Supplying an external PCB
Added by Tom Riddle about 7 years ago
Hi, We're going to be running a few development boards off of the MityDSP L138. For one we plan to use the +12VF from J701. The other it would be nice to use either the +3,3 or 5.0v supplies from TPS5430 buck converters directly. Since we're do not require the onboard audio or CAN (USB mem stick & UART we will use) the +5V seems a good candidate. The TMS5430 are rated for 3A. Would you have a "guesstimate" on how much spare power would be available on the +5V rail. This other dev board would not require more then .5A. Thanks, Tom
Replies (5)
RE: Supplying an external PCB - Added by Jonathan Cormier about 7 years ago
+5V supply Pins 1,2 on J104
TPS5430 3A continuous
Note: 3A at 5V is 15W. There is a 1.1A fuse on the 12V side, which will limit this to 13.2 W. Or 2.64 A @ 5V so 2.5A to be safe...
DSD1791DB Audio - ~15mA on 5V VCC, could be disabled by removing L300
TRS232ECPWR UART - 8-10mA on 5V VCC
TPS2041 USB VBUS - 50uA with no USB load, up to 1000mA with 2 USB powered devices attached.
So even with 2 high powered USB devices plugged in, 5V supply would seem to have ~1.5A of spare power.
The CAN and RS485 have their own +5V supplies.
RE: Supplying an external PCB - Added by Tom Riddle about 7 years ago
Hi, One additional question. The Industrial I/O dev kit doc mentions the Expansion IO Interface mating connectors is 2x25, 2mm header. Do you have a suggested vendor/part number you've used in the past... something that Digikey/Mouser would carry. Thanks, Tom
RE: Supplying an external PCB - Added by Alexander Block about 7 years ago
Tom,
We have used these (https://www.digikey.com/products/en?keywords=87759-5050) on a couple of our expansion boards for the Industrial IO board. Note that they are surface mount headers.
I believe these (https://www.digikey.com/products/en?keywords=0877585016) would be a comparable through-hole version but that was just from filtering through the Digikey options and not something I'm aware that we've used.
Alex
RE: Supplying an external PCB - Added by Tom Riddle about 7 years ago
Alex Thanks... that's helpful. Regs, Tom
