Page 15

Name

Ref.

Desg.

Description

+B

J1

This is the positive supply pin usually connected to +12VDC.

RXIN

J2

This is the input to the audio band pass filter in RX mode.

TXIN

J3

This is the TX Audio Input pin. In the TX mode it may be pre-filtered, using the

TX audio path, Thus helping to avoid talkoff due to intermodulation of low

frequency speech components with the transmitted CTCSS tone.

TXOUT

J4

This is the band pass filtered transmit audio output pin. In TX mode the pin

outputs audio present at the TX audio input pin.

PTL

J5

In RX mode this pin operates as a "Push To Listen" function by enabling the RX

audio path, thus overriding the tone squelch function. Tying PTL to ground will

inhibite audio through the RX audio path till a CTCSS tone is decoded or “No

Tone” is selected on D0-D5

RXOUT

J6

This is the band pass filtered receive audio output pin. This pin outputs audio

when RX tone DECODE is true or PTL is true or when Notone is programmed.

PTT

J7

Logic level input pulled low to enable transmitt mode.

TONEOUT

J8

The CTCSS sine wave output appears on this pin under control of the PTT

input. The level is adjusted using R3.

CARRIER

SENSE

J9

Input that can be connected to the radios carrier sense logic to enable the

CTCSS decoder only when a carrier is present.

DECODE

J10

This is an open collector output used to mute the RX audio path or control

squelch circuitry in a system. It provides a path to ground when a CTCSS tone is

not present and is open collector when a CTCSS tone is detected.

MONIT R

0

J11

This pin will have a +5VDC output till a CTCSS tone is detected. Alternatively

this pin can be used to disable the open collector DECODE output pin and can

0

function.

+5V

J12

This pin is an alternative supply pin that can be connected to an external DC

supply to evaluate performance of the MX465 at supply voltages below 7.0 VDC.

GND

J13

Connection to ground.

SERIAL DATA

J14

In serial operation, Data to control the MX465 is clocked in on this logic input.

Refer to the MX465’s data sheet for operation.

SERIAL CLOCK

J15

Control data is clocked into the MX465 based on the rising and falling edge of

this logic input.

LOAD LATCH

J16

Data is either in the process of loading into the MX465 control registers or is

latched into the MX465’s internal registers using this logic input pin.

Table 2: Connector Signal Descriptions