AD8429ARZ - 1nV/√Hz Ultra-Low Noise In-Amp | Analog Devices
MPN： AD8429ARZ ✓ 啟用中AD8429ARZ 概覽
An instrumentation amplifier (in-amp) is a type of differential amplifier that amplifies the difference between two input signals while rejecting common-mode voltages. It is a specialized variant of an operational amplifier, optimized for high input impedance, high common-mode rejection ratio (CMRR), and precise gain setting with a single external resistor. In-amps are essential in precision measurement systems, bridging the gap between small sensor outputs and the input range of ADCs.
Key features of the AD8429 include a fixed gain of 2000 with access to internal nodes for flexibility, low input voltage noise of 1 nV/√Hz, and high CMRR of 140 dB minimum. It also offers excellent DC accuracy with gain drift of 5 ppm/°C, offset drift of 0.3 µV/°C, and gain accuracy of 0.05%. The device operates over a wide supply range and is specified for -40°C to +125°C, ensuring reliable performance in harsh environments.
The AD8429 uses a three-op-amp topology with laser-trimmed thin-film resistors, achieving high precision and stability. Its high CMRR increases with gain, effectively rejecting common-mode interference from power lines and other sources. The REF pin allows level shifting for single-supply operation, and the device is protected with ESD diodes on the inputs.
Typical applications include precision data acquisition, medical instrumentation (ECG, EEG), strain gauge and bridge amplifiers, and industrial process control. The ultralow noise and high CMRR make it particularly suited for measuring microvolt-level signals in noisy environments.
When designing with the AD8429, ensure proper grounding and shielding to minimize noise pickup. The REF pin should be driven with a low-impedance source (<1 Ω) for best performance, and input protection resistors may be needed for overvoltage conditions.
直接替換替代品，適用於 AD8429ARZ — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： AD8429ARZ （相同外形與佔位） — 差異在於 Operating Temperature Range, Package, Amplifier Type, Gain Range, Input Bias Current.
AD8429BRZ
✅ 直接替換聯絡詢價
查看資料表 →AD8429ARZ-R7
✅ 直接替換📋 參考替代品（不在目錄中）
AD8429BRZ-R7
✅ 直接替換📋 參考替代品（不在目錄中）
AD8429ARZ 最大額定值與電氣特性
| Device Type | Instrumentation Amplifier |
| Number of Channels | 1 |
| Input Voltage Noise | 1 nV/√Hz |
| CMRR (Minimum) | 140 dB |
| Gain (Fixed) | 2000 |
| Gain Drift | 5 ppm/°C |
| Offset Drift | 0.3 µV/°C |
| Gain Accuracy | 0.05% |
| 3 dB Bandwidth | 15 MHz |
| 工作溫度範圍 | -40°C to +125°C |
| 封裝 | 8-SOIC |
| 安裝方式 | Surface Mount |
| 腳位數 | 8 |
| RoHS 狀態 | Compliant |
AD8429ARZ 腳位配置
| 腳位 1 | -IN — Inverting input |
| 腳位 2 | RG — Gain setting resistor connection |
| 腳位 3 | RG — Gain setting resistor connection |
| 腳位 4 | -VS — Negative supply |
| 腳位 5 | REF — Reference voltage for level shifting |
| 腳位 6 | OUT — Output |
| 腳位 7 | +VS — Positive supply |
| 腳位 8 | +IN — Non-inverting input |
典型應用
AD8429ARZ 適用於 6 應用s: Precision Data Acquisition, Medical Instrumentation (ECG/EEG), Strain Gauge and Bridge Amplifiers, Industrial Process Control, Audio Test and Measurement, Vibration Monitoring.
Precision Data Acquisition
The AD8429ARZ's ultralow noise of 1 nV/√Hz and high CMRR of 140 dB make it ideal for precision data acquisition systems. It accurately amplifies small sensor signals while rejecting common-mode noise, ensuring high-resolution measurements. The wide temperature range of -40°C to +125°C allows use in industrial environments. Its fixed gain of 2000 simplifies design, and the REF pin enables level shifting for single-supply ADCs.
推薦
Medical Instrumentation (ECG/EEG)
In medical instrumentation like ECG and EEG, the AD8429ARZ excels due to its ultralow noise and high CMRR, which are critical for capturing microvolt-level biopotential signals. The 1 nV/√Hz noise ensures minimal signal degradation, while the 140 dB CMRR rejects 50/60 Hz power line interference. The wide temperature range and small SOIC package make it suitable for portable and wearable devices. The REF pin allows easy level shifting for single-supply operation.
推薦
Strain Gauge and Bridge Amplifiers
The AD8429ARZ is well-suited for strain gauge and bridge amplifier applications due to its high gain accuracy of 0.05% and low offset drift of 0.3 µV/°C. It provides precise amplification of bridge outputs, which are typically in the millivolt range. The high CMRR of 140 dB rejects common-mode voltages from the bridge supply, ensuring accurate measurements. Its wide temperature range makes it ideal for industrial load cells and pressure sensors.
推薦
Industrial Process Control
In industrial process control, the AD8429ARZ provides reliable amplification of sensor signals in harsh environments. Its operating temperature range of -40°C to +125°C ensures performance in extreme conditions. The high CMRR of 140 dB rejects interference from motors and power lines, while the low noise of 1 nV/√Hz preserves signal integrity. The fixed gain of 2000 simplifies calibration, and the device's robustness makes it suitable for 4-20 mA loop transmitters.
推薦
Audio Test and Measurement
The AD8429ARZ's ultralow noise and high bandwidth of 15 MHz make it suitable for audio test and measurement equipment. It can accurately amplify low-level audio signals without adding significant noise, preserving the dynamic range. The high CMRR ensures rejection of common-mode hum and interference. The device's precision and stability make it ideal for audio analyzers and distortion measurement systems.
推薦
Vibration Monitoring
For vibration monitoring, the AD8429ARZ provides the low noise and high CMRR needed to amplify signals from piezoelectric accelerometers. The 1 nV/√Hz noise ensures that small vibrations are not masked, while the 140 dB CMRR rejects interference from machinery. The wide temperature range allows deployment in industrial settings. The fixed gain of 2000 simplifies signal conditioning, and the REF pin enables interface with single-supply ADCs.
推薦
推薦產品摘要
工程參考資料，適用於 AD8429ARZ — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | AD8429BRZ | AD8221ARZ | AD620ARZ |
|---|---|---|---|---|
| Package | 8-SOIC | 8-SOIC | 8-SOIC | 8-SOIC |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Input Voltage Noise | 1 nV/√Hz | 1 nV/√Hz | 8 nV/√Hz | 9 nV/√Hz |
| CMRR (Minimum) | 140 dB | 140 dB | 90 dB | 100 dB |
| Gain | 2000 (fixed) | 2000 (fixed) | 1 to 1000 (set by resistor) | 1 to 1000 (set by resistor) |
| 3 dB Bandwidth | 15 MHz | 15 MHz | 825 kHz | 120 kHz |
| Operating Temperature Range | -40°C to +125°C | -40°C to +125°C | -40°C to +85°C | -40°C to +85°C |
主要差異化特點
- Ultralow input voltage noise of 1 nV/√Hz (對比AD8221ARZ)
- High CMRR of 140 dB minimum (對比AD620ARZ)
- Wide temperature range of -40°C to +125°C (對比AD8221ARZ)
設計說明
For optimal noise performance, use a solid ground plane and keep input traces short and shielded. Place decoupling capacitors (0.1 µF and 10 µF) close to the supply pins. Avoid routing digital signals near the input pins to prevent coupling.
The REF pin must be driven with a low-impedance source (<1 Ω) to maintain CMRR. Do not exceed the REF pin voltage beyond ±0.3 V of the supplies, as it is protected with ESD diodes. Ensure input voltages stay within the common-mode range to avoid output saturation.
The AD8429ARZ in an 8-SOIC package has a typical thermal resistance (θJA) of around 100°C/W. For high supply voltages and output currents, ensure adequate PCB copper area for heat dissipation. In most precision measurement applications, power dissipation is low, but verify worst-case conditions.
合規資訊
RoHS compliant per distributor data. No AEC-Q100 qualification indicated.
