May 2008

ASM3P2187A/B

rev 0.2

Spread Spectrum Clock Generator for Mobile Applications

2 of 9

Notice: The information in this document is subject to change without notice.

Pin Configurations

Pin Description

Pin#

Pin Name

Type

Description

1

CLKIN/XIN

I

External reference Clock input or Crystal connection.

2

XOUT

O

Crystal connection. If using an external reference, this pin must be left

unconnected.

3

SSON / PDB*

I

Modulation enable pin/ Power down pin. Has an Internal pull up resistor

4

SEL

I

Modulation rate setting pin

Centre spread, SEL = “L” : Frequency Deviation ± 0.5%

Centre spread, SEL = “H” : Frequency Deviation ± 1.0%

Has an Internal pull up resistor.

5

REFOUT

O

Non-modulated clock output pin. The Frequency is same as input

frequency. This pin becomes to “L” at power-down.

6

VSS

P

Ground Connection. Connect to system ground.

7

ModOUT

O

Modulated clock output pin

This pin becomes to“L” at power-down.

8

VDD

P

Power Supply Voltage Pin. Connect to +3.3V.

* SSON Pin is available in ASM3P2187A Device and PDB Pin is available in ASM3P2187B Device

6

REFOUT

1

2

3

4

5

8

ASM3P2187A

CLKIN/ XIN

XOUT

SEL

ModOUT

VSS

SSON

VDD

7

6

REFOUT

1

2

3

4

5

7

8

ASM3P2187B

CLKIN/ XIN

XOUT

SEL

ModOUT

VSS

PDB

VDD