ADE7761AARSZ-RL

ADE7761AARSZ-RL Datasheet

Energy Metering IC with On-Chip Fault and Missing Neutral Detection ADE7761A

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ADE7761AARSZ-RL	ADE7761AARSZ-RL (pdf)

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ADE7761AARSZ	ADE7761AARSZ

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Energy Metering IC with On-Chip Fault and Missing Neutral Detection ADE7761A High accuracy, active energy measurement IC supports IEC 62053-21 Less than 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 Continuous monitoring of the phase and neutral current allows fault detection in 2-wire distribution systems Current channels input level best suited for shunt and current transformer sensors Uses the larger of the two currents phase or neutral to during a fault condition Continuous monitoring of the voltage and current inputs allows missing neutral detection Uses one current input phase or neutral to bill when missing neutral is detected Direct drive for electromechanical counters and 2-phase stepper motors F1 and F2 Proprietary ADCs and DSP provide high accuracy over large variations in environmental conditions and time Reference V ± 8% drift 30 ppm/°C typical with external overdrive capability Single 5 V supply, low power The ADE7761A is a high accuracy, fault-tolerant, electrical energy measurement IC intended for use with 2-wire distribution systems. The part specifications surpass the accuracy requirements as quoted in the IEC 62053-21 standard. The only analog circuitry used on the ADE7761A is in the ADCs and reference circuit. All other signal processing such as 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 ADE7761A incorporates a fault detection scheme similar to the ADE7751 by continuously monitoring both phase and neutral currents. A fault is indicated when the currents differ by more than The ADE7761A incorporates a missing neutral detection scheme by continuously monitoring the input voltage. When a missing neutral condition is voltage ADE7761A continues billing based on the active current signal see the Missing Neutral Mode section . The missing neutral condition is indicated when the FAULT pin goes high. The ADE7761A supplies average active power information on the low frequency outputs, F1 and F2. The CF logic output gives instantaneous active power information. The ADE7761A includes a power-supply monitoring circuit on the VDD supply pin. Internal phase matching circuitry ensures that the voltage and current channels are matched. An internal no-load threshold ensures that the ADE7761A does not exhibit any creep when there is no load. FUNCTIONAL BLOCK DIAGRAM PGA AGND FAULT 15 VDD 1 V1A 2 V1N 4 V1B 3 MISCAL 7 B>A<>B ZERO CROSSING DETECTION MISSING NEUTRAL GAIN ADJUST POWER SUPPLY MONITOR ADE7761A SIGNAL PROCESSING BLOCK V2P 6 V2N 5 2.5V REFERENCE INTERNAL OSCILLATOR MISSING NEUTRAL DETECTION DIGITAL-TO-FREQUENCY CONVERTER 05040-0-001 9 REFIN/OUT 14 RCLKIN 17 DGND Figure Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Analog Inputs 11 Internal Oscillator 12 Analog-to-Digital 13 Active Power Calculation 14 Digital-to-Frequency Conversion 16 Transfer 16 Fault Detection 17 Missing Neutral Mode 18 21 Interfacing to a Microcontroller for Energy Measurement 21 Selecting a Frequency for an Energy Meter Application 21 Negative Power 22 Outline Dimensions 23 Ordering Guide 23 ADE7761A SPECIFICATIONS VDD = 5 V ± 5%, AGND = DGND = 0 V, on-chip reference, on-chip oscillator, TMIN to TMAX = −40°C to +85°C. Table Parameter ACCURACY1 Measurement Error2 Phase Error Between Channels PF = Capacitive PF = Inductive AC Power Supply Rejection2 Output Frequency Variation DC Power Supply Rejection2 Output Frequency Variation FAULT DETECTION2, 3 Fault Detection Threshold Inactive Input <> Active Input Swap Threshold Inactive Input <> Active Input Accuracy Fault Mode Operation V1A Active, V1B = AGND V1B Active, V1A = AGND Fault Detection Delay Swap Delay MISSING NEUTRAL MODE2, 4 Missing Neutral Detection Threshold V2P − V2N Accuracy Missing Neutral Mode V1A Active, V1B = V2P = AGND V1B Active, V1A = V2P = AGND Missing Neutral Detection Delay ANALOG INPUTS Maximum Signal Levels Input Impedance DC Bandwidth −3 dB ADC Offset Error2 Gain Error Gain Error Match2 REFERENCE INPUT REFIN/OUT Input Voltage Range Input Impedance Input Capacitance ON-CHIP REFERENCE Error Temperature Coefficient Current Source ON-CHIP OSCILLATOR Frequency Oscillator Frequency Tolerance Temperature Coefficient Value Unit Test Conditions/Comments % of reading, typ Over a dynamic range of 500 to 1 Degrees, max Degrees, max Phase lead 37° Phase lag 60° %, typ V1A = V1B = V2P = ±100 mV rms %, typ V1A = V1B = V2P = ±100 mV rms See the Fault Detection section %, typ V1A or V1B active % of larger, typ V1A or V1B active % of reading, typ Over a dynamic range of 500 to 1 % of reading, typ Over a dynamic range of 500 to 1 Seconds, typ Seconds, typ See the Missing Neutral Detection section mV peak, min ±660 400 7 15 ±4 ±3 % of reading, typ % of reading, typ Seconds, typ mV peak, max mV peak, max kΩ, min kHz, typ mV, typ %, typ %, typ Over a dynamic range of 500 to 1 Over a dynamic range of 500 to 1 V1A − V1N, V1B − V1N, V2P − V2N Differential input Differential input MISCAL − V2N Uncalibrated error, see the Terminology section for details External V reference External V reference V, max V, min kΩ, min pF, max V + 8% V − 8% ±200 30 20 mV, max ppm/°C, typ uA, min ORDERING GUIDE Model ADE7761AARS-RL ADE7761AARSZ1 ADE7761AARSZ-RL1 ADE7761AARS-REF 1 Z = Pb-free part. Temperature Range to +85°C to +85°C to +85°C to +85°C Package Description 20-Lead Shrink Small Outline Package SSOP 20-Lead Shrink Small Outline Package SSOP 20-Lead Shrink Small Outline Package SSOP 20-Lead Shrink Small Outline Package SSOP Reference Board Package Option RS-20 RS-20 RS-20 RS-20 ADE7761A NOTES 2006 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D05040-0-7/06 0

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Energy Metering IC with On-Chip Fault and Missing Neutral Detection ADE7761A

High accuracy, active energy measurement IC supports IEC 62053-21

Less than 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

Continuous monitoring of the phase and neutral current allows fault detection in 2-wire distribution systems

Current channels input level best suited for shunt and current transformer sensors

Uses the larger of the two currents phase or neutral to during a fault condition

Continuous monitoring of the voltage and current inputs allows missing neutral detection

Uses one current input phase or neutral to bill when missing neutral is detected

Direct drive for electromechanical counters and 2-phase stepper motors F1 and F2

Proprietary ADCs and DSP provide high accuracy over large variations in environmental conditions and time

Reference V ± 8% drift 30 ppm/°C typical with external overdrive capability

Single 5 V supply, low power

The ADE7761A is a high accuracy, fault-tolerant, electrical energy measurement IC intended for use with 2-wire distribution systems. The part specifications surpass the accuracy requirements as quoted in the IEC 62053-21 standard. The only analog circuitry used on the ADE7761A is in the ADCs and reference circuit. All other signal processing such as 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 ADE7761A incorporates a fault detection scheme similar to the ADE7751 by continuously monitoring both phase and neutral currents. A fault is indicated when the currents differ by more than

The ADE7761A incorporates a missing neutral detection scheme by continuously monitoring the input voltage. When a missing neutral condition is voltage ADE7761A continues billing based on the active current signal see the Missing Neutral Mode section . The missing neutral condition is indicated when the FAULT pin goes high. The ADE7761A supplies average active power information on the low frequency outputs, F1 and F2. The CF logic output gives instantaneous active power information.

The ADE7761A includes a power-supply monitoring circuit on the VDD supply pin. Internal phase matching circuitry ensures that the voltage and current channels are matched. An internal no-load threshold ensures that the ADE7761A does not exhibit any creep when there is no load.

FUNCTIONAL BLOCK DIAGRAM

PGA AGND

FAULT 15

VDD 1

V1A 2 V1N 4 V1B 3 MISCAL 7

B>A<>B

ZERO CROSSING DETECTION

MISSING NEUTRAL GAIN ADJUST

POWER SUPPLY MONITOR

ADE7761A

SIGNAL PROCESSING BLOCK

V2P 6 V2N 5
2.5V

REFERENCE

INTERNAL OSCILLATOR

MISSING NEUTRAL DETECTION

DIGITAL-TO-FREQUENCY CONVERTER
05040-0-001
9 REFIN/OUT
14 RCLKIN
17 DGND

Figure

Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Analog Inputs 11 Internal Oscillator 12 Analog-to-Digital 13 Active Power Calculation 14 Digital-to-Frequency Conversion 16 Transfer 16 Fault Detection 17 Missing Neutral Mode 18 21 Interfacing to a Microcontroller for Energy Measurement 21 Selecting a Frequency for an Energy Meter Application 21 Negative Power 22 Outline Dimensions 23 Ordering Guide 23

ADE7761A

SPECIFICATIONS

VDD = 5 V ± 5%, AGND = DGND = 0 V, on-chip reference, on-chip oscillator, TMIN to TMAX = −40°C to +85°C.

Table Parameter ACCURACY1

Measurement Error2 Phase Error Between Channels

PF = Capacitive PF = Inductive AC Power Supply Rejection2 Output Frequency Variation DC Power Supply Rejection2 Output Frequency Variation FAULT DETECTION2, 3 Fault Detection Threshold Inactive Input <> Active Input Swap Threshold Inactive Input <> Active Input Accuracy Fault Mode Operation V1A Active, V1B = AGND V1B Active, V1A = AGND Fault Detection Delay Swap Delay MISSING NEUTRAL MODE2, 4 Missing Neutral Detection Threshold V2P − V2N Accuracy Missing Neutral Mode V1A Active, V1B = V2P = AGND V1B Active, V1A = V2P = AGND Missing Neutral Detection Delay ANALOG INPUTS Maximum Signal Levels

Input Impedance DC Bandwidth −3 dB ADC Offset Error2 Gain Error Gain Error Match2 REFERENCE INPUT REFIN/OUT Input Voltage Range

Input Impedance Input Capacitance ON-CHIP REFERENCE Error Temperature Coefficient Current Source ON-CHIP OSCILLATOR Frequency Oscillator Frequency Tolerance Temperature Coefficient

Value Unit

Test Conditions/Comments
% of reading, typ Over a dynamic range of 500 to 1

Degrees, max Degrees, max

Phase lead 37° Phase lag 60°
%, typ

V1A = V1B = V2P = ±100 mV rms
%, typ

V1A = V1B = V2P = ±100 mV rms See the Fault Detection section
%, typ

V1A or V1B active
% of larger, typ

V1A or V1B active
% of reading, typ Over a dynamic range of 500 to 1
% of reading, typ Over a dynamic range of 500 to 1

Seconds, typ

Seconds, typ

See the Missing Neutral Detection section
mV peak, min
±660 400 7 15 ±4 ±3
% of reading, typ % of reading, typ Seconds, typ
mV peak, max mV peak, max kΩ, min kHz, typ mV, typ %, typ %, typ

Over a dynamic range of 500 to 1 Over a dynamic range of 500 to 1

V1A − V1N, V1B − V1N, V2P − V2N Differential input Differential input MISCAL − V2N

Uncalibrated error, see the Terminology section for details External V reference External V reference

V, max

V, min
kΩ, min
pF, max

V + 8% V − 8%
±200 30 20
mV, max ppm/°C, typ uA, min
ORDERING GUIDE

Model ADE7761AARS-RL ADE7761AARSZ1 ADE7761AARSZ-RL1 ADE7761AARS-REF
1 Z = Pb-free part.

Temperature Range to +85°C to +85°C to +85°C to +85°C

Package Description 20-Lead Shrink Small Outline Package SSOP 20-Lead Shrink Small Outline Package SSOP 20-Lead Shrink Small Outline Package SSOP 20-Lead Shrink Small Outline Package SSOP Reference Board

Package Option RS-20 RS-20 RS-20 RS-20

ADE7761A NOTES
2006 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners.

D05040-0-7/06 0

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Datasheet ID: ADE7761AARSZ-RL 517806