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 [email protected] 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 [email protected] www.cmlmicro.com No 2 Kallang Pudding Road, 09-05/ 06 Mactech Industrial Building, Singapore 349307 Tel: +65 7450426 Fax: +65 7452917 [email protected] www.cmlmicro.com D/CML (D)/2 May 2002