ANALOG DEVICES FEATURES BCD (Binary Coded Decimal) Output Representing 0 to 359.9 or 0 to +179.9 -15V Power Supply Requirement Optional High Tracking Rate (75 revs/sec) Internal Microtransformers for 60Hz, 400Hz and 2.6kHz Options Voltage Scaling with External Resistors (Unique Feature) Transformer Isolated Outputs Low Cost MIL Spec/Hi Ret Options Available APPLICATIONS Visual Display of Angular Information Valve Position Indication Antenna Monitoring Industrial Controls GENERAL DESCRIPTION The SBCD1752, SBCD1753, SBCD1756 and the SBCD1757 are modular, continuous tracking Synchro/Resolver to Digital converters which employ a type 2 servo loop. They are intended for use in both Industrial and Military applications either for displaying angular data directly, or for inputting BCD information directly into a data processing system. The input signals can be either 3 wire synchro plus reference or 4 wire resolver plus reference, depending on the option. The outputs will be presented in parallel Binary Coded Decimal (BCD). Particular attention has been paid in the design, to achieving the highest tracking rates and accelerations possible, com- patible with the resolution and carrier frequency used, while at the same time obtaining a high overall accuracy. One of the outstanding features of these converters is the use made of precision Scott T and reference microtransformers. This bas made it possible to include the trunsformers within the module, even for the 60Hz version as well as providing facilities for external voltage scaling. MODELS AVAILABLE The four Synchro to Digital converters described in this data sheet, differ primarily in the areas of output format and power supply requirements. Model SBCD1752XYZ isa 13 bit plus sign, BCD output con- verter, giving -180.0 to -0.1 and +0.0 tc +179.9 requiring +15V and +5V power supplies, and having an overall accuracy of +0.2 Degrees. Synchro to Digital Converters BCD Output Model SBCD1753XYZ isa 14 bit, BCD output converter, giving 0 to 359.9, requiring 15V and +5V power supplies, and having an overall accuracy of 0.2 Degrees. Model SBCD1756XYZ isa 13 bit plus sign, BCD output con- verter, giving -180.0 to -0.1 and +0.0 to +179.9 requiring +15V and +5V power supplies, and having an overall accuracy of 0.2 Degrees. Model SBCD1757XYZ is a 14 bit, BCD output converter, giving 0 to 359.9 , requiring +15V and +5V power supplies, and having an overall accuracy of +0.2 Degrees. The XYZ code defines the option thus: X signifies the operating temperature range. Y signifies the reference frequency. Z signifies the input voltage and range and whether it will accept Synchro or Resolver information. More information about the option code is given under the heading Ordering Information. DATA TRANSFER (ALL MODELS) The readiness of the converters for data transfer is indicated by the state of the BUSY pin. The voltage appearing on the BUSY pin consists of a train of pulses, at TTL levels, of length according to the option (see Specifications table). The con- verter is busy when the BUSY pin is at TTL High level. The pulses occur for increasing and decreasing counts. The most suitable time for transferring data is 400ns after. the trailing edge of the BUSY pulse, and the times allowable for data transfer are shown in the specification. Even at the maxi- mum speed of the option, these times will be sufficient to transfer data before the next BUSY pulse occurs. (continued on page 273S) S/D AND D/S CONVERTERS 2718SSPECIFICATIONS (typical at 25C unless otherwise stated) MODELS SBCD1752 SBCD1753 SBCD1756 SBCD1757 ACCURACY? (max Error) All Frequency Options 0.2 Degrees . * . QUTPUT Parallel BCD, 8STTL Loads . * * RESOLUTION 13 Bit + Sign Representing 14 bit repre- . * ~-180.0 to -0.1 and senting 0 to +0.0 to +179.9 359.9 SIGNAL AND REFERENCE 60Hz, 400Hz and 2.6kHz * . * FREQUENCY SIGNAL VOLTAGE (Line to Line) Low Level 11.8V rms * . . High Level 90.0V rms * ' * SIGNAL IMPEDANCES Low Level 26kQ. (Resistive) * * * High Level 200kQ. (Resistive) * * * REFERENCE VOLTAGE Low Level 26V (11.8V Signal) * * * High Level 115V (90V Signal) * * * REFERENCE IMPEDANCE Low Level $6kQ (Resistive) * * * High Level 270kQ (Resistive) * * . TRANSFORMER S500V dc * * . ISOLATION TRACKING RATE (min) 60Hz Revolutions Per Second * * . 400Hz 36 Revolutions Per Second . * * 2.6kHz 75 Revolutions Per Second * * . Accel. Constant K, 60Hz 2000/sec? . * * 400Hz 120,000/sec? * * * 2.6kHz 600,000/sec? * * . STEP RESPONSE (179 Step) (For 0.1 Error) 60Hz 1.5sec * . . 400Hz 125ms * . . 2.6kHz 50ms . * POWER LINES +15V @ 25mA * +15V @ 80mA ee -15V @ 25mA . +5V @ 500mA oe +5V @ 500mA * POWER DISSIPATION 3.25 Watts . 3.7 Watts ee BUSY LOGIC OUTPUT, POSITIVE PULSE (1 TTL Load) 60Hz 3.5 to 4.5us . . . 400Hz 0.5 to 1.25us * , . 2.6kHz 0.5 to 1.25us * MAX DATA TRANSFER TIME (From 400ns After Trailing Edge of BUSY at max Velocity) 60Hz 40us . . . 400Hz 5 .Ous . . * 2.6kHz 1.8ys . . . INHIBIT INPUT (To Inhibit) Logic 0 1TTL Load * . TEMPERATURE RANGE 3 Operating 0 to +70 C Standard * . . ~55C to +105C Extended * . . Storage -55C to +125C . . DIMENSIONS 3.125 x 2.625" x 0.8" . . (79.4 x 66.7 x 20.4mm) * . WEIGHT 6.4 ozs. (180 grams) . 6.5 ozs.(185 grams) *** Specified over the appropriate operating temperature range and for (a) 10% signal and reference amplitude variation (b) 10% signal and reference harmonic distortion (c) 45% power supply variation (d) 10% variation in reference frequency. *Specifications same as SBCD1752 **Specifications same as SBCD1753 *Specifications same as SBCD1756 Specifications subject to change without notice. 2728S S/D AND D/S CONVERTERS(continued from page 271S) WIDTK OEPENDS ON I OPTION {SEE SPEC.) | PL er ' OISTANCE DEPENDS ON VELOCITY I 7 ! LL WOE JL ff RECOMMENDED DATA TRANSFER | |e wi07H DEPENDS TIME (HIGH STATE} ON OPTION NOT TO SCALE Data Transfer Diagram The function of the INHIBIT pin is to enable the user to inhibit the update of the converters output counter. This is achieved by taking the INHIBIT pin to a TTL Logic zero. If used, the INHIBIT should be applied 400ns after the trailing edge of the BUSY pulse. This will ensure that the data on the output pins is valid. The data should then be transferred and the INHIBIT released before the next BUSY pulse occurs. The worst case times allowable for data transfer in this case are shown in the Specifications under the heading of MAX DATA TRANSFER TIME (from 400ns After Trailing Edge of BUSY at Max Velocity). It should be noted that the applica- tion of the INHIBIT will not prevent the BUSY pulses appear- ing on the BUSY pin, and thus if the INHIBIT is not released by the time that the next BUSY pulse occurs, the BUSY pulse will still appear, although the internal converter loop will have been opened. Under this condition, a worst case recovery time, equivalent to that of a step of 179 degrees may be encountered (see Spec.). To avoid this and to ensure valid data transfer, the system shown in the diagram is recommended. SBCO SERIES BUSY CONVERTER TITTY {400ne) 74121 TO LATCHES A 4 7a173 74173 74173 7at73 74173 [ TRISTATE 3STATE it | Ji ENABLE ayer Litt tH TTT LATCHES TO COMPUTER tNPUT PORT Suggested External Interface Circuitry In cases where the converter is connected to a data bus or used as a peripheral, the method outlined in the above diagram is recommended, The INHIBIT is not necessary in this case, and the external Enable has control of the converter output. The AC1755 mounting card described later in this data sheet contains the external components shown in the diagram. CONNECTING THE CONVERTER The power lines, which should not be reversed, should be con- nected to +15V, -15V and +5V in the case of the SBCD1752 and SBCD1753, and to +15V and +5V in the case of the SBCD1756 and SBCD1757, with the common con- nection to GND in all cases. It is suggested that 0.1uF and 6.8uF capacitors by placed in parallel from +15V to GND, from -15V tc GND and from +5V to GND. The digital output connections in the case of the SBCD1753 and SBCD1757 should be taken from the pins marked 0.1 through to 200; these values being represented in degrees. In the case of the SBCD1752 and SBCD1756, the data should be taken from the pins marked 0.1 through to 100, these values also being represented in degrees. In the case of these latter units the SIGN pin will indicate the polarity of the output, Logic O representing positive angles and Logic 1 representing negative angles. In the case of a synchro, the signals are connected to S,, S4 and S3 according to the following convention: Synchro connection Egy 3 = ErRLo RHI Sin cot Sin 6 E53 _ so = Erro Rwy Sin wt Sin (6 + 120) Egy _ 51 = Ego py Sin wt Sin (@ + 240) For a resolver, the signals are connected to S1, $2, S3 and S4 according to the following convention: Resolver Connection Eg, 53 = Egro rw Sin wt Sin 0 Eoo _ sa = Epni rio Sin wt Cos @ The BUSY and INHIBIT pin (is used), should be connected as described under the heading DATA TRANSFER. The reference connections are made to pins Ry, and Ryo. PIN CONNECTION DIAGRAM Dimensions shown in inches and (mm). 2.626 (66.7) | 0.8 (20.4) ~~} PINS 0.040 0.001 (10.16 +0.03) DIA I 0.21 (6.3) BRASS HARD GOLD PLATED Lt 3.125 (79.4) NOTES (A) NOT PRESENT ON SBCD1756 AND SBCD1757 (B) ON SBCD1762 ANO S8CD1756 MARKED AS SIGN 0.26 (6.6) {C} PRESENT ON RE- _ SOLVER TO DIGI- TOP VIEW m@ GAID 0.1 (2.5) RESISTIVE SCALING OF INPUTS A unique feature of the SBCD1752/1753/1756/1757 con- verters is that the inputs can be resistively scaled to accommo- date any value of input signal and reference voltage. 4 ES TAL CONVERTER {RBCO) ONLY. In order to calculate the values of the external scaling resistors necessary, add 1.11k& in series with the input per extra volt in the case of the signal, and 2.2kQ per extra volt in the case of the reference. For example, assume that it is required to use a standard 11.8V line to line signal, 26V reference converter with 60V line to line signal and a 115V reference. The resistors should be ar- ranged as in the diagram. S/D AND D/S CONVERTERS 273SRy = Rp = Ry = S3.5k2 STANDARD 11.8V SIGNAL 26Vacr SBCD SERIES CONVERTER INPUT oaan4 60V L-L R282 oo Rp = 195.8kS2 gee oS Note: In the case of R;, Rz, and R3, the ratio error between the resistances is more critical than the absolute value. In general a 1% ratio error will give rise to an extra inaccuracy of 0.28 Degrees, while a ratio accuracy of 0.1% will give rise to an extra inaccuracy of 0.028 Degrees. The absolute value of Rg is not critical. CARD MOUNTING All the converters can be mounted on an AC1755 mounting card. This card contains the latches and monestable, described under the DATA TRANSFER heading, which are necessary to transfer the data on to a computer bus system, as well as sockets for the converter. The latches have a tri-state output to facilitate ease of use. The AC1755 also contains facilities for the inclusion of input signal scaling and reference resistors as described under the heading RESISTIVE SCALING OF INPUTS. The card uses a 22/22 0.156 pitch edge connector. The pin-out is shown below. If it is not required to use the external latches, they can be jumpered on the board. prmss ere 7 r w.t6) BOTTOM 0.36 (9.25) Les 57 woe | Sen AC1755 Mounting Card (First Angle Projection). Dimensions Shown in Inches and (mm). Edge Pin | Function | Edge-Pin Function Number Letter 1 R (Lo) A Tri-State Enable 2 R (Hi) F +15 Volts 3 S3 H +15 Volts 4 S2 J -15 Volts (3) 5 S; K -15 Volts (3) 6 Sa L GND M GND 13 BUSY N +5 Volts 15 INHIBIT P +5 Volts 16 0.1 T 8 17 0.2 U 10 18 0.4 Vv 20 19 0.8 WwW 40 20 1 xX 80 21 2 Y 100 22 4 Z 200 (1) SIGN (2) NOTES (1) SBCD1753 and SBCD1757 only (2) SBCD1752 and SBCD1756 only (3) SBCD1752 and SBCD1753 only AC175& Mounting Card Edge Connections 2748S S/D AND D/S CONVERTERS ORDERING INFORMATION Converters should be ordered by the appropriate part number (.e., SBCD1752, SBCD1753, SBCD1756 or SBCD1757) fol- lowed by the appropriate option code. If the unit is to be a Resolver to Digital converter, the SBCD should be replaced by RBCD in the part number. The XYZ options are as follows: X signifies the operating temperature range thus; X=5 0to+70C (Commercial Temp.) X=6 ~-55Cto +105C (Extended Temp.) Y signifies the reference frequency thus; Y = 1 signifies 400Hz Y = 2 signifies 60Hz* Y = 4 signifies 2.6kHz Z signifies the input signal and reference voltages and whether the converter is a Synchro to Digital or a Resolver to Digital converter. The options for Z are: Z= 1 signifies Synchro, signal 11.8 Volts reference 26 Volts signal 90 Volts reference 115 Volts signal 11.8 Volts reference 26 Volts Z = 2 signifies Synchro, Z = 8 signifies Resolver, Thus an SBCD1753 with a commercial (0 to +70C) operating range, using a 400Hz, 26 volt reference with an 11.8 volt signal would be ordered as an SBCD1753511. *For 50Hz operation, a 60Hz converter can be used with no reduction in accuracy. In addition a 400Hz unit will work with a 2.6kHz reference and a 60Hz unit will work with a 400Hz reference; however they will have the velocity and acceleration characteristics of the lower frequency rated umt. OTHER PRODUCTS The SBCD series of Synchro to Digital converters are just a few of the modules and instruments concerned with Synchro con- version manufactured by us. Some of our other products are listed below and technical data is available. If you have any questions about our products or require advice about the use of them for a particular application, please contact our Applications Engineering Department. SYNCHRO TO DIGITAL CONVERTERS The SDC1700 is a low profile (0.4) converter with a 12 bit natural binary output. Its overall accuracy is $8.5 arc-minutes, and the module contains internal transformers for all reference frequency options including 60Hz. The $DC1702 is similar to the SDC1700 but has a 10 bit natural binary output and an overall accuracy of 22 arc-minutes. The SDC1704 is similar to the above two converters, but has a 14 bit natural binary output and an overall accuracy of 2.0 arc-minutes +1 LSB. TWO SPEED PROCESSORS The TSL1612 and the TSL1729 both produce one digital out- put word up to 20 bits in length from the outputs of 2 Synchro to Digital converters in a coarse/fine system. The TSL1612 is used for ratios of 9:1, 18:1 and 36:1, while the TSL1729 is programmable for all ratios from 1:1 to 63:1. DIGITAL TO SYNCHRO CONVERTERS Resolutions of between 10 and 16 bits are available as well as the DSC1710, a one card, 2 channel, 40VA, DSC system including power amps for use with 2 speed coarse/fine ratios of 9:1, 18:1, 36:1.