ANALOG DEVICES ADE7752, ADE7752A Service Manual

Polyphase Energy Metering IC

www.BDTIC.com/ADI

FEATURES

High accuracy, supports 50 Hz/60 Hz IEC62053-2x
Less than 0.1% error over a dynamic range of 500 to 1
Compatible with 3-phase/3-wire delta and 3-phase/4-wire

Wye configurations

The ADE7752

outputs F1 and F2

High frequency output CF is intended for calibration and

supplies instantaneous real power

Logic output REVP indicates a potential miswiring or

nega

Direct drive for electromechanical counters and 2-phase

epper motors (F1 and F2)

st

Proprietary ADCs and DSP provide high accuracy over large

ariations in environmental conditions and time

v
On-chip power supply monitoring
On-chip creep protection (no load threshold)
On-chip reference 2.4 V ±8% (20 ppm/°C typical) with

external overdrive capability
Single 5 V supply, low power

60 mW t

30 mW typical: ADE7752A
Low cost CMOS process

GENERAL DESCRIPTION

The ADE7752 is a high accuracy polyphase electrical energy
measurement IC. The ADE7752A is a pin-to-pin compatible
low power version of ADE7752. The functions of ADE7752 and

Rev. C

Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Anal og Devices for its use, nor for any infringements of patents or ot her
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.

1

supplies average real power on frequency

tive power for each phase

ypical: ADE7752

5

IAP
IAN

6

16

VAP

IBP

7
8

IBN

15

VBP

9

ICP

10

ICN

VCP

14
13

VN

Ω

2.4V REF

4k

11 12 4 18 21 22 23 24 1

AGND

FUNCTIONAL BLOCK DIAGRAM

ADC

ADC

ADC

ADC

ADC

ADC

REF

IN/OUT

Figure 1. 24-Lead Standard Small Outline Package [SOIC]

HPF

Φ

PHASE

CORRECTION

HPF

Φ

PHASE

CORRECTION

HPF

Φ

PHASE

CORRECTION

with Pulse Output

ADE7752/ADE7752A

ADE7752A are the same. Both products are referred to in the
text of this data sheet as ADE7752.

The part specifications surpass the accuracy requirements as

uoted in the IEC62053-2x standard. The only analog circuitry

q
used in the ADE7752 is in the analog-to-digital converters (ADCs)
and reference circuit. All other signal processing (such as multi­plication, filtering, and summation) is carried out in the digital
domain. This approach provides superior stability and accuracy
over extremes in environmental conditions and over time.

The ADE7752 supplies average real power information on the
lo

w frequency outputs, F1 and F2. These logic outputs may be
used to directly drive an electromechanical counter or to
interface with an MCU. The CF logic output gives instanta­neous real power information. This output is intended to be
used for calibration purposes.

The ADE7752 includes a power supply monitoring circuit on

pin. The ADE7752 remains inactive until the supply

the V

DD

voltage on V
pulses are issued on F1, F2, and CF. Internal phase matching
circuitry ensures that the voltage and current channels are
phase matched. An internal no load threshold ensures the part
does not exhibit any creep when there is no load. The ADE7752
is available in a 24-lead SOIC package.

1

Patent pending.

LPF

LPF

LPF

DIGITAL-TO-FREQUENCY CONVERTER

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] www.analog.com
Fax: [phone] © 2005 Analog Devices, Inc. All rights reserved.

reaches 4 V. If the supply falls below 4 V, no

DD

POWER
SUPPLY

MONITOR

ADE7752/
ADE7752A

Σ

V

DD

3

2

DGND

19

CLKIN

CLKOUT

20

CFS1 F1F2S0SCFREVP

02676-A-001

ABS

17

X

X

X

ADE7752/ADE7752A

www.BDTIC.com/ADI

TABLE OF CONTENTS

Specifications..................................................................................... 3

Voltage Channels Connection .................................................. 15

Timing Characteristics..................................................................... 4

Absolute Maximum Ratings............................................................ 5

ESD Caution.................................................................................. 5

Pin Configuration and Function Descriptions............................. 6

Typical Performance Characteristics ............................................. 8

Test C irc uit ...................................................................................... 10

Te r mi n ol o g y .................................................................................... 11

Theory of Operation ...................................................................... 12

Power Factor Considerations.................................................... 12

Nonsinusoidal Voltage and Current ........................................ 13

Analog Inputs.................................................................................. 14

Current Channels ....................................................................... 14

Voltage Channels ........................................................................14

Typical Con ne c tion Diagrams ...................................................... 15

Current Channel Connection ...................................................15

Meter Connections..................................................................... 15

Power Supply Monitor ................................................................... 17

HPF and Offset Effects .............................................................. 17

Digital-to-Frequency Conversion ................................................ 18

Mode Selection of the Sum of the Three Active Energies..... 19

Power Measurement Considerations....................................... 19

Transfer F u n c tion ........................................................................... 20

Frequency Outputs F1 and F2 .................................................. 20

Frequency Output CF ................................................................ 21

Selecting a Frequency for an Energy Meter Application........... 22

Frequency Outputs..................................................................... 22

No Load Threshold .................................................................... 22

Negative Power Information..................................................... 23

Outline Dimensions ....................................................................... 24

Ordering Guide .......................................................................... 24

REVISION HISTORY

7/05—Rev. B to Rev. C

Added ADE7752A.............................................................. Universal

Changed NEGP Pin Name to REVP................................ Universal

Changes to Table 1.............................................................................3

Changes to Table 6, Table 7 ............................................................21

Changes to Table 8, Table 9, Table 10............................................22

Updated Outline Dimensions........................................................24

Changes to Ordering Guide...........................................................24

9/03—Rev. A to Rev. B

U

pdated Format.................................................................. Universal

Change to Figure 19 ........................................................................15

5/03—Rev. 0 to Rev. A

to F

anged F

Ch

Change to Figure 6 .......................................................................... 10

Changes to Frequency Outputs F1 and F2 section .....................13

Replaced Table II .............................................................................13

Changes to Examples 1, 2, and 3 ...................................................14

Replaced Table III............................................................................14

Replaced Tables IV, V, and VI ........................................................15

Changes to SELECTING A FREQUENCY FOR AN ENERGY

METER APPLICATION section...................................................15

Changes to NO LOAD THRESHOLD section............................16

Replaced Table VII ..........................................................................16

1–5

............................................................ Universal

1–7

Rev. C | Page 2 of 24

ADE7752/ADE7752A

www.BDTIC.com/ADI

SPECIFICATIONS

VDD = 5 V ± 5%, AGND = DGND = 0 V, on-chip reference, CLKIN = 10 MHz, T

Table 1.

ADE7752 ADE7752A

Parameter

ACCURACY

1, 2

Measurement Error on Current

Min Typ Max Min Typ Max

0.1 0.1 % Reading

Channel

Phase Error Between Channels

PF = 0.8 Capacitive ±0.1 ±0.1 Degrees
PF = 0.5 Inductive ±0.1 ±0.1 Degrees

AC Power Supply Rejection SCF = 0; S0 = S1 = 1

Output Frequency Variation

0.01 0.01 % Reading

(CF)

DC Power Supply Rejection S1 = 1; S0 = SCF = 0

Output Frequency Variation

0.1 0.1 % Reading

(CF)

ANALOG INPUTS See the Analog Inputs section.

Maximum Signal Levels ±0.5 ±0.5

Input Impedance (DC) 370 410 370 450 kΩ CLKIN = 10 MHz
Bandwidth (–3 dB) 14 14 kHz CLKIN/256, CLKIN = 10 MHz
ADC Offset Error

1, 2

±25 ±25 mV

Gain Error ±9 ±9 % Ideal

REFERENCE INPUT

REF

Input Voltage Range 2.6 2.6 V 2.4 V + 8%

IN/OUT

2.2 2.2 V 2.4 V – 8%
Input Impedance 3.3 3.3 kΩ
Input Capacitance 10 10 pF

ON-CHIP REFERENCE Nominal 2.4 V

Reference Error ±200 ±200 mV
Temperature Coefficient 25 25 ppm/°C

CLKIN All specifications for CLKIN of 10 MHz

Input Clock Frequency 10 10 MHz

LOGIC INPUTS

3

ACF, S0, S1, and ABS

Input High Voltage, V
Input Low Voltage, V
Input Current, I
Input Capacitance, C

LOGIC OUTPUTS

INH

INL

IN

IN

3

2.4 2.4 V VDD = 5 V ±5%

0.8 0.8 V VDD = 5 V ±5%
±3 ±3 A Typically 10 nA, VIN = 0 V to V
10 10 pF

F1 and F2

Output High Voltage, V
Output Low Voltage, V

OH

OL

4.5 4.5 V I

0.5 0.5 V I

CF and REVP

Output High Voltage, V
Output Low Voltage, V

OH

OL

4 4 V VDD = 5 V, I

0.5 0.5 V VDD = 5 V, I

POWER SUPPLY For specified performance

V

DD

I

DD

1

See the Terminology section for explanation of specifications.

2

See the plots in the Typical Performance Characteristics section.

3

Sample tested during initial release and after any redesign or process change that may affect this parameter.

4.75 5.25 4.75 5.25 V 5 V ±5%
12 16 6 9 mA

MIN

to T

= –40°C to +85°C, unless otherwise noted.

MAX

Unit Conditions

Voltage channel with full-scale signal
(±500 mV), 25

°C, over a dynamic range

of 500 to 1

IA = IB = IC = 100 mV rms,
VA = VB = VC =
ripple on V

100 mV rms, @ 50 Hz,

of 175 mV rms @ 100 Hz

DD

IA = IB = IC = 100 mV rms,

100 mV rms,

CN

Vpeak
differential

VA = VB = VC =
V

= 5 V ±250 mV

DD

V

to VN, VBP to VN, VCP to VN, IAP to IAN,

AP

I

to IBN, ICP to I

BP

External 2.5 V reference,
IA = IB = IC = 50

= 10 mA, V

SOURCE

= 10 mA, VDD = 5 V

SINK

SOURCE

= 5 mA

SINK

0 mV dc

= 5 V

DD

= 5 mA

DD

Rev. C | Page 3 of 24

ADE7752/ADE7752A

www.BDTIC.com/ADI

TIMING CHARACTERISTICS

VDD = 5 V ± 5%, AGND = DGND = 0 V, on-chip reference, CLKIN = 10 MHz, T

to T = –40°C to +85°C, unless otherwise noted .

MAX

MIN

Table 2.

Parameter Conditions Spec Unit

3

t F1 and F2 Pulse Width (Logic High). 275 ms

1

t Output Pulse Period. See the Transfer Function section. See Table 6. sec

2

t Time between F1 Falling Edge and F2 Falling Edge. 1/2 t

3 2

3, 4

t CF Pulse Width (Logic High). 96

4

5

t CF Pulse Period. See the Transfer Function and the Frequency Outputs sections. See Table 7. sec

5

t Minimum Time Between the F1 and F2 Pulse. CLKIN/4 sec

6

1

Sample tested during initial release and after any redesign or process change that may affect this parameter.

2

See Figure 2.

3

The pulse widths of F1, F2, and CF are not fixed for higher output frequencies. See the Frequency Outputs section.

4

CF is not synchronous to F1 or F2 frequency outputs.

5

The CF pulse is always 1 µs in the high frequency mode.

t

1

1, 2

sec
ms

F1

F2

t

4

CF

t

6

t

2

t

3

t

5

02676-A-002

Figure 2. Timing Diagram for Frequency Outputs

Rev. C | Page 4 of 24

ADE7752/ADE7752A

www.BDTIC.com/ADI

ABSOLUTE MAXIMUM RATINGS

T = 25°C, unless otherwise noted.

A

Table 3.

Parameter Rating

V to AGND −0.3 V to +7 V

DD

V to DGND −0.3 V to +7 V

DD

Analog Input Voltage to AGND

VAP, VBP, VCP, VN, IAP, IAN, IBP, IBN,

ICP, and ICN −6 V to +6 V
Reference Input Voltage to AGND −0.3 V to V + 0.3 V
Digital Input Voltage to DGND −0.3 V to V + 0.3 V
Digital Output Voltage to DGND −0.3 V to V + 0.3 V
Operating Temperature Range

Storage Temperature Range −65°C to +150°C
Junction Temperature 150°C
24-Lead SOIC, Power Dissipation 88 mW
θJA Thermal Impedance 250°C/W
Lead Temperature, Soldering

Vapor Phase (60 sec) 215°C

Infrared (15 sec) 220°C

−40°C to +85°C Industrial

DD

DD

DD

Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those listed in the operational sections
of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.

ESD CAUTION

ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on
the human body and test equipment and can discharge without detection. Although this product 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.

Rev. C | Page 5 of 24

ADE7752/ADE7752A

www.BDTIC.com/ADI

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

24
23
22
21
20
19
18
17
16
15
14
13

F1
F2
S1
S0
CLKOUT
CLKIN
SCF
ABS
VAP
VBP
VCP
VN

02676-A-003

REF

CF

DGND

V

REVP

IAP
IAN
IBP
IBN
ICP
ICN

AGND

IN/OUT

DD

10
11
12

1
2
3
4

ADE7752/

5

ADE7752A

6

TOP VIEW

(Not to Scale)

7
8
9

Figure 3. Pin Configuration

Table 4. Pin Function Descriptions

Pin No. Mnemonic Description

1 CF Calibration Frequency Logic Output. The CF logic output gives instantaneous real power information.

This output is intended to be used for calibration purposes. See the SCF pin description.

2 DGND This provides the ground reference for the digital circuitry in the ADE7752: the multiplier, filters, and

digital-to-frequency converter. Because the digital return currents in the ADE7752 are small, it is
acceptable to connect this pin to the analog ground plane of the whole system.

3 V

DD

Power Supply. This pin provides the supply voltage for the digital circuitry in the ADE7752. The supply
voltage should be maintained at 5 V ± 5% for specified operation. This pin should be decoupled to
DGND with a 10 µF capacitor in parallel with a 100 nF ceramic capacitor.

4 REVP

This logic output goes logic high when negative power is detected on any of the three phase inputs,
that is, when the phase angle between the voltage and the current signals is greater than 90°. This
output is not latched and is reset when positive power is once again detected. See the Negative Power
Information section.

5, 6;
7, 8;
9, 10

IAP, IAN;
IBP, IBN;
ICP, ICN

Analog Inputs for Current Channel. This channel is intended for use with the current transducer and is
referenced in this document as the current channel. These inputs are fully differential voltage inputs
with maximum differential input signal levels of ±0.5 V. See the Analog Inputs section. Both inputs have
internal ESD protection circuitry. In addition, an overvoltage of ±6 V can be sustained on these inputs
without risk of permanent damage.

11 AGND

This pin provides the ground reference for the analog circuitry in the ADE7752: the ADCs, temperature
sensor, and reference. This pin should be tied to the analog ground plane or the quietest ground
reference in the system. This quiet ground reference should be used for all analog circuitry, such as
antialiasing filters, current and voltage transducers, and so on. To keep ground noise around the
ADE7752 to a minimum, the quiet ground plane should connect to the digital ground plane at only
one point. It is acceptable to place the entire device on the analog ground plane.

12 REF

IN/OUT

This pin provides access to the on-chip voltage reference. The on-chip reference has a nominal value of

2.4 V ± 8% and a typical temperature coefficient of 20 ppm/°C. An external reference source may also be
connected at this pin. In either case, this pin should be decoupled to AGND with a 1 µF ceramic capacitor.

13–16 VN, VCP, VBP,

VAP

Analog Inputs for the Voltage Channel. This channel is intended for use with the voltage transducer and
is referenced in this document as the voltage channel. These inputs are single-ended voltage inputs with
a maximum signal level of ±0.5 V with respect to VN for specified operation. All inputs have internal ESD
protection circuitry. In addition, an overvoltage of ± 6 V can be sustained on these inputs without risk of
permanent damage.

17

ABS

This logic input is used to select the way the three active energies from the three phases are summed.
This offers the designer the capability to do the arithmetical sum of the three energies (ABS

or the sum of the absolute values (ABS

logic low). See the Mode Selection of the Sum of the Three Active

logic high)

Energies section.

18 SCF Select Calibration Frequency. This logic input is used to select the freq

uency on the calibration output

CF. Table 7 shows how the calibration frequencies are selected.

Rev. C | Page 6 of 24

ADE7752/ADE7752A

www.BDTIC.com/ADI

Pin No. Mnemonic Description

19 CLKIN Master Clock for ADCs and Digital Signal Processing. An external clock can be provided at this logic input.

Alternatively, a parallel resonant AT crystal can be connected across CLKIN and CLKOUT to provide a
clock source for the ADE7752. The clock frequency for specified operation is 10 MHz. Ceramic load
capacitors between 22 pF and 33 pF should be used with the gate oscillator circuit. Refer to the crystal
manufacturer’s data sheet for load capacitance requirements.

20 CLKOUT A crystal can be connected across this pin and CLKIN as described previously to provide a clock source

for the ADE7752. The CLKOUT pin can drive one CMOS load when an external clock is supplied at CLKIN
or when a crystal is being used.

21, 22 S0, S1 These logic inputs are used to select one of four possible frequencies for the digital-to-frequency conver-

sion. This offers the designer greater flexibility when designing the energy meter. See the Selecting a
Frequency for an Energy Meter

24, 23 F1, F2 Low Frequency Logic Outputs. F1 and F2 supply average real power information. The logic outputs can

be used to drive electromechanical counters and two-phase stepper motors directly. See the Transfer
Function section.

Application section.

Rev. C | Page 7 of 24

ADE7752/ADE7752A

www.BDTIC.com/ADI

TYPICAL PERFORMANCE CHARACTERISTICS

0.5

WYE CONNECTION
ON-CHIP REFERENCE

0.4

0.3

0.2

0.1

PHASE B

0

–0.1

–0.2

ERROR (% of Reading)

–0.3

–0.4

–0.5

0.1 1

1.0

WYE CONNECTION
ON-CHIP REFERENCE

0.8

0.6

0.4

0.2

0

–0.2

–0.4

ERROR (% of Reading)

–0.6

–0.8

–1.0

0.1 1

Figure 5. Error as a Percent of Reading over Power Factor

0.5

WYE CONNECTION
EXTERNAL REFERENCE

0.4

0.3

0.2

0.1

0

–0.1

–0.2

ERROR (% of Reading)

–0.3

–0.4

–0.5

0.1 1

Figure 6. Error as a Percent of Reading over Power Factor

PHASE C

S

A

E

P

A

H

CURRENT CHANNEL (% of Full Scale)

PHASE A + B + C

Figure 4. Error as a Percent of Reading

with Internal Reference (Wye Connection)

+85°C PF = +0.5

+25°C PF = –0.5

–40°C PF = +0.5

with Inte

+25°C PF = +1

CURRENT CHANNEL (% of Full Scale)

rnal Reference (Wye Connection)

+85°C PF = +0.5

+25°C PF = +1

–40°C PF = +0.5

+25°C PF = –0.5

CURRENT CHANNEL (% of Full Scale)

with Extern

al Reference (Wye Connection)

02676-A-004

10010

02676-A-005

10010

02676-A-006

10010

1.0

WYE CONNECTION
ON-CHIP REFERENCE

0.8

0.6

0.4

0.2

0

–0.2

–0.4

ERROR (% of Reading)

–0.6

–0.8

–1.0

0.1 1

+85°C PF = 1

–40°C PF = 1

CURRENT CHANNEL (% of Full Scale)

+25°C PF = 1

Figure 7. Error as a Percent of Reading over Temperature

rnal Reference (Wye Connection)

with Inte

0.5

0.4

0.3

0.2

0.1

0

–0.1

–0.2

ERROR (% of Reading)

–0.3

–0.4

–0.5

0.1 1

DELTA CONNECTION
ON-CHIP REFERENCE

PF = –0.5

PF = +1

PF = +0.5

CURRENT CHANNEL (% of Full Scale)

Figure 8. Error as a Percent of Reading over Power Factor

th Internal Reference (Delta Connection)

wi

0.5

WYE CONNECTION
EXTERNAL REFERENCE

0.4

0.3

0.2

0.1

0

–0.1

–0.2

ERROR (% of Reading)

–0.3

–0.4

–0.5

0.1 1

+85°C PF = 1

+25°C PF = 1

–40°C PF = 1

CURRENT CHANNEL (% of Full Scale)

Figure 9. Error as a Percent of Reading over Temperature

with Extern

al Reference (Wye Connection)

02676-A-007

10010

02676-A-008

10010

02676-A-009

10010

Rev. C | Page 8 of 24