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Analog Devices Inc. AD7666AST
- Part No.:
- AD7666AST
- Manufacturer:
- Analog Devices Inc.
- Category:
- Analog to Digital Converters (ADC)
- Package:
- 48-LQFP
- Datasheet:
-
AD7666AST.pdf
- Description:
- IC ADC 16BIT UNIPOLAR 48-LQFP
- Quantity:
- Payment:
- Shipping:
Inventory:231
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Product details
Overview
AD7666AST from Analog Devices is a 16-bit, 500 kSPS charge redistribution SAR analog-to-digital converter with integrated 2.5 V reference, unipolar 0 V to 2.5 V input range, ±2.0 LSB INL, and SPI/parallel interface-designed for high-accuracy data acquisition in medical instruments and spectrum analysis systems.
For engineers reviewing the AD7666AST datasheet, AD7666AST pinout, AD7666AST application, or AD7666AST equivalent, this page delivers verified specifications, package mapping, interface timing constraints, thermal drift behavior, and real-world use context-enabling confident selection for precision DC/AC measurement circuits requiring no pipeline delay and stable internal reference performance.
Technical Context
The AD7666AST implements a factory-calibrated charge redistribution SAR architecture with on-chip error correction, eliminating external calibration while guaranteeing monotonicity and no missing codes across temperature. Its dual-mode digital interface supports both parallel (16-bit bus) and serial (SPI/QSPI/MICROWIRE-compatible) operation with selectable clock source (internal or external) and active-low/high SYNC polarity.
It integrates a buffered 2.5 V reference with ±3 ppm/°C typical drift and 5 ms turn-on settling, alongside dedicated analog/digital power domains (AVDD/DVDD/OVDD), independent ground pins (AGND/DGND/OGND), and temperature-sensing output (TEMP pin). Conversion is initiated by CNVST edge-triggered sampling with 2 ns aperture delay and 750 ns transient response to full-scale step.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Resolution | 16-bit with no missing codes-ensures monotonic transfer function and deterministic code mapping for metrology-grade measurements. |
| Throughput Rate | 500 kSPS maximum-supports real-time spectral analysis up to Nyquist frequency of 250 kHz with full DC accuracy preserved. |
| INL | ±2.0 LSB max (±0.0038% FSR)-limits integral nonlinearity error to sub-40 µV over 0–2.5 V range, critical for calibration-critical instrumentation. |
| S/(N+D) | 88 dB min @ 20 kHz-provides ≥14.3 ENOB at audio band, enabling high-fidelity signal capture in DSP and medical front-ends. |
| Reference Drift | ±3 ppm/°C typical, ±15 ppm/°C max-translates to ≤37.5 µV/°C variation in 2.5 V reference, supporting stable gain scaling over industrial temperature range. |
| Power Dissipation | 66 mW typ at 500 kSPS without REF; 81 mW with REF-enables low-thermal-load integration in compact battery-powered or thermally constrained systems. |
| Analog Input Range | 0 V to 2.5 V unipolar-matches internal reference voltage, eliminating need for external scaling resistors in single-supply designs. |
Pinout & Package
AD7666AST is housed in a 48-lead LQFP (ST-48) package with exposed pad, rated for –40°C to +85°C operation. Pin layout supports separate analog/digital/power domains and includes dedicated reference buffer control (PDBUF), reference enable (PDREF), and temperature sensor output (TEMP).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| IN / INGND | Analog input pair | Differential input path for 0 V to 2.5 V unipolar signal; INGND must be routed adjacent to IN for optimal CMRR (65 dB @ 10 kHz). |
| REF / REFGND | Reference voltage node | 2.5 V output from internal reference; REFGND is isolated analog ground for reference stability-requires local 10 µF capacitor per datasheet. |
| CNVST | Conversion start trigger | Edge-sensitive input initiating sample-to-hold transition; falling edge triggers conversion after acquisition phase completes (t8 = 750 ns). |
| BUSY | Conversion status indicator | Active-HIGH open-drain output signaling conversion progress; falling edge marks data readiness for read via RD/CS handshake. |
| SER/PAR | Interface mode select | LOW enables 16-bit parallel interface (D[15:0]); HIGH configures serial mode using D8–D11 as SDOUT/SCLK/SYNC/RDERROR. |
| PDREF / PDBUF | Reference power control | PDREF LOW enables internal reference; PDBUF LOW activates internal buffer-both required for buffered 2.5 V reference operation. |
Key Features
| Feature | Design Value |
|---|---|
| No pipeline delay | Immediate data availability post-conversion-eliminates latency-induced phase errors in closed-loop control and real-time feedback systems. |
| Internal 2.5 V reference | Guaranteed ±15 ppm/°C drift with 5 ms turn-on settling-reduces BOM count and PCB area vs. discrete reference + buffer solutions. |
| Parallel and serial interface | Pin-multiplexed D[0:11] supports either 16-bit parallel bus or 4-wire SPI-compatible serial port-enables flexible host processor integration (DSP/FPGA/microcontroller). |
| Single 5 V supply | AVDD = DVDD = 5 V operation with OVDD configurable for 3 V or 5 V logic-simplifies power architecture in mixed-voltage embedded systems. |
| Temperature sensor output | TEMP pin provides 300 mV @ 25°C with 1 mV/°C slope-enables on-chip thermal monitoring without external sensors in space-constrained applications. |
Applications
| Medical Instrumentation | Spectrum Analysis |
|---|---|
Use Scenario: High-resolution ECG/EEG front-end digitizing low-amplitude bio-signals with minimal noise floor impact. IC Role / Device Role / Timing Role: Primary ADC capturing 0–2.5 V conditioned analog inputs at 500 kSPS with <2.0 LSB INL and 88 dB S/(N+D). Use Value: Enables detection of microvolt-level cardiac anomalies without external reference or calibration, leveraging internal 2.5 V reference stability. |
Use Scenario: Real-time FFT-based spectral monitoring in portable RF analyzers operating up to 250 kHz Nyquist bandwidth. IC Role / Device Role / Timing Role: High-speed SAR ADC feeding FPGA-based FFT engine with deterministic 2 µs conversion cycle and no pipeline latency. Use Value: Delivers 14.3+ ENOB at 20 kHz, ensuring accurate amplitude/frequency resolution for harmonic distortion analysis. |
| Data Acquisition Systems | Battery-Powered Test Equipment |
Use Scenario: Modular DAQ module acquiring multi-channel sensor data (pressure, temperature, strain) with synchronized sampling. IC Role / Device Role / Timing Role: Precision ADC interfaced via parallel bus to ARM Cortex-M7 MCU, using CNVST for hardware-triggered simultaneous sampling. Use Value: Guarantees monotonic 16-bit linearity and no missing codes across –40°C to +85°C, critical for certified industrial calibration. |
Use Scenario: Handheld multimeter or oscilloscope probe with ultra-low standby power and fast wake-up response. IC Role / Device Role / Timing Role: Low-power ADC entering 132 µW sleep mode at 1 kSPS, activated by PD pin for burst-mode acquisition. Use Value: Extends battery life via dynamic power scaling while maintaining full 16-bit resolution during active measurement windows. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 16-bit SAR ADC applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AD7664ASTZ | Same 48-lead LQFP package, 16-bit, 570 kSPS, but requires external reference and lacks integrated TEMP sensor. | Used where higher throughput is prioritized over reference integration and thermal monitoring. | Select AD7664ASTZ only if external reference design is already established and TEMP output is unnecessary. |
| AD7656ASTZ | 6-channel simultaneous-sampling 16-bit SAR ADC, 250 kSPS per channel, 64-lead LQFP-no internal reference, higher power (120 mW). | Targeted at multi-sensor synchronized acquisition (e.g., motor phase current/voltage), not single-channel high-throughput. | Choose AD7656ASTZ when true simultaneous sampling across ≥2 channels is mandatory, accepting larger footprint and no internal reference. |
Compared with AD7664ASTZ and AD7656ASTZ, the AD7666AST uniquely combines internal 2.5 V reference, temperature sensing, and 500 kSPS throughput in a 48-lead LQFP-making it optimal for space-constrained, single-channel precision systems where reference stability and thermal awareness are design-critical.
Availability
AD7666AST is available at Aetrix Electronics and suitable for medical instrumentation, spectrum analysis, and battery-powered test equipment requiring stable component supply, long-term lifecycle support, and guaranteed parametric compliance across industrial temperature range.
Supply support for AD7666AST includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Analog Devices is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving precision instrumentation, industrial automation, and communications markets since 1965.
The AD7666AST belongs to Analog Devices' PulSAR® family of precision SAR ADCs-engineered for applications demanding high resolution, low latency, and integrated reference stability without external calibration.
FAQ
What is the maximum sampling rate supported by the AD7666AST?
The AD7666AST supports a maximum throughput rate of 500 kSPS, corresponding to a minimum conversion cycle time of 2 µs. This rate is achievable under specified conditions: AVDD = DVDD = 5 V, OVDD = 2.7 V to 5.25 V, and –40°C to +85°C ambient. At lower throughput (e.g., 1 kSPS), power dissipation drops to 132 µW, making the AD7666AST suitable for burst-mode or low-duty-cycle applications.
Does the AD7666AST require an external reference voltage?
No-the AD7666AST includes a factory-trimmed 2.5 V internal reference with ±3 ppm/°C typical drift and ±15 ppm/°C maximum drift over temperature. External reference operation is optional and enabled by pulling PDREF HIGH and applying 2.3 V to AVDD – 1.85 V to REF/REFBUFIN. The AD7666AST's internal reference eliminates external component dependencies while maintaining 88 dB S/(N+D) performance.
How does the AD7666AST handle digital interface selection between parallel and serial modes?
The AD7666AST uses the SER/PAR pin to configure interface mode: LOW selects 16-bit parallel output on D[15:0], while HIGH reassigns D8–D11 as SDOUT/SCLK/SYNC/RDERROR for SPI-compatible serial communication. Interface timing-including BUSY assertion, data validity windows, and SYNC polarity-is fully documented in Tables 3–4 of the AD7666AST datasheet, with load-dependent specifications (10 pF for serial, 60 pF otherwise).
What is the purpose of the TEMP pin on the AD7666AST?
The TEMP pin on the AD7666AST provides an analog voltage output proportional to die temperature: 300 mV at 25°C with 1 mV/°C sensitivity. This enables on-chip thermal monitoring without external sensors-critical for drift compensation in precision measurement systems. The output has 4 kΩ source impedance and should be buffered before ADC input if used for closed-loop thermal management in the AD7666AST's own system.
Can the AD7666AST operate with a 3 V digital interface supply?
Yes-the AD7666AST supports OVDD from 2.7 V to 5.25 V, allowing direct interfacing with 3 V logic families. When OVDD = 3 V, digital outputs (e.g., BUSY, DATA) meet VOH ≥ OVDD – 0.6 V and VOL ≤ 0.4 V, while inputs (RD, CS, SER/PAR) accept VIH ≥ 2.0 V and VIL ≤ 0.8 V. DVDD remains at 5 V for core logic, ensuring full functionality of the AD7666AST's internal SAR and reference circuitry.
AD7666AST Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- PulSAR®
- Package/Case:
- 48-LQFP
- Packaging:
- Bag
- Product Status:
- Obsolete
- Number of Bits:
- 16
- Sampling Rate (Per Second):
- 500k
- Number of Inputs:
- -
- Input Type:
- -
- Data Interface:
- -
- Configuration:
- -
- Ratio - S/H:ADC:
- -
- Number of A/D Converters:
- 1
- Architecture:
- -
- Reference Type:
- -
- Voltage - Supply, Analog:
- -
- Voltage - Supply, Digital:
- -
- Features:
- -
- Operating Temperature:
- -40°C ~ 85°C
- Supplier Device Package:
- 48-LQFP (7x7)
- Mounting Type:
- Surface Mount
- Grade:
- -
- Qualification:
- -
AD7666AST FAQ
1.How can I place an order for AD7666AST through Aetrix?
Please submit a Request for Quotation (RFQ) for AD7666AST on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for AD7666AST reliable?
The price and inventory of AD7666AST are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AD7666AST is usually 5 days.
3.What payment methods are accepted for AD7666AST?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AD7666AST transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AD7666AST?
AD7666AST orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AD7666AST order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for AD7666AST?
For technical support, including AD7666AST datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AD7666AST requirements.
6.How does Aetrix verify that AD7666AST is sourced from the original manufacturer or authorized distributors?
All AD7666AST products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that AD7666AST meets industry standards.
7.What is the process for return or replacement of AD7666AST?
All AD7666AST units undergo pre-shipment inspection (PSI). If there is an issue with AD7666AST, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The AD7666AST part is unused and in its original packaging.
Return procedure for AD7666AST:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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