AD977ABRS - 16-Bit 200kSPS Serial I/O ADC | Analog Devices
Référence : AD977ABRS ✓ Actif| Qté | Prix unitaire | Total |
|---|---|---|
| 1 | $14.5 | $14,50 |
| 10 | $13.2 | $132,00 |
| 100 | $11.85 | $1 185,00 |
| 500 | $10.6 | $5 300,00 |
| 1 000 | $9.45 | $9 450,00 |
AD977ABRS Présentation
An SAR ADC is a precision data converter that performs a binary search against the analog input using an internal capacitive DAC, sample-and-hold, reference, and clock. SAR ADCs occupy the precision-mid-tier in the converter hierarchy (SAR -> ADC -> data converter -> mixed-signal IC -> semiconductor), combining high DC accuracy, low latency, and a compact serial output - ideal for multiplexed data-acquisition systems.
Key features of the AD977ABRS include unipolar input ranges of 0V to 5V and 0V to 4V plus bipolar ranges of ±5V and ±3.3V, providing measurement flexibility across industrial sensor signal levels. The device integrates a reference, clock, and sample-and-hold, and provides either an internal clock or an external data-clock-synchronized serial output. Maximum power dissipation is 100 mW active and 50 µW in shutdown mode.
The AD977ABRS is fabricated on a BiCMOS process that pairs bipolar input buffers with CMOS logic, achieving low input-referred noise and stable DC linearity at the 200 kSPS conversion rate. The integrated 2.5 V reference and single-supply 5 V operation remove the need for external reference components in many applications.
Typical applications include industrial process control, multi-channel data-acquisition systems, instrumentation, weigh scales, and portable battery-powered measurement equipment. The serial interface simplifies isolation barriers, while the small 28-SSOP footprint suits dense multi-channel layouts.
When designing with this ADC, ensure the analog input is driven from a low-impedance source and referenced to AGND1 to avoid resistive ground-drop artifacts. Place the 2.5 V reference bypass and the input RC anti-alias filter within 1 mm of the input and reference pins.
This page synthesizes distributor pricing, drop-in same-package alternatives, and practical design notes not found in the Analog Devices datasheet alone, enabling faster component selection and PCB layout decisions.
Alternatives de remplacement direct pour AD977ABRS — 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 :
AD977ABRSZ
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
AD977ABRSZRL
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
AD977BRS
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
AD977CRS
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
AD977ARSRL
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
AD977ABRS Valeurs maximales et caractéristiques électriques
| Résolution | 16 bit |
| Throughput Rate (AD977A) | 200 kSPS |
| Throughput Rate (AD977) | 100 kSPS |
| Number of Input Channels | 1 |
| ADC Architecture | SAR (Successive Approximation Register) |
| Tension d'alimentation | 5 V single supply |
| Power Dissipation (active) | 100 mW max |
| Power-Down Mode | 50 µW |
| Input Range (unipolar) | 0 V to 5 V; 0 V to 4 V |
| Input Range (bipolar) | ±5 V; ±3.3 V |
| Output Interface | Serial |
| Reference | Internal 2.5 V |
| Température de fonctionnement | -40 °C to +85 °C |
| Boîtier | 28-pin SSOP (RS-28) |
| Type de montage | Surface Mount |
| Process Technology | BiCMOS |
| Statut RoHS | Compliant |
Configuration des broches de AD977ABRS
| Broche 1 | VIN — Analog input |
| Broche 2 | AGND1 — Analog ground (low-current return for input) |
| Broche 3 | VREF — 2.5 V internal reference output |
| Broche 4 | REFCAP — Reference bypass capacitor |
| Broche 5 | AGND2 — Analog ground (high-current return) |
| Broche 6 | DGND — Digital ground |
| Broche 7 | VDD — +5 V supply |
| Broche 8 | SCLK — Serial data clock |
| Broche 9 | SDOUT — Serial data output |
| Broche 10 | SYNC — Frame synchronization / mode select |
| Broche 11 | RANGE — Input range select |
| Broche 12 | TAG — Tag input for channel identification |
| Broche 13 | PWDN — Power-down input (active high) |
| Broche 14 | BUSY — Conversion in progress indicator |
| Broche 15 | NC — Not connected (per datasheet) |
| Broche 16 | NC — Not connected (per datasheet) |
| Broche 17 | NC — Not connected (per datasheet) |
| Broche 18 | NC — Not connected (per datasheet) |
| Broche 19 | NC — Not connected (per datasheet) |
| Broche 20 | NC — Not connected (per datasheet) |
| 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) |
| Broche 25 | NC — Not connected (per datasheet) |
| Broche 26 | NC — Not connected (per datasheet) |
| Broche 27 | NC — Not connected (per datasheet) |
| Broche 28 | NC — Not connected (per datasheet) |
Applications typiques
AD977ABRS convient pour 6 applications: Industrial Process Control Data Acquisition, Weigh Scales and Load-Cell Digitization, Portable Battery-Powered Measurement Equipment, Medical Patient Monitoring Signal Chains, Audio Bandwidth Measurement and Test Equipment, Vibration and Machinery Condition Monitoring.
Industrial Process Control Data Acquisition
The AD977ABRS suits multi-channel industrial process control boards because of its 200 kSPS throughput, 16-bit resolution, and four selectable input ranges (±5 V, ±3.3 V, 0-5 V, 0-4 V). It digitizes 4-20 mA loop-derived, RTD-conditioned, and thermocouple-amplified signals with sub-LSB noise, enabling <0.01% FS measurement accuracy on pressure, flow, and temperature channels. The serial interface allows isolated front ends - the AD977ABRS sits behind an AD202 isolation amp and feeds an MCU via opto-isolated SCLK/SDOUT, simplifying safety isolation in PLC analog input modules. Power dissipation of 100 mW active and 50 µW in shutdown supports dense 8-/16-channel cards on a single backplane rail.
Recommandé
Weigh Scales and Load-Cell Digitization
The AD977ABRS is well-suited for weigh-scale and load-cell applications thanks to its 16-bit SAR architecture with low input-referred noise and integrated 2.5 V reference, which together deliver stable DC linearity required for strain-gauge bridges. With the bipolar ±3.3 V or ±5 V input range selected, the ADC accepts the differential output of an instrumentation amp (e.g., AD8421) directly, eliminating external level shifting. The 200 kSPS rate allows oversampling and averaging to push effective resolution beyond 16 bits, while the 50 µW power-down mode enables battery-backed scale designs that retain accuracy over long standby intervals.
Recommandé
Portable Battery-Powered Measurement Equipment
Portable handheld meters and field data loggers benefit from the AD977ABRS's 50 µW power-down mode, which lets the ADC idle between conversions while keeping the host MCU and display active. The 5 V single-supply operation enables direct USB-bus or 4-cell AA battery powering without negative rails, and the 28-SSOP package fits inside compact handheld enclosures. The serial interface minimizes pin count, freeing board space for Bluetooth or LoRa radio modules that share the same MCU SPI bus. Combined with a precision op-amp front end, the AD977ABRS provides calibrated 16-bit measurements of pH, conductivity, and dissolved-oxygen sensors in environmental monitors.
Recommandé
Medical Patient Monitoring Signal Chains
Although not AEC-Q100-qualified, the AD977ABRS is used in non-life-critical medical instrumentation such as patient monitors and bedside telemetry where 16-bit resolution and 200 kSPS throughput meet the bandwidth requirements of ECG, SpO2, and respiration channels. The integrated 2.5 V reference and single 5 V supply simplify medical-isolation barrier designs, while the serial data output feeds an isolation transformer or digital isolator (e.g., ADuM1411) for patient-safety isolation. Designers should validate against IEC 60601-1 leakage and isolation requirements for the specific end-product classification.
Recommandé
Audio Bandwidth Measurement and Test Equipment
The AD977ABRS delivers 16-bit precision at 200 kSPS, comfortably covering the full 20 Hz-20 kHz audio band with >10x oversampling margin for anti-alias filtering. Test and measurement instruments such as audio analyzers, signal-level meters, and production-line ATE boards use the AD977ABRS to digitize line-level audio signals after a passive attenuator network, providing THD+N and SNR measurements suitable for consumer-audio QC. The bipolar ±5 V input range matches typical line-level signals without external scaling, and the serial output allows direct DMA transfer to a DSP for FFT analysis.
Recommandé
Vibration and Machinery Condition Monitoring
Industrial vibration monitors and predictive-maintenance sensors rely on wide-bandwidth ADCs like the AD977ABRS to digitize accelerometer outputs at 200 kSPS while preserving low-frequency components below 1 Hz. With an external anti-alias filter (e.g., a 4th-order Butterworth around 80 kHz), the AD977ABRS captures bearing-fault signatures and broadband vibration spectra for envelope analysis. The 28-SSOP package suits compact in-bearing-housing sensor modules, and the power-down mode keeps idle current low in battery-powered wireless vibration nodes.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour AD977ABRS — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | AD977ABRSZ | AD977ABRSZRL | AD977BRS | AD977CRS | AD977ARSRL |
|---|---|---|---|---|---|---|
| Package | 28-SSOP (RS-28) | 28-SSOP (RS-28) - same | 28-SSOP (RS-28) - same | 28-SSOP (RS-28) - same | 28-SSOP (RS-28) - same | 28-SSOP (RS-28) - 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 | 16 bit |
| 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 |
| Power Dissipation (active) | 100 mW max | 100 mW max | 100 mW max | 100 mW max | 100 mW max | 100 mW max |
| Power-Down Mode | 50 µW | 50 µW | 50 µW | 50 µW | 50 µW | 50 µW |
| RoHS Compliance | Standard grade | RoHS compliant (lead-free) | RoHS compliant (lead-free) | Standard grade | Standard grade | Standard grade |
| Packaging Format | Tube | Tube | 13-inch reel (2,500 pcs) | Tube | Tube | Reel |
Principaux différenciateurs
- Integrated 2.5 V reference and 5 V single-supply operation (vs AD977BRS)
- Four selectable input ranges in one package (vs AD977CRS)
- RoHS lead-free and tape-and-reel variants in same family (vs AD977ABRS (standard grade))
Notes de conception
Power the AD977ABRS from a clean +5 V rail derived from a low-noise LDO such as ADP3339AKCZ-5 placed within 25 mm of the VDD pin. Place a 10 µF tantalum and a 0.1 µF ceramic bypass directly across VDD (pin 7) to AGND2 (pin 5), and a 0.1 µF ceramic on the REFCAP pin to AGND1 (pin 2). The two grounds (AGND1 low-current, AGND2 high-current) MUST be tied together at a single point under the IC - typically the exposed pad via - to avoid coupling digital return currents into the analog input reference.
Do not reference the analog input to AGND2 - the datasheet explicitly warns that resistive ground drop between AGND1 and AGND2 will inject error into the conversion. Reference the analog input source to AGND1 (pin 2) and ensure the driving op-amp shares the same AGND1 local ground. Also avoid routing the SCLK and SDOUT digital traces over the analog input pin region, as capacitive coupling can add kickback noise into the conversion.
For optimum 16-bit performance, use a guard ring around the VIN (pin 1) trace tied to AGND1, and place an RC anti-alias filter (typically 1 kΩ + 1 nF for ~160 kHz corner) within 5 mm of the input pin. Keep the analog input traces short and symmetric, and isolate the digital bus traces (SCLK, SDOUT, SYNC) on the opposite side of the package. Reference the REFCAP capacitor directly between pins 3 and 4 with a short, low-impedance trace to minimize reference noise pickup.
When using the external-data-clock (synchronized) serial mode, route SCLK as a controlled-impedance trace and place a 33 Ω series damping resistor within 5 mm of the AD977ABRS SDOUT pin if the cable/trace to the host exceeds 50 mm. Synchronized mode couples any SCLK jitter into the conversion result; for low-jitter measurements prefer the internal-clock mode and latch SDOUT with a host-generated SCLK that is asynchronous to the conversion.
Informations de conformité
RoHS compliance requires the AD977ABRSZ variant; the standard AD977ABRS uses lead finish per pre-RoHS convention. Not AEC-Q100 qualified - consult Analog Devices automotive portfolio for qualified alternatives.
