MX465DS - MX-COM, Inc. - Datasheet.Directory

DATA BULLETIN

MX465

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

LOW VOLTAGE

CTCSS ENCODER/DECODER

with Tx and Rx Audio Filters

Features Applications

• Meets TIA/EIA-603 Standards

• 47 CTCSS Tones + Notone

• TX/RX Speech Filters

• Improved Sinad

• Serial or Parallel Programming

• Easy µP Interface

• Scanning on any Channel

• Standard 4MHz Xtal

(See MX165C for 1MHz)

• Low Voltage 3.3V to 5.0V

• Mobile Radio Channel Sharing

• Scan Trunking

• Wireless Intercom Traffic Control

• Hookswitch Supervision

• Repeater Control

The MX465 CTCSS Encoder/Decoder is a low voltage, CMOS device that meets TIA/EIA-603 Standards.

The MX465 will encode and decode the tones 159.8Hz, 183.5Hz, 189.9Hz, 196.6Hz, 199.5Hz, 206.5Hz,

229.1Hz, and 254.1Hz in addition to the 39 standard CTCSS tones, for a total of 47 CTCSS tones + Notone.

With the incorporation of the on-chip TX and RX speech filter, the MX465 enhances voice/tone multiplexing

by attenuating TX and RX speech 36dB at frequencies below 250Hz while passing signals > 300Hz with only

1dB of ripple. This not only minimizes CTCSS talk-off in the TX mode but also improves Hum and Noise

performance in the RX mode.

Low Voltage CTCSS Encoder/Decoder 2 MX465

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

Available in the following package styles: 24-pin TSSOP (MX465TN), 24-pin SSOP (MX465DS),

24-pin SOIC (MX465DW), 24-pin PDIP (MX465P), and 24-pin CDIP (MX465J) the MX465 requires a single

3.3V to 5.0V supply and a 4MHz clock or crystal.

CONTENTS

Section Page

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

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

3 External Components.............................................................................................. 6

4 General Description.................................................................................................7

4.1 Description......................................................................................................................................7

4.2 I/O Conditions .................................................................................................................................7

4.3 Filter Response...............................................................................................................................8

4.4 Serial and Parallel Mode Timing.....................................................................................................8

4.5 CTCSS Programming...................................................................................................................10

5 Performance Specification.................................................................................... 11

5.1 Electrical Performance.................................................................................................................11

5.1.1 Absolute Maximum Ratings.................................................................................................11

5.1.2 Operating Limits ................................................................................................................. 12

5.1.3 Operating Characteristics...................................................................................................12

5.2 Packaging......................................................................................................................................14

MX-COM, Inc. Reserves the right to change specifications at any time and without

notice

Low Voltage CTCSS Encoder/Decoder 3 MX465

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

1 Block Diagram

Figure 1 : Block Diagram

Low Voltage CTCSS Encoder/Decoder 4 MX465

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

2 Signal List

Pin No. Signal Type Description

1 VDD power Positive supply. This pin should be bypassed to VSS by

a capacitor mounted close to the device pins.

2 XTAL/CLOCK input Input to the on-chip inverter used with a 4 MHz Xtal or

external clock source.

3

XTAL

output Output of the on-chip inverter (clock output).

4 LATCH/LOAD input Controls 8 on-chip latches. It is used to latch

TX/RX

,

PTL, and D0-D5. A logic 1 applied to this input places

the 8 latches in the ‘transparent’ mode. A logic 0 applied

to this input places the 8 latches in the ‘latched’ mode. In

Parallel Mode, data is loaded and latched by a logic 1-0

transition (see Figure 4). In Serial Mode, data is loaded

and latched by a 0-1-0 strobe pulse on this pin (see

Figure 5). Internally pulled to VDD

5 D5 / SERIAL ENABLE 1 input Data input D5 (Parallel Mode). A logic 1 applied to this

input together with a logic 0 applied to

D4/SERIAL ENA

BLE 2

will place the device in Serial

Mode (see Figure 5). Internally pulled to VDD.

6 D4/SERIAL ENABLE 2 input Data input D4 (Parallel Mode). A logic 0 applied to this

input together with a logic 1 applied to D5 / SERIAL

ENABLE 1 will place the device in Serial Mode

(see Figure 5). Internally pulled to VDD.

7 D3 / SERIAL DATA IN input Data input D3 (Parallel Mode). In Serial Mode this pin

becomes the serial data input for D5-D0, TXRX/ and

PTL (see Figure 5). D5 is clocked first and PTL last.

Internally pulled to VDD.

8 D2 / SERIAL CLOCK input Data input D2 (Parallel Mode). In Serial Mode this pin

becomes the SERIAL CLOCK input. Data is clocked on

the positive going edge (see Figure 5). Internally pulled

to VDD.

9 D1 input Data input D1 (Parallel Mode). Internally pulled to VDD.

10 D0 input Data input D0 (Parallel Mode). Internally pulled to VDD.

11 VSS power Negative supply.

12 DECODE COMPARATOR

REF. input Internally biased to VDD/3 or 2 VDD/3 via 1M resistors

depending on the logic state of the

RX TONE DE

CODE

pin.

RX TONE DE

CODE

= 1 will

bias this input 2 VDD/3; a logic 0 will bias this input VDD

/3.

This input provides the DECODE COMPARATOR

REFERENCE voltage, and the switching of bias voltages

provides hysteresis to reduce ‘chatter’ under marginal

conditions.

13 RX TONE DECODE output Gated output of the decode comparator. This output is

used to gate the RX Audio path. A logic 0 on this pin

indicates a successful decode and the DECODE

COMPARATOR IN pin is more positive than the

DECODE COMPARATOR REF. input (see Table 3).

14 DECODE COMPARATOR IN input Inverting input of the DECODE COMPARATOR. This pin

is normally connected to the integrated output of the RX

TONE DETECT line.

Low Voltage CTCSS Encoder/Decoder 5 MX465

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

Pin No. Signal Type Description

15 RX TONE DETECT output In RX mode this output will go to logic 1 during a

successful decode. It must be externally integrated to

control response and deresponse times (see Table 3).

16 TX TONE OUT output The CTCSS sinewave output appears on this pin under

control of the TXRX/ pin. When not transmitting a tone,

TX TONE OUT may be biased to VDD/2. (see Table 3).

17 TXRX/ input RX or TX modes selected in Parallel Mode (see Figure

4). In Serial Mode this function is serially loaded. This

pin is internally pulled to VDD via a 1MΩ resistor.

18 PTL input In RX mode this pin operates as a ‘Push To Listen’

function by enabling the RX audio path, thus overriding

the tone squelch function (Parallel Mode). In Serial Mode

this function is loaded serially. Internal pull-up to VDD

19 RX AUDIO OUT output High pass filtered RX AUDIO OUT. This pin outputs

audio when RX TONE DECODE = logic 0, PTL = logic 1,

or when Notone is programmed (see Table 4). In TX

mode this pin is biased to VDD/2.

20 TX AUDIO OUT output High pass filtered TX AUDIO OUT pin. In TX mode this

pin outputs audio present at the TX AUDIO IN pin. In RX

mode this pin is biased to VDD/2

21 VBIAS output Output of an internally generated VDD /2 bias level that

would normally be externally bypassed to VSS via

capacitor C6.

22 TX AUDIO IN input In TX mode TX AUDIO IN may be prefiltered, using the

TX Audio path, thus helping to avoid talk-off due to

intermodulation of speech frequencies with the

transmitted CTCSS tone. Internally biased to VDD/2.

23 RX AUDIO IN input Input to the audio high pass filter in RX mode. Internally

biased to VDD/2.

24 TONE INPUT input Input to the CTCSS tone detector. Internally biased to

VDD/2.

Table 1: Signal List

Low Voltage CTCSS Encoder/Decoder 6 MX465

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

3 External Components

Figure 2 : Recommended External Components for Typical Application

R1 Note 1 1.0MΩ ±10% C6 0.47µF ±20%

R2 560kΩ ±10% C7 Note 2 0.1µF ±20%

R3 820kΩ ±10% C8 Note 2 0.1µF ±20%

C1 0.1µF ±20% C9 Note 2 0.1µF ±20%

C2 Note 1 18pF ±20% C10 Note 2 0.1µF ±20%

C3 Note 1 33pF ±20% C11 Note 2 0.1µF ±20%

C4 Note 2 0.1µF ±20% D1 small signal

C5 Note 2 0.1µF ±20% X1 Note 1 4MHz 100ppm max.

Table 2: External Components

External Components Notes:

1. The values specified for R1, C2, and C3 have been found to be satisfactory when used with a crystal

(X1) whose equivalent series resistance is ≤ 1000Ω. 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.

2. The 0.1µF value for the DC Blocking capacitors, C4, C5, C7, C8, C9, C10, and C11 is not a

requirement. For the capacitors C4, C5, and C10, the input impedance is internal to the device and

specified typical as 550kΩ. For the remaining capacitors external circuits will be important in

determining the input impedance.

Low Voltage CTCSS Encoder/Decoder 7 MX465

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

4 General Description

4.1 Description

Voice on shared radio channels are multiplexed with a subaudible CTCSS (Continuous Tone Controlled

Subaudible Squelch) tone as a means of directing messages among user groups sharing the same RF

frequencies. CTCSS modulates the transmitter with a discrete tone, from 39 standard CTCSS tones in the

range (67.0Hz to 250.0Hz) according to TIA/EIA-603. There are an additional eight CTCSS tones not

specified in TIA/EIA-603 that the MX465 will encode and decode. They are : 159.8Hz, 183.5Hz, 189.9Hz,

196.6Hz, 199.5Hz, 206.5Hz, 229.1Hz, and 254.1Hz, for a total of 47 CTCSS tones plus Notone.

The MX465 also incorporates TX/RX on chip speech filters. In early CTCSS designs, TX speech was not

filtered from the CTCSS tone, rather the filtering was dependent upon the host transmitter’s pre-emphasis

network. At only 6dB/octave, the attenuation of speech components at higher CTCSS tones was only a few

dB which resulted in talk-off (low frequency voice components unsquelching the receiver audio).

4.2 I/O Conditions

D0-D5 Tone No Tone Tone Tone Tone No Tone

Input Pins Condition

RX TX/ 0 0 1 1 1 1

PTL 0 X 0 1 X X

Decode Comparator In X X 0 0 1 X

Output Pins Condition

RX TONE DETECT 0 0 0 0 1 X

RX TONE DECODE 1 1 1 1 0 0

Result / Function

Tone Transmitter Enabled Yes No (Bias) No (Bias) No (Bias) No (Bias) No (Bias)

TX Audio Path Enabled Yes Yes No No No No

Tone Decode Enabled No No Yes Yes Yes Yes

RX Audio Path Enabled No (Bias) No (Bias) No (Bias) Yes Yes Yes

Notes 1 2 3 4 5 6

Notes:

1. Normal tone transmit condition.

2. Notone programmed in TX mode, tone transmit output set to VDD/2. TX audio path enabled.

3. Normal decode standby.

4. Normal decode standby with PTL used to enable audio.

5. Normal decode of correct CTCSS tone condition, PTL has no effect.

6. Notone programmed in RX mode, tone transmit output (Bias). RX audio path enabled.

7. X = don’t care

Table 3: Combinations of Input / Output conditions

Low Voltage CTCSS Encoder/Decoder 8 MX465

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

4.3 Filter Response

Figure 3 : Voiceband Filter Response

4.4 Serial and Parallel Mode Timing

Figure 4 : Parallel Mode

Low Voltage CTCSS Encoder/Decoder 9 MX465

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

Figure 5 : Serial Mode

Low Voltage CTCSS Encoder/Decoder 10 MX465

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

4.5 CTCSS Programming

Tone Programming Inputs

Nominal

Frequency (Hz) MX465

Frequency (Hz) ∆ f0 (%) D5 D4 D3 D2 D1 D0 Hex

67.0 66.98 -0.029 1 1 1 1 1 1 3F

69.3 69.32 0.024 1 1 1 0 0 1 39

71.9 71.901 0.001 0 1 1 1 1 1 1F

74.4 74.431 0.042 1 1 1 1 1 0 3E

77.0 76.965 -0.046 0 0 1 1 1 1 0F

79.7 79.677 -0.029 1 1 1 1 0 1 3D

82.5 82.483 -0.021 0 1 1 1 1 0 1E

85.4 85.383 -0.020 1 1 1 1 0 0 3C

88.5 88.494 -0.007 0 0 1 1 1 0 0E

91.5 91.456 -0.048 1 1 1 0 1 1 3B

94.8 94.76 -0.042 0 1 1 1 0 1 1D

97.4 97.435 -0.036 1 1 1 0 1 0 3A

100.0 99.96 -0.040 0 0 1 1 0 1 0D

103.5 103.429 -0.069 0 1 1 1 0 0 1C

107.2 107.147 -0.05 0 0 1 1 0 0 0C

110.9 110.954 0.049 0 1 1 0 1 1 1B

114.8 114.84 0.035 0 0 1 0 1 1 0B

118.8 118.793 -0.006 0 1 1 0 1 0 1A

123.0 123.028 0.023 0 0 1 0 1 0 0A

127.3 127.328 0.022 0 1 1 0 0 1 19

131.8 131.674 -0.095 0 0 1 0 0 1 09

136.5 136.612 0.082 0 1 1 0 0 0 18

141.3 141.323 0.016 0 0 1 0 0 0 08

146.2 146.044 -0.107 0 1 0 1 1 1 17

151.4 151.441 0.027 0 0 0 1 1 1 07

156.7 156.875 0.112 0 1 0 1 1 0 16

• 159.8 159.936 0.085 1 1 0 0 0 1 31

162.2 162.311 0.069 0 0 0 1 1 0 06

167.9 167.708 -0.114 0 1 0 1 0 1 15

173.8 173.936 0.078 0 0 0 1 0 1 05

179.9 179.654 -0.137 0 1 0 1 0 0 14

• 183.5 183.680 0.098 1 1 0 0 1 0 32

186.2 186.289 0.048 0 0 0 1 0 0 04

• 189.9 190.069 0.089 1 1 0 0 1 1 33

192.8 192.864 0.033 0 1 0 0 1 1 13

• 196.6 196.329 -0.138 1 1 0 1 0 0 34

• 199.5 199.312 -0.094 1 1 0 1 0 1 35

203.5 203.645 0.071 0 0 0 0 1 1 03

Low Voltage CTCSS Encoder/Decoder 11 MX465

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

Tone Programming Inputs

Nominal

Frequency (Hz) MX465

Frequency (Hz) ∆ f0 (%) D5 D4 D3 D2 D1 D0 Hex

• 206.5 206.207 -0.142 1 1 0 1 1 0 36

210.7 210.848 0.070 0 1 0 0 1 0 12

218.1 217.853 -0.113 0 0 0 0 1 0 02

225.7 225.339 -0.160 0 1 0 0 0 1 11

• 229.1 229.279 0.078 1 1 0 1 1 1 37

233.6 233.359 -0.103 0 0 0 0 0 1 01

241.8 241.970 0.070 0 1 0 0 0 0 10

250.3 250.282 -0.007 0 0 0 0 0 0 00

• 254.1 254.162 0.024 1 1 1 0 0 0 38

Notone N/A 1 1 0 0 0 0 30

Serial input mode N/A 1 0 Data Clock X X 2X

• Not specified in the TIA/EIA tone set

Table 4: CTCSS Tones

5 Performance Specification

5.1 Electrical Performance

5.1.1 Absolute Maximum Ratings

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

operating limits is not implied.

General Min. Max. Units

Supply (VDD - VSS) -0.3 7.0 V

Voltage on any pin to VSS -0.3 VDD + 0.3 V

Current

VDD -30 30 mA

VSS -30 30 mA

any other pins -20 20 mA

TN / DW / DIP Package

Total Allowable Power Dissipation at TAMB =25°C 800 mW

Derating above 25°C 10 mW/°C above 25°C

Storage Temperature -55 125 °C

Operating temperature - 40 85 °C

DS Package

Total Allowable Power Dissipation at TAMB =25°C 550 mW

Derating above 25°C 9 mW/°C above 25°C

Storage Temperature -55 125 °C

Operating temperature - 40 85 °C

Low Voltage CTCSS Encoder/Decoder 12 MX465

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

5.1.2 Operating Limits

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

Min. Max. Units

Supply (VDD-VSS) 2.7 5.5 V

Xtal Frequency 4.0 4.0 MHz

Operating Temperature -40 85 °C

5.1.3 Operating Characteristics

For the following conditions unless otherwise specified:

VDD = 3.3V / 5.0V at TAMB = 25°C, VSS = 0V,

Xtal Frequency = 4.0 MHz, 100ppm max.

(Over the life of the XTAL the operating range may vary from 100ppm up to 1000ppm)

0dB ref. = 750mVRMS (proportional to VDD; see note 17)

Composite Signal:

1kHz test tone = 300mVRMS, f0 CTCSS tone = 30 mVRMS, 75mVRMS Noise (band limited to 6kHz

Gaussian)

Notes Min. Typ. Max. Units

Static Values

Supply voltage 2.7 3.3/5.0 5.5 V

Supply current

VDD = 5.0V 3.7 4.2 mA

VDD = 3.3V 1.3 1.6 mA

Analog input impedance 18 480 550 kΩ

Analog output impedance 18 400 1000 Ω

Digital Input impedance 1,18 25 40 kΩ

Input logic 1 1 70%VDD V

Input logic 0 1 30%VDD V

Output Logic 1 source = 0.1mA 2 80%VDD V

Output Logic 0 sink = 0.1mA 2 20%VDD V

Dynamic Values

Speech filter

Total harmonic distortion 5,8,19 1.0 1.5 %

Output noise level (input AC short

circuit, audio switch enabled) 8,18 0.5 1.0 mVRMS

Sinad 8,9 40 50 dB

Spurious emissions 18 - 48 dB

Cutoff frequency 300 Hz

Bandpass ripple 8 1 1.8 dB

Stopband attenuation <250Hz 7,8,19 33 36 dB

Passband gain 1kHz - 0.5 0 0.5 dB

TX/RX isolation 5 60 dB

Low Voltage CTCSS Encoder/Decoder 13 MX465

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

Notes Min. Typ. Max. Units

Encoder

Tone output level 12 - 1.0 0 1.0 dB

Tone Frequency Accuracy (f error) - 0.3 0.3 %f0

Risetime to 90% nominal output

f0>100Hz 4,10 15 75 ms

f0<100Hz 4,10 45 120 ms

Total Harmonic Distortion 19 1.5 2 %

Decoder

Pure tone decode threshold 19 7 15 mVRMS

Composite signal decode threshold 3 30 mVRMS

Decode input signal level 16 -20 3.5 dB

Pure tone decode response time 13,14 95 115 140 ms

Pure tone decode deresponse time 13,15 95 130 170 ms

Decode response time 3,6,10 250 ms

Deresponse time 3,10 180 250 ms

Decode selectivity:

Upper decode band edge 3,11,19,20 1.005f0 1.015f0 0.995f0+1 Hz

Lower decode band edge 3,11,19,20 1.005f0-1 0.985f0 0.995f0 Hz

Serial / Parallel Inputs

Parallel Set Up Time (tSP) 400 ns

Load / Latch Pulse Width (tL) 400 ns

Serial Clock Pulse Width (tC) 400 ns

Serial Data Set-Up Time (tSS) 400 ns

Serial Data Hold Time (tH) 400 ns

Serial Enable Time (t1) 400 ns

Serial Load / Latch Set-Up Time (t2) 400 ns

Serial Clock Frequency 1 MHz

Operating Characteristics Notes:

1. Refers to RX/TX, PTL, Decode Comparator Input, D0-D5.

2. All logic outputs.

3. Composite signal test condition.

4. Any programming tone and RL = 10kΩ, CL = 15pF.

5. With an input level of 0dB @1kHz

6. f0>100Hz (for 100 Hz> f0>67Hz: t=100/ f0Hz x 250ms)

7. See Figure 3.

8. Measured in a 30kHz bandwidth.

9. With an input level of -3.5dB @1kHz

10. Per TIA/EIA-603.

11. Per TIA/EIA-603, device will not decode adjacent TIA/EIA-603 Tones.

12. Tone output level is proportional to VDD.

13. f0=156.7Hz @ -20dB.

14. Typically 12.5 Tone Cycles + 40ms.

Low Voltage CTCSS Encoder/Decoder 14 MX465

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

15. Typically 7 Tone Cycles + 90ms.

16. Max composite signal is 3.5dB with:

Noise (band limited 6kHz Gaussian) = -12dB ref to 1kHz test tone

f0 CTCSS tone = -20dB ref to 1kHz test tone

17. For maximum dynamic range, set audio level to 0dB, VDD x150mVRMS, using minimum VDD under

which system is intended to work. (e.g. for a 2.7V system, use 0dB equal to 405mVRMS).

18. By characterization only.

19. Batch sampled only

20. For example, if: f0 = 100.0Hz (f0-1 = 97.4Hz f0+1 = 103.5Hz)

Decode Selectivity Min Typ Max Unit

Upper Decode Band Edge 100.

5 101.5 102.98 Hz

Lower Decode Band Edge 97.8

9 98.5 99.5 Hz

5.2 Packaging

Figure 6: 24-pin TSSOP Mechanical Outline: Order as part no. MX465TN

Low Voltage CTCSS Encoder/Decoder 15 MX465

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

Figure 7: 24-pin-SSOP Mechanical Outline: Order as part no. MX465DS

Figure 8: 24-pin SOIC Mechanical Outline: Order as part no. MX465DW

Low Voltage CTCSS Encoder/Decoder 16 MX465

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

Figure 9: 24-pin-CDIP Mechanical Outline: Order as part no. MX465J

Figure 10: 24-pin PDIP Mechanical Outline: Order as part no. MX465P