Energy Metering IC with Pulse Output
ADE7755
FEATURES
High accuracy, surpasses 50 Hz/60 Hz IEC 687/IEC 1036
Less than 0.1% error over a dynamic range of 500 to 1
Supplies active power on the frequency outputs, F1 and F2
High frequency output CF is intended for calibration and
supplies instantaneous active power
Synchronous CF and F1/F2 outputs
Logic output REVP provides information regarding the sign
of the active power
Direct drive for electromechanical counters and 2-phase
stepper motors (F1 and F2)
Programmable gain amplifier (PGA) in the current channel
facilitates usage of small shunts and burden resistors
Proprietary ADCs and DSPs provide high accuracy over large
variations in environmental conditions and time
On-chip power supply monitoring
On-chip creep protection (no load threshold)
On-chip reference 2.5 V ± 8% (30 ppm/°C typical) with
external overdrive capability
Single 5 V supply, low power (15 mW typical)
Low cost CMOS process
GENERAL DESCRIPTION
The ADE7755 is a high accuracy electrical energy measurement
IC. The part specifications surpass the accuracy requirements as
quoted in the IEC 1036 standard.
The only analog circuitry used in the ADE7755 is in the ADCs
and reference circuit. All other signal processing (for example,
multiplication and filtering) is carried out in the digital domain.
This approach provides superior stability and accuracy over
extremes in environmental conditions and over time.
The ADE7755 supplies average active power information on the
low frequency outputs, F1 and F2. These logic outputs can be
used to directly drive an electromechanical counter or interface to
an MCU. The CF logic output gives instantaneous active power
information. This output is intended to be used for calibration
purposes or for interfacing to an MCU.
The ADE7755 includes a power supply monitoring circuit on the
AV
DD
supply pin. The ADE7755 remains in a reset condition until
the supply voltage on AV
DD
reaches 4 V. If the supply falls below
4 V, the ADE7755 resets and no pulse is issued on F1, F2, and CF.
Internal phase matching circuitry ensures that the voltage and
current channels are phase matched whether the HPF in Channel 1
is on or off. An internal no load threshold ensures that the
ADE7755 does not exhibit any creep when there is no load.
The ADE7755 is available in a 24-lead SSOP package.
FUNCTIONAL BLOCK DIAGRAM
G0 G1
16 15
AV
DD
3
AGND
11
AC/ DC
2
DV
DD
1
DGND
21
ADE7755
POWER
SUPPLY MONITOR
V1P
5
V1N
6
PGA
×1, ×2, ×8, ×16
...11011001...
DIGITAL-TO-FREQUENCY
CONVERTER
PHASE
CORRECTION
...110101...
HPF
MULTIPLIER
V2P
8
V2N
7
2.5V
REFERENCE
ADC
LPF
SIGNAL
PROCESSING
BLOCK
ADC
9
RESET
4kΩ
10
17
18
12
14
13
20
22
24
23
REF
IN/OUT
CLKIN CLKOUT SCF S0
S1 REVP CF
F1
F2
Figure 1.
1
U.S. Patents 5,745,323; 5,760,617; 5,862,069; and 5,872,469.
Rev. A
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rights of third parties that may result from its use. Specifications subject to change without notice. No
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