0
\$\begingroup\$

I need to design a mil-std-1553 analog front end transceiver to already designed digital 1553 ip for my ms thesis. So I need to convert digital 3.3V to analog specs level and receive and convert to digital 3.3V level. As a newbie designer and of this protocol, I did some reads on the standart of the protocol. I know little bit about system of transmitter and receiver of the protocol. Such as filter, driver blocks etc. I have some infos about alternative supply solutions and transformer issues. But I have no further detailed ideas to use as a transceiver design starting point as a new graduate. I do need detailed knowledges about filter types that is used in receiver and other design details that I havent consider yet.

Any guidence about it will be really appreciateble.

\$\endgroup\$
3
  • 1
    \$\begingroup\$ Please ask a specific question \$\endgroup\$ – Voltage Spike Feb 19 at 11:17
  • \$\begingroup\$ Please clarify your question. Do you only need to convert logic voltage levels to 1553 voltage levels, or do you need to decode/encode the Manchester signals? \$\endgroup\$ – Mattman944 Feb 19 at 15:07
  • \$\begingroup\$ Please edit the question \$\endgroup\$ – Voltage Spike Feb 20 at 18:00
1
\$\begingroup\$

I'm no 1553 expert but reading from the standard (MILs are luckily freely available) the transceiver is 'simply' a bi-phase converter running in manchester at 1Mbps. So you could drive the transformer with some kind of H-bridge and use a differential receiver similar to the one used if RS422 for getting the signal back.

Timings are somewhat strict (microsecond range) so I'd recommend an FPGA (or a really fast MPU).

\$\endgroup\$
1
\$\begingroup\$

I worked with 1553 a lot during my career. A high-level block diagram looks like this. The Controller and Transceiver are sometimes combined into one package.

In my experience, the Controller is always logically separate from the Processor. The latency requirements make it extremely difficult for a processor to handle via software. Of course, a System-On-Chip may combine them in the same die.

The controller design is difficult. The basic messages aren't too complicated, but there are a lot of special messages. A fully qualified design implementing BC, RT and M functions would take a team of people 6 months or so. Companies sometimes integrate the 1553 Controller into an FPGA/ASIC along with other non-1553 functions to minimize component count. The IP can be purchased, or if you are building enough units, designing your own can be justified.

Hopefully your thesis only involves the Transceiver. Note that there is no need to build your own Transceiver from scratch anymore, they are available from several companies.

The Transceiver normally does not decode/encode the Manchester signals, this is done by the Controller. The Transceiver drives and converts the analog voltages to/from logic levels.

A transformer is always required near the Transceiver (isolation is a requirement). The turns ratio is chosen to get the required output voltage (~22Vpp) from the IC voltage (normally 3.3 or 5V). There may also be a second transformer coupler at the bus connection.

An important concept to remember about 1553 is that it is a three state bus, the third state is IDLE (no voltage) and must be considered separately. e.g. the Transceiver RX/RX_N signals are not complementary, both inactive indicates the IDLE state.

enter image description here

Typical Transceiver: enter image description here https://apcplc.com/hideout-app/app-uploads/2018/06/hi-1590_v-rev-d.pdf (red edits mine)

\$\endgroup\$
5
  • \$\begingroup\$ Thanks for your reply. I need to design an analog front end to already designed digital 1553 ip. So I need to convert digital 3.3V to analog specs level and receive and convert to digital 3.3V level. I do need detailed knowledges about filter types that is used in receiver and other design details that I havent consider yet. \$\endgroup\$ – flec137 Feb 20 at 16:38
  • \$\begingroup\$ There are no direct requirements for the receiver filter. Filtering is necessary to meet the higher level requirements. How will your design be evaluated? This will determine how good your filter must be. It is doubtful that your design will be subjected to all 1553 requirements, since they are very rigorous. \$\endgroup\$ – Mattman944 Feb 20 at 20:18
  • \$\begingroup\$ Hi Mattman944. After your starting guides I did more reads about it. It helped me a lot. I have some questions more. The first one is about transformers. Where are these transformers in the system? Are those in connector cables like bj-79 smth. or are they additional circuit structures? The second one is about slope control block in transmitter? What it is for? Does it have to make digital signal to a required sloped shape or does it have to limit the minimum amount of slope of taken digital signals? Thanks. \$\endgroup\$ – flec137 Feb 25 at 7:08
  • \$\begingroup\$ Transformers: see figure 9 in wikipedia article: en.wikipedia.org/wiki/MIL-STD-1553 . Transformer in terminal looks like this: digikey.com/en/products/detail/inrcore-llc/Q1553-20/8030070 . Coupler has transformer also: 1553couplers.com/ExcaliburAccessories/Templates/… . \$\endgroup\$ – Mattman944 Feb 25 at 13:37
  • \$\begingroup\$ Slope: Required to minimize EMI and reflections. A slew-rate limiting circuit is probably used in the transmitter. \$\endgroup\$ – Mattman944 Feb 25 at 13:39

Not the answer you're looking for? Browse other questions tagged or ask your own question.