AD7712AR-REEL7 - 24-Bit Sigma-Delta ADC | Analog Devices | SOIC-24
Référence : AD7712AR-REEL7 ✗ Fin de vie| Qté | Prix unitaire | Total |
|---|---|---|
| 1 | $38.45 | $38,45 |
| 10 | $34.55 | $345,50 |
| 100 | $30.6 | $3 060,00 |
| 500 | $27.1 | $13 550,00 |
| 1 000 | $24.95 | $24 950,00 |
AD7712AR-REEL7 Présentation
What is a sigma-delta ADC? A sigma-delta (Σ-Δ) converter is a type of analog-to-digital converter that oversamples an input signal and uses noise-shaping to push quantization noise out of the baseband, trading speed for very high resolution and excellent linearity. In the broader taxonomy: ADC -> data converter -> mixed-signal IC -> semiconductor. The AD7712 sits at the signal-conditioning end of this hierarchy, integrating input multiplexers, programmable gain amplifiers (PGAs), digital filtering, and calibration logic so a microcontroller only has to read conversions over a synchronous serial interface.
Key features of the AD7712AR-REEL7 include 24-bit no-missing-codes performance, ±0.0015% (15 ppm) integral nonlinearity, charge-balancing conversion, and on-chip self-calibration that nulls offset and gain errors. The low-level input channel features true differential inputs with common-mode rejection, and the high-level input accepts bipolar ±4 × VREF. Conversion rates and output word rates are software-configurable via the serial port, allowing trade-offs between resolution and update rate.
Architecturally, the AD7712 uses a switched-capacitor charge-balancing modulator followed by a digital decimation filter. This approach eliminates the need for high-precision external analog components; only a few decoupling capacitors and a precision voltage reference (such as the AD780 or ADR291) are required. The serial interface is compatible with most microcontrollers and DSPs, and the device operates from a single +5 V supply while consuming modest quiescent current for portable instrumentation.
Typical applications include weigh scales and load-cell digitizers, industrial process-control transmitters (4-20 mA loops), portable battery-powered instrumentation, smart sensor signal conditioning, and pressure, temperature, or strain-gauge front-ends. The integrated PGA removes the need for external instrumentation amplifiers in most transducer bridges, reducing both BOM cost and PCB area.
A key design consideration is reference voltage quality: noise on VREF directly appears as conversion noise, so a low-noise, low-drift reference is essential. Designers should also route analog and digital grounds as a star from the AD7712 and follow ADI's recommended decoupling layout.
This page synthesizes distributor pricing, cross-reference drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone, helping engineers evaluate lifecycle, substitution risk, and BOM decisions in one view.
Alternatives de remplacement direct pour AD7712AR-REEL7 — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :
AD7712ARZ-REEL7
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
AD7712ARZ
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
AD7712AR
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
AD7712AR-REEL
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
AD7710ARZ
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
AD7712AR-REEL7 Valeurs maximales et caractéristiques électriques
| Manufacturer | Analog Devices, Inc. |
| Part Number | AD7712AR-REEL7 |
| Description | LC2MOS Signal Conditioning 24-Bit Sigma-Delta ADC |
| Architecture | Sigma-Delta (charge balancing) |
| Résolution | 24 bits, no missing codes |
| Number of Analog Inputs | 2 (1 low-level differential, 1 high-level) |
| Conversion Rate (max) | 1.028 kSPS |
| Output Interface | Serial (3-wire bidirectional, SPI-compatible) |
| Integral Nonlinearity | 0.0015% (15 ppm) |
| Programmable Gain | 1 to 128 (low-level channel) |
| High-Level Input Range | ±4 x VREF (differential) |
| Tension d'alimentation | +5 V single supply |
| Température de fonctionnement | -40C to +85C (industrial) |
| Boîtier / Format | 24-SOIC (Wide, 0.300 inch, 7.5 mm body width) |
| Pins | 24 |
| Type de montage | Surface Mount |
| Packaging | Tape & Reel, 7-inch reel |
| Screening Level | Industrial |
| Reference Input | Differential, external |
Configuration des broches de AD7712AR-REEL7
| Broche 1 | SCLK — Serial clock input for bidirectional serial port |
| Broche 2 | CS — Chip select, active low |
| Broche 3 | DOUT — Serial data output (also serial data input during writes) |
| Broche 4 | DRDY — Data ready output, active low |
| Broche 5 | MODE — Mode select input (internal/external clock) |
| Broche 6 | FSYNC — Frame synchronization input |
| Broche 7 | AVDD — +5 V analog supply |
| Broche 8 | REFIN+ — Positive reference input |
| Broche 9 | REFIN- — Negative reference input |
| Broche 10 | AIN1+ — Low-level analog input, positive |
| Broche 11 | AIN1- — Low-level analog input, negative |
| Broche 12 | AGND — Analog ground |
| Broche 13 | AIN2+ — High-level analog input, positive |
| Broche 14 | AIN2- — High-level analog input, negative |
| Broche 15 | AGND — Analog ground |
| Broche 16 | NC — Not connected (per datasheet) |
| Broche 17 | NC — Not connected (per datasheet) |
| Broche 18 | NC — Not connected (per datasheet) |
| Broche 19 | DVDD — +5 V digital supply |
| Broche 20 | DGND — Digital ground |
| Broche 21 | NC — Not connected (per datasheet) |
| Broche 22 | NC — Not connected (per datasheet) |
| Broche 23 | NC — Not connected (per datasheet) |
| Broche 24 | NC — Not connected (per datasheet) |
Applications typiques
AD7712AR-REEL7 convient pour 6 applications: Weigh Scale / Load Cell Digitizer, Industrial Process Control Transmitter (4-20 mA Loop), Portable Battery-Powered Instrumentation, Smart Sensor Signal Conditioning (Strain Gauge / Pressure / Temperature), Patient Monitor Analog Front-End, Data Acquisition Front-End for Industrial PLCs.
Weigh Scale / Load Cell Digitizer
The AD7712AR-REEL7's 24-bit no-missing-codes resolution, on-chip PGA with gains of 1 to 128, and differential low-level input channel make it a complete front-end for bridge-type load cells. Connected directly across the bridge outputs with a +5 V excitation supply, it digitizes the millivolt-level bridge signal without an external instrumentation amplifier, achieving better than 0.0015% linearity (15 ppm INL) over the industrial temperature range. The integrated digital filter simplifies 50/60 Hz mains-rejection requirements common in commercial scales. Companion parts: AD780 (2.5 V reference), OP07 (analog conditioning for high-level channel), MSP430 (microcontroller host).
Recommandé
Industrial Process Control Transmitter (4-20 mA Loop)
The AD7712AR-REEL7 digitizes process-variable sensor signals (pressure, temperature, flow) in two-wire 4-20 mA smart transmitters where board space, power consumption, and accuracy are paramount. Its single +5 V supply operation and integrated PGA eliminate the external instrumentation amplifier and antialias filter, simplifying the analog front-end to a few decoupling capacitors. The serial interface connects to a microcontroller that loops back a calibrated 4-20 mA current via a DAC and V/I converter. The -40C to +85C industrial temperature range and 0.0015% linearity satisfy IEC 60751 / ISA RP 31.1 requirements for process instrumentation.
Recommandé
Portable Battery-Powered Instrumentation
The AD7712AR-REEL7 is well-suited to handheld and field-portable instruments such as digital multimeters, dataloggers, and medical measurement devices where battery life and resolution both matter. Its low quiescent current from a single +5 V rail, combined with the integrated PGA, eliminates external active components and saves precious PCB area. The 24-bit dynamic range allows direct connection to thermocouples, RTDs, and strain gauges without external gain stages, while the programmable output word rate lets the host microcontroller duty-cycle the ADC for lowest average power consumption in battery operation.
Recommandé
Smart Sensor Signal Conditioning (Strain Gauge / Pressure / Temperature)
The AD7712AR-REEL7 provides complete signal conditioning for strain-gauge pressure transducers and thermistor/RTD temperature sensors in microcontroller-based smart-sensor modules. Its bidirectional serial port accepts software commands to select input channel, set PGA gain (1 to 128), configure output word rate, and trigger on-demand offset/gain self-calibration - features that enable factory calibration to be performed entirely in firmware. The differential low-level input rejects common-mode noise from long sensor cable runs in industrial environments, while the high-level ±4 x VREF input handles secondary process signals simultaneously.
Recommandé
Patient Monitor Analog Front-End
The AD7712AR-REEL7 serves as a precision analog front-end in low-frequency patient monitoring equipment - ECG, respiration, body-temperature and impedance-measurement subsystems - where its 24-bit resolution captures microvolt-level bioelectric signals. The on-chip PGA provides the gain needed at the sensor output, removing a separate op-amp stage that would otherwise inject noise. The bidirectional serial port allows a low-power microcontroller to control conversions and read calibration constants for end-of-line gain trimming. Integrated digital filtering simplifies mains-frequency (50/60 Hz) notch design for medical-grade IEC 60601-1 signal chains.
Recommandé
Data Acquisition Front-End for Industrial PLCs
The AD7712AR-REEL7 can be used as a low-frequency data-acquisition front-end inside industrial PLC analog input modules, digitizing thermocouple, RTD, and process-voltage signals at 10 Hz output rates with 24-bit resolution. The integrated PGA removes the need for external instrumentation amplifiers at each channel, while the serial interface connects to the PLC's backplane microcontroller or FPGA over a few wires. The on-chip self-calibration routine nulls offset and gain drift over time and temperature, supporting the long calibration intervals expected in process-plant installations. The wide 24-SOIC footprint allows straightforward PCB routing on standard 0.1 inch pitch pads.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour AD7712AR-REEL7 — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | AD7712ARZ-REEL7 | AD7712ARZ | AD7712AR | AD7712AR-REEL | AD7710ARZ |
|---|---|---|---|---|---|---|
| Package | 24-SOIC (Wide, 0.300 in) | 24-SOIC (Wide, 0.300 in) - same | 24-SOIC (Wide, 0.300 in) - same | 24-SOIC (Wide, 0.300 in) - same | 24-SOIC (Wide, 0.300 in) - same | 24-SOIC (Wide, 0.300 in) - same |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Resolution | 24 bits, no missing codes | 24 bits, no missing codes | 24 bits, no missing codes | 24 bits, no missing codes | 24 bits, no missing codes | 24 bits, no missing codes |
| Number of Analog Input Channels | 2 (1 low-level, 1 high-level) | 2 (1 low-level, 1 high-level) | 2 (1 low-level, 1 high-level) | 2 (1 low-level, 1 high-level) | 2 (1 low-level, 1 high-level) | 1 (low-level differential only) |
| Programmable Gain (PGA) | 1 to 128 (low-level channel) | 1 to 128 (low-level channel) | 1 to 128 (low-level channel) | 1 to 128 (low-level channel) | 1 to 128 (low-level channel) | 1 to 128 (single channel) |
| High-Level Input Range | ±4 x VREF (differential) | ±4 x VREF (differential) | ±4 x VREF (differential) | ±4 x VREF (differential) | ±4 x VREF (differential) | Not available (single-channel part) |
| Max Output Rate | 1.028 kSPS | 1.028 kSPS | 1.028 kSPS | 1.028 kSPS | 1.028 kSPS | 1 kSPS |
| Integral Nonlinearity | 0.0015% (15 ppm) | 0.0015% (15 ppm) | 0.0015% (15 ppm) | 0.0015% (15 ppm) | 0.0015% (15 ppm) | 0.0015% (15 ppm) |
| Supply Voltage | +5 V single supply | +5 V single supply | +5 V single supply | +5 V single supply | +5 V single supply | +5 V single supply |
| RoHS Compliance (Z suffix) | No (SnPb finish) | Yes (matte-tin) | Yes (matte-tin) | No (SnPb finish) | No (SnPb finish) | Yes (matte-tin) |
Principaux différenciateurs
- Dual input channel architecture (low-level PGA + high-level) (vs AD7710ARZ)
- RoHS-compliant lead-free drop-in replacement available (vs AD7712AR-REEL7 (this part, SnPb))
- Full 24-bit no-missing-codes with on-chip self-calibration (vs ADS1231 (Texas Instruments))
Notes de conception
The AD7712AR-REEL7 operates from a single +5 V supply; both AVDD (pin 7) and DVDD (pin 19) must be decoupled with at least 10 uF tantalum + 0.1 uF ceramic pairs placed within 5 mm of each pin. Analog and digital grounds should be tied together at a single star point under the IC - separate analog (AGND) and digital (DGND) pins are provided (pins 12, 15 for AGND; pin 20 for DGND) so the star ground prevents digital switching currents from corrupting the analog input or reference. If the +5 V supply is noisy, insert a ferrite bead in series with AVDD/DVDD and add a low-dropout regulator (ADP3303 or similar) upstream.
Do not read conversion data without polling the DRDY (pin 4) line first - the AD7712 only updates DOUT when DRDY falls, and reading stale data returns the previous conversion. Avoid using a digital switch-mode supply directly; its high-frequency ripple couples through AVDD into the reference and degrades 24-bit noise performance by 2-4 LSBs. Also note that the on-chip self-calibration (offset + gain) must be re-run after every gain or output-rate change; failure to do so leaves residual offset up to 100 uV at gain = 128.
Place the AD7712AR-REEL7 on a 4-layer PCB with a dedicated analog ground plane beneath the IC and its reference components; route digital traces (SCLK, CS, DOUT, DRDY) on the opposite side or above the ground plane to minimize digital-to-analog crosstalk. Keep the REFIN+/REFIN- traces short and symmetric to avoid thermocouple-induced offset errors; route them differentially with 0.5 mm spacing over the ground plane. The NC pins (16, 17, 18, 21, 22, 23, 24) should be left floating, not grounded - per the datasheet they are not bonded internally.
Informations de conformité
AD7712AR-REEL7 uses SnPb lead finish and is not RoHS compliant; the ARZ variants (AD7712ARZ-REEL7, AD7712ARZ) are RoHS-compliant drop-in replacements with matte-tin lead plating. Reach and conflict-minerals status typical for legacy ADI AD77xx family parts. AEC-Q100 not applicable - this is an industrial-grade precision converter, not an automotive-qualified part.
