2

SY89426

Micrel, Inc.

M9999-112105

hbwhelp@micrel.com or (408) 955-1690

PACKAGE/ORDERING INFORMATION

28-Pin PLCC (J28-1)

Package

Operating

Package

Lead

Part Number

Type

Range

Marking

Finish

SY89426JC

J28-1

Commercial

SY89426JC

Sn-Pb

J28-1

Commercial

SY89426JC

Sn-Pb

J28-1

Industrial

SY89426JY with

Matte-Sn

Pb-Free bar line indicator

Pb-Free

J28-1

Industrial

SY89426JY with

Matte-Sn

Pb-Free bar line indicator

Pb-Free

Notes:

1. Contact factory for die availability. Dice are guaranteed at T

2. Tape and Reel.

3. Pb-Free package is recommended for new designs.

26

27

28

1

2

3

4

18

17

16

15

14

13

12

25 24

23

22

21 20

19

56

7

8

9

10

11

GND

PLCC

TOP VIEW

J28-1

CK622P

CK622N

CK155

GND

GND

SEL39

RFCK

NC

SEL78

INPUTS

RFCK [Reference Clock] TTL

Reference clock IN. (38.88, 51.84 or 77.76MHz).

SEL39 [38.88MHz Select] TTL

Logic HIGH on this pin denotes a 38.88MHz input reference

clock. Tie to logic LOW if input is not 38.88MHz.

SEL78 [77.76MHz Select] TTL

Logic HIGH on this pin denotes a 77.76MHz input reference

clock. Tie to logic LOW if input is not 77.76MHz.

RST [Reset] TTL

Tie to logic LOW for normal operation; logic HIGH forces reset

of internal Phase Detector & feedback dividers.

FLTRP, FLTRN [Loop Filter, Pos & Neg] Analog

Connect a series RC loop filter between these pins. The

suggested RC values are 500

Ω and 0.1µF, as shown in the

Typical Application.

DISC [Disable Clock] TTL

Logic HIGH on this pin disables the Retimed Reference Clock

output RETRFCK); if this output is not required, it is

recommended that it be disabled to reduce switching noise. A

logic LOW enables the output.

PIN DESCRIPTION

OUTPUTS

CK622P, CK622N [622 Clock Output] Differential PECL.

622.08MHz output clock from PLL B.

CK155 [155 Clock Out] Single-ended PECL

155.52MHz output clock.

RETRFCK [Retimed Reference Clock Out] TTL

An output clock with the same frequency as the input Reference

Clock (RFCK) and a 45-55% duty cycle. This output is derived

by dividing the 622.08MHz output by the appropriate factor

(e.g., divide by 16 for a 38.88MHz inout reference; divide by

12 for 51.84Mhz in; or divide by 8 for 77.76MHz in).

POWER & GROUND

+5V for internal circuits.

+5V for PECL outputs.

GND

Ground (0 volts).