А4

(continued)

PIN

NAME

DESCRIPTION

23

XDC

Transmit detector output. A resistor and capacitor at his pin hold the system in the transmit mode during

pauses between words or phrases. When the XDC pin voltage decays to ground, the attenuators switch

from the transmit mode to idle mode. The internal resistor at XDC is nominally 2.6k ohms(see fig.1).

24

VLC

Volume control input>connecting this pin to the slider of a variable resistor provides receive mode

volume control. The VLC pin voltage should be less than or equal to VB

25

ACF

Attenuator control filter. A capacitor connected to this pin reduces noise transient as the attenuator

control switches level of attenuation

26

RXO

Output of the receive attenuator. Normally this pin is ac coupled to the input of the speaker amplifier

27

RXI

Input of the receive attenuator. Input impedance is nominally is 5.0k ohms

28

RRX

A resistor to ground determines the nominal gain of the receive attenuator. The receive channel gain is

directly proportional to the RRX resistance

PARAMETER

SYMBOL

MIN

TYP

MAX

UNIT

SUPPLY VOLTAGES

V+ Supply Current

V+=11V, Pin 18=0.7V

V+=11V, Pin 18=1.6V

9.0

800

mA

A

VCC Voltage (V+=7.5V)

Line

Regulation (6.5V<V+<11V)

Vcc

Vccsat

4.9

5.4

65

6.0

80

5.9

150

20

300

Vdc

MV

ohms

mV

VB Voltage(V+=7.5V)

Vb

Rovb

2.5

2.9

250

3.3

Vdc

ohms

ATTENUATORS

Receive Attenuator Gain (1.0kHz)

Rx Mode, Pin 24= VB, Pin 27 =

250Mvrms

Range (Rx to Tx Modes)

Idle Mode, Pin 27= 250mVrms

2.0

40

-20

6.0

44

-16

10

48

-12

dB

dB

dB

RXO Voltage (Rx Mode)

1.8

2.3

3.2

mV

Delta RXO Voltage (Switch from Rx

to Tx Mode)

100

mV

RXO Sink Current (Rx mode)

75

A

TXO Source Current (Tx mode)

1.0

3.0

mA

TXO Input Resistance

3.5

5.0

8.0

k

ACF Voltage (VCC-Pin 25 Voltage)

Rx Mode

Tx Mode

Idle Mode

150

6.0

75

mV

mV

mV

SPEAKER AMPLIFIER

Speaker Amp Gain (pin 19 = 20mVrms)

33

34

35

dB

SKI Input Resistance

15

22

37

k

SKO Voltage ( Pin 19 =Cap couple

to GND)

2.4

3.0

3.6

Vdc

SKO High Voltage ( Pin 19 = 0.1V,

-100mA Load at Pin 15)

5.5

Vdc

SKO Low Voltage (pin 19=0.1V,

+100mA Load at Pin 15)

600

mV

MICROPHONE AMPLIFIER

Microphone Amp Gain

( Pin 9 = 10mVrms,1KHz)

32.5

34

35

dB

Microphone Amp Input Resistance

6.5

10

16

k

LOGAMPS

RLO Leakage Current (Pin 8 = VB+1.0V)

2.0

A

TLO Leakage Current (Pin 6 = VB+1.0V)

2.0

A

Transmit-Receive Switching

20 A - to Switch Tx-Rx Comparator)

25

TRANSMIT DETECTOR

XDC Voltage

Idle Mode

Tx Mode

0

4.0

Vdc Vdc

CP2 Current Source

5.0

10

13

A

Distortion

Rx Mode

RXI to SKO

(pin 27 = 10mVrms,1KHz)

1.5

%

Tx Mode

MCI to TXO

(Pin 9 = 5mVrms,1KHz)

2.0

%

Note 1:V+=7.5V, CS =0.7V except where noted.

Note 2:Rx mode:pin7=-100 A, pin5=+100 A, except where noted

Tx mode: pin 5,13=-100 A, pin 7=+100 A, pin 11=0V. Idle mode: Pin 5=-100A, pin 7,13=+100 A

Note 3:Current into a pin designed as + ,current out of a pin designed -;

Note 4:Voltage referred to pin 22,Tamb=25 C