Preliminary

PLL650-04

Low EMI Clock for 10/100 PHY and Gigabit Ethernet

47745 Fremont Blvd., Fremont, California 94538 Tel (510) 492-0990 Fax (510) 492-0991 www.phaselink.com Rev 05/31/05 Page 1

FEATURES

• Full CMOS output swing with 25-mA output drive

capability at TTL level.

• Advanced, low power, sub-micron CMOS processes.

• 25 MHz fundamental crystal or clock input.

• Low jitter (< 80ps cycle-to-cycle)

• 25 MHz and 50 MHz outputs

• Five CLKOUT selectable between 90, 100, 125, 133,

145 and 150 MHz.

• SSTE (SST Enable) Low EMI selector for CLKOUT.

• Output enable functionality.

• Zero PPM synthesis error in all clocks.

• Ideal for Network switches.

• 3.3V operation.

•

DESCRIPTION

The PLL650-04 is a low cost, low jitter, and high

performance clock synthesizer. With PhaseLink proprietary

analog Phase Locked Loop techniques, the chip accepts

25.0 MHz crystal, and produces multiple output clocks for

networking chips. A CLKOUT signal of selectable

frequency (25MHz, 48MHz, 50MHz, 90MHz, 100MHz,

125MHz, 133MHz, 145MHz or 150 MHz) is available at 5

output pins. Through an SST enable (SSTE) selector, the

CLKOUT signal can be modulated to reduce EMI through

Spread Spectrum Technology. Output enable selectors are

available to enable/disable the output signals.

PIN CONFIGURATION

SELECTION TABLE

FS1

FS0

CLKOUT

SSTE

SST

MODULATION

0

0

90 MHz

0

±0.25% Center

0

M

100 MHz

1

OFF

0

1

125 MHz

1

0

133 MHz

1

M

145 MHz

1

1

150 MHz

Tri-level input pins: 0 = connect to GND

M= not connected, 1 = connect to VDD

BLOCK DIAGRAM

1

2

3

4

5

6

7

8

13

14

15

16

17

18

19

20

VDD

50M_EN^

25MHz/25M_EN*^

GND

50MHz

GND

CLKOUTº

FS0

XIN

XOUT/SSTE*^

GND

VDD

CLKOUT_EN^

VDD

CLKOUTº

CLKOUTº

Note: ^: Internal pull-up resistor *: Bi-directional pin º: Low EMI output

9

10

11

12

CLKOUTº

GND

FS1^

CLKOUTº

XTAL

OSC

25MHz

XIN

XOUT

50MHz

CLKOUT (90 100, 125, 133,

145 or 150 MHz)

Control

Logic

FS (0:1)

1

1

5

SSTE

(SST enable)

50M_EN (enable)

25M_EN (enable)

CLKOUT_EN (enable)