Datasheet CT1698FP, CT1698 Datasheet (ACT)

www.aeroflex.com

CT1698

F

E

I

D

C

E

R

T

A

E

R

O

F

L

E

X

L

A

B

S

I

N

C

.

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

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.

CIRCUIT TECHNOLOGY

ISO

900

I

1

Serial NRZ Data

10 MHz Shift Clock

20 MHz Gated Clock

Envelope

Master Reset

Encoder Enable

Power Management

Decoded Data Envelope

Clock Regeneration

Clock

R

Serial

Manchester

Encoder

Power

Management

Manchester

Decoder

and

Data

Reconstruction

Drive 1

XFMR SEC/DATA Input

XFMR SEC

Primary

+5V

Primary

XFMR SEC

XFMR SEC/DATA

Drive 2

Rx Strobe

Data

Output

Data

Output

Input

Decoded Data

R

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 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.

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.

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

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.

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.

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.

Symbol Parameter / Condition Min Typ Max Unit
Encode Timing

t1 Input data set-up time
t2 Encode clock set-up time
t3 Encode envelope set-up time
t4 Encode envelope turn-off time
t5 Transmitter activation set-up time
t6 Transmitter deactivation hold-time
tw1 20 MHz gated CK pulse width high
tw2 Encoder shift CK pulse width high

Output Signals

Va Output amplitude (see Figure 2)
T Pulse period
Ts Width of 1st positive half bit
Te Width of last half bit
T/2 Half pulse period
Tr Pulse rise time
Tf Pulse fall time
Vs Voltage overshoot
Tos Offset Voltage 2T after last zero crossing
Tdtx Delay from 20 MHz clock input to data output on

TXFMR secondary

Zo Output Impedance

10 40 ns
10 40 ns
10 40 ns
10 35 ns

100 ns

50 ns
20 30 ns
45 55 ns

.45 .7 .8 V

97 100 103 ns
45 65 ns
47 65 ns

47 50 53 ns
.05 .3 V/ns
.05 .3 V/ns

100 mV

30 mV

20 55 ns

45 50 55 Ω

Aeroflex Circuit Technology SCDCT1698 REV A 6/12/98 Plainview NY [phone]

2

Aeroflex Circuit Technology SCDCT1698 REV A 6/12/98 Plainview NY [phone]

3

P1 = 50ns ±0.1%
P2 = 100ns ±0.1%

NRZ

BIT NBIT 2BIT 1BIT 0

t

1

Serial Input

t

Encoder

t

2

W2

Shift Clock Input

P2

t

20 MHz

W1

GATED Clock

P1

t

4

NRZ

t

3

Envelope

t

Encoder Enable

5

t

6

Power Management

Pin

T

f

2T

Transmitter

Output

T

dTX

V

a

V

S

V

US

90%

10%

90%

10%

T

T

OS

T/2

T

r

T

Figure 2 Encoder – Transmitter Timing

T

e

Manchester II

Receiver Data

1st Data

BIT

2nd Data

BIT

3rd Data

BIT

4th Data

BIT

5th Data

BIT

Decoded

Data

Envelope

R

Data

X

Data

CK

t

1

t

7

R

R

t

2

t

3

t

4

t

5

t

6

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
t5 Clock

high time 35 50 65 nsec

R

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

Enable

(Pin 10)

Power Management

Input

(Pin 9)

Receiver

Status

0 0 Active Standby
X 1 Active Active
1 X Active Active

Power management timing see Figure 2.

Transmitter

Status

Aeroflex Circuit Technology SCDCT1698 REV A 6/12/98 Plainview NY [phone]

4

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 V

transmitter output offset level.

or Ground must be equal. Unequal resistors will result in a

EE

The formula for peak to peak transmitter output swing with resistors connected between 5 and 6 to V

is:

V

OUT

= 1.39 + 125 ± 15% Volts, R

pk-pk

R

EXT

EXT

> 90Ω

The formula for peak to peak transmitter output swing with resistors connected between pins 5 and 6 to

ground is:

V

OUT

= 1.39 - 50 (VEE -2.5) ± 15% Volts, R

pk-pk

R

EXT

> 180Ω

EXT

Functional Description and Pinout

Pin

Pin Name 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/

Transmitter-receiver I/O pin (usually connected to pin 2)

RX data input

4 No connection

Load or

Drive

EE

5 Drive 2 Output level adjustment selected by resistor to GND or V
6 Drive 1 Output level ajustment selected by resistor to GND or V

EE

EE

7 -5 Volts
8 R
9 Power management

strobe Low level disables receiver 3 S loads

X

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

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 Clock

R

Reconstructed clock; one clock pulse per input bit received 3 S drive
20 No connection
21 Decoded Data

Aeroflex Circuit Technology SCDCT1698 REV A 6/12/98 Plainview NY [phone]

R

NRZ reconstructed data. Sampled on clockR rising edge 3 S drive

5

Functional Description and Pinout (continued)

Pin

Pin Name Function

#

Load or

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

(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.

1 S load

The end of transmission requires an additional edge in conjunction

29 Master reset

with a logic low on the encode envelope. t
Logic low resets encoder 2 S load

, tF < 5nsec.

R

reset pulse <15 nsec
30 No connection
31 No connection
32 TXDATA output/

RX DATA

input

Transmitter-Receiver I/O pin (usually connected to pin 33)

33 XFMR

34 XFMR

TX DATA

Load and Drive Definitions

1 S load: requires

1 S drive:

Power Consumption

I

CC

I

EE

I

CC

I

EE

secondary Secondary isolated winding, same phase as outer signal

primary/

output

= -2mA max., VIL = 0.8V max

I

IL

= 50µA max., VIH = 2.5V min CIN < 15 pf

I

IH

= 50µA min., VOH = 2.5V min

I

OH

= -2 mA min., VOL = 0.5V max

I

OL

Standby mode 325 450

Standby mode 85 105

100% Transmission 380 510

100% Transmission 125 160

conductor
Transformer lead for connection to outer signal conductor of

tri-axial

Absolute Maximum Ratings

V

(Pins 23, 24) +7 Volts Max

CC

(Pins 7, 17) -7 Volts Max

V

EE

Logic Input Voltage Applied:

Logic Low -1.2V @ 10mA Max
Logic High +5.5 Volts

When used with the internal transformer, the
CT1698 will not be damaged by cable open circuits
or by short circuits of the following types:

Current (mA)

Typ Max

• Line-to-line

• Line-to-ground

• To voltage sources of 0 to 115 volts
alternating current, 60 hertz, line-to-ground

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

Aeroflex Circuit Technology SCDCT1698 REV A 6/12/98 Plainview NY [phone]

6

CIRCUIT TECHNOLOGY

Plainview New York 11830

Toll Free Inquiries: 1-(800)THE-1553

Ordering Information

Model Number Package

CT1698
CT1698FP

Plug-In Package Outline

Pin 1 & ESD
Designator

.270 ±.010

.100 ±.005

TYP

Flat Package Outline

.015 ±.003 .100 ±.005

1.810
MAX

.018 ±.002

DIA

(17 Pins/Side)

.200

.120 ±.010
Both Sides

Plug-in Package

Flat Package

1.200 ±.005

.100 TYP

Both Sides

.180 MAX

.400 MIN

1.410
MAX

Lead 1 & ESD
Designator

1.810
MAX

Aeroflex Circuit Technology
35 South Service Road

Specifications subject to change without notice.

Aeroflex Circuit Technology SCDCT1698 REV A 6/12/98 Plainview NY [phone]

7

Telephone: [phone]

FAX: [phone]

.010 ±.002