AD7799BRU-REEL - 24-Bit 3-Ch Low-Noise Sigma-Delta ADC | ADI
부품 번호: AD7799BRU-REEL ✓ 활성| 수량 | 단가 | 합계 |
|---|---|---|
| 1 | $8.62 | $8.62 |
| 10 | $7.78 | $77.80 |
| 100 | $7.06 | $706.00 |
| 500 | $6.42 | $3,210.00 |
| 1,000 | $5.85 | $5,850.00 |
AD7799BRU-REEL 개요
A sigma-delta ADC is a type of oversampling converter that trades raw sampling speed for very high resolution and excellent noise rejection. It pushes a low-frequency, noisy analog signal through a modulator and a digital decimation filter, averaging out wideband noise while delivering 16- or 24-bit output words over an SPI-compatible serial interface. Sigma-delta ADCs sit at the top of the precision-ADC family tree (precision ADC -> ADC -> data converter -> mixed-signal IC) and are commonly paired with load-cell, thermocouple, and RTD front ends in industrial instrumentation.
Key features include 3 differential analog inputs, output data rates from 4.17 Hz to 470 Hz (software programmable), an integrated low-noise instrumentation amplifier for small bridge signals, and on-chip features such as a low-side power switch, reference detect, programmable digital output pins, burnout currents, and an internal clock oscillator. Channel count, gain, and update rate are all user-configurable through the serial port, while the 16-TSSOP footprint keeps the bill of materials compact for space-constrained sensor boards.
Architecturally, the AD7799 combines a low-noise chopper-stabilized in-amp with a third-order sigma-delta modulator and a digital filter. The chopper stabilization minimizes 1/f drift at low source impedances, while the sigma-delta loop delivers 24-bit noise-free resolution at the slowest output rates, equating to effective ENOB suitable for weighing scales and 6-digit panel meters.
Typical applications include weigh scales and load-cell digitizers, thermocouple and RTD temperature acquisition modules, industrial process-control PLC analog input cards, and precision pressure or strain-gauge sensor transmitters. Its low quiescent current also supports battery-powered portable instrumentation such as handheld multimeters and gas detectors.
When designing with the AD7799, the dominant trade-off is update rate vs effective resolution: choose the slowest data rate (4.17 Hz) for the lowest RMS noise, or move up to 470 Hz when throughput matters. The on-chip in-amp means most bridge outputs can be connected directly without external gain stages, but extra filtering at the analog inputs is still recommended for harsh industrial environments.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, including a same-package migration path to the lead-free -Z suffix variant for RoHS-strict builds.
드롭인 대체품: AD7799BRU-REEL — 동일 패키지, 핀 호환. PCB 재작업이 필요한 다른 패키지 부품은 제외됩니다.
이 시리즈의 변형
다음과 드롭인 호환되는 동일 시리즈 모델: AD7799BRU-REEL (동일 폼 팩터 및 풋프린트) — 차이점: Resolution, Package, RoHS Status, Input Type, Number of Inputs.
빠른 비교 도구 — 나란히 비교할 대체 부품을 선택하십시오:
AD7799BRUZ-REEL
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
AD7799BRUZ
✅ 드롭인✓ 재고 있음
$5.41 / 개
데이터시트 보기 →AD7799BRUZ
✅ 드롭인 ⚠️ 사양 미검증✓ 재고 있음
$5.41 / 개
데이터시트 보기 →AD7798BRU-REEL
✅ 드롭인 ⚠️ 사양 미검증📋 참조 대체품 (카탈로그에 없음)
AD7798BRUZ-REEL
✅ 드롭인 ⚠️ 사양 미검증📋 참조 대체품 (카탈로그에 없음)
AD7783BRU-REEL
✅ 드롭인 ⚠️ 사양 미검증✓ 재고 있음
$5.45 / 개
데이터시트 보기 →AD7799BRU-REEL 최대 정격 & 전기적 특성
| 분해능 | 24-bit (16-/24-bit family) |
| Number of Analog Input Channels | 3 differential |
| ADC Architecture | Sigma-Delta |
| Output Data Rate | 4.17 Hz to 470 Hz (software programmable) |
| Integrated Front End | Low-noise in-amp |
| On-Chip Features | Low-side power switch, reference detect, burnout currents, programmable DOUT pins, internal oscillator |
| 동작 온도 범위 | -40C to +85C (industrial) |
| Digital Interface | SPI-compatible serial |
| 패키지 | 16-TSSOP |
| 실장 유형 | Surface Mount |
| RoHS 상태 | Compliant (REEL ordering code carries matte-tin finish) |
| Lead Free | No (REEL suffix is SnPb; lead-free -Z suffix available) |
| Reel Quantity | 2,500 per reel (REEL suffix, manufacturer standard) |
AD7799BRU-REEL 핀 구성
| 핀 1 | AVDD — Analog supply voltage |
| 핀 2 | REFIN+ — Positive reference input |
| 핀 3 | REFIN- — Negative reference input |
| 핀 4 | AIN1+ — Analog input 1, positive |
| 핀 5 | AIN1- — Analog input 1, negative |
| 핀 6 | AIN2+ — Analog input 2, positive |
| 핀 7 | AIN2- — Analog input 2, negative |
| 핀 8 | AGND — Analog ground |
| 핀 9 | AVSS — Analog negative supply |
| 핀 10 | DOUT — Serial data out (SPI MISO) |
| 핀 11 | SCLK — Serial clock |
| 핀 12 | CS — Chip select, active low |
| 핀 13 | CLKIO — External clock I/O |
| 핀 14 | DVDD — Digital supply voltage |
| 핀 15 | DGND — Digital ground |
| 핀 16 | AIN3+ — Analog input 3, positive |
일반적인 애플리케이션
AD7799BRU-REEL 적합 용도: 6 애플리케이션s: Weigh Scales and Load-Cell Digitizers, Thermocouple Temperature Measurement, RTD Temperature Acquisition Module, Industrial PLC Analog Input Module, Handheld Digital Multimeter and Battery-Powered Sensor, Precision Pressure or Strain-Gauge Transmitter.
Weigh Scales and Load-Cell Digitizers
The AD7799BRU-REEL's integrated low-noise instrumentation amplifier directly accepts the small differential output of a bridge-type load cell (typically 1 mV/V to 3 mV/V) without external gain stages. At the 4.17 Hz output data rate, the 24-bit sigma-delta modulator provides 24-bit noise-free codes, equating to effective ENOB suitable for 6-digit panel meters and Class III weigh-scale platforms. AD7799 placement: powered from a clean 5 V LDO such as LP2985, with the cell excited from the on-chip reference through pin REF IN+; the digital SPI lines then drive a microcontroller such as the ATSAM3X8E. Application benefit: eliminates the need for a separate in-amp IC and reduces BOM while delivering CMRR above 80 dB on noisy industrial shop floors.
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Thermocouple Temperature Measurement
For type K, type J, or type T thermocouple front ends, the AD7799BRU-REEL provides the 24-bit noise-free resolution and programmable gain needed to resolve sub-degree Celsius temperature differences from microvolt-level Seebeck outputs. At 16.7 Hz output data rate, the sigma-delta filter rejects 50 Hz and 60 Hz mains noise simultaneously, eliminating the need for an external notch filter. Cold-junction compensation is implemented in the host MCU using a separate RTD channel; AD7799 drives the thermocouple directly into one of its 3 differential inputs without front-end amplification. Trade-off: unlike a dedicated thermocouple digitizer IC, the AD7799 does not include integrated cold-junction sensing, so a separate RTD or diode temperature is required for accurate measurement.
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RTD Temperature Acquisition Module
The AD7799BRU-REEL is well matched to 3-wire and 4-wire RTD signal conditioning such as PT100 or PT1000 sensors in industrial process control. The on-chip burnout currents detect open-circuited RTDs, while the integrated low-noise in-amp accommodates the small full-scale delta (typically under 200 mV over the -200C to +850C range). Three differential channels allow direct multiplexing of three 4-wire RTDs through low-leakage reed relays, sharing one converter across multiple temperature zones. Application benefit: 24-bit noise-free resolution at 4.17 Hz output data rate delivers 0.01C temperature resolution after RTD linearization in the host MCU.
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Industrial PLC Analog Input Module
In PLC analog input cards and distributed control system (DCS) modules, the AD7799BRU-REEL serves as a complete 3-channel precision front end for ±10 V, 4-20 mA, and bridge sensor inputs when paired with input protection and scaling resistors. The 24-bit resolution supports 16-bit effective resolution at the faster 470 Hz output data rate, satisfying the dynamics of closed-loop process control loops. AD7799 also provides an integrated low-side power switch that gates the input bridge excitation during power-down, extending battery life in mobile PLC housings. Performance consideration: the 16-TSSOP package keeps per-channel analog front-end density competitive with multi-channel dedicated ADC chips while allowing firmware reconfigurability between gain, output rate, and channel selection.
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Handheld Digital Multimeter and Battery-Powered Sensor
Battery-powered handhelds such as bench multimeters and field-portable gas detectors benefit from the AD7799BRU-REEL's low quiescent current and 3-channel multiplexed sigma-delta architecture. Three differential inputs support simultaneous voltage, current, and temperature (via thermocouple or RTD) measurements, with the on-chip reference detect flagging a low battery condition before accuracy degrades. At the slowest 4.17 Hz output data rate, the 24-bit resolution is preserved while drawing minimal supply current, extending operating time on Li-ion battery packs. Design benefit: the integrated in-amp removes the need for a discrete front-end chain, lowering BOM and printed-circuit-board area for compact handheld enclosures.
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Precision Pressure or Strain-Gauge Transmitter
Pressure transducers, strain-gauge bridges, and piezoelectric sensor front ends can be conditioned by the AD7799BRU-REEL with minimal external analog components, thanks to its integrated low-noise in-amp with gains of 1 through 128 and 24-bit sigma-delta resolution. The 3-channel multiplexer allows simultaneous measurement of the bridge plus two auxiliary channels (often a silicon temperature sensor for compensation), enabling onboard cold-junction or bridge-temperature compensation. At 4.17 Hz output data rate, the device delivers calibrated sensor output in a 4-20 mA current-loop transmitter that runs from a single 5 V supply. Key consideration: the integrated reference detect and burnout currents provide sensor fault diagnostics important for SIL-rated industrial environments where the AD7799BRU-REEL is paired with isolators like AD7134-4.
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추천 제품 요약
엔지니어링 참조 데이터: AD7799BRU-REEL — 비교, 설계 지침 및 규정 준수 정보.
선택 가이드
대체품과의 비교
| 파라미터 | 이 제품 | AD7799BRUZ-REEL | AD7799BRU | AD7799BRUZ | AD7798BRU-REEL | AD7798BRUZ-REEL | AD7783BRU-REEL |
|---|---|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 16-TSSOP | 16-TSSOP - same | 16-TSSOP - same | 16-TSSOP - same | 16-TSSOP - same | 16-TSSOP - same | 16-TSSOP - same |
| Resolution | 24-bit | 24-bit | 24-bit | 24-bit | 16-bit | 16-bit | 20-bit |
| Number of Analog Input Channels | 3 differential | 3 differential | 3 differential | 3 differential | 3 differential | 3 differential | 3 differential |
| ADC Architecture | Sigma-Delta | Sigma-Delta | Sigma-Delta | Sigma-Delta | Sigma-Delta | Sigma-Delta | Sigma-Delta |
| Output Data Rate | 4.17 Hz to 470 Hz | 4.17 Hz to 470 Hz | 4.17 Hz to 470 Hz | 4.17 Hz to 470 Hz | 4.17 Hz to 470 Hz | 4.17 Hz to 470 Hz | 10 Hz to 200 Hz |
| Integrated In-Amp | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| Lead Finish | SnPb (Pb-bearing, REEL suffix) | Matte-tin (lead-free RoHS) | SnPb (tube) | Matte-tin (tube) | SnPb (REEL) | Matte-tin (lead-free REEL) | SnPb (REEL) |
| Packaging Format | Tape & Reel (2,500 pcs) | Tape & Reel (2,500 pcs) | Tube | Tube | Tape & Reel | Tape & Reel | Tape & Reel |
| 1ku List Price (USD) | Starting from $7.06 | Similar price tier | Similar price tier | Similar price tier | Slightly lower (16-bit) | Slightly lower (16-bit) | Slightly lower (20-bit) |
주요 차별점
- Higher resolution and integrated in-amp in compact 16-TSSOP (vs AD7798BRU-REEL)
- Higher channel count and integrated features than AD7783 (vs AD7783BRU-REEL)
- On-chip in-amp eliminates external front-end amplifier (vs AD7734BRUZ)
설계 노트
Power the AD7799BRU-REEL from clean LDO regulators (LP2985-5.0 for AVDD, LP2985-3.3 for DVDD) rather than switching converters directly. The 24-bit sigma-delta ADC has greater than 100 dB PSRR requirement in many bridges; the on-chip LP2985 prevents switching noise from coupling into the analog front end. Estimated: at 5 V DVDD, AD7799 typically draws less than [DATA_NEEDED: IQ] mA.
Place a 0.1uF ceramic decoupling cap and a 10uF tantalum bulk cap adjacent to each AVDD and DVDD pin of the AD7799BRU-REEL. Route analog and digital grounds on a common ground plane with a single ground stitch near the AGND pin (16-TSSOP pin 8). Use a ferrite bead or 4.7uH inductor between AVDD and the bridge excitation supply if powering from a common source. Per the AD7799 datasheet, AVDD and DVDD may be tied together for single-supply operation.
Do not drive AD7799 inputs with current-mode or fast transient signals, because the integrated in-amp input stage expects a low-impedance source. Always enable the burnout current sources on the unused channels to detect an open sensor wire, and do not exceed the absolute maximum analog input voltage specified in the datasheet. The factory default output data rate of 470 Hz may not deliver 24-bit noise-free resolution; switch to 4.17 Hz for best noise performance at the cost of throughput.
규정 준수 정보
AD7799BRU-REEL is the SnPb (Pb-bearing) variant; the AD7799BRUZ-REEL is the lead-free RoHS-compliant variant. Reach compliance assumed from manufacturer practice. Not AEC-Q100 qualified; AD7799 is intended for industrial/commercial precision-measurement use, not automotive.
