ADE7753 Datasheet, PDF (1/38 Pages) Analog Devices – Active and Apparent Energy Metering IC with di/dt sensor interface

PRELIMINARY TECHNICAL DATA
a
Active and Apparent Energy Metering IC
with di/dt sensor interface
Preliminary Technical Data
ADE7753*
FEATURES
precise phase matching between the current and voltage
High Accuracy, supports IEC 61036 and IEC61268
channels. The integrator can be switched on and off based on
On-Chip Digital Integrator enables direct interface with
the current sensor selected.
current sensors with di/dt output
The ADE7753 contains an Active Energy register. It is
The ADE7753 supplies Active, Reactive and Apparent
capable of holding more than 200 seconds of accumulated
Energy, Sampled Waveform, Current and Voltage RMS
power at full load. Data is read from the ADE7753 via the
Less than 0.1% error over a dynamic range of 1000 to 1
serial interface. The ADE7753 also provides a pulse output
Positive only energy accumulation mode available
(CF) with output frequency is proportional to the active
An On-Chip user Programmable threshold for line
power.
voltage surge and SAG, and PSU supervisory
In addition to rms calculation and active and apparent power
Digital Power, Phase & Input Offset Calibration
information, the ADE7753 also accumulates the signed
An On-Chip temperature sensor (±3°C typical)
reactive energy. The ADE7753 also provides various system
A SPI compatible Serial Interface
calibration features, i.e., channel offset correction, phase
A pulse output with programmable frequency
calibration and power calibration. The part also incorporates
An Interrupt Request pin (IRQ) and Status register
a detection circuit for short duration low or high voltage
Proprietary ADCs and DSP provide high accuracy data over
variations.
large variations in environmental conditions and time
The ADE7753 has a positive only accumulation mode which
Reference 2.4V±8% (20 ppm/°C typical)
gives the option to accumulate energy only when positive
with external overdrive capability
power is detected. An internal no-load threshold ensures that
Single 5V Supply, Low power (25mW typical)
the part does not exhibit any creep when there is no load.
GENERAL DESCRIPTION
The ADE7753 is an accurate active and apparent energy
measurements IC with a serial interface and a pulse output.
The ADE7753 incorporates two second order sigma delta
ADCs, a digital integrator (on CH1), reference circuitry,
temperature sensor, and all the signal processing required to
perform RMS calculation on the voltage and current, active,
reactive, and apparent energy measurement.
A zero crossing output (ZX) produces an output which is
synchronized to the zero crossing point of the line voltage.
This information is used in the ADE7753 to measure the
line's period. The signal is also used internally to the chip in
the line cycle Active and Apparent energy accumulation
mode. This enables a faster and more precise energy accumu-
lation and is useful during calibration. This signal is also
useful for synchronization of relay switching with a voltage
zero crossing.
An on-chip digital integrator provides direct interface to di/
dt current sensors such as Rogowski coils. The digital
integrator eliminates the need for external analog integrator,
and this solution provides excellent long-term stability and
The interrupt request output is an open drain, active low logic
output. The Interrupt Status Register indicates the nature of
the interrupt, and the Interrupt Enable Register controls
which event produces an output on the IRQ pin.
The ADE7753 is available in 20-lead SSOP package.
FUNCTIONAL BLOCK DIAGRAM
AVDD
RESET
DVDD DGND
PGA
V1P
+
V1N
-
ADC
TEMP
SENSOR
PGA
V2P
+
V2N
-
ADC
INTEGRATOR MULTIPLIER LPF2
Ύdt
WGAIN[11:0]
Σ
HPF
PHCAL[5:0]
Φ
APOS[15:0]
IRMSOS[11:0]
:
Σ
VAGAIN[11:0]
LPF1
VRMSOS[11:0]
:
Σ
VADIV[7:0]
ADE7753
CFNUM[11:0]
DFC
CF
CFDEN[11:0]
WDIV[7:0]
ZX
SAG
2.4V
4kΩ
REFERENCE
ADE7753 REGISTERS &
SERIAL INTERFACE
AGND
REF _IN/OUT
CLKIN CLKOUT
DIN DOUT SCLK CS IRQ
*U.S. Patents 5,745,323; 5,760,617; 5,862,069; 5,872,469; others Pending.
REV. PrF 10/02
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© Analog Devices, Inc., 2002