Datasheet AD8428 (Analog Devices)
| Manufacturer | Analog Devices |
| Description | Low Noise, Low Gain Drift, G = 2000 Instrumentation Amplifier |
| Pages / Page | 20 / 1 — Low Noise, Low Gain Drift, G = 2000. Instrumentation Amplifier. Data … |
| Revision | A |
| File Format / Size | PDF / 363 Kb |
| Document Language | English |
Low Noise, Low Gain Drift, G = 2000. Instrumentation Amplifier. Data Sheet. AD8428. FEATURES. FUNCTIONAL BLOCK DIAGRAM
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Low Noise, Low Gain Drift, G = 2000 Instrumentation Amplifier Data Sheet AD8428 FEATURES FUNCTIONAL BLOCK DIAGRAM Fixed gain of 2000 +V –FIL S Access to internal nodes provides flexibility –IN Low noise: 1.5 nV/√Hz input voltage noise 6kΩ 6kΩ 120kΩ High accuracy dc performance 3kΩ Gain drift: 5 ppm/°C Offset drift: 0.3 μV/°C 30.15Ω OUT Gain accuracy: 0.05% 3kΩ CMRR: 140 dB min 6kΩ 6kΩ 120kΩ REF Excellent ac specifications +IN AD8428 Bandwidth: 3.5 MHz
01 0 1-
Slew rate: 40 V/μs –V
73
S +FIL
09
Power supply range: ±4 V to ±18 V
Figure 1.
8-lead SOIC package ESD protection: 5000 V (HBM) Table 1. Instrumentation Amplifiers by Category1 Temperature range for specified performance: General- Zero Military Low Low −40°C to +85°C Purpose Drift Grade Power Noise Operational up to 125°C
AD8220 AD8231 AD620 AD627 AD8428 AD8221 AD8290 AD621 AD623 AD8429
APPLICATIONS
AD8222 AD8293 AD524 AD8235
Sensor interface
AD8224 AD8553 AD526 AD8236
Medical instrumentation
AD8228 AD8556 AD624 AD8426
Patient monitoring
AD8295 AD8557 AD8226 AD8227 AD8420 1 See www.analog.com for the latest instrumentation amplifiers.
GENERAL DESCRIPTION
The AD8428 is one of the fastest instrumentation amplifiers The AD8428 is an ultralow noise instrumentation amplifier available. The circuit architecture is designed for high bandwidth designed to accurately measure tiny, high speed signals. It at high gain. The AD8428 uses a current feedback topology for delivers industry-leading gain accuracy, noise, and bandwidth. the initial preamplifier gain stage of 200, followed by a difference amplifier stage of 10. This architecture results in a 3.5 MHz All gain setting resistors for the AD8428 are internal to the part bandwidth at a gain of 2000 for an equivalent gain bandwidth and are precisely matched. Care is taken in both the chip pinout product of 7 GHz. and layout. This results in excellent gain drift and quick settling to the final gain value after the part is powered on. The AD8428 pinout allows access to internal nodes between the first and second stages. This feature can be useful for modifying The high CMRR of the AD8428 prevents unwanted signals the frequency response between the two amplification stages, from corrupting the signal of interest. The pinout of the AD8428 thereby preventing unwanted signals from contaminating the is designed to avoid parasitic capacitance mismatches that can output results. degrade CMRR at high frequencies. The performance of the AD8428 is specified over the industrial temperature range of −40°C to +85°C. It is available in an 8-lead plastic SOIC package.
Rev. A Information furnished by Analog Devices is b elieved to be accurate and reliable. However, no responsibility is assumed by Analog Devices fo r its use, nor for any infringements of patents or other One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. 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. Tel: 781.329.4700 www.analog.com Trademarks and registered trademarks are the property of their respective owners. Fax: 781.461.3113 ©2011–2012 Analog Devices, Inc. Al l rights reserved.
Document Outline FEATURES APPLICATIONS FUNCTIONAL BLOCK DIAGRAM GENERAL DESCRIPTION TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS THEORY OF OPERATION ARCHITECTURE FILTER TERMINALS REFERENCE TERMINAL INPUT VOLTAGE RANGE LAYOUT Common-Mode Rejection Ratio over Frequency Power Supplies and Grounding Reference Pin INPUT BIAS CURRENT RETURN PATH INPUT PROTECTION IMAX Input Voltages Beyond the Rails Large Differential Input Voltage at High Gain RADIO FREQUENCY INTERFERENCE (RFI) CALCULATING THE NOISE OF THE INPUT STAGE Source Resistance Noise Voltage Noise of the Instrumentation Amplifier Current Noise of the Instrumentation Amplifier Total Noise Density Calculation APPLICATIONS INFORMATION EFFECT OF PASSIVE NETWORK ACROSS THE FILTER TERMINALS CIRCUITS USING THE FILTER TERMINALS Setting the Amplifier to Different Gains Low-Pass Filter Notch Filter Extracting the Common-Mode Voltage of the Input OUTLINE DIMENSIONS ORDERING GUIDE
Low Noise, Low Gain Drift, G = 2000 Instrumentation Amplifier Data Sheet AD8428 FEATURES FUNCTIONAL BLOCK DIAGRAM Fixed gain of 2000 +V –FIL S Access to internal nodes provides flexibility –IN Low noise: 1.5 nV/√Hz input voltage noise 6kΩ 6kΩ 120kΩ High accuracy dc performance 3kΩ Gain drift: 5 ppm/°C Offset drift: 0.3 μV/°C 30.15Ω OUT Gain accuracy: 0.05% 3kΩ CMRR: 140 dB min 6kΩ 6kΩ 120kΩ REF Excellent ac specifications +IN AD8428 Bandwidth: 3.5 MHz
01 0 1-
Slew rate: 40 V/μs –V
73
S +FIL
09
Power supply range: ±4 V to ±18 V
Figure 1.
8-lead SOIC package ESD protection: 5000 V (HBM) Table 1. Instrumentation Amplifiers by Category1 Temperature range for specified performance: General- Zero Military Low Low −40°C to +85°C Purpose Drift Grade Power Noise Operational up to 125°C
AD8220 AD8231 AD620 AD627 AD8428 AD8221 AD8290 AD621 AD623 AD8429
APPLICATIONS
AD8222 AD8293 AD524 AD8235
Sensor interface
AD8224 AD8553 AD526 AD8236
Medical instrumentation
AD8228 AD8556 AD624 AD8426
Patient monitoring
AD8295 AD8557 AD8226 AD8227 AD8420 1 See www.analog.com for the latest instrumentation amplifiers.
GENERAL DESCRIPTION
The AD8428 is one of the fastest instrumentation amplifiers The AD8428 is an ultralow noise instrumentation amplifier available. The circuit architecture is designed for high bandwidth designed to accurately measure tiny, high speed signals. It at high gain. The AD8428 uses a current feedback topology for delivers industry-leading gain accuracy, noise, and bandwidth. the initial preamplifier gain stage of 200, followed by a difference amplifier stage of 10. This architecture results in a 3.5 MHz All gain setting resistors for the AD8428 are internal to the part bandwidth at a gain of 2000 for an equivalent gain bandwidth and are precisely matched. Care is taken in both the chip pinout product of 7 GHz. and layout. This results in excellent gain drift and quick settling to the final gain value after the part is powered on. The AD8428 pinout allows access to internal nodes between the first and second stages. This feature can be useful for modifying The high CMRR of the AD8428 prevents unwanted signals the frequency response between the two amplification stages, from corrupting the signal of interest. The pinout of the AD8428 thereby preventing unwanted signals from contaminating the is designed to avoid parasitic capacitance mismatches that can output results. degrade CMRR at high frequencies. The performance of the AD8428 is specified over the industrial temperature range of −40°C to +85°C. It is available in an 8-lead plastic SOIC package.
Rev. A Information furnished by Analog Devices is b elieved to be accurate and reliable. However, no responsibility is assumed by Analog Devices fo r its use, nor for any infringements of patents or other One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. 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. Tel: 781.329.4700 www.analog.com Trademarks and registered trademarks are the property of their respective owners. Fax: 781.461.3113 ©2011–2012 Analog Devices, Inc. Al l rights reserved.
Document Outline FEATURES APPLICATIONS FUNCTIONAL BLOCK DIAGRAM GENERAL DESCRIPTION TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS THEORY OF OPERATION ARCHITECTURE FILTER TERMINALS REFERENCE TERMINAL INPUT VOLTAGE RANGE LAYOUT Common-Mode Rejection Ratio over Frequency Power Supplies and Grounding Reference Pin INPUT BIAS CURRENT RETURN PATH INPUT PROTECTION IMAX Input Voltages Beyond the Rails Large Differential Input Voltage at High Gain RADIO FREQUENCY INTERFERENCE (RFI) CALCULATING THE NOISE OF THE INPUT STAGE Source Resistance Noise Voltage Noise of the Instrumentation Amplifier Current Noise of the Instrumentation Amplifier Total Noise Density Calculation APPLICATIONS INFORMATION EFFECT OF PASSIVE NETWORK ACROSS THE FILTER TERMINALS CIRCUITS USING THE FILTER TERMINALS Setting the Amplifier to Different Gains Low-Pass Filter Notch Filter Extracting the Common-Mode Voltage of the Input OUTLINE DIMENSIONS ORDERING GUIDE
