P2779A

http://onsemi.com

2

Figure 1. Block Diagram

XIN

REF

XOUT

Crystal

Oscillator

VSS

LF

VDD

Frequency

Divider

Feedback

Divider

Modulation

Loop

Filter

VCO

PLL

Output

Divider

ModOUT

PD

Phase

Detector

Table 1. ABSOLUTE MAXIMUM RATINGS

Symbol

Parameter

Rating

Unit

Voltage on any pin with respect to Ground

−0.5 to +4.6

V

Storage temperature

−65 to +125

°C

Operating temperature

−40 to +85

°C

Max. Soldering Temperature (10 sec)

260

°C

Junction Temperature

150

°C

Static Discharge Voltage (As per JEDEC STD22− A114−B)

2

KV

Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the

Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect

device reliability.

Table 2. PIN DESCRIPTION

Pin#

Pin Name

Type

Description

1

XIN / CLKIN

I

Connect to crystal or clock input.

2

XOUT

O

Crystal output.

3

PD

I

Power−down control pin. Pull low to enable power−down mode.

This pin has an internal pull−up resistor. (Note 1)

4

LF

I

External loop filter for the PLL. By changing the value of the CRC circuit,

the percentage spread can be adjusted accordingly.

(See Loop Filter Selection Table for detail values.)

5

VSS

P

Ground connection. Connect to system ground.

6

ModOUT

O

Spread spectrum clock output.

7

REF

O

Provides a reference clock output of the input frequency.

8

VDD

P

Connect to +3.3 V.

1. Connect to VDD if not used.