AD8629ARZ-REEL7 - Dual Zero-Drift Op Amp | Analog Devices
MPN： AD8629ARZ-REEL7 ✓ 啟用中AD8629ARZ-REEL7 概覽
Zero-drift amplifiers, also known as auto-zero or chopper-stabilized amplifiers, are a class of operational amplifiers that continuously correct their input offset voltage and drift, achieving near-zero offset and drift over temperature and time. They are essential in precision measurement systems where accuracy is paramount, such as in sensor signal conditioning, medical instrumentation, and precision current sensing. The AD8629ARZ-REEL7 fits into the hierarchy of operational amplifiers, specifically precision amplifiers, and is a key component in analog signal processing chains.
Key features include a maximum offset voltage of 1 µV, a temperature drift of 0.005 µV/°C, and a bias current of 30 pA. The amplifier provides a gain bandwidth product of 2.5 MHz and a slew rate of 1 V/µs, with a low noise density of 22 nV/√Hz. It also features a high open-loop gain of 130 dB and a power supply rejection ratio of 130 dB, ensuring stable performance in noisy environments. The rail-to-rail input and output capability allows maximum dynamic range in low-voltage applications.
Technically, the AD8629 uses a proprietary auto-zero topology that reduces digital switching noise, a common issue in chopper-stabilized amplifiers. This results in a clean output with minimal ripple, making it suitable for high-resolution ADC drivers and precision filters. The device is fully specified over the industrial temperature range of -40°C to +125°C, ensuring reliable operation in harsh environments.
Typical applications include precision instrumentation, thermocouple and RTD signal conditioning, load cell amplifiers, and battery-powered portable devices where low power consumption and high accuracy are critical. The dual-channel configuration allows for compact designs, reducing board space and component count.
When designing with the AD8629ARZ-REEL7, ensure proper decoupling with 0.1 µF capacitors close to the supply pins to maintain stability. The rail-to-rail input stage requires careful attention to common-mode voltage limits to avoid phase reversal. For best performance, use a solid ground plane and minimize parasitic capacitance on the inputs.
直接替換替代品，適用於 AD8629ARZ-REEL7 — 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： AD8629ARZ-REEL7 （相同外形與佔位） — 差異在於 Package, Amplifier Type, RoHS Status, Number of Channels, Operating Temperature Range.
AD8629ARZ
✅ 直接替換聯絡詢價
查看資料表 →AD8629WARZ-R7
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
AD8629TRZ-EP-R7
✅ 直接替換📋 參考替代品（不在目錄中）
OPA2335AIDR
✅ 直接替換聯絡詢價
查看資料表 →ADA4522-2ARZ
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →AD8629ARZ-REEL7 最大額定值與電氣特性
| Number of Channels | 2 |
| Gain Bandwidth Product | 2.5 MHz |
| Slew Rate | 1 V/µs |
| Maximum Offset Voltage | 1 µV |
| Offset Voltage Drift | 0.005 µV/°C |
| Bias Current | 30 pA |
| 雜訊密度 | 22 nV/√Hz |
| Open-Loop Gain | 130 dB |
| Power Supply Rejection Ratio | 130 dB |
| Supply Voltage (Single) | 2.7 V to 5 V |
| Supply Voltage (Dual) | ±1.35 V to ±2.5 V |
| Rail-to-Rail Input/Output | Yes |
| 工作溫度範圍 | -40°C to +125°C |
| 封裝 | 8-SOIC |
| 安裝類型 | Surface Mount |
| MSL 等級 | 1 (Unlimited) |
| RoHS 狀態 | Compliant |
AD8629ARZ-REEL7 腳位配置
| 腳位 1 | OUT A — Output of amplifier A |
| 腳位 2 | -IN A — Inverting input of amplifier A |
| 腳位 3 | +IN A — Non-inverting input of amplifier A |
| 腳位 4 | V- — Negative supply voltage |
| 腳位 5 | +IN B — Non-inverting input of amplifier B |
| 腳位 6 | -IN B — Inverting input of amplifier B |
| 腳位 7 | OUT B — Output of amplifier B |
| 腳位 8 | V+ — Positive supply voltage |
典型應用
AD8629ARZ-REEL7 適用於 6 應用s: Precision Instrumentation, Medical Instrumentation, Sensor Signal Conditioning, Battery-Powered Portable Devices, ADC Driver, Load Cell Amplifier.
Precision Instrumentation
The AD8629ARZ-REEL7's ultralow offset voltage (1 µV) and drift (0.005 µV/°C) make it ideal for precision instrumentation amplifiers. In a typical bridge sensor interface, the dual op amp can be configured as a two-op-amp instrumentation amplifier, providing high common-mode rejection and accurate measurement of small differential signals. The rail-to-rail output allows direct connection to ADCs without additional level shifting, simplifying the signal chain. The low bias current (30 pA) minimizes errors when interfacing with high-impedance sensors, ensuring measurement accuracy over the industrial temperature range.
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Medical Instrumentation
In medical devices such as patient monitors and diagnostic equipment, the AD8629ARZ-REEL7 provides the precision and low noise required for biosignal amplification. Its zero-drift architecture ensures stable DC performance over time and temperature, critical for ECG and EEG signal conditioning. The low supply voltage operation (2.7 V to 5 V) is compatible with battery-powered portable medical devices. The dual-channel configuration allows for compact designs, reducing board space in space-constrained medical instruments. The high open-loop gain (130 dB) ensures linearity in precision measurement paths.
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Sensor Signal Conditioning
The AD8629ARZ-REEL7 excels in sensor signal conditioning for thermocouples, RTDs, and load cells. Its ultralow offset and drift eliminate the need for frequent calibration, reducing maintenance in industrial systems. The low bias current (30 pA) is ideal for high-impedance sensors, preventing loading errors. The rail-to-rail input and output allow the amplifier to handle signals near the supply rails, maximizing dynamic range. In a typical RTD interface, the dual op amp can be used for excitation and amplification, providing a complete solution in a single package.
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Battery-Powered Portable Devices
For battery-powered portable devices, the AD8629ARZ-REEL7 offers low power consumption and operation down to 2.7 V, extending battery life. The rail-to-rail output maximizes signal swing in low-voltage systems, improving dynamic range. The dual-channel configuration reduces component count and board space, ideal for compact handheld instruments. The zero-drift performance ensures accuracy over the battery discharge cycle, maintaining measurement integrity. Applications include portable gas detectors, handheld multimeters, and wearable health monitors.
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ADC Driver
The AD8629ARZ-REEL7 is well-suited as an ADC driver for high-resolution converters. Its low noise (22 nV/√Hz) and high open-loop gain (130 dB) ensure minimal distortion and accurate signal transfer. The rail-to-rail output can drive the full-scale input range of ADCs, maximizing resolution. The zero-drift architecture eliminates offset errors that could otherwise degrade ADC performance. In a typical SAR ADC interface, the dual op amp can be used for anti-aliasing filtering and buffering, providing a clean signal to the converter.
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Load Cell Amplifier
In load cell and weigh scale applications, the AD8629ARZ-REEL7 provides the precision and stability required for accurate weight measurement. The ultralow offset voltage (1 µV) and drift (0.005 µV/°C) minimize zero drift, ensuring consistent readings over temperature. The low bias current (30 pA) reduces errors from the bridge's high output impedance. The dual op amp can be configured as a differential amplifier to reject common-mode noise, improving measurement accuracy. The rail-to-rail output allows direct interface to ADCs, simplifying the design.
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推薦產品摘要
工程參考資料，適用於 AD8629ARZ-REEL7 — 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 | AD8629ARZ | AD8629WARZ-R7 | OPA2335AIDR | ADA4522-2ARZ |
|---|---|---|---|---|---|
| Package | 8-SOIC | 8-SOIC | 8-SOIC | 8-SOIC | 8-SOIC |
| Brand | Analog Devices | Analog Devices | Analog Devices | Texas Instruments | Analog Devices |
| Number of Channels | 2 | 2 | 2 | 2 | 2 |
| Gain Bandwidth Product | 2.5 MHz | 2.5 MHz | 2.5 MHz | 2 MHz | 2.7 MHz |
| Maximum Offset Voltage | 1 µV | 1 µV | 1 µV | 1 µV | 2.5 µV |
| Offset Voltage Drift | 0.005 µV/°C | 0.005 µV/°C | 0.005 µV/°C | 0.02 µV/°C | 0.002 µV/°C |
| Bias Current | 30 pA | 30 pA | 30 pA | 70 pA | 50 pA |
| Noise Density | 22 nV/√Hz | 22 nV/√Hz | 22 nV/√Hz | 12 nV/√Hz | 5.8 nV/√Hz |
主要差異化特點
- Ultralow offset voltage and drift (對比OPA2335AIDR)
- Lower bias current (對比OPA2335AIDR)
- Same-brand family compatibility (對比ADA4522-2ARZ)
設計說明
The AD8629ARZ-REEL7 operates from 2.7 V to 5 V single supply or ±1.35 V to ±2.5 V dual supply. Ensure the supply voltage is within the specified range to avoid damage. Use 0.1 µF ceramic capacitors close to the V+ and V- pins for decoupling, and a 10 µF bulk capacitor for low-frequency stability. The low quiescent current makes it suitable for battery-powered designs, but verify the supply current in the datasheet for your specific configuration.
For optimal performance, place the AD8629ARZ-REEL7 on a solid ground plane and minimize parasitic capacitance on the input pins. Keep traces short and direct, especially for high-impedance inputs. Use guard rings around the input pins to reduce leakage currents, which is critical for achieving the low bias current (30 pA) specification. Ensure proper thermal relief for the SOIC package to avoid overheating in high-temperature environments.
Avoid exceeding the common-mode input voltage range, which is rail-to-rail, but ensure inputs do not go beyond the supply rails to prevent phase reversal. The auto-zero architecture may introduce a small clock noise at the switching frequency; use a low-pass filter if this is a concern. Do not leave unused inputs floating; tie them to a suitable voltage to prevent oscillation. Always refer to the datasheet's typical application circuits for guidance.
合規資訊
RoHS compliant per Analog Devices product page. Not AEC-Q100 qualified; use AD8629WARZ-R7 for automotive.
