SMPS IC selection for automotive use: 12V to 5V

Thread Starter

Marcel DaJanchar

Joined Sep 9, 2015

I am working on automated pressure controller which will be used in a car. The controller consists of following:
- Power supply (10V-20V input, 5Vdc 1A max output)
- MCU STM32 (valve controller for pressure regulation + reading 4 pressure sensors)
- WiFi functionality (ESP8266)
- 8 relays used for valve activation (each relay has wired one valve on it)

The question I have is linked to the power supply. I need to generate stable 5V (1A max) which will not change if the input voltage fluctates (10-20V). I did a research and found MC34063 buck controller which could do the job, but a lot of people on the forum discourage the use of this chip as it is old and not efficient enough + its switching frequency is low so it will need an expensive inductor. So I am wondering, what are 'modern' solution to achieve my requirements? I need a cheap-ish solution, because I have found a lot of SMPS ICs (like LTC4359), but they are 6eur per piece which is too much for my budget. I have found A7985A from ST and it is only 2eur per piece. Will it be good replacement for MC34063?

ST A7985A datasheet:

Power supply scheme (note: values of components are not yet fully defined):

Thanks in advance