CKTX: The transmit clock is dependent on the Baud-Rate setting BD1,2.

BD1

BD2

division factor fom CKSYS

Baud-Rate (CKTX)

0

0

600Hz

1

0

1200Hz

0

1

1200Hz

1

1

2400Hz

IF-SCCLK: The intermediate frequency SC-filter is settable to two different modes, one for

dF=600Hz and the other for dF=1200Hz (dF=Fspace-Fmark). These modes are defined by the

SC-clock frequency which is generated in the timing block.

BD1

BD2

IFcenter

IFbandw

division factor fom CKSYS

IF-SC-CLK

0

X

2700Hz

1200Hz

57.6kHz

1

X

5400Hz

2400Hz

115.2kHz

1.2 TRANSMITTER

M/S-UDC

BD1

TXD

SUM

9

FSYNTH

DIV16

DAC

TxEn

CKSYS

FSYNTH

SUM

BD1

SCCLK

SC-CLK

AAF

BPFa

TXI

SC-CLK

BPFb BPFc

OutStage

TxOut1

TxFb

M1M

P1M

BIAS

FREG-GEN

BPF & OutStage

Switched Cap Filter Clock Generator

TX-FSK / MIXER-Fref Generator

Fmixer

AGND

CKTX

FG

BD1,2

MRK-REG

(+20,

+40)

(+0..4,

+0..8)

0..511

SMF

TxOut2

TxEnI

PLL

AFCF

DIVn

AS5501 / AS5502 Multimode Powerline Modem

Data Sheet

Rev A, May 2000

Page 8/25