P1819

Rev.3 | Page 2 of 6 | www.onsemi.com

Pin Configuration

Pin Description

Pin#

Pin Name

Type

Description

P1819B

P1819G

1

1

XIN / CLKIN

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

2

VSS

P

Ground Connection. Connect to system ground.

3

SRS

I

Spread range select. Digital logic input used to select

frequency deviation (Refer to Spread Deviation Selection

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

3

3

D_C / NC

I

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

(HIGH) spread options (Refer to Spread Deviation

Selection

Table). This pin has an internal pull-up

resistor.

4

4

ModOUT

O

Spread spectrum clock output. (Refer to Input Frequency

and Modulation Rate

Table and Spread Deviation

Selection

Table).

5

5

REF

O

Non-modulated Reference clock output of the input

frequency.

6

6

PD#

I

Power down control pin. Pull XIN/CLKIN and PD# LOW

to enable Power-Down mode. This pin has an internal

pull-up resistor.

7

7

VDD

P

Power Supply for the entire chip.

8

8

XOUT

O

Crystal Connection. Input connection for an external

crystal. If using an external reference, this pin must be

left unconnected.

Note: Pin 3 is NC in P1819Q.

Input Frequency and Modulation Rate

Part Number

Input Frequency Range

Output Frequency range

Modulation rate

P1819

20MHz to 40MHz

20MHz to 40MHz

Input Frequency / 896

VDD

PD#

XOUT

REF

1

2

3

4

5

6

7

8

P1819 B

XIN / CLKIN

VSS

SRS

ModOUT

VDD

REF

1

2

3

4

5

6

7

8

P1819 G

XIN / CLKIN

VSS

D_C / NC

ModOUT

PD#

XOUT