STM8S207R8T6 Header Board

Thread Starter

kaveh2020

Joined May 6, 2020
2
STM8S207R8T6 Header Board.PNG
This is a header board I've designed for STM8S207R8T6.
Features:
5v and GND pins on both rows of pinouts
Full access to GPIO even PA1 and PA2 which can be used for OSC
CH340 USART to USB with mini USB
Onboard regulator
Pins specified for SWIM
Onboard Crystal

The Altium files and the BOM is attached in the link:
Files
STM8S207R8T6 Header Board.PNGSTM8S207R8T6 Header Board Bottom.PNG
A note on designing based on STM8 MCUs:

There is a pin on the STM8 called VCAP which according to documentation is the 1.8v output of the internal regulator used to power the core of the MCU. If you leave this pin on it's own, it will reset the MCU every 100ms. In order to avoid this disaster the VCAP pin has to be decoupled with a 470 nf capacitor at minimum. The ideal capacitor for this is 680 nf.
I'd love to hear feedback.
 

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MrChips

Joined Oct 2, 2009
23,541
Many STM MCUs have internal voltage regulators with access on one or more pins labelled VCAP or VCAP1, VCAP2. These are not intended to be used as output. The capacitors are mandatory. Without the capacitors the MCU will not operate. Read the datasheet for the recommended capacitance, and max ESR, ESL.
 

Thread Starter

kaveh2020

Joined May 6, 2020
2
Many STM MCUs have internal voltage regulators with access on one or more pins labelled VCAP or VCAP1, VCAP2. These are not intended to be used as output. The capacitors are mandatory. Without the capacitors the MCU will not operate. Read the datasheet for the recommended capacitance, and max ESR, ESL.
It is obvious that the MCU shouldn't be used as a power source. As mentioned in the datasheet the min value is 470 nf and the max is 3300nf . I have chosen the capacitor by the document I've read which suggested 680 nf. My appreciation for your feedback.
 
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