November 2003

P2560B

rev 1.0

Low Frequency EMI Reduction

2 of 7

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

Pin Configuration

Standby Mode Selection

CLKIN

SSON/SBM

Spread Spectrum

ModOUT

PLL

Mode

Disabled

0

N/A

Disabled

Disabled

Standby

Disabled

1

N/A

Disabled

Free

running

Free running

Enabled

0

Off

Reference

Disabled

Buffer out

Enabled

1

On

Normal

Normal

Normal

Spread Range Selection, VDD = 3.3 V

CLKIN frequency

Spreading range

Modulation rate

20 MHz

±1.16%

25 MHz

±1.13%

27 MHz

±1.11%

30 MHz

±1.0%

32 MHz

±1.0%

(CLKIN/10) * 20.83 kHz

Pin Description

Pin#

Pin Name

Type

Description

1

XIN/CLK

I

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

functions. It can be connected to either an external crystal or an external

reference clock.

2

XOUT

O

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

unconnected.

3

DIV2

I

Digital logic input used to select normal output mode or divide-by-2 output mode.

When this pin is HIGH, the frequency of the output clock is the same as the input

clock frequency. When it is tied LOW, the output frequency is half the input clock

frequency. This pin has an internal pull-up resistor.

4

VSS

P

Ground to entire chip.

5

SR0

I

Digital logic input used to select Spreading Range (Refer Spread Deviation

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

6

SSON#

I

Digital logic input used to enable Spread Spectrum function (Active LOW).

Spread Spectrum function enabled when LOW, disabled when HIGH. This pin

has an internal pull-low resistor.

7

MODOUT

O

Spread spectrum low EMI output.

8

VDD

P

Power supply for the entire chip (5V).

P2560B