Datasheet MX014P, MX014J Datasheet (MX COM)

DATA BULLETIN

MX014

Voice Band inverter

Features Applications

•

CTCSS Compatible

•

Fixed Frequency Inversion

•

Low Power CMOS

TX Audio Feedback

TX Audio In

BIAS

RX Audio In

RX Audio Feedback

Rx Path

RX Path

6dB/Octave

Pre-emphasis

10dB Gain

Bandpass

Filter

300-3033 Hz

Filsav1

Filter

BALMOD

Carrier

•

Land Mobile Radio Systems

•

Community Repeaters

PathInv ert

Bandpass

Filter

300-3033 Hz

BPF Out

6dB/Octave

De-emphasis

Filsav1

Filsav2

DEEMP Out

TX

TX BufferIn

RX BufferIn

BIAS

RX Path

TX Audio Out

TX

RX Audio Out

Clock

Clock

PTT
PTT

RX Audio Enable
RX Audio Enable

PTL
PTL

Privacy Enable

3333 Hz

LOGIC

Carrier

Filsav1
Filsav2

RX Path

EMPSAV
TX

PathInv ert

CLK

3333 Hz

CLK Generator

V

DD

V

SS

BIAS

The MX014 Voice Band Inverter gives the security of private voice communications to land mobile radio users, as well as
to the users of other shared radio channel systems. Designed for use in half-duplex systems, the MX014 exchanges high
and low frequencies in the voiceband and renders transmitted messages unintelligible. This privacy function is achieved
by a single frequency inversion. When used with CTCSS,

SQUELCH

Pvt

TM

privacy adapter operation is achieved.

Sharp cut-off in the internal voiceband filters permits operation with CTCSS and similar sub-audio signaling schemes. This
results in high quality recovered audio.

The core of the MX014 consists of two audio band pass filters and a balanced modulator. The device uses a
programmable clock divider which controls the carrier and filter cut-off frequencies. Control of the RX/TX, PTL and
privacy function is by pin selection.

The MX014 operates from a single 5V supply and uses a 4 MHz crystal oscillator to ensure the correct pitch in recovered
speech. Signal coupling and decoupling are the only external components needed. The device is available in 24-pin
PLCC (MX014LH), 24-pin PDIP (MX014P) and 24-pin CDIP (MX014J) packages.

 1997 MX•COM, INC. www.mxcom.com Tele: 800 638 5577 910 744 5050 Fax: [phone] Doc. # 20480013.006

4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by there respective companies.

Voice Band Inverter 2 MX014

CONTENTS

Section Page

1. Block Diagram.................................................................................................................................. 3

2. Signal List......................................................................................................................................... 4

3. External Components...................................................................................................................... 5

4. Application ....................................................................................................................................... 6

5. Performance Specification.............................................................................................................. 8

5.1 Electrical Performance.............................................................................................................................. 8

5.1.1 Absolute Maximum Ratings...............................................................................................................................8

5.1.2 Operating Limits.................................................................................................................................................8

5.1.3 Operating Characteristics ..................................................................................................................................8

5.2 Packaging ................................................................................................................................................ 10

MX•COM, Inc. reserves the right to change specifications at any time and without notice.

 1997 MX•COM, INC. www.mxcom.com Tele: 800 638 5577 910 744 5050 Fax: [phone] Doc. # 20480013.006

4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by there respective companies.

Voice Band Inverter 3 MX014

1. Block Diagram

TX Audio Feedback

TX Audio In

BIAS

RX Audio In

RX Audio Feedback

RX Audio Enable
RX Audio Enable

Privacy Enable

Rx Path

PTT
PTT

PTL
PTL

RX Path

3333 Hz

6dB/Octave

Pre-emphasis

10dB Gain

LOGIC

Bandpass

Filter

300-3033 Hz

Filsav 1

Carrier

Filsav 1
Filsav 2

RX Path

EMPSAV
TX

Path Invert

Filter

BALMOD

Carrier

Path Invert

Bandpass

Filter

300-3033 Hz

Filsav 2

CLK

3333 Hz

BPF Out

6dB/Octave

De-emphasis

Filsav 1

CLK Generator

TX

DEEMP Out

TX Buffer In

RX Buffer In

BIAS

RX Path

TX

V

DD

V

SS

BIAS

TX Audio Out

RX Audio Out

Clock

Clock

Figure 1: Device Block Diagram

 1997 MX•COM, INC. www.mxcom.com Tele: 800 638 5577 910 744 5050 Fax: [phone] Doc. # 20480013.006

4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by there respective companies.

Voice Band Inverter 4 MX014

2. Signal List

Pin No. Name Description

1 XTAL An external 4MHz clock can be applied to this input. The clock circuit on chip has a resistor

and capacitors so that only one external crystal is required.

2

XTAL

3PTT
4

PTT

5PTL
6

PTL

7 RXAUDEN
8

RXAUDEN

9 PRIVEN Privacy Enable controls the input action of the balanced modulator by switching the carrier

10 RXOUT This is the receive audio output pin. It is biased at VDD/2 when in the TX mode.
11 TXOUT This is the “send” voice output pin. It is biased at VDD/2 when in RX mode.
12 V

SS

13 BPFOUT For a gain of one in the RX Output stage, these two pins are wire linked together. However,
14 RXBIN

15 DEMPOUT The pre-emphasis circuit has a 10dB gain at 1 kHz. Additional gain, or attenuation can
16 TXBIN
17 BIAS This is the internally generated VDD/2 decoupling pin.
18 FILTR This filter is the output of the Input Audio BPF and must be a.c. coupled into the Balanced

19 BALMOD This is the input to the balanced modulator. It must be a.c. coupled to the Filter Output.
20 RXIN This is a negative input of an op-amp at the input of the RX path. It can be used, along with

21 RXFB RX Audio Feedback is the output of an op-amp at the input of the RX path. See RXIN.
22 TXIN The negative input of an op-amp at the input of the TX path. It can be used, along with TX

23 TXFB TX Audio Feedback is the output of an op-amp at the input of the TX path. See TXIN.
24 V

DD

This is the inverted 4MHz clock output for use when a crystal oscillator is used, or as a buffer
for driving other clocked devices.

Push To Talk is an input with a 3MΩ pull-down resistor.
This is the inverted PTT output. It has a 100kΩ output impedance.
Push To Listen is an input with a 3MΩ pull-down resistor.

Push To Listen

is the inverted output of PTL; it has a 100kΩ output impedance.

RX Audio Enable is an input with a 3MΩ pull-down resistor.

RX Audio Enable

is the inverted output of RX Audio Enable; it has a 100kΩ output impedance.

clock. When audio signals are inverted, the signal path gain is adjusted automatically to
compensate for the upper sideband loss. It contains a 3MΩ pull-down resistor.

The negative supply pin (ground).

if gain is introduced at the RX input, attenuation may be introduced at the RX Output using
these pins and two resistors.

be introduced as in the RX path.

Modulator Input through a 0.1µF capacitor.

RX Audio Feedback and two external resistors, to increase the signal to its optimum level prior
to frequency inversion/filtering. This may improve the S/N.

Audio Feedback and two external resistors, to increase the signal to its optimum level prior to
frequency inversion/filtering. This may improve S/N.

The positive supply pin.

Table 1: Signal List

 1997 MX•COM, INC. www.mxcom.com Tele: 800 638 5577 910 744 5050 Fax: [phone] Doc. # 20480013.006

4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by there respective companies.

Voice Band Inverter 5 MX014

g

g

g

g

3. External Components

Configuration for Radios with

Existing Pre- and De-emphasis.

X1

1

MX014

XTAL

2

XTAL

3

PTT

4

PTT

5

PTL

6
7
8

9

10
11

12

PTL
RXAUDEN
RXAUDEN
PRIVEN
RXOUT

TXOUT
V

BALMOD

DEMPOUT

SS

TX Attenuation
For a

ain of 1, R8 , R7 0

BPFOUT

24

V

DD

23

TXFB

22

TXIN

21

RXFB

20

RXIN

19
18

FILTR

17

BIAS

TXBIN

16
15
14

RXBIN

13

Figure 2: External Components Connections

R8

=

+

R7 R8

=∞ =

R1

R3

R7

R5

C4

V

DD

R2

R4

C3

R8

R6

C1

C2

Bias

Bias

TX Channel

RX Channel

For Use in Radios without

Pre- and De-emphasis.

1

MX014

X1

TX Attenuation

For a

XTAL

2

XTAL

3

PTT

4

PTT

5

PTL

6

PTL

7

RXAUDEN

8

RXAUDEN

9

PRIVEN

10
11

12

RXOUT
TXOUT

V

SS

DEMPOUT

ain of 1, R9 0, R10

24

V

DD

23

TXFB

TXIN

RXFB

RXIN

BALMOD

FILTR

BIAS

TXBIN

RXBIN

BPFOUT

=

R9 R10

R10

R1

22
21

R3

20
19
18

17

C4

16
15

R11

14
13

+

==∞

R9

V

DD

R2

R4
C3

R10
R12

C1

C2

TX Channel

RX Channel

Bias
Bias

RX Attenuation
For a

ain of 1, R6 , R5 0

R6

=

R5 R6

=∞ =

+

RX Attenuation
For a

ain of 1, R11 0, R12

R12

=

+

R11 R12

==∞

Table 2: Gain and Attentuation Calculations

Recommended External Component Notes:

1. Component Values: C1- C3 = 0.1 µF, C4 = 1.0 µF, X1 = 4 MHz crystal

2. R1 to R12 values will depend on the configuration and the gain or attenuation required. However R1, R3, R5, R7,
and R11 should be 100 kΩ or greater. To add gain or attenuate, use R5-R12 as shown. See pin descriptions for
more information.

3. For best results, a crystal oscillator design should drive the clock inverter input with signal levels of at least 40% of
VDD, peak to peak. Tuning fork crystals generally cannot meet this requirement. To obtain crystal oscillator
design assistance, consult your crystal manufacturer.

 1997 MX•COM, INC. www.mxcom.com Tele: 800 638 5577 910 744 5050 Fax: [phone] Doc. # 20480013.006

4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by there respective companies.

Voice Band Inverter 6 MX014

4. Application

BIAS

R8

C1

R7

TX Channel

TX Audio Feedback

C1

RX Channel

R2

C2

R1

TX Audio In

R4

BIAS

R3

­+

BIAS

RX Audio In

RX Audio Feedback

6dB/Octave

Pre-emphasis

+

-

10dB Gain

Note: Dotted Lines contain on-chip functions

Bandpass

Filter

300-3033 Hz

Bandpass

Filter

300-3033 Hz

Filter

C3

Filter

BALMOD

Carrier

BALMOD

Carrier

Bandpass

300-3033 Hz

Path Invert

Bandpass

Filter

300-3033 Hz

Path Invert

Filter

BPF Out

-6dB/Octave

De-emphasis

R5

DEEMP Out

BIAS

TX Audio Out

TX Buffer In

R6

RX Buffer In

RX Audio Out

TX

RX

Figure 3: Voice Privacy Application (Add-on)

 1997 MX•COM, INC. www.mxcom.com Tele: 800 638 5577 910 744 5050 Fax: [phone] Doc. # 20480013.006

4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by there respective companies.

Voice Band Inverter 7 MX014

BIAS

R10

C1

R9

TX Channel

TX Audio Feedback

C1

RX Channel

R2

R1

TX Audio In

C2

R4

BIAS

­+

RX Audio In

R3

RX Audio Feedback

Pre-emphasis

BIAS

6dB/Octave

10dB Gain

+

-

Note: Dotted Lines contain on-chip functions

Bandpass

Filter

300-3033 Hz

Bandpass

Filter

300-3033 Hz

Filter

C3

Filter

BALMOD

Carrier

BALMOD

Carrier

PathInvert

Bandpass

Filter

300-3033 Hz

PathInvert

Bandpass

Filter

300-3033 Hz

BPF Out

-6dB/Octave

De-emphasis

R11

DEEMP Out

TX Audio Out

TX BufferIn

BIAS

R12

RX BufferIn

RX Audio Out

TX

RX

Figure 4: Voice Processing Application (OEM)

 1997 MX•COM, INC. www.mxcom.com Tele: 800 638 5577 910 744 5050 Fax: [phone] Doc. # 20480013.006

4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by there respective companies.

Voice Band Inverter 8 MX014

5. Performance Specification

5.1 Electrical Performance

5.1.1 Absolute Maximum Ratings

Exceeding these maximum ratings can result in damage to the device.

General Min. Max. Units

Supply Voltage -0.3 7.0 V
Input Voltage at any pin

(ref. VSS + 0 V) -0.3 (VDD + 0.3 ) V

Current:

V

DD

V

SS

Any other pin 20 mA

J / P / LH Packages

Maximum Device Dissipation at T

= 25°C 800 mW

AMB

Derating above 25°C 10 mW/°C above 25°C
Operating Temperature Range: -40 85 °C
Storage Temperature Range: -55 125 °C

30 mA
30 mA

5.1.2 Operating Limits

Correct operation of the device outside these limits is not implied.

Min. Typ. Max. Units

V

DD

4.5 5.0 5.5 V
Clock Frequency 4.0 MHz
Operating Temperature -40 85 °C

5.1.3 Operating Characteristics

For the following conditions unless otherwise specified:
V

= 5.0V at T

DD

Clock Frequency = 4.0MHz, 0dB reference = 300mV
exceed 300mV

= 25°C

AMB

at 1kHz in Tx and 500mV

RMS

(Note: Measured at pin 18, the FILTR output. This pin must not

RMS

at any frequency in Rx, or clipping may occur. The difference in levels is

RMS

due to the pre-emphasis filter in the Tx path.

Notes Min. Typ. Max Units

Static Values

Supply Current:
RX/TX Operating (Private) 11.0 mA
RX/TX Operating (Clear) 8.0 mA
Standby 4 1.8 mA
Audio Input Impedance 10
Audio Output Impedance 5 0.5
Digital Output Impedance(Pulldown) 1
Digital I/O Impedance 100
Input Logic “1” 70% V
Input Logic “0” 30% V

M

M

Ω

Ω

k

Ω

Ω

k

DD
DD

 1997 MX•COM, INC. www.mxcom.com Tele: 800 638 5577 910 744 5050 Fax: [phone] Doc. # 20480013.006

4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by there respective companies.

Voice Band Inverter 9 MX014

Notes Min. Typ. Max Units

RX Clear Performance

Total Harmonic Distortion 1 2 5 %
Output Noise Level 2 2 mV

RMS

Passband Gain 0 dB
Passband Ripple (300-3033 Hz) 1 -3 +2 dB
Stopband Attenuation

(fin > 3333 Hz) 20 dB
(fin > 3633 Hz) 45 dB
(fin < 250 Hz) 42 dB

RX Inverted

Total Harmonic Distortion 1,3 4 %
Output Noise Level 2,3 4 mV

RMS

Passband Ripple (300 - 3033 Hz) 3 4 dB
Stopband Attenuation

(fin > 3333 Hz) 50 dB
(fin > 3633 Hz) 60 dB

Highpass Attenuation

(fin < 250 Hz) 60 dB

TX Clear

Total Harmonic Distortion 1 2 5 %
Output Noise Level 2 2 mV

rms

Passband Gain

(fin = 300 - 3033 Hz) 1 0 dB

Passband ripple

(fin = 300 - 3033 Hz) 1 4 dB

Stopband Attenuation

(fin > 3333 Hz) 2 20 dB
(fin > 3633 Hz) 45 dB
(fin < 250 Hz) 42 dB

TX Inverted

Total Harmonic Distortion 1,3 4 %
Output Noise Level 2 4 mV

rms

Passband Ripple

(fin = 300 - 3333 Hz) 1,3 4 dB

Stopband Attenuation

(fin > 3333 Hz) 3 50 dB
(fin > 3633 Hz) 3 60 dB
(fin < 250 Hz) 3 60 dB

Pre-Emphasis

Frequency Response 6 dB/Octave
Gain at 1 kHz 10 dB

De-emphasis

Frequency response -6 dB/Octave
Gain at 1 kHz 0 dB

 1997 MX•COM, INC. www.mxcom.com Tele: 800 638 5577 910 744 5050 Fax: [phone] Doc. # 20480013.006

4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by there respective companies.

Voice Band Inverter 10 MX014

Operating Characteristics Notes:

1. Input signal = 1kHz tone 0dB (300 mV

RMS

)

2. Input AC short circuit, audio path enabled. Measured in 30 kHz band

3. Due to frequency inversion (and pre- and de-emphasis), this refers to deviation from expected ideal response

4. Standby occurs in RX with RX Audio Enable = 0, RX Audio Enable = 1, and PTL = 1

5. TX Audio Out and RX Audio Out only

5.2 Packaging

D

E
B

Y

A

W

W

PIN 1

P

G

C

K

J

T

H

PackageTolerances

TYP. MAX.MIN.DIM.

0.380 (9.61)

A

0.380 (9.61)

B

0.128 (3.25)

C

0.417 (10.60)

D

0.417 (10.60)

E
F

G

H

J

0.047 (1.19)

K

0.049 (1.24)

P

0.006 (0.152)

T

30°

W

Y

NOTE: All dimensions in inches (mm.)

0.250 (6.35)

0.250 (6.35)

0.023 (0.58)

Angles are in degrees

0.409 (10.40)

0.409 (10.40)

0.146 (3.70)

0.435 (11.05)

0.435 (11.05)

0.022 (0.55)0.018 (0.45)

0.048 (1.22)

0.051 (1.30)

0.009 (0.22)

45°

6°

F

Figure 5: 24-pin PLCC Mechanical Outline: Order as part no. MX014LH

 1997 MX•COM, INC. www.mxcom.com Tele: 800 638 5577 910 744 5050 Fax: [phone] Doc. # 20480013.006

4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by there respective companies.

Voice Band Inverter 11 MX014

A

PIN1

PIN1

K

H

L

A

E

B

B

PP

JJ

J1J1

C

C

E1

E1

Y

E

T

T

PackageTolerances

TYP. MAX.MIN.DIM.

1.200 (30.48)

A

0.500 (12.70)

B

0.151 (3.84)

C

0.600 (15.24)

E

0.590 (14.99) 0.625 (15.88)

E1

0.015 (0.38) 0.045 (1.14)

H

0.015 (0.38) 0.023 (0.58)

J

0.040 (1.02) 0.065 (1.65)

J1

0.066 (1.67) 0.074 (1.88)

K

0.121 (3.07)

L

P

0.008 (0.20) 0.015 (0.38)

T
Y

NOTE: All dimensions in inches (mm.)

0.100 (2.54)

Angles are in degrees

1.270 (32.26)

0.555 (14.04)

0.220 (5.59)

0.670 (17.02)

0.160 (4.05)

7°

PIN1

K
H

L

Figure 6: 24-pin PDIP Mechanical Outline: Order as part no. MX014P

A

B

E1

E

T

C

K1

P

J

J1

F

Pac kageTolerances

DIM.

1.240 (31.50)

A

0.514 (13.06)

B

0.165 (4.19)

C

0.600 (15.23)

E

0.594 (15.09) 0.615 (15.61)

E1

F
H

J

J1

0.050 (1.27)

K

0.074 (1.88)

K1

0.115 (2.92)

L
P

0.0094 (0.239)

T

NOTE: All dimensions in inches (mm.)

Angles are in degrees

TYP. MAX.MIN.

1.260 (32.00)

0.583 (14.79)

0.230 (5.84)

0.670 (17.00)

1.100 (27.94)

0.02 (0.51)

0.018 (0.46)

0.055 (1.39)

0.080 (2.03)

0.080 (2.03)

0.200 (5.08)

0.10 (2.54)

0.0106 (0.269)

Figure 7: 24-pin CDIP Mechanical Outline: Order as part no. MX014J

 1997 MX•COM, INC. www.mxcom.com Tele: 800 638 5577 910 744 5050 Fax: [phone] Doc. # 20480013.006

4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by there respective companies.