ADE7759ARSRL Analog Devices Inc, ADE7759ARSRL Datasheet

IC ENERGY METERING 1PHASE 20SSOP

ADE7759ARSRL

Manufacturer Part Number
ADE7759ARSRL
Description
IC ENERGY METERING 1PHASE 20SSOP
Manufacturer
Analog Devices Inc
Datasheet

Specifications of ADE7759ARSRL

Rohs Status
RoHS non-compliant
Input Impedance
390 KOhm
Measurement Error
0.1%
Voltage - I/o High
2.4V
Voltage - I/o Low
0.8V
Current - Supply
3mA
Voltage - Supply
4.75 V ~ 5.25 V
Operating Temperature
-40°C ~ 85°C
Mounting Type
Surface Mount
Package / Case
20-SSOP (0.200", 5.30mm Width)
Meter Type
Single Phase
For Use With
EVAL-ADE7759EBZ - BOARD EVALUATION FOR ADE7759
a
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. 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 companies.
GENERAL DESCRIPTION
The ADE7759 is an accurate active power and energy measure-
ment IC with a serial interface and a pulse output. The ADE7759
incorporates two second-order Σ-∆ ADCs, a digital integrator
(on CH1), reference circuitry, temperature sensor, and all the
signal processing required to perform active power and energy
measurement.
An on-chip digital integrator allows direct interface to di/dt
current sensors such as a Rogowski coil. The digital integrator
eliminates the need for an external analog integrator and pro-
vides excellent long-term stability and precise phase matching
between the current and the voltage channels. The integrator
*U.S. Patents 5,745,323; 5,760,617; 5,862,069; 5,872,469; others pending.
REV. A
FEATURES
High Accuracy, Supports IEC 687/1036
On-Chip Digital Integrator Allows Direct Interface with
Less Than 0.1% Error over a Dynamic Range of 1000 to 1
On-Chip User-Programmable Threshold for Line Voltage
Supplies Sampled Waveform Data and Active Energy
(40 Bits)
Digital Power, Phase, and Input DC Offset Calibration
On-Chip Temperature Sensor (Typical 1 LSB/ C Resolution)
SPI Compatible Serial Interface
Pulse Output with Programmable Frequency
Interrupt Request Pin (IRQ) and IRQ Status Register
Proprietary ADCs and DSP provide High Accuracy over
Reference 2.4 V
Single 5 V Supply, Low Power Consumption (25 mW
Current Sensors with di/dt Output Such as Rogowski Coil
SAG Detection and PSU Supervisory
Large Variations in Environmental Conditions and Time
Overdrive Capability
Typical)
V1N
V2P
V2N
V1P
8% (20 ppm/ C Typical) with External
REFERENCE
AGND
SENSOR
2.4V
TEMP
AV
DD
4k
REF
ADC
ADC
IN/OUT
FUNCTIONAL BLOCK DIAGRAM
APGAIN[11:0]
MULTIPLIER
LPF1
RESET
HPF1
DIN DOUT SCLK
PHCAL[7:0]
SERIAL INTERFACE
REGISTERS AND
INTEGRATOR
can be switched off if the ADE7759 is used with conventional
current sensors.
The ADE7759 contains a sampled waveform register and an
active energy register capable of holding at least 11.53 seconds
of accumulated power at full ac load. Data is read from the
ADE7759 via the serial interface. The ADE7759 also provides a
pulse output (CF) with frequency that is proportional to the
active power.
In addition to active power information, the ADE7759 also
provides various system calibration features, i.e., channel offset
correction, phase calibration, and power offset correction. The
part also incorporates a detection circuit for short duration
voltage drop (SAG). The voltage threshold and the duration (in
number of half-line cycles) of the drop are user programmable.
An open-drain logic output (SAG) goes active low when a sag
event occurs.
A zero crossing output (ZX) produces an output that is synchro-
nized to the zero crossing point of the line voltage. This output
can be used to extract timing or frequency information from the
line. The signal is also used internally to the chip in the line
cycle energy accumulation mode; i.e., the number of half-line
cycles in which the energy accumulation occurs can be con-
trolled. Line cycle energy accumulation enables a faster and
more precise energy accumulation and is especially useful dur-
ing calibration. This signal is also useful for synchronization of
relay switching with a voltage zero crossing.
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 ADE7759 is available
in a 20-lead SSOP package.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700
Fax: 781/326-8703
Active Energy Metering IC with
dt
CS
MULTIPLIER
IRQ
DV
DD
CFNUM[11:0]
CFDEN[11:0]
DGND
di/dt Sensor Interface
© 2002 Analog Devices, Inc. All rights reserved.
LPF2
CLKIN CLKOUT
ADE7759
APOS[15:0]
DFC
ZX
SAG
CF
ADE7759
www.analog.com
*

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ADE7759ARSRL Summary of contents

Page 1

FEATURES High Accuracy, Supports IEC 687/1036 On-Chip Digital Integrator Allows Direct Interface with Current Sensors with di/dt Output Such as Rogowski Coil Less Than 0.1% Error over a Dynamic Range of 1000 to 1 On-Chip User-Programmable Threshold for Line ...

Page 2

ADE7759 TABLE OF CONTENTS FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...

Page 3

SPECIFICATIONS T MIN Parameter ENERGY MEASUREMENT ACCURACY Measurement Bandwidth 1 Measurement Error on Channel 1 Channel 1 Range = 0.5 V Full-Scale Gain = 1 Gain = 2 Gain = 4 Gain = 8 Gain = 16 Channel ...

Page 4

ADE7759–SPECIFICATIONS Parameter REFERENCE INPUT REF Input Voltage Range IN/OUT Input Capacitance ON-CHIP REFERENCE Reference Error Current Source Output Impedance Temperature Coefficient CLKIN Input Clock Frequency LOGIC INPUTS RESET, DIN, SCLK, CLKIN, and CS Input High Voltage, V INH Input Low ...

Page 5

TIMING CHARACTERISTICS Parameter A, B Versions Unit Write Timing (min 150 ns (min 150 ns (min (min (min (min ...

Page 6

... ADE7759 features proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality. ORDERING GUIDE Model ADE7759ARS ADE7759ARSRL EVAL-ADE7759EB *RS = Shrink Small Outline Package in tubes; RSRL = Shrink Small + 0 Outline Package in reel. ...

Page 7

Pin No. Mnemonic Description RESET 1 Reset Pin for the ADE7759. A logic low on this pin will hold the ADCs and digital circuitry (including the serial interface reset condition Digital Power Supply. This pin provides ...

Page 8

ADE7759 Pin No. Mnemonic Description 12 ZX Voltage Waveform (Channel 2) Zero Crossing Output. This output toggles logic high and low at the zero crossing of the differential signal on Channel 2—see Zero Crossing Detection section. SAG 13 This open-drain ...

Page 9

0.3 + 0.2 0.1 0.0 –0.1 + –0.2 FULL SCALE = 0.5V –0.3 GAIN = 1 INTEGRATOR OFF –0.4 INTERNAL REFERENCE –0.5 0.01 0.1 1 ...

Page 10

ADE7759 0.5 0.4 0.3 – 0.2 0.1 0.0 –0.1 –0.2 FULL SCALE = 0.5V –0.3 GAIN = 4 INTEGRATOR OFF –0.4 EXTERNAL REFERENCE –0.5 0.01 0.1 1 CURRENT – A TPC 7. Error ...

Page 11

Test Circuits 100nF 100nF RESET DIN 1k V1P 33nF DOUT RB 1k SCLK V1N U1 33nF CS ADE7759 CLKOUT V2N 1k 33nF CLKIN 600k V2P IRQ 110V 33nF 1k SAG ZX ...

Page 12

ADE7759 It is also possible to adjust offset errors on Channel 1 and Channel 2 by writing to the offset correction registers (CH1OS and CH2OS, respectively). These registers allow channel offsets in the range ± ± 50 ...

Page 13

FREQUENCY – Hz Figure 10. Gain Response of the Digital Integrator –88.0 –88.5 –89.0 –89.5 –90.0 –90.5 –91.0 –91.5 –92 FREQUENCY – ...

Page 14

ADE7759 The ZX signal will go logic high on a positive going zero crossing and logic low on a negative going zero crossing on Channel 2. The zero crossing signal ZX is generated from the output of LPF1. LPF1 has ...

Page 15

INTERRUPTS ADE7759 interrupts are managed through the interrupt status register (STATUS[7:0]) and the interrupt enable register (IRQEN[7:0]). When an interrupt event occurs in the ADE7759, the corresponding flag in the status register is set to a Logic 1—see Interrupt Status ...

Page 16

ADE7759 TEMPERATURE MEASUREMENT ADE7759 also includes an on-chip temperature sensor. A temperature measurement can be made by setting Bit 5 in the mode register. When Bit 5 is set logic high in the mode register, the ADE7759 will initiate a ...

Page 17

ALIASING EFFECTS IMAGE FREQUENCIES 0 2 447 FREQUENCY – kHz Figure 21. ADC and Signal Processing in Channel 1 For a di/dt sensor such as a Rogowski coil, however, the sensor has 20 dB per decade gain. This will neutralize ...

Page 18

ADE7759 2.42V, 1.21V, 0. REFERENCE 8, 16 {GAIN[2:0]} V1P ADC 1 PGA1 V1 V1N V1 0.5V, 0.25V, 0.125V, 62.5mV, 31.3mV, 15.6mV, 40000h 0V 2851Fh 00000h ANALOG INPUT RANGE D7AE1h C0000h ADC OUTPUT WORD RANGE *WHEN DIGITAL INTEGRATOR ...

Page 19

CHANNEL 2 ADC Channel 2 Sampling In Channel 2 waveform sampling mode (MODE[14:13 and WSMP = 1), the ADC output code scaling for Channel 2 is the same as Channel 1, i.e., the output swings between D7AE1h ...

Page 20

ADE7759 V1P HPF PGA1 ADC 1 V1 V1N V2P 1 DELAY BLOCK PGA2 ADC 2 V2 1.12 s/LSB V2N PHCAL [7:0] 0.1 –110 s TO +103 s V1 60Hz Figure 28. Phase ...

Page 21

INSTANTANEOUS p( – POWER SIGNAL 1999Ah VI CCCDh 00000h CURRENT i( sin( t) VOLTAGE v( sin( t) Figure 32. Active Power Calculation 0 –4 –8 –12 –16 –20 –24 ...

Page 22

ADE7759 CURRENT CHANNEL VOLTAGE CHANNEL AENERGY [39:0] 7F,FFFF,FFFFh 3F,FFFF,FFFFh 00,0000,0000h 23s 5.8s 11.5s 40,0000,0000 80,0000,0000h Figure 37. Energy Register Rollover Time for Full-Scale Power (Minimum and Maximum Power Gain) Note that the energy register contents will roll over to full-scale ...

Page 23

This output frequency can provide a simple, single-wire, optically isolated interface to external calibration equipment. Figure 38 illustrates the energy-to-frequency con- version in the ADE7759. The energy-to-frequency conversion is accomplished by accu- mulating the active power signal in ...

Page 24

ADE7759 E(t) Vlt VI – 4 ƒ 2ƒ /8.9Hz Figure 39. Output Frequency Ripple LINE CYCLE ENERGY ACCUMULATION MODE In line cycle energy accumulation mode, the energy accumula- tion of the ADE7759 can be synchronized to ...

Page 25

For 255 half cycles this would give a total integration time of 2.125 seconds. This would mean that the energy register was updated 2.125/1.1175 µs (4/CLKIN) times. The average output value of LPF2 is given as: Contents of LENERGY [ ...

Page 26

ADE7759 Table III. Frequency Dependencies of the ADE7759 Parameters Parameter Nyquist frequency for CH 1 and 2 ADCs CLKIN/8 PHCAL resolution (seconds per LSB) Active Energy register update rate (Hz) Waveform sampling rate (Number of samples per second) WAVSEL 1, ...

Page 27

As explained earlier, the data write is initiated by a write to the communications register followed by the data. During a data write operation to the ADE7759, data is transferred to all on-chip registers one byte at a time. After ...

Page 28

ADE7759 CHECKSUM REGISTER The ADE7759 has a checksum register (CHKSUM[5:0]) to ensure that the data bits received in the last serial read operation are not corrupted. The 6-bit checksum register is reset before the first bit (MSB of the register ...

Page 29

Address Name R/W No. of Bits 0Bh APGAIN R/W 12 0Ch PHCAL R/W 8 0Dh APOS R/W 16 0Eh ZXTOUT R/W 12 0Fh SAGCYC R/W 8 10h IRQEN R/W 8 11h SAGLVL R/W 8 12h TEMP R 8 13h LINECYC ...

Page 30

ADE7759 REGISTER DESCRIPTIONS All ADE7759 functionality is accessed via the on-chip registers. Each register is accessed by first writing to the communications register and then transferring the register data. A full description of the serial interface protocol is given in ...

Page 31

Mode Register (06H) The ADE7759 functionality is configured by writing to the mode register—see Figure 45. Table VI summarizes the functionality of each bit in the mode register. Bit Bit Location Mnemonic Description 0 DISHPF The HFP (high-pass filter) in ...

Page 32

ADE7759 TEST1 (TEST MODE SELECTION SHOULD BE SET TO 0) WAVSEL (WAVEFORM SELECTION FOR SAMPLE MODE LPF2 01 = CH1 + CH2 (40-BIT WAVEFORM SAMPLES CH1 11 = CH2 DTRT (WAVEFORM SAMPLES OUTPUT DATA RATE) 00 ...

Page 33

ENERGY REGISTER OVERFLOW) (END OF A HARDWARE OR SOFTWARE RESET) (TEMPERATURE REGISTER READY) (ZERO CROSSING DETECTED) (ACTIVE ENERGY REGISTER OVERFLOW) (TEMPERATURE REGISTER READY) (ZERO CROSSING DETECTED) CH1OS Register (08H) The CH1OS register is an 8-bit, read/write enabled register. The ...

Page 34

ADE7759 0.05 MIN COPLANARITY OUTLINE DIMENSIONS 20-Lead Shrink Small Outline Package [SSOP] (RS-20) Dimensions shown in millimeters 7.50 7.20 6. 8.20 5.60 7.80 5.30 7.40 5. 1.85 1.75 2.00 MAX 1.65 0.25 0.09 8 0.65 0.38 ...

Page 35

Revision History Location 12/02—Data Sheet changed from REV REV. A. Changes to SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . ...

Page 36

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