M2050/51/52 Datasheet Rev 1.0

3 of 12

Revised 23Jun2005

Integ r ated Circuit Systems, Inc. ● Communications Modules ● www.ics t.com ● tel (508) 852-5400

M2050/51/52

Preliminar y In f o r m atio n

Integrated

Circuit

Systems, Inc.

Figure 3: Detailed Block Diagram

Mfin Divider Look-Up Tables (LUT)

(“Mfin”). Since the VCSO frequency is fixed, this allows

input reference selection. The look-up tables vary by

device variant.

M2050/51/52: Mfin Value LUT

Mfec and Rfec Divider Look-Up Tables (LUTs)

The look-up tables vary by device variant. The Mfec

and Rfec values also establish phase detector

frequency. A lower phase detector frequency improves

jitter tolerance and lowers loop bandwidth.

Phase

Locked

Loop

(PLL)

M2050, 51, 52

SAW Delay Line

Phase

Shifter

VCSO

C

POST

C

POST

VC

nVC

R

POST

nOP_OUT

OP_OUT

R

POST

R

LOOP

R

LOOP

C

LOOP

C

LOOP

OP_IN

nOP_IN

Phase

Detector

Loop Filter

Amplifier

External

Loop Filter

Components

FOUT0

nFOUT0

FEC_SEL1:0

FIN_SEL1:0

Rfec

Div

MUX

0

REF_SEL

DIF_REF0

nDIF_REF0

1

Mfin Divider

LUT

Mfin Divider

(1, 4, 5, 25)

Mfec Div

FOUT1

nFOUT1

P Divider

(1, 4, 5, 25,

or TriState)

P_SEL2:0

NBW

R

IN

R

IN

Mfec/Rfec Divider

LUT

DIF_REF1

nDIF_REF1

LOL

Phase Buildout Option

Hitless Switch Option

P Divider

LUT

FIN_SEL1:0

Mfin

Value

Sample Input Reference Freq. (MHz) Options

Note 1: For M2050 with Fvcso = 669.6429

Note 2: For M2051 and M2052 with Fvcso = 625.0000.

00

25

25.00

0 1

5

125.00

1 0

4

156.25

1 1

1

625.00

Table 3: M2050/51/52: Mfin Value LUT

FEC_SEL1:0

1

0

Description

Base Input

Rate (MHz)

Fvcso =

Base Output

Rate (MHz)

For M2050 with Fvcso = 644.5313 (10GbE to 10GbE LAN rate):

0 0

625.0000

644.5313

0 1

644.5313

644.5313

For M2050 with Fvcso = 669.6429 (10GbE to 10GbE 255/238 FEC rate):

1 0

625.0000

669.6429

1 1

669.6429

669.6429

For M2050 with Fvcso = 690.5692 (10GbE LAN to 10GbE LAN 255/238 FEC):

1 0

15 14

10GbE LAN

to 10GbE LAN

255/238 FEC

644.5313

690.5692

1 1

690.5692

For M2050 with Fvcso = 693.4830 (10GbE LAN to 10GbE LAN 255/237 FEC):

0 0

85 79

10GbE LAN

to 10GbE LAN

255/237 FEC

644.5313

693.4830

0 1

693.4830

Table 4: M2050: Map LUT (10GbE to LAN, 255/238 FEC, or 255/237 FEC)