AN2159

Devices overview

Doc ID 11400 Rev 3

3/23

1

Devices overview

1.1

STPM01

The STPM01 is an ASSP designed for effective measurement of active, reactive and

apparent energy in a power line system using Rogowski coil, current transformer and shunt

sensors. This device can be implemented as a single chip in single phase energy meters or

as a peripheral in microcontroller based meter.

The STPM01 consists, essentially, of two parts: the analog part and the digital part. The

voltage reference, low drop voltage regulator, the latter by system control, oscillator, hard

wired DSP and SPI interface.

There is also an OTP block, which is controlled through the SPI by means of a dedicated

command set. The configured bits are used for testing, configuration and calibration

purpose.

The DSP unit computes active, reactive and apparent energy, RMS and instantaneous

values of voltage and current. The results of computation are available as pulse frequency

and states on the digital outputs of the device or into the internal data registers, which can

be read from the device by means of SPI.

For more details on the device please refer to datasheet.

1.2

STPM10

The STPM10 is designed for effective measurement of active, reactive and apparent energy

in a power line system using Current Transformer or Shunt sensors. This device is intended

to be a peripheral measurement device in a microcontroller based meter.

The STPM10 consists of an analog part and a digital part. The former, is composed by

voltage regulator, the latter by system control, oscillator, hard wired DSP and SPI interface.

Configuration and calibration bits should be set by a microcontroller.

The DSP unit computes active, reactive and apparent energy, RMS and instantaneous

values of voltage and current. The results of computation are available in the internal data

registers, which can be read from the device by means of SPI.

For more details on the device please refer to datasheet.