TCM8000

CELLULAR TELEPHONE AUDIO PROCESSOR

SCTS041A – D4086, AUGUST 1992 – REVISED APRIL 1993

POST OFFICE BOX 655303

3

Terminal Functions

PIN

NAME

NO.

I/O

DESCRIPTION

NAME

FN

FR

CIN

31

36

I

Compressor analog input

CMPR

35

40

I

Compressor rectifier analog input

CO

34

39

O

Compressor analog output. CO should be ac coupled to TXVI and to CMPR.

CTC

32

27

O

Compressor time constant control, analog output. A 220-nF capacitor should be connected between CTC and

GND.

CTI

13

18

I

Call tone analog input. Signals on CTI are summed into the receive voice path prior to the volume control

circuit. CTI can be muted under control of the serial interface.

CVE

33

38

I

Compressor virtual earth, analog input

DAC

7

12

O

Digital-to-analog converter output, programmable between GND and VCC /2 in sixteen steps

DATA

5

10

I

Serial interface digital data input

DCLK

6

11

I

Serial interface digital clock input

ETC

17

22

O

Expander time constant control, analog output. A 220-nF capacitor should be connected between ETC and

GND.

EXIN

16

21

I

Expander analog input

EXO

15

20

O

Expander analog output. EXO should be ac coupled to RXVI.

GND

19

24

Ground

HFO

11

16

O

Normal drive receiver voice analog output

HSO

10

15

O

High drive receiver voice analog output

LIMIN

39

44

I

Transmit limiter analog input

LOAD

43

4

I

Serial interface load, digital input. Data shifted into DATA under control of DCLK is transferred to internal

registers when LOAD goes high.

M1N

25

30

I

Preamplifier 1 negative analog input

M1O

23

28

O

Preamplifier 1 analog output

M1P

24

29

I

Preamplifier 1 positive analog input

M2N

27

32

I

Preamplifier 2 negative analog input

M2O

28

33

O

Preamplifier 2 analog output

M2P

26

31

I

Preamplifier 2 positive analog input

POUT

38

43

O

Preemphasis filter analog output. POUT should be ac coupled to LIMIN.

PSO

42

3

O

Analog output of SAT filter

REF

3

8

Unbuffered midsupply voltage, nominal output VCC /2

RXDO

9

14

O

Receive data filter analog output

RXIN

18

23

I

Receive analog input

RXLIM

8

13

I/O

Receive limiter adjust voltage, controls maximum signal output on HSO. The dc input is between GND and

VCC /2.

RXO

4

9

O

Receive voice filter analog output

RXVI

14

19

I

Receive voice analog input to volume control circuit. RXVI can be muted under control of the serial interface.

ST

12

17

I

Side tone analog input. Signals on this terminal are summed into the HSO output signal.

TDI

29

34

I

Tone of DTMF analog input. Signals on this terminal can be used in place of the main voice signal in the TX

path and summed into the RX voice path, under control of the serial interface.

TXDA

22

27

I

Transmit data analog input

TXLIM

37

42

I

Transmit-limiter level adjust, controls maximum signal level at TXO. The dc input is between GND and VCC /2.

TXO

40

1

O

Transmit section analog output

TXSUM

41

2

I

Transmit summing analog input. The signal on TXSUM is summed into the main TX output after all filter stages.

TXSUM can be muted under control of the serial interface.

TXVI

36

41

I

Transmit voice analog input

TXVO

30

35

O

Transmit voice analog output. TXVO is the output from the preamplifier and microphone gain adjust sections.

It should be ac coupled into the compressor input CIN.

VBRX

2

7

Buffered midsupply voltage to receive sections, nominal output VCC /2