Voltages in Multichannel Design - Page 1
Forum section: electronics / general

author: luky315
author_rank: Regular Contributor
timestamp: September 27, 2019, 06:07:23 pm
content: I have a question regarding voltages in a multichannel design (BLDC Driver)I have 3 Channels (U, V, W) with a high - and a low side MOSFET and I would like to have appropriately and individualy named Power Ports (12V_U_High, 12V_U_LOW, 12V_V_High, 12V_V_LOW, ...) for each of the 3 Channels.How can I do that?Or is there another way?

author: thm_w
author_rank: Super Contributor
timestamp: September 27, 2019, 08:41:11 pm
content: Are you saying all are connected together physically? Put 12V_U_High, V etc. symbols on the schematic.Then tie them together to the main supply (12V/Gnd) with a net tie.https://www.altium.com/documentation/19.1/display/ADES/((Creating+Connectivity))_AD#!CreatingConnectivity-IntentionallyConnectingTwoNets

author: ajb
author_rank: Super Contributor
timestamp: September 27, 2019, 09:01:20 pm
content: You don't even need the net tie unless you want to use that to control your PCB connectivity (like making sure you have separate paths back to the supply from each half-bridge, for example). You can just place power ports in your schematic with whatever names you want and then somewhere else place power ports with the same names and connect them all together (be sure to check your connectivity across sheets if necessary). I'm not sure why you'd want to do that in this context, but it works, although you may get a warning about nets with multiple names depending on your compile settings.you might get more helpful answers with more info about what exactly you want to do.

author: luky315
author_rank: Regular Contributor
timestamp: September 28, 2019, 09:15:03 am
content: I want a multichannel design (channels U, V, W are the same), but I would like to have different and clearly named voltages for each of the 3 channels. The voltages are not connected together (there is a galvanic isolation between the channels).For example the gate driver has an auxilliary 5V output which I woult like to name 5V_U, 5V_V and 5V_W.So the question is how to reuse the design for one Channel, but with differently named (not connected) voltages?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: September 28, 2019, 12:02:28 pm
content: If you use individual channels rather than REPEATed ones, you can name the nets coming out of the block.You may need all six channels on a master sheet to name them that way. As opposed to two and three channels on intermediate sheets.Tim

author: ajb
author_rank: Super Contributor
timestamp: September 30, 2019, 04:12:28 pm
content: There are a couple of ways to do this. One is to do as Tim said, and place separate sheet instances without using repeat. You should be able to place the instances on different sheets without trouble if you need to (like if there's a bunch of instance-specific surrounding circuitry. Then you can name the nets from outside the sheet, and make sure your net name resolution rules allow the higher-level sheet names to override the lower-level ones.The other is to use repeat and to rely on the connectivity/net naming settings. This means that if you place the sheet with "Repeat(Foo,1,3)" then the net "12V_LOW" on the sub sheet will be translated into something like "12V_LOW_Foo1", "12V_LOW_Foo2", etc, on the different sheets, depending on your hierarchical naming rules. I don't know if this will be close enough to what you want. With repeat, you'll need to use the repeated sheet entry syntax to bring out a bus of signals to each instance, and then break those busses out to be able to get at the signals to each channel. It gets kinda messy, TBH.Note that, either way, power ports default to global connect (IIRC), so you can't use them in your subsheet for signals that should be separate per-instance unless you change that. But you can bring that signal out of the subsheet via a port, and then connect to a power port in the higher level sheet.Repeat really works best when every channel is identical in both form and function, like input channels on an audio mixer or something, if you are bolting on additional functionality that varies between one channel and the next it gets clunky and you're probably better off doing separate sheet instances.