CT1698 MIL-STD-1397 Type E 10MHz Low Level Serial Interface Features Optional transformer isolation Internally set threshold Matched to 50 ohm system impedance power on and off Operates with ±5 volt supplies Power management External output level adjustment Accepts synchronous input data Unique Manchester decoder requires no clock Generates one clock per received bit May be used for serial decoding of indefinite word lengths Interfaces directly to the CT2500 protocol device Other Wire and Fiber Optic types available CIRCUIT TECHNOLOGY LE X LA ISO 9001 E I NC . C F S A E RO www.aeroflex.com B • • • • • • • • • • • • RTIFIE D General Description CT1698 is a single hybrid microcircuit which incorporates a serial encoder, transceiver, and Manchester decoder in one package. The encoder accepts serial NRZ data in conjunction with two synchronous clocks. The CT1698 receiver section accepts bipolar Manchester encoded signals and passes level detected signals to the serial decoder. The CT1698 has a power management function and a variable drive level option. The transmitter standby mode is available to reduce the overall power consumption of the CT1698. The variable drive level output is externally programmable for testing purposes. Aeroflex Circuit Technology is a 80,000 square foot MIL-PRF-38534 certified facility in Plainview, N.Y. Drive 1 XFMR SEC/DATA Input Serial NRZ Data 10 MHz Shift Clock XFMR SEC 20 MHz Gated Clock +5V Serial Manchester Encoder Envelope Primary Data Output Primary Data Output XFMR SEC Master Reset Encoder Enable Power Management XFMR SEC/DATA Input Power Management Drive 2 Decoded Data Envelope Manchester Decoder and Clock Regeneration Data Reconstruction Rx Strobe ClockR Decoded DataR Figure 1 – Block Diagram eroflex Circuit Technology – Data Bus Modules For The Future © SCDCT1698 REV A 6/12/98 Transmission Reception The CT1698 accepts synchronous NRZ Data in conjunction with two clocks signals. The NRZ data stream is then converted to Manchester code which is transformer coupled to a 50 ohm Tri-axial cable for transmission up to 1000 ft. The CT1698 receiver section accepts a bipolar signal which is level detected and passed to the serial decoder. The decoder section reconstructs the data and strips the clock from the serial stream. An NRZ decoded data stream is then produced synchronously with a recovered clock. The receiver is designed to meet the MIL-STD-1397 Type E requirements. The transmitter may be placed into standby condition. This reduces power consumption by approximately 600mW. Power management is made available via two standard TTL input pins. The Receiver is always active and is not affected by the power management circuitry. Electrical Requirements The specification detailed herein encompasses a hybrid Transceiver/Encoder-Decoder designed to meet the requirements of the MIL-STD-1397 Type E. The transceiver is transformer coupled to the specified triaxial cable. The drive level of the transmitter may be changed by adding external resistors to the drive pins. These pins allow the designer to externally program the transmitter output level from 0.7 to 2.8 Volts peak to peak. See Figure 1 for Block Diagram. Inputs and Outputs are all Synchronous NRZ DATA STREAMS. The transformer is internal to the package with its use being optional. The transceiver is matched for 50 ohm operation over a wide band of frequencies. This condition is maintained with power on and off. Encoding Timing / Transmitter Specification Symbol Parameter / Condition Min Typ Max Unit Encode Timing t1 Input data set-up time 10 40 ns t2 Encode clock set-up time 10 40 ns t3 Encode envelope set-up time 10 40 ns t4 Encode envelope turn-off time 10 35 ns t5 Transmitter activation set-up time 100 ns t6 Transmitter deactivation hold-time 50 ns tw1 20 MHz gated CK pulse width high 20 30 ns tw2 Encoder shift CK pulse width high 45 55 ns Va Output amplitude (see Figure 2) .45 .7 .8 V T Pulse period 97 100 103 ns Ts Width of 1st positive half bit 45 65 ns Te Width of last half bit 47 65 ns T/2 Half pulse period 47 53 ns Tr Pulse rise time .05 .3 V/ns Tf Pulse fall time .05 .3 V/ns Vs Voltage overshoot 100 mV Tos Offset Voltage 2T after last zero crossing 30 mV Tdtx Delay from 20 MHz clock input to data output on TXFMR secondary 20 55 ns Zo Output Impedance 50 55 Ω Output Signals Aeroflex Circuit Technology 45 2 50 SCDCT1698 REV A 6/12/98 Plainview NY (516) 694-6700 Aeroflex Circuit Technology BIT 0 BIT 1 BIT 2 P1 = 50ns ±0.1% P2 = 100ns ±0.1% BIT N t1 NRZ Serial Input t W2 t2 Encoder Shift Clock Input P2 t W1 20 MHz GATED Clock P1 t3 t4 NRZ Envelope 3 t5 t6 Encoder Enable Power Management Pin Tf 2T SCDCT1698 REV A 6/12/98 Plainview NY (516) 694-6700 Transmitter Output 90% Va VS T 90% V US T dTX 10% T/2 10% Tr T Figure 2 Encoder – Transmitter Timing TOS Te 1 st Data BIT 2 nd Data BIT 3 rd Data BIT 4 th Data BIT 5 th Data BIT Manchester II Receiver Data Decoded Data Envelope R X Data t6 t1 t5 t7 t2 Data R t4 t3 CK R t5 Figure 3 Receiver / Decode Timing Symbol Parameter / Condition Min Nom Max Units t1 Envelope delay time - - 100 nsec t2 Data decode delay - 115 125 nsec t3 Clock low transition delay - 130 - nsec t4 ClockR high time 35 50 65 nsec t5 ClockR low time 35 50 65 nsec t6 Envelope off delay 120 - 270 nsec t7 Receiver strobe enable to input data set-up time 5 nsec t8 Receiver strobe disable to input data hold-time 20 ? Power Management Functional Table Encoder Enable (Pin 10) Power Management Input (Pin 9) Receiver Status Transmitter Status 0 0 Active Standby X 1 Active Active 1 X Active Active Power management timing see Figure 2. Aeroflex Circuit Technology 4 SCDCT1698 REV A 6/12/98 Plainview NY (516) 694-6700 Drive Level Control Pins External Resistors may be connected from pins 5 and 6 to VEE or GND to change the Transmitter Output Level. If pins 5 and 6 are left open the CT1698 operates within the MIL-STD-1397 Type E specification. Resistors connected from pins 5 and 6 to VEE or Ground must be equal. Unequal resistors will result in a transmitter output offset level. The formula for peak to peak transmitter output swing with resistors connected between 5 and 6 to VEE is: VOUT pk-pk = 1.39 + 125 ± 15% Volts, REXT REXT > 90Ω The formula for peak to peak transmitter output swing with resistors connected between pins 5 and 6 to ground is: VOUT pk-pk = 1.39 - 50 (VEE -2.5) ± 15% Volts, REXT REXT > 180Ω Functional Description and Pinout Pin # Pin Name Load or Drive Function 1 XFMR primary/ TX data output Transformer lead for connection to center conductor of tri-axial cable 2 XFMR secondary Secondary isolated winding, same phase as center conductor 3 TXDATA output/ RX data input Transmitter-receiver I/O pin (usually connected to pin 2) 4 No connection 5 Drive 2 Output level adjustment selected by resistor to GND or VEE 6 Drive 1 Output level ajustment selected by resistor to GND or VEE 7 -5 Volts 8 RX strobe Low level disables receiver 3 S loads 9 Power management input Controls transmitter power consumption in conjunction with pin 10 1 S load 10 Encoder enable Controls transmitter power consumption in conjunction with pin 9 1 S load 11 Case/signal GND 12 Case/signal GND 13 Decoded data envelope High after reception of first half bit; goes low after reception of last half bit (normally low in inactive state) 4 S drive 14 TP3 test point Alignment point: no electrical connection permitted 15 TP1 test point Alignment point: no electrical connection permitted 16 TP2 test point Alignment point: no electrical connection permitted 17 -5 Volts 18 TP4 test point Alignment point: no electrical connection permitted 19 ClockR Reconstructed clock; one clock pulse per input bit received 3 S drive 20 No connection 21 Decoded DataR NRZ reconstructed data. Sampled on clockR rising edge 3 S drive Aeroflex Circuit Technology 5 SCDCT1698 REV A 6/12/98 Plainview NY (516) 694-6700 Functional Description and Pinout (continued) Function Load or Drive One cycle required per data bit. Must be high in first half of bit cell 1 S load 26 NRZ serial input data Serial input to be Manchester encoded with the 20 MHz gated CK 1 S load 27 Encode envelope Must be high to enable transmission; must go low before reception of last 20 MHz positive edge to complete transmission 1 S load 28 20 MHz gated clock (encoder) Each bit to be encoded requires two positive edges of the 20 MHz CK. These edges must occur at 25ns and 75ns into the bit cell. The end of transmission requires an additional edge in conjunction with a logic low on the encode envelope. tR, tF < 5nsec. 1 S load 29 Master reset reset pulse <15 nsec Logic low resets encoder 2 S load 30 No connection 31 No connection 32 TXDATA output/ RX DATA input Transmitter-Receiver I/O pin (usually connected to pin 33) 33 XFMR secondary Secondary isolated winding, same phase as outer signal conductor 34 XFMR primary/ TX DATA output Transformer lead for connection to outer signal conductor of tri-axial Pin # Pin Name 22 No connection 23 +5 volts 24 +5 volts 25 10 MHz encoder shift clock Absolute Maximum Ratings Load and Drive Definitions VCC (Pins 23, 24) +7 Volts Max VEE (Pins 7, 17) -7 Volts Max Logic Input Voltage Applied: Logic Low -1.2V @ 10mA Max Logic High +5.5 Volts 1 S load: requires IIL = -2mA max., VIL = 0.8V max IIH = 50µA max., VIH = 2.5V min CIN < 15 pf 1 S drive: IOH = 50µA min., VOH = 2.5V min IOL = -2 mA min., VOL = 0.5V max When used with the internal transformer, the CT1698 will not be damaged by cable open circuits or by short circuits of the following types: • Line-to-line • Line-to-ground • To voltage sources of 0 to 115 volts alternating current, 60 hertz, line-to-ground Power Consumption Current (mA) Typ Max ICC Standby mode 325 450 IEE Standby mode 85 105 ICC 100% Transmission 380 510 IEE 100% Transmission 125 160 Aeroflex Circuit Technology Environmental Parameters Operating Temperature -55°C to +100°C Case Storage Temperature -55°C to +150°C Screened per individual test methods of MIL-STD-883 6 SCDCT1698 REV A 6/12/98 Plainview NY (516) 694-6700 CIRCUIT TECHNOLOGY Ordering Information Model Number Package Plug-in Package CT1698 Flat Package CT1698FP Plug-In Package Outline 1.200 ±.005 Pin 1 & ESD Designator 1.810 MAX .100 TYP Both Sides .200 .270 ±.010 .100 ±.005 TYP .018 ±.002 DIA .120 ±.010 Both Sides (17 Pins/Side) Flat Package Outline .015 ±.003 .180 MAX .100 ±.005 .400 MIN 1.410 MAX Lead 1 & ESD Designator 1.810 MAX .010 ±.002 Aeroflex Circuit Technology 35 South Service Road Plainview New York 11830 Telephone: (516) 694-6700 FAX: (516) 694-6715 Toll Free Inquiries: 1-(800)THE-1553 Specifications subject to change without notice. Aeroflex Circuit Technology 7 SCDCT1698 REV A 6/12/98 Plainview NY (516) 694-6700