0
\$\begingroup\$

I have a circuit which uses a STM32F205RGY MCU, and two SN65HVD230 CAN Bus transceivers, one 20mA LED with a 100Ω resistor and a USB port.

The MCU will run a 24MHz crystal.

Each CAN Bus Transceiver will run at 1Mbps

The USB is standard speed.

The circuit is 3v3 and the working input voltage is 8-30v.

I'm struggling to work out what current my regulator needs to supply. Due to size constraints I will probably use a LDO regulator.

I have a similar circuit built but with 4 LEDs, and a STM32F105 and that uses 0.04A-0.1A with no data on the CAN Bus as I have no CAN analyser at my current location, this seems awfully low though.

What current can I expect my circuit to use? Will a 300mA LDO be ok?

|improve this question
\$\endgroup\$
0
\$\begingroup\$

Power budget:

  1. SN65HVD23 datasheet table 8.3 - maximum current value 48mA (times two)

  2. STM32F205RGY datasheet table 12 - maximum total current 120mA. This value probably assumes that totally everything is running at the same time. Your real consumption will be lower than that.

  3. LED - 20mA

Total 236mA. 300mA LDO should be fine.

|improve this answer
\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

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