ECRI Microelectronics

Synchro to Digital converters or Resolver to Digital Converters (MSDC/MRDC37 series)

1. Features of Synchro/Resolver-Digital Converter (MSDC/MRDC37 series)(for outside view, see Fig. 1) 

High accuracy
Small size
High tracking speed
Uninterrupted tracking during data transfer 
Three-state latch output
Low power consumption


2. Application of Synchro to Digital Converters or Resolver to Digital Converters (MSDC/MRDC37 series)

Servo mechanism; antenna monitoring; navigation system; cannon control; industrial control; robot system; radar control system.


3. Description of Synchro to Digital Converters or Resolver to Digital Converters (MSDC/MRDC37 series)

MSDC/MRDC37 series are 16-bit digital to synchro or digital to resolver converters. The input signal is divided into four-wire resolver and excitation signal or three-wire synchro and excitation signal. The output signal is parallel natural binary code buffered through three-state latch and compatible with TTL level.
The product applies second-order servo circuit with small size and light weight,  and the user can use it very conveniently by controlling signal pins.

Table 2  Rated conditions and recommended operating conditions

Max. absolute rating value

Supply voltage +VS: 12.5~17.5V

Supply voltage -VS: -17.5~-12.5V

Logical voltage VL: 7V

Storage temperature range: -40~+100℃

Recommended operating conditions

Supply voltage +VS: 15V±5%

Supply voltage -VS: -15V±5%

Reference voltage (effective value) VRef: nominal value ±10%

Signal voltage (effective value) V1*: nominal value ±10%

Reference frequency f*: nominal value ±10%

Operating temperature range TA: -40~+85℃

Note: * indicates it can be customized as per user's requirement.

Table 2  Electric characteristics

Parameter

Conditions (-40~+85℃)

(Unless otherwise specified)

(MSDC/MRDC37 series)

Unit

Min.

Max.

Resolution/RES

Range of 0~360º

12

16

Bit

Tracking speed/St①

3

36

rps

High output level/VOH

TA=25℃

2.4

V

Low output level/VOL

TA=25℃

0.8

V

Power consumption/ PD

TA=25℃

1.3

W

Vel linearity/ERl

TA=25℃

1.0

%

Range of reference voltage

2

115

V

Range of signal voltage

2

90

V

Frequency range

30

2 600

Hz

Density

±3

±8.5

Angular minute


Note: ① the tracking speed is 3 rps for 16-bit resolution and 36 rps for 12-bit resolution; St can be designed according to the user’s requirement.


4. Operating principle of Synchro to Digital Converters or Resolver to Digital Converters (MSDC/MRDC37 series) (Fig. 2)

The synchro input signal (or input signal of resolver) is converted into the orthogonal signal through internal differential isolation:
Operating principle of Synchro/Resolver-Digital Converter (MSDC/MRDC37 series)
Fig.2  Block diagram for operating principle

Where, θ is analog input angle
These two signals and the digital angle φ of internal reversible counter are multiplied in the multiplier of Sine and Cosine functions and are error treated:

These two signals and the digital angle φ of internal reversible counter are multiplied in the multiplier of Sine and Cosine functions and are error treated

The signals are sent to voltage controlled oscillator after amplification, phase discrimination and integration filtration, if θ-φ≠0, the voltage controlled oscillator will output pulse to change the data in the reversible counter, till θ-φ becomes zero within the accuracy of the converter, during this process, the converter tracks the change of input angle θ all the time. For the block diagram of working principle, see Fig. 2.

Transfer function of the converter is shown in Fig. 3. Closed-loop function

Transfer function of the converter is shown in Fig. 3. Closed-loop function

Function transfer of the converter
Fig. 3  Function transfer of the converter

Methods of data transfer and time sequence
There are two methods for reading the effective data in the converter: synchronous reading and asynchronous reading.
(1) method (synchronous reading):
A: the converter is connected with 16-bit bus. Bysel is connected with logic "1".
Set from logic "1" to logic "0" (data lock), and wait for 1μs; set to logic "0" to allow the latch in the converter to output data; read 12-bit, 14-bit or 16-bit data; set to logic "1" in order to get ready for reading the next effective data (Fig. 4);
B: the converter is connected to 8-bit bus, D1~D8 bit are connected to data bus, and the rest are empty.
Set from logic "1" to logic "0" (data lock), and wait for 1μs; set to logic "0" to allow the latch in the converter to output data; set Bysel to logic "1", directly read the high 8-bit data, set Bysel to logic "0", read the data in other bits with automatic zero padding in the vacant bits; set to logic "1" in order to get ready for reading the next effective data (Fig. 5).

Time sequence of 16-bit bus transfer Time sequence of 8-bit bus transfer
Fig4  Time sequence of 16-bit bus transfer                                       Fig5  Time sequence of 8-bit bus transfer

(2) Busy method (asynchronous reading):
In asynchronous reading mode,  is set to logic "1" or empty, whether the internal loop is always in the stable state or whether the output data is valid shall be determined through the status of busy signal Busy. When Busy signal is at high level, it indicates the data is being converted, and the data at this time is unstable and invalid; when Busy signal is at low level, it indicates the data conversion has been completed, and the data at this time is stable and valid. Once high level occurs in Busy during reading, the reading at this time is invalid. In asynchronous reading mode, the Busy output is pulse train of TTL level, its width depends on its rotational speed, there are also two use methods of the bus, i.e. 8-bit and 16-bit, the data reading during effective data output is also controlled by , please refer to the time sequence diagram for data transfer (Fig. 6 and Fig. 7).

Fig.6 Time sequence diagram for 16-bit bus transfer Fig.7 Time sequence diagram for 8-bit bus transfer

Fig.6  Time sequence diagram for 16-bit bus transfer Fig.7  Time sequence diagram for 8-bit bus transfer

Status signal pins: Busy, DIR, R, C.
When the input of the converter changes, Busy outputs a train of pulses of CMOS level, its frequency is determined by the highest rotational speed. When Busy is at high level, it means the second-order servo circuit in the converter is operating, the data at digital output end is changing; on the contrary, the computer can directly read the data.
DIR signal is used to indicate forward/reverse rotation. When the output code is up count, the output is high level; when the output code is down count, the output is low level.
Zero signal output R.C: when the output data increments from all "1" to all "0", or the output data decrements from all "0" to all "1", the output is positive pulse, the pulse width is 200μs.

5. MTBF curve of Synchro to Digital Converters or Resolver to Digital Converters (MSDC/MRDC37 series)(Fig. 7)


MTBF-temperature curve

Fig. 8  MTBF-temperature curve
(Note: as per GJB/Z299B-98, envisaged good ground condition)

6. Pin designation of Synchro to Digital Converters or Resolver to Digital Converters (MSDC/MRDC37 series)(Fig. 9, Table 3)


Pin designation of Synchro/Resolver-Digital Converter (MSDC/MRDC37 series)

Fig.9  Pin designation (top view)

Table 3  Pin designation

Pin

Symbol

Meaning

Pin

Symbol

Meaning

Pin

Symbol

Meaning

1

D1

Digital output 1 (highest bit)

13

D13

Digital output 13

25

D16

Digital output 16

2

D2

Digital output 2

14

D14

Digital output 14

26

D15

Digital output 15

3

D3

Digital output 3

15

RHi

Reference signal input (high end)

27

Bysel

Byte select signal

4

D4

Digital output 4

16

RLo

Reference signal input (low end)

28

Enable signal

5

D5

Digital output 5

17

NC

Dead end

29

Busy

Busy signal

6

D6

Digital output 6

18

Vel

Velocity voltage output

30

Inhibit signal

7

D7

Digital output 7

19

S4

Signal input

31

+Vs

+15V Power supply

8

D8

Digital output 8

20

S3

Signal input

32

GND

Power ground

9

D9

Digital output 9

21

S2

Signal input

33

-Vs

-15V Power supply

10

D10

Digital output 10

22

S1

Signal input

34

VL

+5V Power supply

11

D11

Digital output 11

23

R, C

Zero cross signal




12

D12

Digital output 12

24

DIR

Direction signal





Notes: S1, S2, S3, S4 are signal input of synchro to digital converters or resolver to digital converters, and S4 is left unconnected for synchro;
D1~D16 are binary data output, for MSDC/MRDC3752 series converter, pin 13, 14, 25 and 26 are left unconnected;
for MSDC/MRDC3754 series converter, pin 25 and 26 are left unconnected.

7. Table of weight values of Synchro to Digital Converters or Resolver to Digital Converters (MSDC/MRDC37 series)(Table 4)

Table 4  Table of weight values

Bit

Angle

Bit

Angle

Bit

Angle

1(MSB)

180,000 0

7

2,812 5

13

0,043 9

2

90,000 0

8

1,406 3

14

0,022 0

3

45,000 0

9

0,703 1

15

0,011 0

4

22,500 0

10

0,351 6

16

0,005 5

5

11,250 0

11

0,175 8



6

5,625 0

12

0,087 9




8. Connection diagram for typical application of Synchro to Digital Converters or Resolver to Digital Converters (MSDC/MRDC37 series)(Fig. 10 and Fig. 11)

Connection diagram for typical application of Synchro/Resolver-Digital Converter (MSDC/MRDC37 series)
Fig.10  Connection diagram for typical application of MRDC3756 series
Fig.11  Interface for direct data reading of MRDC3756

Note: the supply voltage shall not exceed the specified range; do not connect reference RHi and RLo to other pins.

9. Package specifications (unit: mm) of Synchro to Digital Converters or Resolver to Digital Converters (MSDC/MRDC37 series)(Fig. 12)


Package specifications (unit: mm) of Synchro/Resolver-Digital Converter (MSDC/MRDC37 series)

Fig. 12 Outside view and dimensions of package

10. Part numbering key of Synchro to Digital Converters or Resolver to Digital Converters (MSDC/MRDC37 series)(Fig. 13)

Part numbering key of Synchro/Resolver-Digital Converter (MSDC/MRDC37 series)

Fig. 13 Part numbering key
Note: when the above signal voltage and reference voltage (Z) are non-standard, they shall be given as follows:


reference voltage 5V and signal voltage 3V are expressed as -5/3

(e.g. reference voltage 5V and signal voltage 3V are expressed as -5/3)


Application notes of Synchro to Digital Converters or Resolver to Digital Converters (MSDC/MRDC37 series):

  • Supply the power correctly, during the power-up, accurately connect the positive and negative poles of power to avoid burnout.
  • When the max. absolute rating value is exceeded, the device may be damaged.
  • Upon assembly, the bottom of the product shall fit to the circuit board closely so as to avoid damage of pins, and shockproof provision shall be added, if necessary.
  • When the user places an order for the product, detailed electric performance indexes shall refer to the relevant enterprise standard.
Model Series Max. Output Power (W) Input DC Voltage (V) Output Voltage (V)
Synchro to Digital Converters or Resolver to Digital Converters (HSDC/HRDC211 Series) 10 bits, 12 bits, 14 bits +5V,±15V ±8.5 arc min (12bits) ,±5.3 arc min (14bits)
Synchro to Digital Converters or Resolver to Digital Converters 2S44RDC/SDC Series Two-channel 14 bits +5V,±15V ±5.3 arc min
Synchro to Digital Converters or Resolver to Digital Converters HTS20R64 Series Two-speed RDC Conver differs from 17 to 20 bits +5V,±15V ±40 arc sec(17 bits), ±20 arc sec(18 bits),±10 arc sec(19 bits),±5 arc sec(20 bits)
Synchro to Digital Converters or Resolver to Digital Converters HTS20 Series Programmable 2-speed SD differs from 17 to 20 bits +5V,±15V ±40 arc sec(17 bits), ±20 arc sec(18 bits),±10 arc sec(19 bits),±5 arc sec(20 bits)
Synchro to Digital Converters or Resolver to Digital Converters (HSDC/HRDC27 Series) 12 or 14 bits +5V,±15V ±8.5 arc min (12bits) ,±5.3 arc min (14bits)
Synchro to Digital Converters or Resolver to Digital Converters (HSDC/HRDC1459 Series) 12,14 or 16 bits +5V,±15V ±8.5 arc min (12bits) ,±5.3 arc min (14bits),±2.93 arc min (16bits)
Model Series Max. Output Power (W) Input DC Voltage (V) Output Voltage (V)
Synchro to Digital Converters or Resolver to Digital Converters (HSDC/HRDC211 Series) 10 bits, 12 bits, 14 bits +5V,±15V ±8.5 arc min (12bits) ,±5.3 arc min (14bits)
Synchro to Digital Converters or Resolver to Digital Converters 2S44RDC/SDC Series Two-channel 14 bits +5V,±15V ±5.3 arc min
Synchro to Digital Converters or Resolver to Digital Converters HTS20R64 Series Two-speed RDC Conver differs from 17 to 20 bits +5V,±15V ±40 arc sec(17 bits), ±20 arc sec(18 bits),±10 arc sec(19 bits),±5 arc sec(20 bits)
Synchro to Digital Converters or Resolver to Digital Converters HTS20 Series Programmable 2-speed SD differs from 17 to 20 bits +5V,±15V ±40 arc sec(17 bits), ±20 arc sec(18 bits),±10 arc sec(19 bits),±5 arc sec(20 bits)
Synchro to Digital Converters or Resolver to Digital Converters (HSDC/HRDC27 Series) 12 or 14 bits +5V,±15V ±8.5 arc min (12bits) ,±5.3 arc min (14bits)
Synchro to Digital Converters or Resolver to Digital Converters (HSDC/HRDC1459 Series) 12,14 or 16 bits +5V,±15V ±8.5 arc min (12bits) ,±5.3 arc min (14bits),±2.93 arc min (16bits)
Model Series Max. Output Power (W) Input DC Voltage (V) Output Voltage (V)
Synchro to Digital Converters or Resolver to Digital Converters (HSDC/HRDC211 Series) 10 bits, 12 bits, 14 bits +5V,±15V ±8.5 arc min (12bits) ,±5.3 arc min (14bits)
Synchro to Digital Converters or Resolver to Digital Converters 2S44RDC/SDC Series Two-channel 14 bits +5V,±15V ±5.3 arc min
Synchro to Digital Converters or Resolver to Digital Converters HTS20R64 Series Two-speed RDC Conver differs from 17 to 20 bits +5V,±15V ±40 arc sec(17 bits), ±20 arc sec(18 bits),±10 arc sec(19 bits),±5 arc sec(20 bits)
Synchro to Digital Converters or Resolver to Digital Converters HTS20 Series Programmable 2-speed SD differs from 17 to 20 bits +5V,±15V ±40 arc sec(17 bits), ±20 arc sec(18 bits),±10 arc sec(19 bits),±5 arc sec(20 bits)
Synchro to Digital Converters or Resolver to Digital Converters (HSDC/HRDC27 Series) 12 or 14 bits +5V,±15V ±8.5 arc min (12bits) ,±5.3 arc min (14bits)
Synchro to Digital Converters or Resolver to Digital Converters (HSDC/HRDC1459 Series) 12,14 or 16 bits +5V,±15V ±8.5 arc min (12bits) ,±5.3 arc min (14bits),±2.93 arc min (16bits)
Model Series Max. Output Power (W) Input DC Voltage (V) Output Voltage (V)
Synchro to Digital Converters or Resolver to Digital Converters (HSDC/HRDC211 Series) 10 bits, 12 bits, 14 bits +5V,±15V ±8.5 arc min (12bits) ,±5.3 arc min (14bits)
Synchro to Digital Converters or Resolver to Digital Converters 2S44RDC/SDC Series Two-channel 14 bits +5V,±15V ±5.3 arc min
Synchro to Digital Converters or Resolver to Digital Converters HTS20R64 Series Two-speed RDC Conver differs from 17 to 20 bits +5V,±15V ±40 arc sec(17 bits), ±20 arc sec(18 bits),±10 arc sec(19 bits),±5 arc sec(20 bits)
Synchro to Digital Converters or Resolver to Digital Converters HTS20 Series Programmable 2-speed SD differs from 17 to 20 bits +5V,±15V ±40 arc sec(17 bits), ±20 arc sec(18 bits),±10 arc sec(19 bits),±5 arc sec(20 bits)
Synchro to Digital Converters or Resolver to Digital Converters (HSDC/HRDC27 Series) 12 or 14 bits +5V,±15V ±8.5 arc min (12bits) ,±5.3 arc min (14bits)
Synchro to Digital Converters or Resolver to Digital Converters (HSDC/HRDC1459 Series) 12,14 or 16 bits +5V,±15V ±8.5 arc min (12bits) ,±5.3 arc min (14bits),±2.93 arc min (16bits)
Model Series Max. Output Power (W) Input DC Voltage (V) Output Voltage (V)
Synchro to Digital Converters or Resolver to Digital Converters (HSDC/HRDC211 Series) 10 bits, 12 bits, 14 bits +5V,±15V ±8.5 arc min (12bits) ,±5.3 arc min (14bits)
Synchro to Digital Converters or Resolver to Digital Converters 2S44RDC/SDC Series Two-channel 14 bits +5V,±15V ±5.3 arc min
Synchro to Digital Converters or Resolver to Digital Converters HTS20R64 Series Two-speed RDC Conver differs from 17 to 20 bits +5V,±15V ±40 arc sec(17 bits), ±20 arc sec(18 bits),±10 arc sec(19 bits),±5 arc sec(20 bits)
Synchro to Digital Converters or Resolver to Digital Converters HTS20 Series Programmable 2-speed SD differs from 17 to 20 bits +5V,±15V ±40 arc sec(17 bits), ±20 arc sec(18 bits),±10 arc sec(19 bits),±5 arc sec(20 bits)
Synchro to Digital Converters or Resolver to Digital Converters (HSDC/HRDC27 Series) 12 or 14 bits +5V,±15V ±8.5 arc min (12bits) ,±5.3 arc min (14bits)
Synchro to Digital Converters or Resolver to Digital Converters (HSDC/HRDC1459 Series) 12,14 or 16 bits +5V,±15V ±8.5 arc min (12bits) ,±5.3 arc min (14bits),±2.93 arc min (16bits)
Model Series Max. Output Power (W) Input DC Voltage (V) Output Voltage (V)
Synchro to Digital Converters or Resolver to Digital Converters (HSDC/HRDC211 Series) 10 bits, 12 bits, 14 bits +5V,±15V ±8.5 arc min (12bits) ,±5.3 arc min (14bits)
Synchro to Digital Converters or Resolver to Digital Converters 2S44RDC/SDC Series Two-channel 14 bits +5V,±15V ±5.3 arc min
Synchro to Digital Converters or Resolver to Digital Converters HTS20R64 Series Two-speed RDC Conver differs from 17 to 20 bits +5V,±15V ±40 arc sec(17 bits), ±20 arc sec(18 bits),±10 arc sec(19 bits),±5 arc sec(20 bits)
Synchro to Digital Converters or Resolver to Digital Converters HTS20 Series Programmable 2-speed SD differs from 17 to 20 bits +5V,±15V ±40 arc sec(17 bits), ±20 arc sec(18 bits),±10 arc sec(19 bits),±5 arc sec(20 bits)
Synchro to Digital Converters or Resolver to Digital Converters (HSDC/HRDC27 Series) 12 or 14 bits +5V,±15V ±8.5 arc min (12bits) ,±5.3 arc min (14bits)
Synchro to Digital Converters or Resolver to Digital Converters (HSDC/HRDC1459 Series) 12,14 or 16 bits +5V,±15V ±8.5 arc min (12bits) ,±5.3 arc min (14bits),±2.93 arc min (16bits)
Model Series Max. Output Power (W) Input DC Voltage (V) Output Voltage (V)
Synchro to Digital Converters or Resolver to Digital Converters (HSDC/HRDC211 Series) 10 bits, 12 bits, 14 bits +5V,±15V ±8.5 arc min (12bits) ,±5.3 arc min (14bits)
Synchro to Digital Converters or Resolver to Digital Converters 2S44RDC/SDC Series Two-channel 14 bits +5V,±15V ±5.3 arc min
Synchro to Digital Converters or Resolver to Digital Converters HTS20R64 Series Two-speed RDC Conver differs from 17 to 20 bits +5V,±15V ±40 arc sec(17 bits), ±20 arc sec(18 bits),±10 arc sec(19 bits),±5 arc sec(20 bits)
Synchro to Digital Converters or Resolver to Digital Converters HTS20 Series Programmable 2-speed SD differs from 17 to 20 bits +5V,±15V ±40 arc sec(17 bits), ±20 arc sec(18 bits),±10 arc sec(19 bits),±5 arc sec(20 bits)
Synchro to Digital Converters or Resolver to Digital Converters (HSDC/HRDC27 Series) 12 or 14 bits +5V,±15V ±8.5 arc min (12bits) ,±5.3 arc min (14bits)
Synchro to Digital Converters or Resolver to Digital Converters (HSDC/HRDC1459 Series) 12,14 or 16 bits +5V,±15V ±8.5 arc min (12bits) ,±5.3 arc min (14bits),±2.93 arc min (16bits)
Model Series Max. Output Power (W) Input DC Voltage (V) Output Voltage (V)
Synchro to Digital Converters or Resolver to Digital Converters (HSDC/HRDC211 Series) 10 bits, 12 bits, 14 bits +5V,±15V ±8.5 arc min (12bits) ,±5.3 arc min (14bits)
Synchro to Digital Converters or Resolver to Digital Converters 2S44RDC/SDC Series Two-channel 14 bits +5V,±15V ±5.3 arc min
Synchro to Digital Converters or Resolver to Digital Converters HTS20R64 Series Two-speed RDC Conver differs from 17 to 20 bits +5V,±15V ±40 arc sec(17 bits), ±20 arc sec(18 bits),±10 arc sec(19 bits),±5 arc sec(20 bits)
Synchro to Digital Converters or Resolver to Digital Converters HTS20 Series Programmable 2-speed SD differs from 17 to 20 bits +5V,±15V ±40 arc sec(17 bits), ±20 arc sec(18 bits),±10 arc sec(19 bits),±5 arc sec(20 bits)
Synchro to Digital Converters or Resolver to Digital Converters (HSDC/HRDC27 Series) 12 or 14 bits +5V,±15V ±8.5 arc min (12bits) ,±5.3 arc min (14bits)
Synchro to Digital Converters or Resolver to Digital Converters (HSDC/HRDC1459 Series) 12,14 or 16 bits +5V,±15V ±8.5 arc min (12bits) ,±5.3 arc min (14bits),±2.93 arc min (16bits)