DATA BULLETIN MX469 1200/2400/4800bps MSK Modem Features Applications Selectable Data Rates 1200/2400/4800bps Full-Duplex MSK RX and TX Bandpass Filters Clock Recovery and Carrier Detect Capabilities Pin Selected Xtal/Clock Inputs 1.008MHz or 4.032MHz TX GENERATOR Radio and General Applications Data-Over-Radio PMR/Cellular Signaling Portable Data Terminals Personal/Cordless Telephone TX FILTER TX SIGNAL O/P TX DATA I/P TX ENABLE TX SYNC O/P CLOCK RATE VDD XTAL/CLOCK CLOCK OSCILLATOR DIVIDER f.. V BIAS n XTAL VSS 1200/2400 BPS SELECT 4800 BPS SELECT BANDPASS O/P RX ENABLE RX FILTER LIMITER RETRIGGERABLE MONOSTABLE RX SIGNAL I/P DATA FILTER LIMITER UNCLOCKED DATA O/P DIGITAL FILTER RECTIFIER DIGITAL PLL CLOCKED DATA O/P DATA LATCH RX SYNC O/P NOISE FILTER RECTIFIER S/N COMPARATOR CARRIER DETECT O/P CARRIER DETECT TIME CONSTANT The MX469 is a full-duplex pin-selectable 1200/2400/4800bps Minimum Shift Key (MSK) Modem for FM radio links. The mark and space frequencies are 1200/1800, 1200/2400, and 2400/4800Hz respectively. Tone frequencies are phase continuous; transitions occur at the zero crossing point. The use of a common Xtal oscillator with a choice of two clock frequencies (1.008MHz or 4.032MHz) provides data-rate, transmit frequencies, and RX/TX synchronization. The transmitter and receiver operate entirely independently including individual section powersave functions. The MX469 includes on-chip circuitry for Carrier Detect and RX Clock Recovery, both of which are made available at output pins. RX, TX, and Carrier Detect circuits contain bandpass filters to provide high quality signals in their respective paths. The carrier detect time constant is set by an external capacitor, whose value should be arranged as required to further enhance this product's performance in high-noise environments. The MX469 demonstrates high sensitivity and good bit-error-rate under adverse signal conditions. This low-power device requires few external components and is available in the following packages: 24-pin SOIC (MX469DW), 22-pin PDIP (MX469P), and 20-pin SOIC (MX469D3). 1998 MX-COM, 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. # 20480081.010 All trademarks and service marks are held by their respective companies. 1200/2400/4800bps MSK Modem 2 MX469 Contents Section Page 1. Block Diagram................................................................................................................ 3 2. Signal List....................................................................................................................... 4 3. External Components.................................................................................................... 6 4. General Description....................................................................................................... 7 4.1 Timing.................................................................................................................................. 7 4.1.1 1200bps .................................................................................................................................. 7 4.1.2 2400bps .................................................................................................................................. 8 4.1.3 4800bps .................................................................................................................................. 9 5. Application ................................................................................................................... 10 5.1 Synchronous Modem Design Considerations ................................................................... 10 5.2 Bit Error Rate..................................................................................................................... 11 6. Performance Specifications........................................................................................ 12 6.1 Electrical Specifications..................................................................................................... 12 6.1.1 Absolute Maximum Limits ..................................................................................................... 12 6.1.2 Operating Limits .................................................................................................................... 12 6.1.3 Operating Characteristics...................................................................................................... 13 6.1.4 Packages .............................................................................................................................. 15 MXCOM, Inc. reserves the right to change specifications at any time and without notice. 1998 MX-COM, 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. # 20480081.010 All trademarks and service marks are held by their respective companies. 1200/2400/4800bps MSK Modem 3 MX469 1. Block Diagram TX GENERATOR TX FILTER TX SIGNAL O/P TX DATA I/P TX ENABLE TX SYNC O/P CLOCK RATE VDD XTAL/CLOCK CLOCK OSCILLATOR DIVIDER f.. V BIAS n XTAL VSS 1200/2400 BPS SELECT 4800 BPS SELECT BANDPASS O/P RX ENABLE RX FILTER RETRIGGERABLE MONOSTABLE LIMITER RX SIGNAL I/P DATA FILTER LIMITER DIGITAL FILTER RECTIFIER DIGITAL PLL DATA LATCH UNCLOCKED DATA O/P CLOCKED DATA O/P RX SYNC O/P NOISE FILTER RECTIFIER S/N COMPARATOR CARRIER DETECT O/P CARRIER DETECT TIME CONSTANT Figure 1: Block Diagram 1998 MX-COM, 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. # 20480081.010 All trademarks and service marks are held by their respective companies. 1200/2400/4800bps MSK Modem 4 MX469 2. Signal List Signal Type Description The input to the on-chip inverter, for use with either a 1.008MHz or a 4.032MHz Xtal or external clock. Clock frequency selection is by the “Clock Rate” input pin. The selection of this frequency will affect the operational Data Rate of this device. Refer to Table 3. Operation of any MX•COM IC without a Xtal or clock input may cause device damage. To minimize damage in the event of a Xtal/drive failure, it is recommended that a current limiting device (resistor or fast-reaction fuse) be installed on the power supply (VDD). P DW D3 1 1 1 Xtal/Clock input 2 2 2 Xtal output Output of the on-chip inverter. 3 3 3 TX Sync output A squarewave, produced on-chip, to synchronize the input of logic data and transmission of the MSK signal (See Figure 3). 5 5 4 TX Signal output When the transmitter is enabled, this pin outputs the (140-step pseudo sinewave) MSK signal (See Figure 3). With the transmitter disabled, this output is set to a highimpedance state. 6 7 5 TX Data input Serial logic data to be transmitted is input to this pin. 7 8 6 TX Enable Input A logic ‘0’ will enable the transmitter (See Figure 3). A logic ‘1’ at this input will put the transmitter into powersave while forcing “TX Sync Out” to a logic ‘1’ and “TX Signal Out” to a high-impedance state. This pin is internally pulled to VDD. 8 9 7 Bandpass output The output of the RX Bandpass Filter. This output impedance is typically 10k and may require buffering prior to use. 9 10 8 RX Enable Input The control of the RX function. The control of other outputs is provided in Table 2 10 11 9 VBIAS power The output of the on-chip analog bias circuitry. Held internally at VDD/2, this pin should be decoupled to VSS by a capacitor (C2). See Figure 2 and RX Enable notes. This bias voltage is maintained under all powersave conditions. 11 12 10 VSS power Negative supply (GND). 12 13 11 Unclocked Data output The recovered asynchronous serial data output from the receiver. 13 14 12 Clocked Data output The recovered synchronous serial data output from the receiver. Data is latched out by the recovered clock, available at the “RX Sync O/P”. (See Figure 4 and Figure 6). 14 15 13 Carrier Detect output For 1200 and 2400bps operation only. When an MSK signal is being received this output is a logic ‘1’. The Carrier Detect signal should be ignored during 4800bps operation. 15 16 14 RX Signal input The MSK signal input for the receiver. This input should be coupled via a capacitor, C3. 1998 MX-COM, 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. # 20480081.010 All trademarks and service marks are held by their respective companies. 1200/2400/4800bps MSK Modem 5 MX469 Signal Type Description A flywheel squarewave output. This clock will synchronize to incoming RX MSK data. (See Figure 4 and Figure 6). P DW D3 17 18 15 RX Sync output 16 19 16 1200/ 2400 BPS Select input A logic ‘1’ on this pin selects the 1200bps option; tone frequencies are one cycle of 1200Hz represents a logic ‘1’, one-and-a-half cycles of 1800Hz represents a logic ‘0’. A logic ‘0’ on this pin selects the 2400bps option; tone frequencies are one-half cycle of 1200Hz represents a logic ‘1’, one cycle of 2400Hz represents a logic ‘0’. This pin has an internal 1M pull-up resistor. Operational Data Rate Configurations are illustrated in Table 3 18 20 17 4800 BPS Select input A logic '1' on this pin combined with a logic '0' on the 1200/2400 BPS Select pin will select the 4800 option (1M pulldown resistor). Tone frequencies are: one-half cycle of 2400Hz represents a logic '1', one cycle of 4800Hz represents a logic '0'. This state can only be achieved using a 4.032MHz Xtal input. Operational Data Rate Configurations are illustrated in Table 3 19 21 18 Clock Rate input A logic input to select and allow the use of either a 1.008MHz or 4.032MHz Xtal/clock. Logic ‘1’ = 4.032MHz, logic ‘0’ = 1.008MHz. This input has an internal pulldown resistor (1.008MHz). 20 23 19 Carrier Detect Time Constant output Part of the carrier detect integration function. The value of C4 connected to this pin will affect the carrier detect response time and therefore the noise performance (See Figure 2, Note 3). 22 24 20 VDD power Positive supply. A single 5-volt supply is required. 4, 21 4, 6, 17, 22 N/C No Internal Connection. Table 1: Signal List RX Enable = RX Function Clock Data Output Carrier Detect Rx Sync Out 1 = Enabled Enable Enabled Enabled 0 = Powersave 0 0 1 or 0 Table 2: RX Enable Control Functions XTAL/CLOCK Frequency 1.008MHz 4.032MHz Clock Rate pin 0 0 1 1 1 1200/2400 Select Pin 1 0 1 0 0 4800 Select Pin 0 0 0 0 1 Data Rate (bps) 1200 2400 1200 2400 4800 Table 3: Operational Data Rate Configuration 1998 MX-COM, 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. # 20480081.010 All trademarks and service marks are held by their respective companies. 1200/2400/4800bps MSK Modem 6 MX469 3. External Components VDD XTAL/CLOCK X1 C1 R1 VDD C7 1 20 XTAL 2 19 TX SYNC OUT 3 18 CLOCK RATE TX SIGNAL OUT 4 17 4800 BPS SELECT TX DATA IN 5 16 C6 TX ENABLE VDD BANDPASS OUT C5 RX ENABLE VBIAS VSS 6 MX469 CARRIER DETECT TIME CONSTANT C4 1200/2400 BPS SELECT 15 RX SYNC OUT RX SIGNAL IN 7 14 8 13 9 12 10 11 C3 CARRIER DETECT OUT CLOCKED DATA OUT UNCLOCKED DATA OUT C2 Figure 2: Recommended External Components Component Notes R1 Value Tolerance 1.0M ±10% C1 33pF ±5% C2 1.0µF ±20% C3 0.1µF ±20% C4 Note 1 0.1µF ±10% C5 Note 2 1.0µF ±25% C6 Note 3 33pF ±5% C7 Note 2 1.0µF ±20% X1 Note 4 1.008MHz or 4.032MHz See ‘Clock-Rate’ Pin Table 4: Recommended External Components Notes: 1. The value of C4 determines the Carrier Detect time constant. A long time constant results in improved noise immunity but increased response time. C4 may be varied to trade-off response time for noise immunity. 2. Decoupling circuits depend upon whether the input signal is referenced to VBIAS or VSS. Use C5 when the input signal is referenced to VBIAS. Use C7 when the input signal is referenced to VSS. It is not necessary to use both C5 and C7. 3. C6 reduces Xtal voltage overshoot. Reference the MX-COM Xtal Application Note. 4. 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 MX-COM, 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. # 20480081.010 All trademarks and service marks are held by their respective companies. 1200/2400/4800bps MSK Modem 7 MX469 4. General Description 4.1 Timing 4.1.1 1200bps Characteristics Note TX Enable to TX Sync Rise Time tSYNC TX Delay, Signal to Disable Time tESET Data Set-Up Time tDSET Data Hold Time tDH TX Delay to O/P Time tTXD TX Data Rate Period tTDR RX Data Rate Period tRDR Min. Typ. Max. 416 µs 2.0 1 800 µs 2.0 µs 2.0 µs 1.2 µs 833 µs 800 Undetermined State Internal RX Delay Unit tID 865 µs 2.0 µs 1.5 ms Notes: 1. Consider the Xtal/clock tolerance. 2. All TX timings are related to the TX Sync Output. t SYNC t ESET TX ENABLE TX SYNC t DH t DSET TX DATA DC = Don't Care DV = Data Valid DC DC DV t TDR t TDR DV DC DV DC t TXD OPEN CIRCUIT OPEN CIRCUIT 1200 BPS TX OUTPUT Figure 3: Transmitter Timing: 1200bps LOGIC '0' LOGIC '1' RX SIGNAL I/P 1200 BPS t ID 1 RX SYNC O/P (1200Hz) 0 t RDR Undetermined State 1 CLOCKED DATA O/P LOGIC '1' LOGIC '0' 0 Figure 4: Receiver Timing Diagram: 1200bps 1998 MX-COM, 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. # 20480081.010 All trademarks and service marks are held by their respective companies. 1200/2400/4800bps MSK Modem 8 MX469 4.1.2 2400bps Characteristics Note TX Enable to TX Sync Rise Time tSYNC TX Delay, Signal to Disable Time tESET Data Set-Up Time tDSET Min. Typ. Max. 208 µs 2.0 1 Unit 400 2.0 µs µs Data Hold Time tDH TX Delay to O/P Time tTxD 2.0 1.2 µs µs TX Data Rate Period tTDR 416 µs RX Data Rate Period tRDR 400 Undetermined State Internal RX Delay tID 433 µs 2.0 µs 1.5 ms Notes: 1. Consider the Xtal/Clock tolerance. 2. All TX timings are related to the TX Sync Output. t SYNC t ESET TX ENABLE TX SYNC t DH t DSET TX DATA DC = Don't Care DV = Data Valid DC DV DC DV t TDR DC DV DC DV DC t TDR DV DC DV DC t TXD 2400 BPS TX OUTPUT OPEN CIRCUIT OPEN CIRCUIT Figure 5: Transmitter Timing: 2400bps LOGIC '1' LOGIC '0' LOGIC '1' LOGIC '0' RX SIGNAL I/P 2400 BPS t ID 1 RX SYNC O/P (2400Hz) 0 Undetermined State t RDR 1 CLOCKED DATA O/P LOGIC '1' LOGIC '0' LOGIC '1' LOGIC '0' 0 Figure 6: Receiver Timing: 2400bps 1998 MX-COM, 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. # 20480081.010 All trademarks and service marks are held by their respective companies. 1200/2400/4800bps MSK Modem 9 MX469 4.1.3 4800bps Characteristics Note TX Enable to TX Sync Rise Time tSYNC TX Delay, Signal to Disable Time tESET Data Set-Up Time tDSET Min. Typ. Max. Unit 104 µs 2.0 1 200 µs 2.0 µs Data Hold Time tDH TX Delay to O/P Time tTxD 2.0 1.2 µs µs TX Data Rate Period tTDR 208 µs RX Data Rate Period tRDR 200 Undetermined State Internal RX Delay tID 216 µs 2.0 µs 1.0 ms Notes: 1. Consider the Xtal/Clock tolerance. 2. All TX timings are related to the TX Sync Output. t SYNC t ESET TX ENABLE TX SYNC t DH t DSET TX DATA DC = Don't Care DV = Data Valid DC DV DC DV t TDR DC DV DC DV DC t TDR DV DC DV DC t TXD 4800 BPS TX OUTPUT OPEN CIRCUIT OPEN CIRCUIT Figure 7: Transmitter Timing: 4800bps LOGIC '1' LOGIC '0' LOGIC '1' LOGIC '0' RX SIGNAL I/P 4800 BPS t ID 1 RX SYNC O/P (4800Hz) 0 Undetermined State t RDR 1 CLOCKED DATA O/P LOGIC '1' LOGIC '0' LOGIC '1' LOGIC '0' 0 Figure 8: Receiver Timing: 4800bps 1998 MX-COM, 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. # 20480081.010 All trademarks and service marks are held by their respective companies. 1200/2400/4800bps MSK Modem 10 MX469 5. Application 5.1 Synchronous Modem Design Considerations The MX469 is an easily applied data pump, which can be used with many protocols. Because it is an MSK, or minimum shift keying, modem, it achieves a more noise resistant, higher data rate in a narrower bandwidth than other FSK (frequency shift keying) modems. This characteristic is especially important for wireless applications because it fundamentally determines the bandwidth of RF transmissions, which are strictly limited and controlled by regulatory agencies. Using MSK signaling, the MX469 data modem can achieve a 2400bps data rate within the typical 300-3000 Hz voice band of many common radios. In order to achieve this advantage, an MSK modem must precisely control the bit rate and timing of the modulated Tx output signal bits. This control is asserted by the MSK modem with a data clock signal, which is output, by the modem to pace the Tx data source (e.g. a microcontroller). The data clock signal, in effect, indicates when the Tx data source should provide the next Tx data bit to the modem. See Figure 9. Because this type of interface involves the use of a modem generated bit clock signal to control the timing of when new Tx data bits must be supplied from the data source, the interface is called synchronous. Another characteristic of a synchronous modem is that, to receive data, it must first learn the data bit timing of the Rx signal stream before it can accurately demodulate Rx data bits. Accordingly, a synchronous modem undergoes a period of training or synchronization when it first begins to receive a stream of MSK modulated signal. During this initial receive phase, the received signal is evaluated over several bit times as the modem ‘locks on’ and achieves proper receive synchronization. The training sequence, called a preamble, is a specific data pattern which must be added to the ‘front’ of a transmit data stream with the start of each new transmission. A specific preamble data pattern (e.g. 16 bits of alternating 0,1,0,1… for the MX469) is used to optimize the training accuracy while minimizing the number of preamble bits required. Tx data DATA: 0 1 1 0 1 1 Data Bit Tx Source (e.g. µC) MSK Modem Transmitting I took BIT 3 Give me BIT 3 I took BIT 2 Give me BIT 2 I took BIT 1 Give me BIT 1 Tx SYNC (data clock) MSK Tx Out Figure 9: Synchronous Transmit Operation Non-synchronous or asynchronous interfaces are commonly found in wired applications which do not have the bandwidth efficiency requirements of wireless systems. A well known example is the serial port of a personal computer which can transmit a 1200 bps (or faster) data signal over a single Tx signal without using an additional data clock signal to control the precise rate and timing of data bits being transmitted to a typical telephone line data modem. Popular modem standards such as Bell 202 and v.23 use FSK signaling to pass such asynchronous serial port data signals over telephone systems. Another aspect of asynchronous interfaces and modems is that they can carry data streams which are not at the exact, nominal data rate. For example, a 1200 bps FSK modem will typically operate properly when supplied with transmit data streams of 1201 bps or 1199 bps. Because of the differences in synchronous and asynchronous interfaces, they cannot successfully operate if directly connected. In other words, a personal computer’s RS232 serial port cannot directly interface to an MSK modem. This is because: The asynchronous interface may provide data bits too fast or too slow compared to the precise rate required for MSK signaling (a bit rate, or pacing, incompatibility). The timing of each specific data bit presented by an asynchronous interface will not be aligned with the precise bit timing required for MSK signaling (a bit timing incompatibility). Synchronous and asynchronous interface can be successfully interfaced for applications requiring the advantages of both. This typically involves the use of data buffering and retiming circuits to resolve the timing and pacing issues. 1998 MX-COM, 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. # 20480081.010 All trademarks and service marks are held by their respective companies. 1200/2400/4800bps MSK Modem 11 MX469 5.2 Bit Error Rate VDD VDD MILLIAMMETER MILLIAMMETER CLOCKED DATA OUT TX DATA I/P PREAMBLE & PSEUDO-RANDOM DATA GENERATOR TX SIGNAL O/P MX469 TRANSMITTER BUFFER (INTERFACE) CIRCUIT (components as Fig. 2) RX SIGNAL IN S3 TELEPHONE CHANNEL SIMULATOR RX SYNC MX469 RECEIVER (with attenuator & 5kHz BW noise gen) ERROR DETECTOR (components as Fig. 2) Tx SYNC OSCILLOSCOPE TRUE RMS VOLTMETER TRUE RMS VOLTMETER CARRIER DETECT OUT CARRIER DETECT OUT HIGH DETECTOR Figure 10: MX469 Test Set-Up Figure 11: Typical Variation of Bit Error Rate with Input Level 1998 MX-COM, 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. # 20480081.010 All trademarks and service marks are held by their respective companies. 1200/2400/4800bps MSK Modem 12 MX469 IDEAL COHERENT MSK 2 x 10-2 MX469 BIT ERROR RATE (log scale) 10 -2 10 -3 10 -4 8 6 4 2 10 -5 0 1 2 3 4 5 7 6 8 9 10 11 13 12 14 15 16 SNR (dB) BIT RATE BANDWIDTH (lin scale) Figure 12: RX Bit-Error-Rate vs. Signal-to-Noise Ratio 6. Performance Specifications 6.1 Electrical Specifications 6.1.1 Absolute Maximum Limits Exceeding these maximum ratings can result in damage to the device. General Notes Min. Typ. Max. Units Supply (VDD-VSS) -0.3 7.0 V Voltage on any pin to VSS -0.3 VDD + 0.3 V VDD -30 30 mA VSS -30 30 mA Any other pin -20 20 mA Current DW / D3 / P Packages 10 Derating above 25C mW/C above 25C Operating Temperature -40 85 C Storage Temperature -55 125 C 6.1.2 Operating Limits Correct Operation of the device outside these limits is not implied. Notes Min. Typ. Max. Units Supply (VDD-VSS) 4.5 5.0 5.5 V Operating Temperature -40 85 C 1.008 4.032 MHz Xtal Frequency 1998 MX-COM, 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. # 20480081.010 All trademarks and service marks are held by their respective companies. 1200/2400/4800bps MSK Modem 13 MX469 6.1.3 Operating Characteristics For the following conditions unless otherwise specified. VDD = 5.0V @ TAMB = 25C Audio Level 0dB ref. = 300mVRMS, Xtal/Clock Frequency = 4.032MHz Signal-to-Noise Ratio measured in the Bit-Rate Bandwidth 1200bps BRB = 1200Hz 2400bps BRB = 2400Hz 4800bps BRB = 4800Hz Notes Min. Typ. Max. Units Static Values Supply Current RX Enabled, TX Disabled 3.6 mA RX and TX Enabled 4.5 mA RX and TX Disabled 650 µA Logic ‘1‘ Level 1 Logic ‘0’ Level 1 4.0 V 1.0 Digital Output Impedance 4.0 Analog and Digital Input Impedance k 100 TX Output Impedance V k 0.6 1.0 k On-Chip Xtal Oscillator RIN 10.0 ROUT M 10.0 k Inverter DC Voltage Gain 10.0 V/V Gain Bandwidth Product 10.0 MHz Dynamic Values Receiver Signal Input Dynamic Range SNR = 50dB 3, 4 100 230 1000 mVRMS Bit Error Rate 7.0 10-4 1200bps 2.5 10-4 2400bps 1.5 10-3 4800bps 1.5 10-3 1.0 10-8 Probability of Bit 8 Being Correct 99 % Probability of Bit 16 Being Correct 99.5 % SNR = 12dB 4 SNR = 20dB 4 1200/2400/4800bps Receiver Synchronization SNR =12dB 7 5, 10 Carrier Detect Sensitivity 7, 8 150 mVRMS Probability of C.D. Being High After Bit 8 (1200bps) SNR = 12dB 5, 9 98 % SNR = 12dB 5, 9 99.5 % 9 5 % After Bit 16 0dB Noise 1998 MX-COM, Inc. No Signal 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. # 20480081.010 All trademarks and service marks are held by their respective companies. 1200/2400/4800bps MSK Modem 14 MX469 Notes Min. Typ. Max. Units Transmitter Output TX Output Level 775 mVRMS Output Level Variation 1200/1800Hz 0 ±1.0 dB 1200/2400Hz 0 ±1.0 dB 2400/4800Hz 0 ±1.0 dB Output Distortion 3.0 5.0 % 3rd Harmonic Distortion 2.0 3.0 % Logic ‘1’ Carrier Frequency 1200bps 6 1200 Hz 2400bps 6 1200 Hz 4800bps 6 2400 Hz 1200bps 6 1800 Hz 2400bps 6 2400 Hz 4800bps 6 4800 Hz Logic ‘0’ Carrier Frequency Isochronous Distortion 1200Hz - 1800Hz/1200Hz 2400Hz 25.0 40.0 s 1800Hz - 1200Hz/2400Hz 1200Hz 20.0 40.0 s 2400Hz - 4800Hz/4800Hz 2400Hz 10.0 20.0 s Operating Characteristics Notes: 1. With reference to VDD = 5.0 volts. 2. Xtal frequency (ref. Clock Rate pin), type and tolerance depends upon system requirements. 3. See Figure 4 (variation of BER with Input Signal Level). 4. SNR = Signal-to-Noise in the Bit-Rate Bandwidth. 5. See Figure 2. 6. Dependent upon Xtal tolerance. 7. 10101010101 ...01 pattern. 8. Measured with a 150mVRMS input signal (no noise). 9. Reference (0dB) level for C.D. probability measurements is 230mVRMS. 10. For 1200bps and 2400bps operation only: when operating at 4800bps the carrier detect output should be ignored. 1998 MX-COM, 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. # 20480081.010 All trademarks and service marks are held by their respective companies. 1200/2400/4800bps MSK Modem 15 MX469 6.1.4 Packages Figure 13: 24-pin SOIC Mechanical Outline: Order as part no. MX469DW Package Tolerances A B E1 E Y T PIN 1 K C H L J1 J P DIM. A B C E E1 H J J1 K L P T Y MIN. TYP. MAX. 1.100 (27.94) 0.360 (9.14) 1.080 (27.43) 0.330 (8.38) 0.185 (4.70) 0.420 (10.67) 0.480 (12.19) 0.390 (9.91) 0.420 (10.67) 0.020 (0.51) 0.045 (1.14) 0.015 (0.38) 0.020 (0.51) 0.065 (1.65) 0.040 (1.02) 0.066 (1.68) 0.128 (3.25) 0.100 (2.54) 0.010 (0.25) 7° NOTE : All dimensions in inches (mm.) Angles are in degrees Figure 14: 22-pin PDIP Mechanical Outline: Order as part no. MX469P 1998 MX-COM, 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. # 20480081.010 All trademarks and service marks are held by their respective companies. 1200/2400/4800bps MSK Modem 16 MX469 Package Tolerances A Z B ALTERNATIVE PIN LOCATION MARKING E W L T PIN 1 X Y C J H K P DIM. MIN. TYP. MAX. A B C E H J K L P T W X Y Z 0.510 (12.95) 0.495 (12.57) 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) 0.046 (1.17) 0.036 (0.91) 0.050 (1.27) 0.016 (0.41) 0.050 (1.27) 0.009 (0.23) 0.0125 (0.32) 45° 0° 10° 5° 7° 5° NOTE : All dimensions in inches (mm.) Angles are in degrees Figure 15: 20-pin SOIC Mechanical Outline: Order as part no. MX469D3 1998 MX-COM, 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. # 20480081.010 All trademarks and service marks are held by their 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