Singmai Electronics SM20 User manual

SM20 User Manual Revision 0.1 Page 1 of 11
SM20
3G-/HD-/SDI
Distribution Amplifier
User Manual
Revision 0.1
1st November 2022

SM20 User Manual Revision 0.1 Page 2 of 11
Revisions
Date
Revisions
Version
01-11-2022
First draft
0.1

SM20 User Manual Revision 0.1 Page 3 of 11
Contents
Revisions...................................................................................................................................................2
Contents ...................................................................................................................................................3
Figures ......................................................................................................................................................3
1. Introduction ....................................................................................................................................4
2. Quick start guide.............................................................................................................................5
3. SM20 Technical Details ...................................................................................................................6
4. Specification....................................................................................................................................8
Appendix A: AC-DC adaptor......................................................................................................................9
Figures
Figure 1 SM20 Connections......................................................................................................................5
Figure 2 SM20 Block diagram. ..................................................................................................................6
Figure 3 SDI waveform. ............................................................................................................................6
Figure 4 SDI jitter......................................................................................................................................7
Figure 5 Power supply specification –Page 1...........................................................................................9
Figure 6 Power supply specification –Page 2.........................................................................................10
Figure 7 Power supply specification –Page 3.........................................................................................11

SM20 User Manual Revision 0.1 Page 4 of 11
1. Introduction
SM20 is a serial digital interface (SDI) distribution amplifier module supporting 3G-SDI, HD-SDI and SDI
standards. The SDI input is equalized and re-clocked to provide four buffered outputs.
SM20 requires 5VDC which is provided via the supplied AC-DC converter.

SM20 User Manual Revision 0.1 Page 5 of 11
2. Quick start guide
Connect the SM20 to the supplied AC/DC adaptor. The adaptor should be supplied with a power lead
appropriate to your country. The adaptor accepts AC between 100 and 240VAC –the full specification
is provided in Appendix A.
Connect the 5VDC jack from the adaptor to the +5VDC ‘Power in’ socket on the SM20.
Connect an SDI video input to the ‘SDI In’ BNC –SM20 supports SMPTE 259M, SMPTE 292M, SMPTE
296M, SMPTE 372M and SMPTE 425M standards. Any or all of the four ‘SDI Out’ BNCs may be
connected. Each ‘SDI out’ is an equalized and re-clocked copy of the video input.
Figure 1 SM20 Connections.

SM20 User Manual Revision 0.1 Page 6 of 11
3. SM20 Technical Details
A simplified block diagram of the SM20 is shown in Figure 2.
Figure 2 SM20 Block diagram.
The +5VDC from the AC/DC power adaptor is filtered and protected from over-range or reverse
polarity inputs by a resettable fuse. This fuse will protect the SM20 until the out-of-range condition is
removed when it automatically reset itself. The 5VDC input is then regulated to provide a ‘clean’
3.3VDC supply for the module.
The SDI input is terminated in 75Ω. It is then equalized and re-clocked to compensate for cable loss
and reduce jitter. Each SDI output is individually buffered.
Figure 3 SDI waveform.

SM20 User Manual Revision 0.1 Page 7 of 11
Figure 4 SDI jitter.

SM20 User Manual Revision 0.1 Page 8 of 11
4. Specification
Power: +5VDC ± 5% @ ~250mA (all outputs driven).
Dimensions: 160mm x 78mm x 27mm.
Video input: Supports SMPTE 259M, SMPTE 292M, SMPTE 296M,
SMPTE 372M and SMPTE 425M standards.
Input return loss: TBA.
Output level: 800mV pk-pk.
Operating temperature: -10 –40 degC.

SM20 User Manual Revision 0.1 Page 9 of 11
Appendix A: AC-DC adaptor
The specification for the supplied AC-DC adaptor is shown in Figures 5-7.
Figure 5 Power supply specification –Page 1.

SM20 User Manual Revision 0.1 Page 10 of 11
Figure 6 Power supply specification –Page 2.

SM20 User Manual Revision 0.1 Page 11 of 11
Figure 7 Power supply specification –Page 3.