CMLMICRO MX315A

DATA BULLETIN
MX315A
CTCSS Encoder
Features
Applications
Field Programmable Tone
Encoder
40 CTCSS Frequencies
Crystal-Controlled Frequency
Stability
Low Distortion Sinewave Output
Few External Components
Required
CMOS Low Power Requirements
Mobile Radio Base Stations & Repeater
Stations
Mobile Radios
Hand-Held Radios
Industrial Controls
Intercom Systems
Door-Entry Systems
Clock
Generator
Xtal/Clock
Xtal
Binary
Rate
Multiplier
D0-D5
VDD
Programmed Clocks
TX Tone
Square
Wave
TX Tone
Sinewave
Output
Emitter
Follower
TX Tone Output
TX Enable
Enable
TX Enable
The MX315A is a monolithic CMOS tone encoder for sub-audible tone squelch systems, which provides three
additional frequencies over the earlier MX315A. These frequencies are 69.3, 97.4 and 206.5Hz. The tone
frequencies are derived from an input reference frequency. An on-chip inverter is provided to drive an
external crystal circuit.
Tone selection is achieved through six programming inputs and two control inputs (which allow either a logic
“1” or “0” to enable the device). A low distortion sinewave is generated at the TX Tone Output when the
MX315A is enabled. The emitter follower output stage can source 1mW directly into a 600 load (0dBm).
The MX315A is available in the following package styles: 16-pin SOIC (MX315ADW), 14-pin PDIP
(MX315AP) and 14-pin CDIP (MX315AJ).
1998 MXCOM, INC.
www.mxcom.com
tel: 800 638 5577 336 744 5050 fax: 336 744 5054
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
Doc. # 20480054.006
All Trademarks and service marks are held by there respective companies.
CTCSS Encoder
2
MX315A
CONTENTS
Section
Page
1. Block Diagram................................................................................................................ 3
2. Signal List....................................................................................................................... 4
3. External Components.................................................................................................... 5
4. Application ..................................................................................................................... 6
4.1
Interfacing and Electromagnetic Capability ......................................................................... 6
4.2
CTCSS Programming.......................................................................................................... 7
5. Performance Specification............................................................................................ 8
5.1
5.2
Electrical Performance ........................................................................................................ 8
5.1.1
Absolute Maximum Ratings.................................................................................................... 8
5.1.2
Operating Limits ..................................................................................................................... 8
5.1.3
Operating Characteristics....................................................................................................... 8
Packaging............................................................................................................................ 9
MX•COM, Inc. reserves the right to change specifications at any time and without notice.
1998 MXCOM, INC.
www.mxcom.com
tel: 800 638 5577 336 744 5050 fax: 336 744 5054
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
Doc. # 20480054.006
All Trademarks and service marks are held by there respective companies.
CTCSS Encoder
3
MX315A
1. Block Diagram
Clock
Generator
Xtal/Clock
Xtal
Binary
Rate
Multiplier
D0-D5
VDD
Programmed Clocks
TX Tone
Square
Wave
TX Tone
Sinewave
Output
Emitter
Follower
TX Tone Output
TX Enable
Enable
TX Enable
Figure 1: Device Block Diagram
1998 MXCOM, INC.
www.mxcom.com
tel: 800 638 5577 336 744 5050 fax: 336 744 5054
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
Doc. # 20480054.006
All Trademarks and service marks are held by there respective companies.
CTCSS Encoder
4
MX315A
2. Signal List
Pins
Signal
Description
J,P
DW
Name
Type
1
1
D3
input
2
2
D2
input
3
3
D1
input
4
4
D0
input
5
5
D4
input
6
6
D5
input
7
7
VSS
power
Negative Supply Voltage.
8
8
Xtal/Clock In
input
This is the input to the CMOS inverter. It can be used in
conjunction with the Xtal output to form the active element in a
crystal oscillator circuit. Alternatively, a logic level 1MHz
frequency can be injected at this pin. However, the supply
voltage should never be applied without the input clock signal.
9
9
Xtal Output
output
This is the output of the CMOS inverter. When used as a
crystal oscillator, track lengths and loading of this pin should be
minimized.
10
10
Internal Connection
11
N/C
D0-D5 are tone select inputs with internal pull-up resistors.
The logic combination at these inputs determines the encoded
CTCSS tone. See Table 1. The input sequence is not latched
and may be changed at any time. A logic “1” will be
programmed if the input is open circuit, allowing the use of
SPST switches.
Do not use
No Connection
12
N/C
11
13
TX Tone Output
output
This is the tone output pin. It includes a low impedance emitter
follower stage for sourcing sinusoidal tone. The tone is
generated about a DC level of approximately VDD/2. The pin is
high impedance when not encoding.
No Connection
12
14
TX Enable Input
input
This logic input has an internal pull-up resistor. A logic “0” at
this pin enables the MX315A.
13
15
TX Enable Input
input
This logic input has an internal pull-down resistor. A logic “1”
at this pin enables the MX315A.
14
16
VDD
power
Positive Supply Voltage.
Table 1: Signal List
1998 MXCOM, INC.
www.mxcom.com
tel: 800 638 5577 336 744 5050 fax: 336 744 5054
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
Doc. # 20480054.006
All Trademarks and service marks are held by there respective companies.
CTCSS Encoder
5
MX315A
3. External Components
MICROPHONE
VOICE BAND
FILTER
SUMMING
AMPLIFIER
TO
MODULATOR
VSS
4
8
X1
1MHz
1M
9
D0
3
2
D1 D2
1
D3
5
D4
6
D5
XTAL/CLOCK
XTAL
11
TX TONE OUT
MX315AJ
33pF
12
PTT
TX ENABLE
Figure 2: External Components
R1
Note 1
C1
X1
Note 2, 3
1M
20%
33pF
20%
1MHz
0.19%
Table 2: Recommended External Components
Notes:
1. The 1M resistor is used to bias the internal CMOS inverter into its linear mode. A tolerance of ±20%
is acceptable.
2. “X1” is a parallel resonant crystal. A reference frequency of 1MHz ±0.19% is required to maintain a
tone accuracy within 0.5%.
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.
1998 MXCOM, INC.
www.mxcom.com
tel: 800 638 5577 336 744 5050 fax: 336 744 5054
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
Doc. # 20480054.006
All Trademarks and service marks are held by there respective companies.
CTCSS Encoder
6
MX315A
4. Application
The MX315A is dedicated to Continuous Tone-controlled Squelch Systems (CTCSS) in radio applications.
However, it can be used wherever encoding of low-frequency tones is required, such as intercoms, door-entry
systems and various industrial applications.
The performance of a CTCSS system can be degraded if speech frequencies in the signaling spectrum are
not removed prior to transmission. This can be accomplished by filtering the microphone signals to attenuate
frequencies below 250 Hz. Figure 2 illustrates the addition of TX Tone Output to the filtered microphone
signals prior to modulation. Figure 3 illustrates the TX Tone Output sequence and a typical spectral analysis.
Where two or more circuits are required to use a single oscillator (i.e. repeater applications), the signal at
Xtal can be used to drive one additional Xtal/Clock input. Any further circuits can be driven from the buffered
Xtal output of the second device.
The program code can be set on the D0-D5 inputs by hardwired logic levels or SPST switches to VSS, as
illustrated in Figure 2 (allowing the internal pull-up resistors to program a logic “1”).
The MX315A provides both a TX Enable input and a TX Enable input. Either input can be used to enable the
tone output, with the unused pin left open circuit (internal resistors establish a valid logic level and prevent
damage). Any configuration of PTT switch or TX signal can therefore be interfaced.
TX ENABLE
RISE-TIME
ENVELOPE
TX TONE
OUTPUT
RELATIVE HARMONIC
LEVELS (dB)
D.C. GROUND
D.C. GROUND
0
FUNDAMENTAL
10
20
30
TX TONE SPECTRUM
40
50
60
70
f0
2f 0
3f 0
4f 0
5f 0
6f 0
7f 0
8f 0
FREQUENCY
Figure 3: Tone Encoding Sequence and Spectral Response
4.1
Interfacing and Electromagnetic Capability
The MX315A requires a clock of 1MHz, which is internally converted to logic level square waves.
Consideration should therefore be given to possible interference problems with RF or IF circuitry caused by
1MHz or its harmonics.
A decoupling capacitor can be used to reduce ripple on the power supply. This will reduce the level of
superimposed noise on the supply caused by internal switching transients (particularly at 1MHz and f0).
1998 MXCOM, INC.
www.mxcom.com
tel: 800 638 5577 336 744 5050 fax: 336 744 5054
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
Doc. # 20480054.006
All Trademarks and service marks are held by there respective companies.
CTCSS Encoder
4.2
7
MX315A
CTCSS Programming
Tone
Programming Inputs
Nominal Frequency (Hz)
MX315A Freq. (Hz)
fo (%)
D5
D4
D3
D2
D1
D0
Hex
67.0
67.06
+.10
1
1
1
1
1
1
3F
69.3
69.37
+.10
1
1
1
0
0
1
39
71.9
71.84
-.08
0
1
1
1
1
1
1F
74.4
74.33
-.10
1
1
1
1
1
0
3E
77.0
76.99
-.02
0
0
1
1
1
1
0F
79.7
79.65
-.06
1
1
1
1
0
1
3D
82.5
82.50
0.0
0
1
1
1
1
0
1E
85.4
85.34
-0.7
1
1
1
1
0
0
3C
88.5
88.62
+.14
0
0
1
1
1
0
0E
91.5
91.38
-.13
1
1
1
0
1
1
3B
94.8
94.88
+.08
0
1
1
1
0
1
1D
97.4
97.46
+.06
1
1
1
0
1
0
3A
100.0
99.87
-.13
0
0
1
1
0
1
0D
103.5
103.39
-.11
0
1
1
1
0
0
1C
107.2
107.17
-.03
0
0
1
1
0
0
0C
110.9
110.85
-.04
0
1
1
0
1
1
1B
114.8
114.80
0.0
0
0
1
0
1
1
0B
118.8
118.60
-.17
0
1
1
0
1
0
1A
123.0
123.12
+.10
0
0
1
0
1
0
0A
127.3
127.50
+.16
0
1
1
0
0
1
19
131.8
131.67
-.10
0
0
1
0
0
1
09
136.5
136.69
+.14
0
1
1
0
0
0
18
141.3
141.48
+.13
0
0
1
0
0
0
08
146.2
145.96
-.16
0
1
0
1
1
1
17
151.4
151.45
+.03
0
0
0
1
1
1
07
156.7
156.59
-.07
0
1
0
1
1
0
16
162.2
162.10
-.06
0
0
0
1
1
0
06
167.9
168.01
+.07
0
1
0
1
0
1
15
173.8
173.43
-.21
0
0
0
1
0
1
05
179.9
180.21
+.17
0
1
0
1
0
0
14
186.2
186.46
+.14
0
0
0
1
0
0
04
192.8
193.16
+.19
0
1
0
0
1
1
13
203.5
202.88
-.31
0
0
0
0
1
1
03
206.5
206.78
+.14
1
1
1
0
0
0
38
210.7
210.84
+.07
0
1
0
0
1
0
12
218.1
217.96
-.07
0
0
0
0
1
0
02
225.7
225.58
-.05
0
1
0
0
0
1
11
233.6
233.75
+.07
0
0
0
0
0
1
01
241.8
242.54
+.31
0
1
0
0
0
0
10
250.3
250.06
+.10
0
0
0
0
0
0
00
Test
4032
0.0
1
1
0
0
1
1
*33
* - or any invalid address
Table 3: CTCSS Tones
1998 MXCOM, INC.
www.mxcom.com
tel: 800 638 5577 336 744 5050 fax: 336 744 5054
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
Doc. # 20480054.006
All Trademarks and service marks are held by there respective companies.
CTCSS Encoder
8
MX315A
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
800
mW
10
mW/°C above 25°C
J / P /DW Packages
Total Allowable Device Dissipation at TAMB = 25°C
Derating above 25°C
Operating Temperature
-30
+85
°C
Storage Temperature
-55
+125
°C
5.1.2
Operating Limits
Correct operation of the device outside these limits is not implied.
Notes
Min.
Typ.
Max.
VDD
4.5
5.0
5.5
V
Operating Temperature
-30
85
°C
Clock
Note 1
Units
1
MHz
Operating Limits Note:
1. “X1” is a parallel resonant crystal. A reference frequency of 1 MHz ±0.19% is required to maintain a
tone accuracy within 0.5%.
5.1.3
Operating Characteristics
For the following conditions unless otherwise specified:
VDD = 5.0V , TAMB = 25°C, Xtal Frequency = 1MHz
Notes
Min.
Supply Current (operating)
Typ.
Max
Units
1.5
4.5
mA
Input Impedance
1
500
k
Input Impedance
2
10
M
Logic Input “1”
3.5
V
Logic Input “0”
1.5
TX Output EMF
3
550
V
775
mVRMS
1
ms
TX Risetime
TX Tone Output Load Current
TX Distortion
3
2
Variation in Output Level Between Tones
3
0.1
5
mA
5
%
dB
Operating Characteristics Notes:
1. Refers to D0, D1, D2, D3, D4, D5, TX Enable and TX Enable inputs
2. Refers to Xtal/Clock input
3. Any program tone and RL = 600, CL = 15pF. THD measurements are taken in the 0-6 kHz
bandwidth.
1998 MXCOM, INC.
www.mxcom.com
tel: 800 638 5577 336 744 5050 fax: 336 744 5054
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
Doc. # 20480054.006
All Trademarks and service marks are held by there respective companies.
CTCSS Encoder
5.2
9
MX315A
Packaging
Package Tolerances
A
Z
ALTERNATIVE
PIN
LOCATION
MARKING
B
E
W
L
T
PIN 1
X
Y
K
C
P
J
H
DIM.
MIN.
TYP.
MAX.
0.413 (10.49)
0.395 (10.03)
0.299 (7.59)
0.286 (7.26)
0.093 (2.36)
0.105 (2.67)
0.419 (10.64)
0.390 (9.90)
0.003 (0.08)
0.020 (0.51)
0.013 (0.33)
0.020 (0.51)
0.041 (1.04)
0.050 (1.27)
0.016 (0.41)
0.050 (1.27)
0.009 (0.23)
0.0125 (0.32)
45°
0°
10°
7°
5°
5°
A
B
C
E
H
J
K
L
P
T
W
X
Y
Z
NOTE : All dimensions in inches (mm.)
Angles are in degrees
Figure 4: 16-pin SOIC Mechanical Outline: Order as part no. MX315ADW
Package Tolerances
A
B
E1
E
Y
PIN 1
T
K
C
H
L
MIN.
TYP.
MAX.
0.810 (20.57)
0.740 (18.80)
0.260 (6.60)
0.240 (6.10)
0.135 (3.43)
0.200 (5.06)
0.300 (7.62)
0.390 (9.91)
0.290 (7.37)
0.325 (8.26)
0.015 (0.38)
0.070 (1.77)
0.015 (0.38)
0.023 (0.58)
0.040 (1.01)
0.065 (1.65)
0.056 (1.42)
0.064 (1.63)
0.121 (3.07)
0.150 (3.81)
0.100 (2.54)
0.008 (0.20)
0.015 (0.38)
7°
NOTE : All dimensions in inches (mm.)
Angles are in degrees
J1 P
J
DIM.
A
B
C
E
E1
H
J
J1
K
L
P
T
Y
Figure 5: 14-pin PDIP Mechanical Outline: Order as part no. MX315AP
1998 MXCOM, INC.
www.mxcom.com
tel: 800 638 5577 336 744 5050 fax: 336 744 5054
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
Doc. # 20480054.006
All Trademarks and service marks are held by there respective companies.
CTCSS Encoder
10
MX315A
Package Tolerances
A
B
E1
E
T
PIN 1
K
K1 C
H
L
J
J1 P
DIM.
MIN.
A
B
C
E
E1
F
H
J
J1
K
K1
L
P
T
0.754 (19.15)
0.240 (6.10)
0.165 (4.19)
TYP.
MAX.
0.766 (19.46)
0.288 (7.32)
0.230 (5.84)
0.420 (10.67)
0.360 (9.14)
0.305 (7.75)
0.315 (8.00)
0.600 (15.24)
0.015 (0.38)
0.018 (0.46)
0.060 (1.52)
0.053 (1.35)
0.080 (2.03)
0.075 (1.91)
0.080 (2.03)
0.115 (2.92)
0.200 (5.08)
0.100 (2.54)
0.010 (0.254)
NOTE : All dimensions in inches (mm.)
Angles are in degrees
F
Figure 6: 14-pin CDIP Mechanical Outline: Order as part no. MX315AJ
1998 MXCOM, INC.
www.mxcom.com
tel: 800 638 5577 336 744 5050 fax: 336 744 5054
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
Doc. # 20480054.006
All Trademarks and service marks are held by there respective companies.
CML Microcircuits
COMMUNICATION SEMICONDUCTORS
CML Product Data
In the process of creating a more global image, the three standard product semiconductor
companies of CML Microsystems Plc (Consumer Microcircuits Limited (UK), MX-COM, Inc
(USA) and CML Microcircuits (Singapore) Pte Ltd) have undergone name changes and, whilst
maintaining their separate new names (CML Microcircuits (UK) Ltd, CML Microcircuits (USA)
Inc and CML Microcircuits (Singapore) Pte Ltd), now operate under the single title CML
Microcircuits.
These companies are all 100% owned operating companies of the CML Microsystems Plc
Group and these changes are purely changes of name and do not change any underlying legal
entities and hence will have no effect on any agreements or contacts currently in force.
CML Microcircuits Product Prefix Codes
Until the latter part of 1996, the differentiator between products manufactured and sold from
MXCOM, Inc. and Consumer Microcircuits Limited were denoted by the prefixes MX and FX
respectively. These products use the same silicon etc. and today still carry the same prefixes.
In the latter part of 1996, both companies adopted the common prefix: CMX.
This notification is relevant product information to which it is attached.
CML Microcircuits (USA) [formerly MX-COM, Inc.] Product Textual Marking
On CML Microcircuits (USA) products, the ‘MX-COM’ textual logo is being replaced by a ‘CML’
textual logo.
Company contact information is as below:
CML Microcircuits
(UK)Ltd
CML Microcircuits
(USA) Inc.
CML Microcircuits
(Singapore)PteLtd
COMMUNICATION SEMICONDUCTORS
COMMUNICATION SEMICONDUCTORS
COMMUNICATION SEMICONDUCTORS
Oval Park, Langford, Maldon,
Essex, CM9 6WG, England
Tel: +44 (0)1621 875500
Fax: +44 (0)1621 875600
uk.sales@cmlmicro.com
www.cmlmicro.com
4800 Bethania Station Road,
Winston-Salem, NC 27105, USA
Tel: +1 336 744 5050,
0800 638 5577
Fax: +1 336 744 5054
us.sales@cmlmicro.com
www.cmlmicro.com
No 2 Kallang Pudding Road, 09-05/
06 Mactech Industrial Building,
Singapore 349307
Tel: +65 7450426
Fax: +65 7452917
sg.sales@cmlmicro.com
www.cmlmicro.com
D/CML (D)/2 May 2002