Datasheet AD202, AD204 (Analog Devices)

a
Low Cost, Miniature Isolation Amplifiers AD202/AD204 FEATURES PRODUCT HIGHLIGHTS Small Size: 4 Channels/lnch
The AD202 and AD204 are full-featured isolators offering
Low Power: 35 mW (AD204)
numerous benefits to the user:
High Accuracy: 0.025% Max Nonlinearity (K Grade) Small Size:
The AD202 and AD204 are available in SIP and
High CMR: 130 dB (Gain = 100 V/V)
DIP form packages. The SIP package is just 0.25" wide, giving
Wide Bandwidth: 5 kHz Full-Power (AD204)
the user a channel density of four channels per inch. The isolation
High CMV Isolation: 2000 V pk Continuous (K Grade)
barrier is positioned to maximize input to output spacing. For
(Signal and Power)
applications requiring a low profile, the DIP package provides a
Isolated Power Outputs
height of just 0.350".
Uncommitted Input Amplifier High Accuracy:
With a maximum nonlinearity of ± 0.025%
APPLICATIONS
for the AD202K/AD204K (± 0.05% for the AD202J/AD204J)
Multichannel Data Acquisition
and low drift over temperature, the AD202 and AD204 provide
Current Shunt Measurements
high isolation without loss of signal integrity.
Motor Controls Process Signal Isolation Low Power:
Power consumption of 35 mW (AD204) and
High Voltage Instrumentation Amplifier
75 mW (AD202) over the full signal range makes these isolators ideal for use in applications with large channel counts or tight
GENERAL DESCRIPTION
power budgets. The AD202 and AD204 are general purpose, two-port, trans-
Wide Bandwidth:
The AD204’s full-power bandwidth of 5 kHz former-coupled isolation amplifiers that may be used in a broad makes it useful for wideband signals. It is also effective in appli- range of applications where input signals must be measured, cations like control loops, where limited bandwidth could result processed, and/or transmitted without a galvanic connection. in instability. These industry standard isolation amplifiers offer a complete isolation function, with both signal and power isolation provided
Excellent Common-Mode Performance:
The AD202K/ for in a single compact plastic SIP or DIP style package. The AD204K provide ±2000 V pk continuous common-mode isola- primary distinction between the AD202 and the AD204 is that tion, while the AD202J/AD204J provide ±1000 V pk continuous the AD202 is powered directly from a 15 V dc supply while the common-mode isolation. All models have a total common-mode AD204 is powered by an externally supplied clock, such as the input capacitance of less than 5 pF inclusive of power isolation. recommended AD246 Clock Driver. 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 The AD202 and AD204 provide total galvanic isolation between (2 mA maximum). the input and output stages of the isolation amplifier through the use of internal transformer-coupling. The functionally com-
Flexible Input:
An uncommitted op amp is provided at the plete AD202 and AD204 eliminate the need for an external, input of all models. This provides buffering and gain as required, user-supplied dc-to-dc converter. This permits the designer and facilitates many alternative input functions including filtering, to minimize the necessary circuit overhead and consequently summing, high voltage ranges, and current (transimpedance) input. reduce the overall design and component costs.
Isolated Power:
The AD204 can supply isolated power of The design of the AD202 and AD204 emphasizes maximum ±7.5 V at 2 mA. This is sufficient to operate a low-drift input flexibility and ease of use, including the availability of an preamp, provide excitation to a semiconductor strain gage, or uncommitted op amp on the input stage. They feature a bipolar power any of a wide range of user-supplied ancillary circuits. ±5 V output range, an adjustable gain range of from 1V/V to The AD202 can supply ±7.5 V at 0.4 mA, which is sufficient to 100 V/V, ± 0.025% max nonlinearity (K grade), 130 dB of operate adjustment networks or low power references and op CMR, and the AD204 consumes a low 35 mW of power. amps, or to provide an open-input alarm. The functional block diagrams can be seen in Figures 1a and 1b. REV. D 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
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Document Outline FEATURES APPLICATIONS GENERAL DESCRIPTION PRODUCT HIGHLIGHTS SPECIFICATIONS AD246–SPECIFICATIONS AD246 Pin Designations PIN DESIGNATIONS ORDERING GUIDE DIFFERENCES BETWEEN THE AD202 AND AD204 INSIDE THE AD202 AND AD204 USING THE AD202 AND AD204 Powering the AD204 AD246 Clock Drive Input Configurations Adjustments Common-Mode Performance Dynamics and Noise Using Isolated Power Operation at Reduced Signal Swing PCB Layout for Multichannel Applications Synchronization APPLICATIONS EXAMPLES Low Level Sensor Inputs Process Current Input with Offset High Compliance Current Source Motor Control Isolator. Floating Current Source/Ohmmeter Photodiode Amplifier OUTLINE DIMENSIONS Revision History