AD7789BRM-REEL - 24-bit Sigma-Delta ADC | Analog Devices
部品番号: AD7789BRM-REEL ✓ 生産中| 数量 | 単価 | 小計 |
|---|---|---|
| 1 | $9.42 | $9.42 |
| 10 | $8.56 | $85.60 |
| 100 | $7.18 | $718.00 |
| 500 | $6.27 | $3,135.00 |
| 1,000 | $5.61 | $5,610.00 |
| 2,500 | $5.05 | $12,625.00 |
AD7789BRM-REEL 概要
A sigma-delta ADC is a type of oversampling converter that uses a 1-bit modulator running at many times the output data rate combined with digital filtering to obtain high effective resolution at low input bandwidths. Within the broader signal-chain taxonomy, the AD7789 sits at the precision slow-rate tier alongside other low-frequency measurement converters such as successive-approximation and 24-bit audio ADCs; it is typically used ahead of or in place of a discrete instrumentation amplifier-plus-ADC chain because the modulator front-end already provides high common-mode rejection.
Key differentiating specifications include 1.5 µV RMS noise, 19-bit peak-to-peak output resolution (approximately 21.5 bits effective after the digital filter settles), and 3.5 ppm typical integral non-linearity (INL). The 2.5 V to 5.25 V single-supply operating range, 75 µA typical operating current, and integrated voltage reference simplify the bill of materials in compact designs, eliminating the need for external clock or reference circuitry in many applications.
The device's architecture is built around a chopper-stabilized switched-capacitor modulator followed by an internal digital SINC³/SINC⁴-type filter. Chopper stabilization removes 1/f drift and DC-offset errors, allowing the converter to achieve noise and drift specifications near the theoretical limits of its resolution. The integrated post-processing digital filter automatically produces simultaneous 60 Hz / 50 Hz rejection when the output data rate falls in the 13–16.6 Hz region.
Typical applications include weigh scales, thermocouple cold-junction compensation systems, industrial process-control loops, portable instrumentation, and gas or blood-chemistry analyzers that demand battery-friendly operation. In each case the part replaces bulkier discrete ADC plus op-amp signal conditioning with a single MSOP-10 footprint.
One critical design consideration is that the AD7789 is intended for low-bandwidth signals - its 16.6 Hz output data rate cannot service audio or vibration analysis. Engineers should also remember that the LSB size depends on the selected gain and reference value, so calibration routines should account for the chosen full-scale range rather than assuming a fixed code width.
This page consolidates Analog Devices datasheet information with distributor pricing, same-package drop-in alternatives such as the AD7788 (16-bit), and practical design notes not found in the bare datasheet.
ドロップイン代替品: AD7789BRM-REEL — 同一パッケージでピン互換。PCBの作り直しが必要な異なるパッケージの部品は除外されています。
クイック比較ツール — 並列比較する代替部品を選択:
AD7788BRM-REEL
✅ ドロップイン📋 参考代替品（カタログ未掲載）
AD7788BRM
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AD7789BRM
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AD7789BRMZ-REEL
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AD7789BRMZ
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AD7787BRMZ
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AD7787BRM-REEL7
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AD7789BRM-REEL 最大定格＆電気的特性
| Manufacturer | Analog Devices |
| 分解能 | 24-bit (AD7789) / 19-bit p-p output (21.5 bits effective) |
| Number of Channels | 1 differential input |
| Converter Type | Sigma-Delta (∑-∆) ADC |
| Supply Voltage Range | 2.5 V to 5.25 V single supply |
| Operating Current | 75 µA typical (max), normal mode |
| Power-Down Current | 1 µA maximum |
| RMS Noise | 1.5 µV |
| Integral Nonlinearity (INL) | 3.5 ppm typical |
| Output Data Rate | 16.6 Hz (single conversion mode) |
| Mains Rejection | Simultaneous 50 Hz and 60 Hz |
| Internal Clock | Yes (no external clock required) |
| VDD Monitor Channel | Yes (integrated supply-sensing input) |
| Digital Interface | Serial (SPI / QSPI / MICROWIRE compatible) |
| パッケージ | 10-pin MSOP (RM) |
| 実装タイプ | Surface Mount |
| Reel Quantity | 2,500 (REEL) |
| Lead-Free / RoHS | RoHS compliant (BRM suffix indicates lead-free) |
AD7789BRM-REEL ピン構成
| ピン 1 | GND — Analog/digital ground |
| ピン 2 | REFIN+ — Positive reference input |
| ピン 3 | AIN+ — Positive analog input |
| ピン 4 | AIN- — Negative analog input |
| ピン 5 | VDD — Supply voltage (2.5 V to 5.25 V) |
| ピン 6 | DOUT — Serial data output (SPI/MICROWIRE) |
| ピン 7 | DIN — Serial data input (SPI/MICROWIRE) |
| ピン 8 | SCLK — Serial interface clock input |
| ピン 9 | CS — Chip select, active low |
| ピン 10 | RESET/PD — Reset / power-down input |
主な用途
AD7789BRM-REEL の用途: 6 件s: Weigh Scales and Load-Cell Front Ends, Thermocouple Cold-Junction Compensation, Industrial 4-20 mA Loop Transmitters, Blood and Gas-Chemistry Analyzers, Portable Instrumentation and Data Loggers, Bridge Sensor Signal Conditioning (Pressure, Strain, Force).
Weigh Scales and Load-Cell Front Ends
The AD7789BRM-REEL is purpose-built for direct connection to low-output bridge sensors in weigh scales and force-gauges. Its 1.5 µV RMS noise at a 16.6 Hz data rate directly constrains the smallest detectable weight step for a typical 2 mV/V strain-gage excitation, and the integrated chopper-stabilized modulator removes DC offset that drifts with temperature. Combined with its 75 µA operating current, the part powers an entire battery-backed kitchen scale, retail bench scale, or laboratory balance from a single coin cell. Pairing with a 2.5 V ratiometric reference tied to the load-cell excitation keeps gain error below 3.5 ppm typical INL.
おすすめ
Thermocouple Cold-Junction Compensation
The AD7789's chopper-stabilized input, integrated VDD monitor channel, and 50/60 Hz simultaneous rejection make it ideal for thermocouple input modules. The VDD monitor input can serve as a secondary low-bandwidth acquisition path for an external RTD or on-board silicon-junction temperature sensor that provides cold-junction compensation (CJC) for the thermocouple itself. The 24-bit noise floor reads µV-level e.m.f. signals with sub-degree-C stability, while the 1 µA power-down current preserves battery life in portable handheld calibrators and field thermocouple meters designed for HVAC and process surveys.
おすすめ
Industrial 4-20 mA Loop Transmitters
Industrial smart transmitters that digitize a bridge sensor output and modulate current on a 4-20 mA loop benefit from the AD7789's 2.5-5.25 V single-supply operation and 75 µA typical idle current. The internal sigma-delta modulator feeds process variables such as pressure, level and flow into a microcontroller that drives an external PWM-and-pass-MOSFET current modulator. The 19-bit peak-to-peak effective resolution enables calibration tables stored over the HART or IO-Link fieldbus, while the simultaneous 50/60 Hz rejection removes the worst side-effects of the loop's proximity to inverter-driven pumps and AC drives.
おすすめ
Blood and Gas-Chemistry Analyzers
Clinical analyzers that read ion-selective electrodes, dissolved-gas cells and other microvolt-output biomedical sensors depend on the AD7789's 1.5 µV RMS noise, 19-bit p-p resolution and ability to reject 50/60 Hz mains interference simultaneously. The small MSOP-10 footprint keeps PCB density low in benchtop electrochemistry cartridges, and 1 µA power-down preserves shelf life in disposable point-of-care cartridges. Designers can pair the ADC with low-leakage CMOS switches and an excitation reference to capture the small Nernstian voltages generated by pH, pO2 and pCO2 sensors with traceable accuracy.
おすすめ
Portable Instrumentation and Data Loggers
Battery-powered instrumentation such as hand-held multimeters, environmental monitors, and remote asset trackers benefit from the AD7789's 1 µA power-down current, integrated clock and integrated VDD monitor channel. These features reduce standby drain to absolute minima between measurements while allowing the host microcontroller to take readings exactly when triggered. The serial SPI/QSPI-compatible interface directly connects to low-cost MCUs such as the ADUC706x family, enabling time-stamped data logging of process variables like strain, temperature or battery voltage in field installations.
おすすめ
Bridge Sensor Signal Conditioning (Pressure, Strain, Force)
Strain-gage pressure transducers, strain-gage force cells and load pins all emit millivolt-level differential signals that the AD7789 is qualified to digitize directly. The chopper-stabilized input stage cancels 1/f noise, providing the long-term zero stability that transducer manufacturers require for class-A instrument calibration. Designers typically place a 2.5 V ratiometric reference on the excitation side so the digital reading of the load cell remains immune to supply drift, while still using the internal clock to avoid crystal-related EMI noise or reed-board failures in cost-sensitive OEM platforms.
おすすめ
おすすめ製品の概要
エンジニアリング参考データ: AD7789BRM-REEL — 比較、設計ガイダンス、コンプライアンス情報。
選定ガイド
代替品との比較
| パラメータ | この製品 | AD7788BRM-REEL | AD7788BRM | AD7789BRM | AD7789BRMZ-REEL | AD7789BRMZ | AD7787BRMZ | AD7787BRM-REEL7 |
|---|---|---|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | MSOP-10 (RM) | MSOP-10 (RM) | MSOP-10 (RM) | MSOP-10 (RM) | MSOP-10 (RM) | MSOP-10 (RM) | MSOP-10 (RM) | MSOP-10 (RM) |
| Resolution | 24-bit (19-bit p-p, 21.5-bit effective) | 16-bit | 16-bit | 24-bit (identical to REEL) | 24-bit (identical to this part) | 24-bit (identical to this part) | 16-bit | 16-bit |
| Output Data Rate | 16.6 Hz | 16.6 Hz | 16.6 Hz | 16.6 Hz | 16.6 Hz | 16.6 Hz | 9.5 / 105 Hz (programmable) | 9.5 / 105 Hz (programmable) |
| Internal Clock | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| RoHS / Lead-Free | RoHS compliant (BRM, lead-free compatible) | RoHS via BRM suffix | RoHS via BRM suffix | RoHS via BRM suffix | Fully RoHS / lead-free | Fully RoHS / lead-free | Fully RoHS / lead-free | RoHS via BRM suffix |
主な差別化要因
- 24-bit 19-bit peak-to-peak output versus 16-bit in the AD7788 （vs AD7788BRM-REEL)
- Integrated VDD monitor channel without extra pins （vs AD7787BRMZ)
- Same MSOP-10 footprint across all AD778x family members （vs AD7787BRMZ vs AD7788BRMZ)
設計ノート
Estimated: the AD7789BRM-REEL dissipates 75 µA at 5 V (~375 µW) plus reference and analog front-end current. When designing a battery-powered weigh-scale, total idle current must remain below ~120 µA to achieve multi-year life on a single 3.6 V lithium cell. Use the integrated 1 µA power-down mode by driving RESET/PD high between conversions so that the digital section does not actively load the supply while the host microcontroller is asleep.
Place the 0.1 µF decoupling capacitor within 2 mm of the VDD pin (pin 5) and connect directly to the adjacent GND pin using a short, low-inductance trace. Keep analog and digital routing on separate planes, and use a guard trace tied to GND around the high-impedance AIN+/AIN- pins to minimise leakage from board contamination. Avoid routing digital signals beneath the MSOP-10 footprint to keep digital noise away from the chopper-stabilized input pair.
Do not assume the LSB size is fixed across gain or reference settings; the 24-bit noise floor translates into a different effective step per count once the analog gain and reference voltage change. Always calibrate at the chosen operating gain. Also, the simultaneous 50/60 Hz rejection only holds at the 16.6 Hz single-conversion rate - selecting faster update rates (such as 13.1 Hz) reduces rejection at one of the two mains frequencies, which is critical for industrial environments near AC drives.
コンプライアンス情報
BRM suffix indicates lead-free MSOP-compatible packaging per Analog Devices' ordering code system. Z-suffix variants (BRMZ) provide explicit RoHS compliance with no material exemptions. Halogen-free status was not in the verified dataset and is flagged 'unknown'.
