What is the maximum error of STPM32?

Stp1 · ‎2025-01-02

Hello,

in the Datasheet of the STPM32 the accuracy of the active power is 0,1% error over 500:1 dynamic range.

Is this the best case error or the maximum error of the enerqy measurement after calibration?

What does the dynamic range of 5000:1 mean?

Didier HERROUIN · ‎2025-01-06

Hello,
The STPM32 accuracy is < 0.1% error over 5000 : 1 (not 500:1).
It means that for a given voltage (230 VAC for instance), the error on the measured Energy after calibration will stay < 0.1% for a current from 10mA (for instance) to 50A (considering a linear response of the current sensor).
The calibration has to be performed at 1 operating point only (typically the nominal values to be measured, 230V/5A for instance).
See AN4470 for details.

Best regards,
Didier Herrouin

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View solution in original post

Roger SHIVELY · ‎2025-01-03

Hello @Stp1

This post has been escalated to the ST Online Support Team for additional assistance. We'll contact you directly.

Regards,

Roger

Didier HERROUIN · ‎2025-01-06

Hello,
The STPM32 accuracy is < 0.1% error over 5000 : 1 (not 500:1).
It means that for a given voltage (230 VAC for instance), the error on the measured Energy after calibration will stay < 0.1% for a current from 10mA (for instance) to 50A (considering a linear response of the current sensor).
The calibration has to be performed at 1 operating point only (typically the nominal values to be measured, 230V/5A for instance).
See AN4470 for details.

Best regards,
Didier Herrouin

In order to give better visibility on the answered topics, please click on 'Accept as Solution' on the reply which solved your issue or answered your question.