POR/PDR voltage threshold doesn't match with STM32G070RBT6 specification

[LPiro.1]

I have tested Power On Reset / Power Down Reset (POR/PDR) voltage threshold on two STM32G070RBT6 sourced by different suppliers. The threshold isn't matching the specified voltage 2.06<VPOR<2.14 and 1.96<VPDR<2.04 but it fits values stated in STM32G081 datasheet, 1.62<VPOR<1.70 and 1.60<VPDR<1.69. The brownout reset feature is functional on both STM32G070 and STM32G081 but it's not available on STM32G070 according to spec. I looks like STM32G070 uses the same silicon as STM32G081. Thus I'm concerning what to expect from different batches of STM32G070, can we relly on spec or rather consider STM32G070 to be equal with STM32G081.

[Bruno_ST · Accepted solution]

Hello @LPiro.1​,

Yes, i confirm STM32G070 is the same silicon as STM32G081 (cf RM), so it is expected that G070 matches behavior of G081. But to differentiate these value lines, spec is reduced on G070, so as the tests performed by ST in production on these features.

BR,

Bruno

[LPiro.1]

Hi Bruno, thanks for quick response. Functionality of target application is strongly dependant on POR/PDR threshold. If understood correctly POR/PDR threshold voltage of G070 cannot be guaranteed within G081 spec therefore lower values are specified. Should we take into account high spread of the values? 1.62<VPOR<2.14 and 1.60<VPDR<2.04?

[Bruno_ST]

You are welcome.

G070 samples are programmed in production (and should remain during the device life time) with a BOR active and Brownout reset threshold = 1, so VPOR and VPDR values becomes 2.06V < VPOR < 2.14V and 1.96V < VPDR < 2.04V (like stated in G070 the datasheet).

Hope it clarify the point ?

[LPiro.1]

thanks for confirmation, I was referring to real measurement done on G070 which violates POR/PDR specification as you can see attached.

1. BOR disabled, POR/PDR active, thresholds out of spec
2. BOR enabled, set to highest Level, thresholds within spec