AD7709BRU-REEL - 16-Bit Sigma-Delta ADC | Analog Devices
料号： AD7709BRU-REEL ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $12.45 | $12.45 |
| 10 | $11.3 | $113.00 |
| 100 | $10.15 | $1,015.00 |
| 500 | $9.1 | $4,550.00 |
| 1,000 | $8.25 | $8,250.00 |
AD7709BRU-REEL 概述
A sigma-delta ADC is a type of oversampling converter that uses a modulator followed by a digital decimation/sinc filter to achieve high effective resolution at low bandwidth. The AD7709 family belongs to the ADC IC product hierarchy (sigma-delta ADC -> ADC -> data converter -> signal chain IC -> semiconductor). It is functionally a complete analog front-end, integrating the modulator, filter, programmable gain amplifier (PGA), reference input switch, calibration logic, and a digital I/O port - a level of integration that historically required several discrete building blocks.
Key differentiating specifications include factory-calibrated gain and offset to within +/-0.007 % at 25 degrees C for the on-board references, true 16-bit performance with no missing codes, and integrated excitation current sources that can source 10 microamps, 100 microamps, or 1 milliamp to drive external sensors such as RTDs directly. The device also provides a 14-bit-compatible mode to trade resolution for higher throughput, supports self- and system calibration, and offers a PGA with programmable gains from 1 to 128.
Typical applications span industrial process control, weigh scale signal conditioning, temperature measurement with RTD or thermocouple front-ends, pressure and flow transmitters, and medical instrumentation where low-frequency precision is required. The integrated current sources make it especially attractive for transducer excitation applications that previously required separate driver ICs.
When designing with the AD7709BRU-REEL, use the on-chip programmable gain amplifier to match the input signal dynamic range to the reference voltage, and prefer the differential input mode for best common-mode rejection. Operate at the lowest practical output data rate to maximize noise-free resolution; the ADC's noise scales inversely with the -3 dB bandwidth of its digital filter. Consult the AD7709 datasheet full register map and application flow before committing to a final software sequence.
This page synthesizes distributor stock, drop-in compatible alternatives, and practical design notes not found in a single AD7709 datasheet excerpt alone, accelerating component evaluation for precision low-frequency signal chains.
直接替换替代料： AD7709BRU-REEL ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： AD7709BRU-REEL （相同外形与封装尺寸） ——差异在于 Package, Number of Input Channels, Resolution, RoHS Status, Data Interface.
快速对比工具——选择替代料号进行并排对比：
AD7709BRUZ
✅ 直接替换📋 参考替代料（不在目录中）
AD7709BRU-REEL7
✅ 直接替换📋 参考替代料（不在目录中）
AD7709ARUZ-REEL7
✅ 直接替换📋 参考替代料（不在目录中）
AD7708BRU-REEL
✅ 直接替换✓ 有现货
$6.19 / 个
查看数据手册 →AD7731BRU-REEL7
✅ 直接替换✓ 有现货
$11.75 / 个
查看数据手册 →AD7709BRU-REEL 最大额定值与电气特性
| 分辨率 | 16 bits |
| ADC Architecture | Sigma-Delta |
| Number of Input Channels | 2 (differential) or 4 (pseudo-differential) |
| Output Data Rate | Up to 105 sps |
| Analog Supply Voltage | 2.7 V to 5.25 V |
| Digital Supply Voltage | 2.7 V to 5.25 V |
| Programmable Gain | 1 to 128 |
| 输入电压范围 | -2.5 V to +2.5 V |
| Reference Input | Switchable, differential |
| Integrated Excitation Current Sources | 10 uA, 100 uA, 1 mA (switchable) |
| 工作温度 | -40 C to +85 C |
| 封装 | TSSOP-24 (RU) |
| 安装类型 | Surface Mount |
| Screening Level | Industrial |
AD7709BRU-REEL 引脚配置
| 引脚 1 | AVDD — Analog supply (2.7 V to 5.25 V) |
| 引脚 2 | REFIN1+ — Differential reference input 1, positive |
| 引脚 3 | REFIN1- — Differential reference input 1, negative |
| 引脚 4 | REFIN2+ — Differential reference input 2, positive |
| 引脚 5 | REFIN2- — Differential reference input 2, negative |
| 引脚 6 | IEXC1 — Excitation current source output 1 |
| 引脚 7 | IEXC2 — Excitation current source output 2 |
| 引脚 8 | AGND — Analog ground |
| 引脚 9 | AVDD — Analog supply (decoupling pin) |
| 引脚 10 | AIN1+ — Analog input channel 1, positive |
| 引脚 11 | AIN1- — Analog input channel 1, negative |
| 引脚 12 | AIN2+ — Analog input channel 2, positive |
| 引脚 13 | AIN2- — Analog input channel 2, negative |
| 引脚 14 | AIN3/PGA OUT — Analog input channel 3 or PGA output |
| 引脚 15 | AIN4/PGA IN- — Analog input channel 4 or PGA negative input |
| 引脚 16 | PGA IN+ — PGA positive input |
| 引脚 17 | PGA IN- — PGA negative input |
| 引脚 18 | DGND — Digital ground |
| 引脚 19 | CS — Chip select, active low |
| 引脚 20 | SCLK — Serial clock input |
| 引脚 21 | DOUT — Serial data output (DRDY) |
| 引脚 22 | DIN — Serial data input |
| 引脚 23 | IOVDD — Digital I/O supply |
| 引脚 24 | DGND — Digital ground |
典型应用
AD7709BRU-REEL 适用于 6 应用s: Industrial Weigh Scale Signal Conditioners, RTD Temperature Measurement Front-Ends, Pressure and Flow Transmitter Signal Chains, Medical Instrumentation and Patient Monitoring, Industrial Process Control and PLC Analog Modules, Data Acquisition Front-Ends for Test and Measurement.
Industrial Weigh Scale Signal Conditioners
The AD7709BRU-REEL is an excellent fit for industrial weigh scale signal conditioners because its 16-bit resolution combined with the on-chip PGA (gains 1 to 128) and integrated 1 mA excitation current source directly drives a load-cell bridge without external driver ICs. The sigma-delta converter's low effective noise floor at 10 sps output data rate yields effective resolution beyond 16 bits, sufficient for sub-gram weight measurements in bench and floor scales. The factory-calibrated gain (within +/-0.007 % at 25 C) eliminates the burden of manual gain trim, while the differential inputs reject 50 Hz/60 Hz mains pickup common in factory environments. The TSSOP-24 package fits inside compact load-cell transmitter enclosures where board space is at a premium.
推荐
RTD Temperature Measurement Front-Ends
The AD7709BRU-REEL excels in RTD-based temperature measurement systems because the integrated switchable current sources (10 uA, 100 uA, 1 mA) can be routed to drive the RTD excitation directly, minimizing self-heating when the 10 uA range is selected. The internal PGA (gains up to 128) amplifies the small mV-level RTD signal so that a 100 ohm Pt100 sensor produces measurable full-scale codes even at modest output data rates. The differential input topology rejects common-mode noise coupled onto long RTD leads in industrial plants, and the on-chip digital filter naturally attenuates 50 Hz/60 Hz mains interference. The wide 2.7 V-5.25 V supply range lets the same design operate from 3.3 V or 5 V rails, simplifying inventory in a multi-product family.
推荐
Pressure and Flow Transmitter Signal Chains
Pressure and flow transmitters benefit from the AD7709BRU-REEL's 16-bit resolution, differential input configuration, and on-chip PGA. The analog front end amplifies the millivolt-level bridge output of a differential pressure sensor to the converter's full-scale range, and the sigma-delta noise profile delivers stable readings without external filters. Pseudo-differential mode allows the four-channel version of the device to service multiple transducer outputs through one IC, reducing BOM in compact flow meters and differential-pressure gauges. The TSSOP-24 footprint simplifies integration into the small inline transmitter housings used in HVAC and process-control applications, while the industrial -40 C to +85 C rating covers the typical outdoor process environment.
推荐
Medical Instrumentation and Patient Monitoring
In medical instrumentation the AD7709BRU-REEL enables precision low-frequency measurement of physiological signals such as respiration waveform and body-temperature. The sigma-delta architecture delivers sub-LSB noise on DC-type signals, while the integrated current sources can bias resistive sensors like thermistors without additional driver circuitry. The on-chip calibration logic (factory-calibrated gain/offset, plus user-initiated self- and system calibration) maintains accuracy over long deployments, critical for hospital-grade patient monitors. The TSSOP-24 package is small enough for portable and bedside instruments, and the 2.7 V minimum supply allows battery-backed operation on a single Li-ion cell with a low-dropout regulator.
推荐
Industrial Process Control and PLC Analog Modules
PLC analog input modules and industrial process-control loops rely on the AD7709BRU-REEL for multi-channel 4-20 mA, 0-10 V, or RTD signal acquisition. Two fully-differential or four pseudo-differential channels allow a single chip to cover multiple sensor types, while the integrated PGA lets one ADC accept both high-level voltage and millivolt-level thermocouple inputs through channel-specific gain settings. The 2.7 V-5.25 V supply range aligns with the 5 V backplane common to PLC analog cards, eliminating the need for separate ADC rails. The serial interface (SCLK/DOUT/DIN/CS) is easily routed to the host microcontroller via SPI, freeing GPIOs for other control functions. Industrial -40 C to +85 C operation covers unconditioned control cabinets.
推荐
Data Acquisition Front-Ends for Test and Measurement
Data acquisition systems and lab-grade test instruments can use the AD7709BRU-REEL as a flexible low-frequency analog front end. The combination of a built-in PGA and high-resolution sigma-delta ADC provides excellent DC accuracy for measurements such as strain, voltage, or thermal gradients, while the I/O port allows software-controlled switching between test points, reducing external multiplexer chips. Switchable reference inputs permit on-the-fly re-calibration against an external precision reference, and self-calibration routines further improve long-term stability. The compact TSSOP-24 package simplifies integration into PC-USB-style DAQ dongles and bench-top test fixtures, where board space and thermal stability are key constraints.
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推荐产品汇总
工程参考数据： AD7709BRU-REEL ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | AD7709BRUZ | AD7709BRU-REEL7 | AD7709ARUZ-REEL7 | AD7708BRU-REEL | AD7731BRU-REEL7 |
|---|---|---|---|---|---|---|
| Package | TSSOP-24 (RU) | TSSOP-24 (RU) - same | TSSOP-24 (RU) - same | TSSOP-24 (RU) - same | TSSOP-24 (RU) - same | TSSOP-24 (RU) - same |
| Brand | Analog Devices | Analog Devices - same | Analog Devices - same | Analog Devices - same | Analog Devices - same | Analog Devices - same |
| Resolution | 16-bit | 16-bit | 16-bit | 16-bit | 16-bit | 24-bit |
| Number of Input Channels | 2 diff / 4 pseudo-diff | 2 diff / 4 pseudo-diff | 2 diff / 4 pseudo-diff | 2 diff / 4 pseudo-diff | 8 / 16 single-ended | 2/3 differential |
关键差异点
- Integrated excitation current sources (10 uA / 100 uA / 1 mA) （对比 AD7731BRU-REEL7)
- Pin-compatible 16-bit drop-in family in TSSOP-24 （对比 AD7708BRU-REEL)
- Pb-free and reel-7 packaging siblings in same die （对比 AD7709BRUZ)
设计说明
Decouple the AVDD and IOVDD pins with separate ceramic capacitors (10 uF bulk + 100 nF high-frequency) placed as close to the package pin as possible, with the cap ground pigtail tied directly to the nearby AGND/DGND plane. Star-route AGND and DGND back at a single point under the IC to prevent digital return currents from coupling into the analog front end - this typically reduces noise on the analog supply by 10 dB-20 dB in 16-bit sigma-delta designs.
Route analog input traces as a differential pair with matched length and continuous ground-side shielding; keep a minimum of 3x trace-width spacing to other digital signals. The TSSOP-24 thermal pad - if available - should be soldered to a copper pour that extends over the analog ground plane to aid heat spreading; this IC dissipates a few tens of mW under typical load, but the solder-pad connection also provides a low-impedance analog ground reference beneath the package.
Estimated: at room-temperature 25 C operation with both excitation current sources active simultaneously, total consumption is approximately 5 mA from AVDD plus digital overhead; ensure that the analog LDO has at least 10 mA headroom above this figure for transient settling. Avoid leaving the PGA inputs floating while the output data rate is high - tie unused PGA inputs through a defined resistor divider to mid-supply, otherwise modulator idle tones may show up at the output.
合规信息
The 'REEL' suffix typically denotes Pb-finish parts on tape-and-reel; Pb-free versions have the 'Z' suffix (AD7709BRUZ). The exact RoHS/REACH status of the AD7709BRU-REEL was not present in the verified web data and is marked [DATA_NEEDED]. All AD7709 family parts are industrial screening level per DigiKey listing.
