 V.

8

OE

Input

Output Enable. Tri-states outputs when low. Connect to VDD for normal operation.