P2180

Rev. 2 | Page 2 of 6 | www.onsemi.com

Block Diagram

Pin Diagram

Pin Description

Pin#

Pin Name

Type

Description

1

XIN

I

Connect to externally generated clock signal or crystal.

2

NC

No connect.

3

VSS

P

Ground to entire chip.

4

SRS

I

Spread Range Select. Digital logic input used to select frequency deviation Refer

Spread Deviation Selections Table

. This pin has an internal pull-up resistor.

5

ModOUT

O

Spread spectrum low EMI output.

6

VDD

P

Connect to +3.3V.

7

NC

No connect.

8

NC

No connect.

1

2

3

4

5

6

7

8

XIN

VSS

SRS

P2180X

VDD

NC

ModOUT

NC

NC

XIN

XOUT

VSS

Frequency

Divider

Feedback

Divider

Modulation

Phase

Detector

Loop

Filter

VCO

Output

Divider

ModOUT

PLL

VDD

SRS

Crystal

Oscillator