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Электронный компонент: AD1021

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One Technology Way, P.O. Box 9106, Norwood. MA 02062-9106, U.S.A.
Tel: 617/329-4700
Fax: 617/326-8703
FUNCTIONAL BLOCK DIAGRAM
REV. 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
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
a
General Purpose
Input Isolation Amplifier
AD102/AD104
FEATURES
Integral Isolated Power Supply
500 V rms CMV Isolation Rating (100% Tested)
High Accuracy: 0.05% Max Nonlinearity
Small SIP Style Footprint
Lowest Priced Isolation Amplifiers
APPLICATIONS
Single/Multichannel Data Acquisition Systems
Process Control Input Signal Isolation
Motor Control
Utility Power Monitoring
General Input Protection Circuits
Ground Loop Interruption
GENERAL DESCRIPTION
The AD102 and AD104 are general purpose, two-port, isolation
amplifiers suitable for use where input signal isolation is desired.
Each offers a functionally complete, compact isolation solution
rated at 500 V rms common mode, based upon the proven and
reliable transformer-coupled, galvanic isolation technique used
in all AD200 series isolation amplifier products.
Each model is offered in a minimum footprint package requiring
no external components to operate. Though similar to the
AD202 and AD204, the AD102 and AD104 models are in-
tended as lower cost solutions where the performance of the
AD202 or AD204 is not demanded.
Both the AD102 and AD104 can be used in applications where
input-to-input and/or input-to-system isolation is desired. The
AD102 is best suited for single input uses as it requires only
+15 V dc power to operate. It may also be appropriate for
multichannel applications when input-to-input isolation is not
required such as where a single input multiplexer selects a spe-
cific channel prior to isolation.
For applications where input to input isolation is required, the
AD104 may be a more desirable choice. It offers the lowest cost
per channel especially when powered from a common clock
source, the cost of which may be amortized over many channels.
The clock necessary for AD104 operation is a 25 kHz, 15 V p-p
square wave applied to the clock input pin. Most standard oscil-
lator components like a CD4047 or TL555 may be used, or a
designer may choose the AD246 clock driver developed for the
AD204 product.
PRODUCT HIGHLIGHTS
Complete, Single Device Solution for Input Isolation
The AD102 offers full isolation without external parts or need
for an external dc/dc power source. The AD104 features the
same functionality at a lower price for multichannel uses when
supplied with a 25 kHz clock signal.
High Accuracy
A maximum nonlinearity of 0.05% is specified for both the
AD102 and AD104 over the rated temperature range.
Wide Bandwidth
Each is specified with a full power (3 dB) bandwidth. The
AD104 at 4 kHz and the AD102 at 1.5 kHz.
High Performance Common-Mode Rejection
While providing continuous 500 V rms isolation, greater than
100 dB rejection is provided. Each part has only 5.5 pF (typical)
of common-mode input capacitance.
Uncommitted Input Stage
Both models offer an uncommitted op amp input stage for user
flexibility and input gain optimization up to 100 V/V.
Low Power Consumption
The AD104 consumes only 35 mW from the clock source, the
AD102 only 75 mW from the +15 V dc supply.
5V
F S
SIGNAL
ICOM
PWR/CLK
COM
25kHz
POWER
DEMOD
AMPLIFIER
AND
MODULATOR
POWER
RECTIFIER
OSCILLATOR
FILTER
AD102
OUT H I
OUT LO
+15V DC
IN+
IN
FB 3
6
5
4
9
1
7
2
Parameter
Min
Typ
Max
Unit
Notes
ACCURACY
Gain Range
1
100
V/V
Unity Gain Error
0.5
5.0
%
vs. Temperature
45
ppm/
C
100 ppm/
C max
vs. Time
50
ppm
Per
1,000
Hours
vs. Supply Voltage, AD102
1
0.01
%/V
vs. Supply Voltage, AD104
1
0.001
%/V
Nonlinearity
2
0.05
%
INPUT VOLTAGE RATINGS
Linear Differential Range
5.0
V
Between IN+ and IN
CMV, Input to Output
2
AC, 60 Hz, Sinusoidal Waveform
500
V rms
100% Tested
DC
700
V pk-pk
Common-Mode Rejection (CMR)
R
S
100
, AD102
1
100
dB
R
S
100
, AD104
1
105
dB
R
S
1 k
, AD102
1
95
dB
R
S
1 k
, AD104
1
105
dB
Leakage Current
0.5
A
2
A max, In to Out,
240 V rms @ 60 Hz
INPUT CHARACTERISTICS
Input Offset Voltage, Initial
(
15
15/G)
mV
+25
C
vs. Temperature
(
10
10/G)
V/
C
0
C to +70
C
Input Bias Current, Initial
100
pA
+25
C
vs. Temperature
20
nA
0
C to +70
C
Input Difference Current, Initial
10
pA
+25
C
vs. Temperature
2
nA
0
C to +70
C
Input Voltage Noise
0.1 Hz to 100 Hz
4
V pk-pk
f > 200 Hz
50
nV/
Hz
Differential Input Impedance
10
12
Common-Mode Input Impedance
2G 5.5
pF
FREQUENCY RESPONSE
Bandwidth, Full Power (3 dB)
AD102
1
1.5
kHz
V
IN
5 V, G = 150 V/V
AD104
1
4.0
kHz
V
IN
5 V, G = 150 V/V
Settling Time
1.0
ms
Time to
10 mV from
10 V Step Input
RATED OUTPUT
Output Voltage Range
Between OUT HI and OUT LO
5.0
V
Between OUT HI or LO to PWR/CLK COM
6.5
V
Output Resistance
AD102
1
8
k
AD104
1
4
k
Output Ripple
100 kHz Bandwidth
10
mV pk-pk
5 kHz Bandwidth
0.5
mV rms
POWER SUPPLY (AD102 ONLY)
1
Supply Voltage
Rated Performance
+14.25
+15
+15.75
V dc
Operational Performance
+13.5
+15
+16.5
V dc
Supply Current
5
mA
AD102/AD104SPECIFICATIONS
REV. A
2
(@ T
A
= +25 C and power supply of +15 V 5% unless otherwise noted)
Parameter
Min
Typ
Max
Unit
Notes
CLOCK OSCILLATOR (AD104 ONLY)
1
Source Voltage Amplitude
14.25
15
15.75
V pk-pk
7.5 V Amplitude Within
15 V Range
Square Wave Frequency
25
kHz
5 kHz
Duty Cycle
50
% Hi vs. Low
2%
TEMPERATURE RANGE
Rated Performance
0
+70
C
Operating
40
+85
C
Storage
40
+85
C
PACKAGE DIMENSIONS
SIP Style Package (Y)
2.08
0.260
0.625 in. (max)
Not Including Pin Length
NOTES
1
Specification(s) apply to one model only, either AD102 or AD104, as indicated.
2
Nonlinearity is specified as a % deviation from a best fit straight line.
3
All units 100% tested by "Partial Discharge" method @ 750 V rms for 5 sec, 150 pc maximum allowable discharge.
Specifications subject to change without notice.
PIN DESIGNATIONS
Pin
Function
1
OUT HI
2
PWR/CLK COM
3
FB
4
ICOM
5
IN+
6
IN
7
+15 V DC (AD102)
8
CLOCK INPUT (AD104)
9
OUT LO
ORDERING GUIDE
Model
Package
Max CMV
Nonlinearity
AD102JY
SIP Style
500 V rms
0.05%
AD104JY
SIP Style
500 V rms
0.05%
DIFFERENCES BETWEEN THE AD102 AND AD104
The primary difference between the AD102 and AD104 is that
the AD102 contains an integral clock oscillator circuit and the
AD104 does not. As a result, the AD102 operates when sup-
plied +15 V dc power while the AD104 requires power in the
form of 15 V, 25 kHz square wave source. Typically a clock
source for an AD104 will drive multiple devices to reduce the
per channel cost of the source and to provide perfect oscillator
synchronization between devices. The AD104 also consumes
slightly less power and has more than twice the bandwidth of
the AD102.
In situations where only one or a few isolators are used, the con-
venience of stand-alone operation offered by the AD102 may
provide a greater user advantage than use of the AD104. For
maximum product flexibility both the AD102 and AD104 can
be accommodated by using a single universal layout for device
interchangeability.
REV. A
3
WARNING!
ESD SENSITIVE DEVICE
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 these devices feature 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.
AD102/AD104
REV. A
4
AD102/AD104
INSIDE THE AD102 AND AD104
The AD102 and AD104 use an amplitude modulation tech-
nique to exploit transmission of low frequency signal levels
through an isolation barrier produced by a signal transformer
including signals at a dc level (Figures 1 and 2). Additionally a
separate transformer is incorporated to provide power to the
isolated input port of the device. It is driven by a 25 kHz, 15 V
amplitude square wave generated internally by the AD102, sup-
plied externally for the AD104.
The device outputs are not buffered so the user may inter-
change output leads for signal inversion. In multichannel appli-
cations the outputs can be multiplexed with a single buffer
following the multiplexer to minimize offset errors while reduc-
ing power consumption and cost.
5V
F S
SIGNAL
ICOM
PWR/CLK
COM
25kHz
POWER
DEMOD
AMPLIFIER
AND
MODULATOR
POWER
RECTIFIER
OSCILLATOR
FILTER
AD102
OUT H I
OUT LO
+15V DC
IN+
IN
FB 3
6
5
4
9
1
7
2
Figure 1. AD102 Functional Block Diagram
5V
F S
SIGNAL
ICOM
PWR/CLK
COM
25kHz
POWER
DEMOD
AMPLIFIER
AND
MODULATOR
POWER
RECTIFIER
FILTER
AD104
OUT H I
OUT LO
CLK IN
I N +
I N
FB 3
6
5
4
9
1
8
2
Figure 2. AD104 Functional Block Diagram
USING THE AD102 AND AD104
Powering the AD102
The AD102 requires only a single +15 V DC power supply con-
nected as shown in Figure 3 to operate. A series 1.3 k
resistor
and 1.0
F capacitor are connected across the +15 V DC and
COMMON pins to aid in filtering power line variations.
1.0F
AD102
1.3k
PWR/CLK
COM
+15VDC
7
2
Figure 3. AD102 Power Input
Powering the AD104
The AD104 requires its power in the form of a 15 V p-p,
25 kHz square wave from an external source as shown in Fig-
ure 4 (NOTE: pinout for AD246 clock driver shown).
2
8
AD104
AD104
2
8
2
8
AD104
15V
p - p
@ 25kHz
2
13
12
+15VDC
PWR/CLK
COM
AD246
CLOCK DRIVER
1
Figure 4. Typical Multiple AD104 Connection
AD104 Clock Source
The AD246 clock driver designed to power the AD204 is a
clock driver that can be used to supply the required clock for the
AD104 from a +15 V DC supply (refer to the AD202/AD204
data sheet for AD246 specifications).
For designs where the lowest cost per channel approach is de-
sired, it is usually more cost efficient for designers to consider a
discrete onboard clock source such as the circuit shown in
Figure 5 (essentially an AD246).
180pF
12
9
8
7
4
1
3
2
10
2
4
7
5
6
3
TELEDYNE
TSC426
1N914
1N914
1F
35V
+15V
CLK
OUT
CLK/PWR
COM
14
6
5
49.9k
C
RC
Q
R
CD4047B
Figure 5. Typical Clock Driver Circuit
AD102/AD104
REV. A
5
Although this circuit generates a unipolar clock output of
0 V15 V, any 15 V amplitude square wave at 25 kHz with a
duty cycle of 50% is acceptable. This is possible since the
AD104 clock input is ac coupled by means of a 0.1
F capacitor
as shown in Figure 6. The source, therefore, only needs to be
7.5 V p-p in total amplitude and may be offset as desired. A
recommended maximum amplitude limit of
15 V with respect
to PWR/CLK COM should not be exceeded.
AD104
PWR/CLK
COM
CLK IN
T
R
A
N
S
F
O
R
M
E
R
0.1F
0.1F
+V
V
0.1F
2
8
Figure 6. AD104 Clock Input
One clock circuit will usually drive multiple AD104s (typically
4, 8 or 16 units). If many AD104s are to be operated from a
single source, external bypass capacitors should be used with a
value of at least 1
F for every five isolators used. Place the
capacitor as close as possible to the clock driver.
Input Configuration
The AD102 and AD104 are very easy to use in a wide range of
applications. The input stage connections (IN+, IN, FB,
ICOM) approximate a "vanilla" type op amp input and may for
all intents and purposes be treated as such. Most any typical cir-
cuit connection that is valid for a standard op amp can be
accommodated, so long as it is expected to perform within
the specifications herein (i.e., limited gain and bandwidth
parameters).
Figure 7 shows the most common input configuration, which is
unity gain operation. This configuration is appropriate where
the input signal is within the range of
5 V or where larger sig-
nals have been previously attenuated, usually by means of a tra-
ditional resistor divider technique.
ISOLATION
BARRIER
ICOM
AD102
OR
AD104
OUT HI
OUT LO
CLOCK IN
IN+
IN
FB
3
6
5
4
9
1
8
2k
(
SEE TEXT)
V
SIG
(
5V)
AMPLIFIER
AND
MODULATOR
V
OUT
(
5V)
7
2
COMMON
15VDC (AD102)
OR
CLOCK (AD104)
15VDC
Figure 7. Unity Gain Application
For gains larger than unity, the addition of a gain and feedback
resistor allows amplification of smaller signals up to a higher
level. Whenever practical, any low level signal should be ampli-
fied to meet a full
5 V output swing. This helps reduce the
effective output ripple contribution introduced to the original
signal during modulation, isolation and subsequent filtering as
seen at the output.
ISOLATION
BARRIER
ICOM
AD102
OR
AD104
OUT HI
OUT LO
IN+
IN
FB
3
6
5
4
9
1
2k
V
SIG
(
5V)
AMPLIFIER
AND
MODULATOR
V
OUT
(
5V)
R
G
R
F
100pF
V
OUT
= V
SIG
x
(
1 +
)
R
G
R
F
R
F
20k
Figure 8. Input Connection for Gain > 1
When taking a gain of more than 5 V/V, addition of a 100 pF
capacitor is recommended; it is not needed at lower gains, but if
used will not adversely affect operation. Additionally, whenever
the isolation amplifier is not powered, a negative input voltage
of approximately 2 V may cause an input current to flow. If the
signal source can supply more than a few mA of current, a 2 k
limiting resistor in series with IN+ is recommended. This is es-
pecially advised when using AD102s as they may not power up
properly with a high input current present, (see Figures 7 and 8
for examples).
Synchronization
Since the AD104 operates from a common clock, synchroniza-
tion is inherent. AD102s will normally not interact to produce
beat frequencies even when mounted on 0.3 inch centers. Inter-
action may occur in very rare situations where a large number of
long, unshielded input cables are bundled together. In such
cases, shielded cable may be required or AD104s can be used.
For related information and application examples refer to the
AD202/AD204 and AD210 data sheets.