September 2003

ASM3P2811A/B

ASM3P2812A/B

ASM3P2814A/B

rev 1.0

Low Power EMI Reduction IC

3 of 6

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

Pin Description

Pin#

Pin Name

Type

Description

1

XIN

I

Crystal connection or external frequency input. This pin has dual functions.

It can be connected to either an external crystal or an external reference

clock.

2

VSS

P

Ground to entire chip.

3

D_C

I

Digital logic input used to select Down (LOW) or Center (HIGH) spread

options. (Refer Output Frequency Deviation and Spread Option Selection

Table). This pin has an internal pull-up resistor.

4

SRS

I

Spread range select. Digital logic input used to select frequency deviation

(Refer Output Frequency Deviation and Spread Option Selection Table).

This pin has an internal pull-up resistor.

5

ModOUT

O

Spread spectrum clock output (Refer Input/Output Frequency Range

Selection Table and Output Frequency Deviation and Spread Option

Selection Table).

6

FRS

I

Frequency range select. Digital logic input used to select input frequency

range (Refer Input/Output Frequency Deviation and Spread Option

Selection Table). This pin has an internal pull-up resistor.

7

VDD

P

Power supply for the entire chip (3.3V).

8

XOUT

I

Crystal connection. Input connection for an external crystal. If using an

external reference, this pin must be left unconnected.

Input/Output Frequency Range Selection Table

Part Number

ASM3P2811 (1X)

ASM3P2812 (2X)

ASM3P2814 (4X)

FRS (pin 6)

Input

(MHz)

Output

(MHz)

Input

(MHz)

Output

(MHz)

Input

(MHz)

Output

(MHz)

Modulation Rate

0

10-20

10-20

10-20

20-40

10-20

40-80

Input Frequency / 448

1

20-40

20-40

20-40

40-80

20-40

80-160

Input Frequency / 896