Is there any RS232 transceiver with 10mbps datarate? - Page 1
Forum section: electronics / projects

author: muthukural001
author_rank: Regular Contributor
timestamp: March 26, 2020, 07:56:54 am
content: Hello All,I am looking for a RS232 transceiver with 10mbps datarate...I could not get anything for this...If anyone have come across this, please share.Thanks,Muthu

author: greenpossum
author_rank: Frequent Contributor
timestamp: March 26, 2020, 08:19:52 am
content: What is it you are trying to make?

author: LateLesley
author_rank: Frequent Contributor
timestamp: March 26, 2020, 08:26:47 am
content: I think you will struggle with this, as RS 232 is only meant to officially support a speed of 19,600bps.http://www.soc.napier.ac.uk/~bill/pdf/P_ch16.pdfThere are other standards which would probably be more suited to your needs, like RS-485, which is designed up to 10Mbps.http://www.rs485.com/rs485spec.html

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: March 26, 2020, 08:36:11 am
content: At that speed, you need to be using RS485, with a correctly terminated twisted-pair.

author: AndyC_772
author_rank: Super Contributor
timestamp: March 26, 2020, 08:45:46 am
content: If you'd like to learn more, have a look at the data sheet (or even get an eval board) for the Exar SP510.It's a multi-protocol transceiver that does RS232 as well as a number of other, higher speed standards. You can switch between them with software and observe the differences on the wire with a scope.https://www.mouser.com/datasheet/2/146/SP510-1166392.pdf

author: coromonadalix
author_rank: Super Contributor
timestamp: March 26, 2020, 01:49:45 pm
content: You have some rs232 who goes up to 1 meg bauds, i have some interfaces who are running at 921600 bauds, i'm trying to sniff out the data.

author: coppice
author_rank: Super Contributor
timestamp: March 26, 2020, 02:01:59 pm
content: Quote from: coromonadalix on March 26, 2020, 01:49:45 pm921600 bps is way beyond the RS232C spec, but typically works just fine. Much greater than 1Mbps only works if the drivers have complete disregard for the RS232C spec, as proper slew rate limiting won't allow such high bit rates through.

author: SiliconWizard
author_rank: Super Contributor
timestamp: March 26, 2020, 02:08:36 pm
content: Quote from: mikeselectricstuff on March 26, 2020, 08:36:11 amI also suggest any RS485 transceiver (that can handle this rate), many available these days.Or you could also consider LVDS transceivers depending on max. length.

author: David Hess
author_rank: Super Contributor
timestamp: March 26, 2020, 05:01:06 pm
content: 10 Mbit/sec with RS-232 signal levels is possible but it conflicts with the RS-232 standard which requires unterminated singled ended signalling. There are some UARTs which can operate that fast but they are intended for RS-422 or RS-485. I do not know of any RS-232 level shifters which support more than 1 or maybe 2 Mbit/sec.

author: SiliconWizard
author_rank: Super Contributor
timestamp: March 26, 2020, 05:04:34 pm
content: Unless you absolutely can't use some simple twisted pair cable for this, I see no reason not to use RS-485 transceivers anyway. Problem solved for a couple bucks.

author: David Hess
author_rank: Super Contributor
timestamp: March 26, 2020, 06:16:05 pm
content: Quote from: SiliconWizard on March 26, 2020, 05:04:34 pmIf you can use twisted pair cable, then you can also use singled ended signalling. There *are* 10 Mbit/sec and probably higher standards which use single ended signaling like 10-base2.So what would a practical implementation look like? Assuming a 100 ohm twisted pair (you are going to need a transmission line for this but it will also work for normal RS-232), I would series or shunt terminate the transmitter side and drive it to +/-5 volts on the receiver side. (1) The receiver side then has no termination but also sees no reflection, or rather all it sees is the reflection but that reflection is the full +/-5 volts. Now the cable capacitance which normally limits RS-232 data rate is irrelevant.But I know of no suitable integrated drives which do that. I have build discrete drivers before which could.(1) This means that the series termination requires a +/- 5 volt driver with a peak current of +/- 100 milliamps (actually +/- 50 milliamps) and the shunt termination requires a +/-50 milliamp driver with a voltage compliance of +/- 5 volts. Now you know why RS-485/RS-422 used such low voltages.

author: jbb
author_rank: Super Contributor
timestamp: March 26, 2020, 07:38:10 pm
content: What equipment have you got that has 10MBit RS232? Maybe you could copy that...If you’re making new equipment and want it to feel like RS232, I have found RS422 very good in the past. (RS485 is great, but it’s half duplex and needs different communication software.) It will need twisted pair cables and termination resistors, but that’s not too hard.