Analog Devices AD204JY, AD204JN, AD202KY, AD202KN, AD202JY Datasheet

Low-Cost, Miniature

a

FEATURES
Small Size: Four Channels/lnch
Low Power: 35 mW (AD204)
High Accuracy: 0.025% Max Nonlinearity (K Grade)
High CMR: 130 dB (Gain = 100 V/V)
Wide Bandwidth: 5 kHz Full-Power (AD204)
High CMV Isolation: 2000 V pk Continuous (K Grade)

(Signal and Power)
Isolated Power Outputs
Uncommitted Input Amplifier

APPLICATIONS
Multichannel Data Acquisition
Current Shunt Measurements
Motor Controls
Process Signal Isolation
High Voltage Instrumentation Amplifier

GENERAL DESCRIPTION

The AD202 and AD204 are general purpose, two-port, trans­former-coupled isolation amplifiers that may be used in a broad
range of applications where input signals must be measured,
processed and/or transmitted without a galvanic connection.
These industry standard isolation amplifiers offer a complete
isolation function, with both signal and power isolation provided
for in a single compact plastic SIP or DIP style package. The
primary distinction between the AD202 and the AD204 is that
the AD202 is powered directly from a 15 V dc supply while the
AD204 is powered by an externally supplied clock, such as the
recommended AD246 Clock Driver.

The AD202 and AD204 provide total galvanic isolation between
the input and output stages of the isolation amplifier through
the use of internal transformer-coupling. The functionally com­plete AD202 and AD204 eliminate the need for an external,
user-supplied dc/dc converter. This permits the designer to
minimize the necessary circuit overhead and consequently reduce
the overall design and component costs.

The design of the AD202 and AD204 emphasizes maximum
flexibility and ease of use, including the availability of an
uncommitted op amp on the input stage. They feature a bipolar

±5 V output range, an adjustable gain range of from 1 to 100 V/V,
±0.025% max nonlinearity (K grade), 130 dB of CMR and the

AD204 consumes a low 35 mW of power.

PRODUCT HIGHLIGHTS

The AD202 and AD204 are full-featured isolators offering
numerous benefits to the user:

Small Size: The AD202 and AD204 are available in SIP and
DIP form packages. The SIP package is just 0.25" wide, giving
the user a channel density of four channels per inch. The isolation

Isolation Amplifiers

AD202/AD204

FUNCTIONAL BLOCK DIAGRAM

FB

V

SIG

+V

–V

IN COM

OUT

ISO

OUT

ISO

IN–

IN+

+7.5V

–7.5V

5V

FS

RECT

AND

FILTER

MOD

25kHz

SIGNAL

POWER

25kHz

barrier is positioned to maximize input to output spacing. For
applications requiring a low profile, the DIP package provides a
height of just 0.350".

High Accuracy: With a maximum nonlinearity of ±0.025%
for the AD202K/AD204K (±0.05% for the AD202J/AD204J)
and low drift over temperature, the AD202 and AD204 provide
high isolation without loss of signal integrity.

Low Power: Power consumption of 35 mW (AD204) and
75 mW (AD202) over the full signal range makes these isolators
ideal for use in applications with large channel counts or tight
power budgets.

Wide Bandwidth: The AD204’s full-power bandwidth of 5 kHz
makes it useful for wideband signals. It is also effective in appli­cations like control loops, where limited bandwidth could result
in instability.

Excellent Common-Mode Performance: The AD202K/
AD204K provide ±2000 V pk continuous common-mode isola­tion, while the AD202J/AD204J provide ±1000 V pk continuous
common-mode isolation. All models have a total common-mode
input capacitance of less than 5 pF inclusive of power isolation.
This results in CMR ranging from 130 dB at a gain of 100 dB to
104 dB (minimum at unity gain) and very low leakage current
(2 µA maximum).

Flexible Input: An uncommitted op amp is provided at the
input of all models. This provides buffering and gain as required,
and facilitates many alternative input functions including filtering,
summing, high-voltage ranges, and current (transimpedance) input.

Isolated Power: The AD204 can supply isolated power of
±7.5 V at 2 mA. This is sufficient to operate a low-drift input
preamp, provide excitation to a semiconductor strain gage, or
to power any of a wide range of user-supplied ancillary circuits.
The AD202 can supply ±7.5 V at 0.4 mA which is sufficient to
operate adjustment networks or low-power references and op
amps, or to provide an open-input alarm.

AD202

DEMOD

OSCILLATOR

5V
FS

HI

V

OUT

LO

15V DC

POWER
RETURN

REV. C

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
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] World Wide Web Site: www.analog.com
Fax: [phone] © Analog Devices, Inc., 2001

AD202/AD204–SPECIFICATIONS

Model AD204J AD204K AD202J AD202K

GAIN

Range 1 V/V–100 V/V ***
Error ±0.5% typ (±4% max) ***
vs. Temperature ±20 ppm/°C typ (± 45 ppm/°C max) ***
vs. Time ±50 ppm/1000 Hours ***
vs. Supply Voltage ±0.01%/V ±0.01%/V ±0.01%/V ±0.01%/V
Nonlinearity (G = 1 V/V)
Nonlinearity vs. Isolated Supply Load ±0.0015%/mA ***

INPUT VOLTAGE RATINGS

Input Voltage Range ±5 V ***
Max lsolation Voltage (Input to Output)

AC, 60 Hz, Continuous 750 V rms 1500 V rms 750 V rms 1500 V rms

Continuous (AC and DC) ±1000 V Peak ±2000 V Peak ±1000 V Peak ±2000 V Peak

Isolation-Mode Rejection Ratio (IMRR) @ 60 Hz

RS ≤ 100 Ω (HI & LO Inputs) G = 1 V/V 110 dB 110 dB 105 dB 105 dB

G = 100 V/V 130 dB ***

RS ≤ l kΩ (Input HI, LO, or Both) G = 1 V/V 104 dB min 104 dB min 100 dB min 100 dB min

G = 100 V/V 110 dB min ***

Leakage Current Input to Output @ 240 V rms, 60 Hz 2 µA rms max ***

INPUT IMPEDANCE

Differential (G = 1 V/V) 1012 Ω ***
Common-Mode 2 GΩ储4.5 pF ***

INPUT BIAS CURRENT

Initial, @ 25°C ±30 pA ***
vs. Temperature (0°C to 70°C) ±10 nA ***

INPUT DIFFERENCE CURRENT

Initial, @ 25°C ±5 pA ***
vs. Temperature (0°C to 70°C) ±2 nA ***

INPUT NOISE

Voltage, 0.1 Hz to 100 Hz 4 µV p-p ***

f > 200 Hz 50 nV/√Hz ***

FREQUENCY RESPONSE

Bandwidth (VO ≤ 10 V p-p, G = 1 V–50 V/V) 5 kHz 5 kHz 2 kHz 2 kHz
Settling Time, to ± 10 mV (10 V Step) 1 ms ***

OFFSET VOLTAGE (RTI)

Initial, @ 25°C Adjustable to Zero (±15 ± 15/G)mV max (±5 ±5/G)mV max (±15 ± 15/G)mV max (±5 ±5/G)mV max

vs. Temperature (0°C to 70°C)

RATED OUTPUT

Voltage (Out HI to Out LO) ±5 V ***
Voltage at Out HI or Out LO (Ref. Pin 32) ±6.5 V ***
Output Resistance 3 kΩ 3 kΩ 7 kΩ 7 kΩ
Output Ripple, 100 kHz Bandwidth 10 mV p-p ***

ISOLATED POWER OUTPUT

Voltage, No Load ±7.5 V ***
Accuracy ±10% ***
Current 2 mA (Either Output)
Regulation, No Load to Full Load 5% ***
Ripple 100 mV p-p ***

OSCILLATOR DRIVE INPUT

Input Voltage 15 V p-p Nominal 15 V p-p Nominal N/A N/A
Input Frequency 25 kHz Nominal 25 kHz Nominal N/A N/A

POWER SUPPLY (AD202 Only)

Voltage, Rated Performance N/A N/A 15 V ± 5% 15 V ± 5%
Voltage, Operating N/A N/A 15 V ± 10% 15 V ± 10%
Current, No Load (VS = 15 V) N/A N/A 5 mA 5 mA

TEMPERATURE RANGE

Rated Performance 0°C to 70°C ***
Operating –40°C to +85°C ***
Storage –40°C to +85°C ***

PACKAGE DIMENSIONS

SIP Package (Y) 2.08" × 0.250" × 0.625" ***
DlP Package (N) 2.10" × 0.700" × 0.350" ***

NOTES
*Specifications same as AD204J.

1

Nonlinearity is specified as a % deviation from a best straight line.

2

1.0 µF min decoupling required (see text).

1

5 kHz Bandwidth 0.5 mV rms ***

2

4

±0.05% max ±0.025% max ±0.05% max ±0.025% max

10



±10 ±



G



(Typical @ 25C and VS = 15 V unless otherwise noted.)



mV/ °C




3

3

3 mA with one supply loaded.

4

Width is 0.25" typ, 0.26" max.

Specifications subject to change without notice.

***

2 mA (Either Output)3400 µA Total 400 µA Total

–2–

REV. C

AD202/AD204

AD246–SPECIFICATIONS
(Typical @ 25°C and VS = 15 V unless otherwise noted.)

Model AD246JY AD246JN

OUTPUT

l

Frequency 25 kHz Nominal *
Voltage 15 V p-p Nominal *
Fan-Out 32 Max *

POWER SUPPLY
REQUIREMENTS

Input Voltage 15 V ± 5% *
Supply Current

Unloaded 35 mA *
Each AD204 Adds 2.2 mA *
Each 1 mA Load on AD204

+V

or –V

ISO

NOTES
*Specifications the same as the AD246JY.

1

The high current drive output will not support a short to ground.

Specifications subject to change without notice.

Adds 0.7 mA *

ISO

AD246 Pin Designations

Pin (Y) Pin (N) Function

1 12 15 V POWER IN

2 1 CLOCK OUTPUT
12 14 COMMON
13 24 COMMON

PIN DESIGNATIONS

AD202/AD204 SIP Package

Pin Function

1 +INPUT
2 INPUT/V

COMMON

ISO

3 –INPUT
4 INPUT FEEDBACK
5 –V
6+V

OUTPUT

ISO

OUTPUT

ISO

31 15 V POWER IN (AD202 ONLY)
32 CLOCK/POWER COMMON
33 CLOCK INPUT (AD204 ONLY)
37 OUTPUT LO
38 OUTPUT HI

AD202/AD204 DIP Package

Pin Function

1 +INPUT
2 INPUT/V

COMMON

ISO

3 –INPUT
18 OUTPUT LO
19 OUTPUT HI
20 15 V POWER IN (AD202 ONLY)
21 CLOCK INPUT (AD204 ONLY)
22 CLOCK/POWER COMMON
36 +V
37 –V

OUTPUT

ISO

OUTPUT

ISO

38 INPUT FEEDBACK

ORDERING GUIDE

Package Max Common-Mode Max

Model Option Voltage (Peak) Linearity

AD202JY SIP 1000 V ±0.05%
AD202KY SIP 2000 V ± 0.025%
AD202JN DIP 1000 V ±0.05%
AD202KN DIP 2000 V ± 0.025%

AD204JY SIP 1000 V ±0.05%
AD204KY SIP 2000 V ± 0.025%
AD204JN DIP 1000 V ±0.05%
AD204KN DIP 2000 V ± 0.025%

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
the AD202/AD204 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

–3–

WARNING!

ESD SENSITIVE DEVICE

AD202/AD204

DIFFERENCES BETWEEN THE AD202 AND AD204

The primary distinction between the AD202 and AD204 is in
the method by which they are powered: the AD202 operates
directly from 15 V dc while the AD204 is powered by a non­isolated externally-supplied clock (AD246) which can drive up
to 32 AD204s. The main advantages of using the externally­clocked AD204 over the AD202 are reduced cost in multichannel
applications, lower power consumption, and higher bandwidth.
In addition, the AD204 can supply substantially more isolated
power than the AD202.

Of course, in a great many situations, especially where only one
or a few isolators are used, the convenience of stand-alone opera­tion provided by the AD202 will be more significant than any
of the AD204’s advantages. There may also be cases where it is
desirable to accommodate either device interchangeably, so the
pinouts of the two products have been designed to make that
easy to do.

V

SIG

+V

–V

IN COM

OUT

ISO

OUT

ISO

IN–

IN+

FB

SIGNAL

MOD

5V

FS

+7.5V

–7.5V

RECT

AND

FILTER

25kHz

POWER

25kHz

AD202

DEMOD

OSCILLATOR

5V
FS

HI

V

OUT

LO

15V DC

POWER
RETURN

Figure 1a. AD202 Functional Block Diagram

the output leads to get signal inversion. Additionally, in multi­channel applications, the unbuffered outputs can be multiplexed
with one buffer following the mux. This technique minimizes
offset errors while reducing power consumption and cost. The
output resistance of the isolator is typically 3 kΩ for the AD204
(7 kΩ for AD202) and varies with signal level and temperature,
so it should not be loaded (see Figure 2 for the effects of load
upon nonlinearity and gain drift). In many cases a high-imped­ance load will be present or a following circuit such as an output
filter can serve as a buffer, so that a separate buffer function will
not often be needed.

GAIN

(%)

–10

–8

–6

–4

–2

0

GAIN TC

CHANGE

(ppm/C)

–500

–400

–300

–200

–100

0

NON-

LINEARITY

(%)

0.25

0.20

0.15

0.10

0.05

0

0 1.00.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

AD202 GAIN AND GAIN TC

AD202 NONLINEARITY

AD204 GAIN AND GAIN TC

AD204 NONLINEARITY

OUTPUT LOAD – M

CHANGE

Figure 2. Effects of Output Loading

V

SIG

+V

–V

IN COM

OUT

ISO

OUT

ISO

IN–

IN+

FB

SIGNAL

MOD

5V

FS

+7.5V

–7.5V

RECT

AND

FILTER

25kHz

POWER

25kHz

DEMOD

POWER

CONV.

AD204

5V
FS

HI

V

OUT

LO

CLOCK
15V p-p
25kHz

POWER
RETURN

Figure 1b. AD204 Functional Block Diagram
(Pin Designations Apply to the DIP-Style Package)

INSIDE THE AD202 AND AD204

The AD202 and AD204 use an amplitude modulation technique
to permit transformer coupling of signals down to dc (Figure 1a
and 1b). Both models also contain an uncommitted input op
amp and a power transformer which provides isolated power to
the op amp, the modulator, and any external load. The power
transformer primary is driven by a 25 kHz, 15 V p-p square
wave which is generated internally in the case of the AD202, or
supplied externally for the AD204.

Within the signal swing limits of approximately ±5 V, the out­put voltage of the isolator is equal to the output voltage of the
op amp; that is, the isolation barrier has unity gain. The output
signal is not internally buffered, so the user is free to interchange

USING THE AD202 AND AD204

Powering the AD202. The AD202 requires only a single 15 V

power supply connected as shown in Figure 3a. A bypass capaci­tor is provided in the module.

AD202

15V 5%

15V RETURN

Figure 3a.

Powering the AD204. The AD204 gets its power from an
externally supplied clock signal (a 15 V p-p square wave with a
nominal frequency of 25 kHz) as shown in Figure 3b.

AD246

AD204 AD204 AD204

15V

+

15V RETURN

Figure 3b.

(NOTE: Circuit figures shown on this page are for SIP-style packages. Refer to
Page 3 for proper DIP package pinout.)

–4–

REV. C