Mux-State 1(IF-Test):

In this mode the IFBPF can be measured by forcing the IFI via pin TST-IN and measuring

IFO via pin TST-OUT. With pin CKSYS the FSK-ZC signal can be measured.

Mux-State 2 (TXPATH / RXO):

In this mode the TXPATH can be measured by forcing TXI via pin TST-IN and measuring

the TX-Output-Stage output. The SC-CLK can be measured via pin CKSYS. The receiver

bandpass filter can be measured by forcing RXIN and measuring TST-OUT (RXO).

Mux-State 3 (DPLL / DATAFIL):

In this mode the input of the RX-DPLL can be forced by TST-IN for digital verification of

this block. Further the output of the data LP-filter can be measured at TST-OUT. The

MIXER- PLL output can be measured via pin CKSYS.

TX Timeout / RES-Delay Test-Mode: With bit "Test2" set to 1 the TX-timeout (3sec) and

the RES-Delay (300ms) gets reduced by a factor of 256 for production test.

ASYN Test-Mode: The contol-bit "ASYN" is used for global verification of the

receiver-block and especially for verification of the MIXER and the DataFilter by measuring

the RXDA-jitter (isochronous-distortion).

TST-OUT

op

MUX

VREF

IFO

RXO

MUX

TST-IN

IFI

TXI

1

1

0

2

3

nc.

0

2

DPLL-IN

3

op

D F O

1.5 Supply and Analog Ground

There are two different pairs of supply pins, one for analog (AVSS,AVDD) and one for

digital (DVSS, DVDD). The two VSS-pins have to be at the same level to avoid

substrate-current. The two VDD-pins should not differ more than 0.25V. The reason for

splitting the supply lines is to avoid noise from the digital circuit injected to the analog

section.

The analog-ground is generated by resistive division of the supply-voltage to AVDD/2. Since

the SC-clock is working in the range of >1MHz, an external capacitor of 1uF is needed to

decouple the AGND to AVSS.

There has to be sufficient decoupling from AVDD to AVSS and from DVDD to DVSS

separately. Usually a combination of a 10uF tantal and 100nF ceramic-capacitor is used

dependent on the supply structure.

AVSS

AGND

AVDD

DVDD

DVSS

1uF

100n

10uF

10uF

100nF

+5V

+5V

0V

AS5501 / AS5502 Multimode Powerline Modem

Data Sheet

Rev A, May 2000

Page 17/25