C . N I S B C E A R L T CT1698 MIL-STD-1397 Type E 10MHz Low Level Serial Interface Features • Optional transformer isolation CIRCUIT TECHNOLOGY • Internally set threshold www.aeroflex.com • 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 ISO • Generates one clock per received bit 9001 • May be used for serial decoding of indefinite word lengths • Interfaces directly to the CT2500 protocol device I • Other Wire and Fiber Optic types available 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 Primary Data +5V Serial Output Envelope Manchester Encoder Primary Data Master Reset Output Encoder Enable XFMR SEC Power Management XFMR SEC/DATA Input Power Management Drive 2 Decoded Data Envelope Manchester Data Decoder Rx Strobe and Reconstruction Clock Regeneration Clock R Decoded Data R Figure 1 – Block Diagram eroflex Circuit Technology – Data Bus Modules For The Future © SCDCT1698 REV A 6/12/98 X F E I L E F D O R E A Transmission Reception The CT1698 accepts synchronous NRZ Data in The CT1698 receiver section accepts a bipolar conjunction with two clocks signals. The NRZ data signal which is level detected and passed to the stream is then converted to Manchester code which serial decoder. The decoder section reconstructs is transformer coupled to a 50 ohm Tri-axial cable for the data and strips the clock from the serial stream. transmission up to 1000 ft. An NRZ decoded data stream is then produced synchronously with a recovered clock. The receiver The transmitter may be placed into standby is designed to meet the MIL-STD-1397 Type E condition. This reduces power consumption by requirements. approximately 600mW. Power management is made available via two standard TTL input pins. The Electrical Requirements Receiver is always active and is not affected by the The specification detailed herein encompasses a power management circuitry. hybrid Transceiver/Encoder-Decoder designed to meet the requirements of the MIL-STD-1397 Type E. The drive level of the transmitter may be changed by adding external resistors to the drive pins. These The transceiver is transformer coupled to the specified triaxial cable. pins allow the designer to externally program the transmitter output level from 0.7 to 2.8 Volts peak to See Figure 1 for Block Diagram. Inputs and peak. Outputs are all Synchronous NRZ DATA STREAMS. The transformer is internal to the package with its The transceiver is matched for 50 ohm operation over a wide band of frequencies. This condition is use being optional. 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 Output Signals 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 50 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 20 55 ns TXFMR secondary Zo Output Impedance 45 50 55 Ω 2 Aeroflex Circuit Technology SCDCT1698 REV A 6/12/98 Plainview NY (516) 694-6700 3 Aeroflex Circuit Technology SCDCT1698 REV A 6/12/98 Plainview NY (516) 694-6700 P1 = 50ns ±0.1% BIT 0 BIT 1 BIT 2 BIT N P2 = 100ns ±0.1% t 1 NRZ Serial Input t W2 t 2 Encoder Shift Clock Input P2 t W1 20 MHz GATED Clock P1 t 3 t 4 NRZ Envelope t 5 t 6 Encoder Enable Power Management Pin T f 2T 90% 90% T V Transmitter a Output V S V US T dTX 10% 10% T OS T T T/2 r e T Figure 2 Encoder – Transmitter Timing 1st Data 2nd Data 3rd Data 4th Data 5th Data BIT BIT BIT BIT BIT Manchester II Receiver Data t t 1 6 Decoded Data Envelope t 5 R Data t X 7 t 2 Data R t t 4 3 CK R t 5 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 Clock high time 35 50 65 nsec R t5 Clock low time 35 50 65 nsec R 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 Power Management Receiver Transmitter Enable Input Status Status (Pin 10) (Pin 9) 0 0 Active Standby X 1 Active Active 1 X Active Active Power management timing see Figure 2. 4 Aeroflex Circuit Technology 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 V or GND to change the Transmitter Output EE 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 V or Ground must be equal. Unequal resistors will result in a EE transmitter output offset level. The formula for peak to peak transmitter output swing with resistors connected between 5 and 6 to V EE is: V = 1.39 + 125 ± 15% Volts, R > 90Ω OUT EXT pk-pk R EXT The formula for peak to peak transmitter output swing with resistors connected between pins 5 and 6 to ground is: V = 1.39 - 50 (V -2.5) ± 15% Volts, R > 180Ω OUT EE EXT pk-pk R EXT Functional Description and Pinout Pin Load or Pin Name Function # Drive 1 XFMR primary/ Transformer lead for connection to center conductor of tri-axial TX data output cable 2 XFMR secondary Secondary isolated winding, same phase as center conductor 3 TXDATA output/ Transmitter-receiver I/O pin (usually connected to pin 2) RX data input 4 No connection 5 Drive 2 Output level adjustment selected by resistor to GND or V EE 6 Drive 1 Output level ajustment selected by resistor to GND or V EE 7 -5 Volts 8 R strobe Low level disables receiver 3 S loads X 9 Power management Controls transmitter power consumption in conjunction with pin 10 1 S load input 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 High after reception of first half bit; goes low after reception of last 4 S drive envelope half bit (normally low in inactive state) 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 Clock Reconstructed clock; one clock pulse per input bit received 3 S drive R 20 No connection 21 Decoded Data NRZ reconstructed data. Sampled on clock rising edge 3 S drive R R 5 Aeroflex Circuit Technology SCDCT1698 REV A 6/12/98 Plainview NY (516) 694-6700 Functional Description and Pinout (continued) Pin Load or Pin Name Function # Drive 22 No connection 23 +5 volts 24 +5 volts 25 10 MHz encoder shift One cycle required per data bit. Must be high in first half of bit cell 1 S load clock 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 1 S load of last 20 MHz positive edge to complete transmission 28 20 MHz gated clock Each bit to be encoded requires two positive edges of the 20 MHz 1 S load (encoder) 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. t , t < 5nsec. R F 29 Master reset Logic low resets encoder 2 S load reset pulse <15 nsec 30 No connection 31 No connection 32 TXDATA output/ Transmitter-Receiver I/O pin (usually connected to pin 33) RX DATA input 33 XFMR secondary Secondary isolated winding, same phase as outer signal conductor 34 XFMR primary/ Transformer lead for connection to outer signal conductor of TX DATA output tri-axial Load and Drive Definitions Absolute Maximum Ratings 1 S load: requires V (Pins 23, 24) +7 Volts Max CC = -2mA max., V = 0.8V max I IL IL V (Pins 7, 17) -7 Volts Max EE I = 50µA max., V = 2.5V min C < 15 pf IH IH IN Logic Input Voltage Applied: 1 S drive: Logic Low -1.2V @ 10mA Max I = 50µA min., V = 2.5V min OH OH Logic High +5.5 Volts I = -2 mA min., V = 0.5V max OL OL When used with the internal transformer, the Power Consumption CT1698 will not be damaged by cable open circuits or by short circuits of the following types: • Line-to-line Current (mA) • Line-to-ground Typ Max • To voltage sources of 0 to 115 volts alternating current, 60 hertz, line-to-ground I Standby mode 325 450 CC I Standby mode 85 105 EE Environmental Parameters I 100% Transmission 380 510 CC Operating Temperature -55°C to +100°C Case I 100% Transmission 125 160 EE Storage Temperature -55°C to +150°C Screened per individual test methods of MIL-STD-883 6 Aeroflex Circuit Technology 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 .100 TYP MAX Both Sides .200 .270 ±.010 .018 ±.002 .120 ±.010 .100 ±.005 DIA Both Sides TYP (17 Pins/Side) Flat Package Outline .180 MAX .015 ±.003 .100 ±.005 .400 MIN 1.410 MAX Lead 1 & ESD Designator 1.810 MAX .010 ±.002 Aeroflex Circuit Technology Telephone: (516) 694-6700 35 South Service Road FAX: (516) 694-6715 Plainview New York 11830 Toll Free Inquiries: 1-(800)THE-1553 Specifications subject to change without notice. 7 Aeroflex Circuit Technology SCDCT1698 REV A 6/12/98 Plainview NY (516) 694-6700