ST EVALSTPM34, EVALSTPM33, EVALSTPM32 User Manual

September 2015

DocID026226 Rev 2

1/15

www.st.com

UM1748

User manual

EVALSTPM34, EVALSTPM33, EVALSTPM32 evaluation board

Introduction

This user manual describes the EVALSTPM34, EVALSTPM33, EVALSTPM32 evaluation board.
The STPM3x is an ASSP family of mixed signals designed for high accuracy measurement of power

and energy in power line systems using the Rogowski coil, current transformer or shunt current sensors.
According to p/n, the device has up to two voltages and two current channels, for energy measurement
in dual-phase and single-phase (with or without neutral current monitoring) electricity metering systems.

The STPM3x devices provide instantaneous voltage and current waveforms and calculate voltage and
current RMS values, active, reactive and apparent powers and energies for each channel. Moreover,
they embed a full set of calibration and compensation parameters which allow the meter to fit tight
accuracy standards (EN 50470-x, IEC 62053-2x, ANSI12.2x for AC watt meters). All calculated data, as
well as configuration parameters, are stored in internal 32-bit registers accessible through SPI or UART
peripheral. Three boards are available for evaluation purpose:

 EVALSTPM34 board with 2 CT
 EVALSTPM33 board with CT and shunt
 EVALSTPM32 board with shunt

The main features of these boards are:

 0.2% accuracy single-phase meter reference design
 USB port for connection to the isolated hardware programmer STEVAL-IPE023V1 and PC GUI
 RS232 and UART isolated port for connection to PC GUI
 SPI/UART switch for device peripheral selection
 2x programmable LEDs on-board
 Digital expansion to external system-on-chip or MCU
 Power supply 3.3 V: external or through the STEVAL-IPE023V1 isolated USB board
 IEC61000 standard compliant

Contents

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Contents

1 Overview .......................................................................................... 3

1.1 Safety rules ....................................................................................... 4

1.2 Operating conditions ......................................................................... 4

1.3 Recommended readings ................................................................... 5

1.4 Getting technical support .................................................................. 5

2 EVALSTPM34, EVALSTPM33, EVALSTPM32 board ...................... 6

2.1 Board description .............................................................................. 6

2.1.1 Hardware configuration ...................................................................... 6

2.1.2 Power supply ...................................................................................... 6

2.1.3 Enable and reset ................................................................................ 6

2.1.4 Digital output ....................................................................................... 7

2.1.5 SPI connection ................................................................................... 7

2.1.6 UART connection ............................................................................... 8

2.1.7 Metrology ............................................................................................ 8

2.1.8 LED ..................................................................................................... 9

2.1.9 Clock ................................................................................................... 9

2.1.10 Voltage reference ............................................................................... 9

2.2 Connection to the line ....................................................................... 9

2.3 Board setup ..................................................................................... 12

2.3.1 Connection to PC GUI through the STEVAL-IPE023V1 .................. 12

2.3.2 Connection to PC GUI through the RS232 port ............................... 12

2.4 The device basic configuration ........................................................ 13

3 Revision history ............................................................................ 14

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Overview

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1 Overview

Figure 1: EVALSTPM34 board

Figure 2: EVALSTPM33 board

Overview

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Figure 3: EVALSTPM32 board

1.1 Safety rules

These boards can be connected to the mains voltage (230 V/110 V). In the case of
improper use, wrong installation or malfunction, there is a danger of serious personal injury
and damage to property. All operations such as: transport, installation, and commissioning,
as well as maintenance, should be carried out by skilled technical personnel (national
accident prevention rules must be observed) only.

1.2 Operating conditions

Table 1: Operating conditions

Parameter

Value

VN nominal voltage

230 V

RMS

IN nominal current

5 A

RMS

I

max.

maximum current

100 A

RMS

CP constant pulses

41600 imp/kWh

f

line

line frequency

50/60 Hz ± 10%

TOP operating temperature

-40/+85 °C

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1.3 Recommended readings

This document describes how to use and set up a basic test session with a GUI interface.
Additional information is available in the following documents:

 STPM3x datasheet
 AN4470
 UM1719
 EVALSTPM32 schematics
 EVALSTPM33 schematics
 EVALSTPM34 schematics

1.4 Getting technical support

All our customers receive free technical assistance through local ST distributor/office or by
visiting www.st.com; upgrades are also available free of charge on www.st.com/metering.
Customers should work with the latest version of software/firmware before contacting us.