The signal chain above is representative of a typical power distribution device. The technical requirements of the blocks vary,

but the products listed in the table below representative ADI's key promotion parts for the power distribution application.

Main Challenges and System Considerations

• Higher reliability and lower assembly/manufacturing costs.

• High signal dynamic range (up to 4000:1) and resolution (≥12 bits

system ENOB) in some applications.

• Various requirements of system accuracy (protection up to 0.5%,

measurement up to 0.1%).

• Multichannel (simultaneously as optional).

• Real-time processing (10 ms, 20 ms for all channels).

• System level connectivity: RS-232, RS-485, Ethernet, CAN, USB. In most

cases, the communication interfaces also require isolation (≥ 500 V).

• Robustness requirements such as overvoltage protection, EMC/EMI,

industry operation temperature range, long lifetime.

• To develop a low voltage device, the designer usually needs to consider

different system requirements, including dynamic range, accuracy,

bandwidth, channels, isolation, real-time processing, cost, and robustness.

Typical Distribution System Categories

• Low voltage system: <35 kV, including 10 kV, 6 kV, 3 kV.

• Ultralow voltage system: 1 kV, 380 V, 220 V.

ADI Energy—Protective Relay Platform for

Power Distribution Systems

energy.analog.com

Typical Power Distribution Device Signal Chain

POWER MANAGEMENT

AMP

AC OR DC

110V/220V

±10V

±5V

ADC

PROCESSOR

DAC

AC-TO-DC

DC-TO-DC LDO

POWER

SUPERVISOR

INTERFACES

ISOLATION

DAC

ISOLATED

iCOUPLER

(OPTIONAL)

RS-485/

RS-232

ISOLATED

CAN/USB

ANALOG

OUTPUT

4mA~20mA

ISOLATED

iCOUPLER

ISOLATED

DC-TO-DC

REF

DIDO

PT/CT

AC OR DC

110V/220V

±10V

±5V

ADC

DAC

AC-TO-DC

DC-TO-DC

LDO

POWER

SUPERVISOR

POWER MANAGEMENT

INTERFACES

ISOLATION DAC

PROCESSOR

DSP/MCU

ISOLATED

iCOUPLER

(OPTIONAL)

RS-485/

RS-232

ISOLATED

CAN/USB

ANALOG

OUTPUT

4mA~20mA

ISOLATION

iCOUPLER

ISOLATED

DC-TO-DC

REF

DIDO

PT/CT

AMP

External ADC solution

Integrated ADC solution

Power Distribution Application Theory and Typical Architecture

In the modern automatic power distribution system, more and more intelligent electronic devices are used to monitor the power quality and quickly isolate

any fault from affecting the overall grid operation. The architecture of such devices is mostly composed of processor, multichannel ADC, signal condition

circuit, power supply, and communication interfaces. Analog Devices, as the worldwide technical leader of mixed-signal processing, is the major electronic

system solution supplier in this area.

• ADI’s expertise in integrated energy measurement—300 million ADI

metrology-based meters deployed.

• Precision measurement of current and voltage through highly accurate

converters and ampliﬁers.

• Enable robust and reliable power networks using high performance

processing technology.

• 50% of all electrical grid equipment worldwide uses ADI converters.

• Mixed-signal conversion and processing enable ease of design and

reduced time to market.

• Enable system cost reductions through innovation, with integration of

features such as additional channel count and on-board ampliﬁers.

ADI Recommended

Amplifier

OP2177, OP4177, AD8672, AD8674,

ADA4077-2, AD8602, AD8604, AD8608

ADC

AD7606, AD7607, AD7658-1, AD7689,

AD7327, AD7490, ADE7878

Reference ADR421, ADR431, ADR3425

Processor ADSP-BF51x, ADSP-21469

Isolation

Power isolation: ADuM5000

Signal isolation: ADuM141x

DAC AD5422

Interface

RS-485: ADM487E, ADM2587E

RS-232: ADM3251E

Isolated CAN: ADM3053

Isolated USB: ADuM4160

Power Management

LDO: ADP1

DC-to-DC: ADP1612, ADP2301, ADP5034

Power supervisor: ADM6710

ADI Recommended

Amplifier

AD8602, AD8604, AD8608,

AD8618, AD8666

Reference ADR3425

Processor ADSP-BF506F, ADuC702x

Isolation

Power isolation: ADuM5000

Signal isolation: ADuM141x

DAC AD5422

Interface

RS-485: ADM487E, ADM2587E

RS-232: ADM3251E

Isolated CAN: ADM3053

Isolated USB: ADuM4160

Power Management

LDO: ADP125

DC-to-DC: ADP5034

Power supervisor: ADM6710

energy.analog.com

Reference circuits are subsystem-level building blocks that have been engineered and tested for quick and easy system integration.

• Layout Considerations for an Expandable Multichannel Simultaneous Sampling Data Acquisition System (DAS) Based on the AD7606 16-Bit, 8-Channel

DAS (CN0148)—www.analog.com/CN0148

• A Low Cost, 8-Channel, Simultaneously Sampled, Data Acquisition System with 84 dB SNR and Excellent Channel-to-Channel Matching

(CN0175)—www.analog.com/CN0175

• 24-Bit, 4-Channel, High Dynamic Range, 156 KSPS per Channel Simultaneous Sampling Data Acquisition System (CN0157)—www.analog.com/CN0157

• Half-Duplex, Isolated RS-485 Interface (CN0031)—www.analog.com/CN0031

• More reference circuits are available at www.analog.com/circuits

Customer Interaction Center cic.asia@analog.com

Engineer Zone ez.analog.com

Free Sample www.analog.com/sample

If you need more information about ADI energy applications and products,

please visit: energy.analog.com

Trademarks and registered trademarks are the

property of their respective owners.

BR10138-.5-8/11Printed in China

ADI Products

Main Features

• 2 × AD7606 as analog front, with no ampliﬁer

• ADSP-BF51x can run RTOS, protection algorithm, and communication stack in the same time

• ADSP-BF518 has IEEE 1588, which is required by digital substation applications

• Free schematics, PCB, software (OS, drivers, etc), and documents are provided

(Design by ADI third party - Beijing Eﬂag)

Reference Design for Low Voltage Energy Distribution System

Circuits from the Lab

™

Reference Circuits for Energy Management

Part Number Description Key Features Benefits

Amplifier

OP2177/OP4177 Precision low noise op amp

= 60 μV (max), drift = 0.7 mV/ºC, V

noise

= 8 nV/

√

Hz @ 1 kHz, V

supply

= ±2.5 V to ±15 V

Low noise, low offset and offset drift,

no phase reversal

ADA4077-2 Precision low noise op amp

= 25 μV (B-grade), drift = 0.15 μV/ºC, V

noise

= 8 nV/

√

Hz, V

supply

= ±2.5 V to ±15 V

Very low offset voltage drift and low input

bias current

AD8604 Precision CMOS single supply op amp

= 500 μV (max), V

supply

= 2.7 V to 5.5 V, wide bandwidth: 8 MHz

RRIO, low cost 4 amplifier

ADC

AD7490

16-channel, 12-bit

non-simultaneous ADC

0 to V

REF

/2x V

REF

uni-polar single-ended analog input, SPI interface, 1 MSPS, SINAD

> 69 dB

Low cost, 16-channel, 12-bit ADC

AD7689/AD7699

8-channel, 16-bit

non-simultaneous ADC

0 to V

REF

unipolar/differential analog input, SPI interface, 250 kSPS (AD7689)/

500 kSPS (AD7699) , SINAD = 92.5 dB

8-channel, 16-bit ADC, low cost

AD7606/AD7607

8-channel, 16-bi

t/14-bit

simultaneous ADC

True bipolar analog input ranges: ±10 V, ±5 V, single 5 V analog supply, 2.3 V to +5 V

VDRIVE

, 1 MΩ analog input impedance, analog input clamp protection

8-channel simultaneous sampling,

single 5 V supply

Reference

ADR421 Voltage reference

Initial accuracy ≤ 0.05% with drift ≤ 3 ppm/˚C, high output current: 10 mA, different

output voltage option 2.5 V, low noise (0.1 Hz to 10.0 Hz): 1.75 μV

p-p

@ 2.5 V output

High performance (3 ppm), high output

current: 10 mA

ADR3425 Voltage reference

Initial accuracy: ±0.1% (maximum), maximum temperature coefficient: 8 ppm/

operating temperature range:

−

C to +125

Low co

st, SOT-23 package, 10 mA source and

3 mA sink reference

Processor

ADSP-BF51x DSP

300 MHz/400 MHz DSP, 116 kB on-chip RAM, on-chip RTC, ethernet Mac

(10/100) with IEEE 1588 supported

400 MHz DSP, IEEE 1588 supported

ADSP-BF506F Embedded ADC DSP

300 MHz/400 MHz Blackfin core, embedded 12-b

it ADC and 4 MB flash, 6-pair PWM

output and multi-interface

12-bit ADC and >300 MHz core

ADuC702x Precision Analog Microcontroller 41 MHz ARM7 core and embedded 12-bit ADC, 3-pair PWM out

put, 32 kB or 64 kB flash Processor with embedded 12-bit ADC

Isolation

ADuM5000/

ADuM6000

Isolated dc-to-dc

isoPower

integrated isolated dc-to-dc converter, up to 500 mW output power,

thermal overload protection

Isolated dc-

to-dc

ADuM141x Quad channel digital isolator

High data rate: dc to 10 Mbps (NRZ), high common-mode transient immunity:

>25 kV/μs, low power operation and bidirectional communication

Long lifetime, easy to select different direction

Interface

ADuM2587E Isolated RS-485/RS-422 transceiver Half or full duplex, 500 kbps, 5 V or 3.3 V operation

RS485 with integrated isolated dc-to-dc

converter, ±15 kV ESD prote

ction

ADM3053 Isolated CAN transceiver

Signal and power isolated CAN transceiver, complies with ISO 11898 standard,

high speed data rates up to 1 Mbps

CAN bus interface with integrated isolated

dc-to-dc

Power Management

ADP5034 Multi-output dc-to-dc regulator Dual 1.2 A bucks and dual 300 mA LDOs in LFCSP; up to 96% buck power efficiency

4-channel output PMU, single part power

chain solution

ADP1612 Step-up

(boost) regulator V

1.8 V to 5.5 V, V

OUT

adjustable up to 20 V, 1.4 A

1.4 A step up dc-to-dc with pin selectable

650 kHz or 1.3 MHz PWM frequency, soft start

ADP2301 Step-down (buck) switch regulator

3.0 V to 20 V, output voltage from 0.8 V to 0.85 × V

, 1.2 A, high efficiency up

to 91%, current-mode control architecture

Integrated high side MOSFET, integrated

bootstrap diode, internal compensation, and

soft start