STPM10 datasheet(13/47 Pages) STMICROELECTRONICS

13 / 47 page

STPM10

Terminology

DocID17728 Rev 5

13/47

Terminology

5.1

Measurement error

The error associated with the energy measurement made by the STPM10 is defined as:

percentage error = [STPM10 (reading) - true energy] / true energy.

5.2

ADC offset error

This is the error due to the DC component associated with the analog inputs of the A/D

converters. Due to the internal automatic DC offset cancellation, the STPM10

measurement is not affected by DC components in the voltage and current channel. The

DC offset cancellation is implemented in the DSP.

5.3

Gain error

The power section is implemented with an avalanche ruggedness N-channel MOSFET,

which guarantees safe operation within the specified energy rating as well as high dv/dt

capability. The power section has a BVDSS of 800 V min. and a typical RDS(on)

of 20 Ω

at 25 °C.

The integrated SenseFET structure allows a virtually loss-less current sensing.

The gate driver is designed to supply a controlled gate current during both turn-on and turn-

off in order to minimize common mode EMI. Under UVLO conditions an internal pull-down

circuit holds the gate low in order to ensure that the Power section cannot be turned on

accidentally.

5.4

Power supply DC and AC rejection

This parameter quantifies the STPM10 measurement error as a percentage of the reading

when the power supplies are varied. With reference to the PSRRAC measurement, a

reading at two nominal supply voltages (3.3 and 5 V) is taken. A second reading is

obtained with the same input signal levels when an AC (200 mVRMS/100 Hz) signal is

introduced on the supplies. Any error introduced by this AC signal is expressed as a

percentage of the reading. Concerning the PSRRDC measurement, a reading at two

nominal supply voltages (3.3 and 5 V) is taken. A second reading is obtained with the same

input signal levels when the supplies are varied ± 10%. Any error introduced is again

expressed as a percentage of the reading.

5.5

Conventions

The lowest analog and digital power supply voltage is called VSS, which represents system

ground (GND). All voltage specifications for digital input/output pins are referred to GND.

Positive currents flow into a pin. Sinking current refers to the current flowing into the pin,

and thus it is positive. Sourcing current means that the current is flowing out of the pin, so it

is negative. Timing specifications of signals treated by the digital control part are relative to

CLKOUT. This signal is provided by the 4.194 MHz nominal-frequency crystal oscillator or

from the internal RC oscillator. An external source of 4.194 MHz or 8.192 MHz can also be

used. Timing specifications of signals from the SPI interface are relative to the SCL, and

there is no direct relationship between the clock (SCL) of the SPI interface and the clock of

the DSP block. A positive logic convention is used in all equations.

STPM10 数据表(PDF) 13 Page - STMicroelectronics

STPM10 数据表(HTML) 13 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47

数据表下载