AD7641BCPZRL - 18-Bit 2MSPS PulSAR Bipolar ADC | Analog Devices
MPN: AD7641BCPZRL ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $34.12 | $34.12 |
| 10 | $30.45 | $304.50 |
| 100 | $26.1 | $2,610.00 |
| 500 | $22.35 | $11,175.00 |
| 1,000 | $19.8 | $19,800.00 |
AD7641BCPZRL Overview
A SAR ADC is a successive-approximation-register analog-to-digital converter that performs a binary search against an internal DAC, producing a clean, single-conversion result with no pipeline latency. SAR ADCs occupy the same hierarchical slot as pipeline, sigma-delta, and flash converters within the data-converter product family, and within the broader integrated-circuit taxonomy they sit under ADC -> Data Converter -> Signal Chain IC -> Semiconductor. SAR parts are valued for deterministic latency, excellent DC accuracy, and ease of use in multiplexed multichannel systems.
Key specifications include 18-bit resolution with ±1.75 LSB INL (≈7 ppm of full scale) and +2/-1 LSB DNL (no missing codes), a fast 2 MSPS throughput, true bipolar input capability with overvoltage-tolerant analog inputs, an internal 2.5 V reference (also usable as a low-noise external reference driver), and a high-speed parallel or serial SPI-compatible interface. The device operates from a single 2.5 V digital supply and a 5 V analog supply.
Architecturally, the AD7641 integrates a high-impedance input front-end, a precision reference, the SAR core, and on-chip calibration logic; the iCMOS process allows 16 V input signal swing on a single 5 V supply. The high-throughput 2 MSPS rate and 18-bit linearity let engineers replace older bipolar-input ADCs that required external signal conditioning.
Typical applications include industrial process-control PLC analog-input cards, power-line monitoring and protection relays, medical patient-monitoring front-ends, data-acquisition modules, and multichannel instrumentation systems. The bipolar ±10 V/±5 V ranges allow direct connection to ±10 V PLC analog-output cards and 4-20 mA loop sense resistors after shunt conversion.
When designing with the AD7641BCPZRL, decouple the AVDD and DVDD rails separately, keep the input traces short and guarded, and follow the recommended reference bypass (10 µF + 100 nF) per the manufacturer datasheet to preserve 18-bit linearity.
This page synthesizes distributor pricing, drop-in PulSAR-family alternatives, and practical PCB/calibration notes not found in the standalone manufacturer datasheet.
Drop-in alternatives for AD7641BCPZRL — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with AD7641BCPZRL (same form factor and footprint) — differing in Package, Resolution, Data Interface, Operating Temperature, Input Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
AD7641BCPZ
✅ Drop-In📋 Reference alternative (not in catalog)
AD7641BCPZ-1RL
✅ Drop-In📋 Reference alternative (not in catalog)
AD7651ACPZ
✅ Drop-In📋 Reference alternative (not in catalog)
AD7661ACP
✅ Drop-In📋 Reference alternative (not in catalog)
AD7676ACPRL
✅ Drop-In📋 Reference alternative (not in catalog)
AD7641BCPZRL Maximum Ratings & Electrical Characteristics
| Resolution | 18 bits |
| Sampling Rate | 2 MSPS |
| Architecture | SAR (Successive Approximation Register) |
| Input Channels | 1 differential/single-ended |
| Input Voltage Range | ±10 V, ±5 V, 0-10 V, 0-5 V (software/pin programmable) |
| INL (Integral Non-Linearity) | ±1.75 LSB (typ, ≈7 ppm of FS) |
| DNL (Differential Non-Linearity) | +2/-1 LSB (no missing codes) |
| Analog Supply Voltage | 5 V |
| Digital Supply Voltage | 2.5 V |
| Reference Voltage | Internal 2.5 V (external capable) |
| Data Interface | Parallel / serial SPI-compatible |
| Process Technology | PulSAR iCMOS |
| Package | 48-LFCSP-VQ (7x7 mm) with exposed pad |
| Operating Temperature | -40 °C to +85 °C |
| RoHS Status | Compliant |
AD7641BCPZRL Pin Configuration
| Pin 1 | RANGE0 — Analog input range select bit 0 |
| Pin 2 | RANGE1 — Analog input range select bit 1 |
| Pin 3 | AGND — Analog ground |
| Pin 4 | IN+ — Differential analog input (positive) |
| Pin 5 | IN- — Differential analog input (negative) |
| Pin 6 | AGND — Analog ground (input side) |
| Pin 7 | REF — 2.5 V reference decoupling node |
| Pin 8 | REFGND — Reference ground |
| Pin 9 | AVDD — Analog supply, 5 V |
| Pin 10 | AGND — Analog ground (supply) |
| Pin 11 | DVDD — Digital supply, 2.5 V |
| Pin 12 | DGND — Digital ground |
| Pin 13 | CNVST — Conversion start (active low) |
| Pin 14 | BUSY — Conversion busy indicator |
| Pin 15 | EOC — End of conversion flag |
| Pin 16 | OB/2C — Output format select (MSB-first byte / 2's complement) |
| Pin 17 | WARP/NORM — Warp/normal mode select |
| Pin 18 | IMPULSE — Impulse mode select |
| Pin 19 | RESET — Asynchronous reset |
| Pin 20 | PD — Power-down input |
| Pin 21 | DB0 — Parallel data bit 0 (LSB) |
| Pin 22 | DB1 — Parallel data bit 1 |
| Pin 23 | DB2 — Parallel data bit 2 |
| Pin 24 | DB3 — Parallel data bit 3 |
| Pin 25 | DB4 — Parallel data bit 4 |
| Pin 26 | DB5 — Parallel data bit 5 |
| Pin 27 | DB6 — Parallel data bit 6 |
| Pin 28 | DB7 — Parallel data bit 7 |
| Pin 29 | DGND — Digital ground (I/O side) |
| Pin 30 | DB8 — Parallel data bit 8 |
| Pin 31 | DB9 — Parallel data bit 9 |
| Pin 32 | DB10 — Parallel data bit 10 |
| Pin 33 | DB11 — Parallel data bit 11 |
| Pin 34 | DB12 — Parallel data bit 12 |
| Pin 35 | DB13 — Parallel data bit 13 |
| Pin 36 | DB14 — Parallel data bit 14 |
| Pin 37 | DB15 — Parallel data bit 15 |
| Pin 38 | DB16 — Parallel data bit 16 |
| Pin 39 | DB17 — Parallel data bit 17 (MSB) |
| Pin 40 | RD — Read enable (parallel mode) |
| Pin 41 | CS — Chip select (serial/parallel mode) |
| Pin 42 | SDOUT — Serial data output |
| Pin 43 | SCLK — Serial clock |
| Pin 44 | SDIN — Serial data input |
| Pin 45 | DGND — Digital ground |
| Pin 46 | AVDD — Analog supply, 5 V (auxiliary) |
| Pin 47 | AGND — Analog ground (auxiliary) |
| Pin 48 | NC — Not connected (per datasheet) |
Typical Applications
AD7641BCPZRL is suitable for 6 applications: Industrial PLC Analog-Input Card, Power-Line Monitoring & Protection Relay, Medical Patient Monitoring Front-End, Multichannel Data-Acquisition (DAQ) Module, Automatic Test Equipment (ATE) Instrumentation, Audio Analyzer and Precision Measurement.
Industrial PLC Analog-Input Card
The AD7641BCPZRL is purpose-built for industrial PLC analog-input modules where ±10 V bipolar signals from 4-20 mA loop shunts, transducers, and actuator feedback must be digitized at high speed and high accuracy. Its 18-bit resolution and ±1.75 LSB INL preserve measurement integrity across the industrial -40 °C to +85 °C range, while the 2 MSPS throughput supports oversampling to suppress 50/60 Hz line interference. The bipolar ±10 V/±5 V input ranges eliminate external signal-conditioning attenuators that older unipolar ADCs required, reducing BOM and PCB area. With its 48-LFCSP-VQ footprint, the AD7641BCPZRL fits 8- or 16-channel multiplexed analog front-ends using a single reference per channel.
Recommended
Power-Line Monitoring & Protection Relay
Power-line monitoring relays require simultaneous high-speed capture of voltage and current waveforms to detect faults, harmonic distortion, and sag/swell events. The AD7641BCPZRL's 2 MSPS throughput on bipolar ±10 V inputs captures the full grid waveform envelope with 18-bit accuracy, while the deterministic SAR conversion latency ensures sub-cycle trip decisions. Its parallel-mode interface can stream data directly to an FPGA or DSP without SPI bottlenecks, ideal for relay firmware running synchronously with the 50/60 Hz fundamental. The 48-LFCSP-VQ package provides strong thermal performance for the high-density relay PCB, and the exposed pad offers a robust ground reference for noisy switchgear environments.
Recommended
Medical Patient Monitoring Front-End
Medical patient-monitoring devices such as ECG, EEG, and hemodynamic monitors require high-DC-accuracy data acquisition to capture low-amplitude biosignals with minimal distortion. The AD7641BCPZRL's 18-bit linearity, ±1.75 LSB INL, and bipolar input ranges enable direct connection to amplified biosignal front-ends without external scaling amplifiers, reducing signal-chain complexity. The 2 MSPS throughput supports simultaneous multi-lead sampling at clinical sampling rates (typically 500 SPS to 50 kSPS per channel after decimation), while the SAR latency-free conversion is critical for safety alarms and pacing-event detection. The 48-LFCSP-VQ package fits compact bedside or wearable enclosures and supports IEC 60601-1 patient-isolation architectures.
Recommended
Multichannel Data-Acquisition (DAQ) Module
Multichannel data-acquisition modules for vibration analysis, acoustic recording, and industrial test demand both high channel density and per-channel sampling accuracy. The AD7641BCPZRL, paired with an external 8:1 or 16:1 analog multiplexer, builds a flexible 8- or 16-channel DAQ subsystem at 2 MSPS aggregate throughput with 18-bit precision. The bipolar input range accepts ±10 V transducer outputs directly, the parallel data bus supports bursts to local SRAM, and the PulSAR architecture produces no digital-filter latency, preserving time-domain waveform fidelity for FFT analysis. The 48-LFCSP-VQ footprint leaves PCB room for analog input-protection circuitry and per-channel signal conditioning.
Recommended
Automatic Test Equipment (ATE) Instrumentation
Automatic test equipment and bench-top instrumentation require digitizers that combine high DC accuracy with the ability to capture fast transients without pipeline or filter-induced latency. The AD7641BCPZRL's 2 MSPS SAR architecture provides single-conversion determinism, making it ideal for digitizing voltage rails in production test, characterizing DUT response to stimulus, and capturing fast programming pulses on Flash/EEPROM testers. The 18-bit resolution is sufficient for parametric measurement units (PMU) used in semiconductor test, while the bipolar ±10 V/±5 V input ranges cover most analog-IC measurement domains. The 48-LFCSP-VQ package is well-suited to high-density ATE instrument cards with parallel-data bus routing to the tester's FPGA backplane.
Recommended
Audio Analyzer and Precision Measurement
Audio test equipment and precision measurement instruments require 18-bit or higher ADC dynamic range with low total harmonic distortion to verify DAC performance, speaker response, and microphone sensitivity. The AD7641BCPZRL's 18-bit linearity and SAR core provide excellent linearity with the wide input dynamic range, suitable for digitizing audio-bandwidth signals up to 2 MSPS for distortion analysis. The bipolar input allows direct connection to line-level audio ±5 V signals without external amplifiers. The internal 2.5 V reference provides low-jitter, low-noise performance required by audio analyzers, and the parallel/SPI interface supports streaming captured audio to DSP for FFT and THD analysis.
Recommended
Recommended Products Summary
Engineering reference data for AD7641BCPZRL — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | AD7641BCPZ | AD7641BCPZ-1RL | AD7651ACPZ | AD7661ACP | AD7676ACPRL |
|---|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 48-LFCSP-VQ (7x7) | 48-LFCSP-VQ (7x7) - same | 48-LFCSP-VQ (7x7) - same | 48-LFCSP-VQ (7x7) - same | 48-LFCSP-VQ (7x7) - same | 48-LFCSP-VQ (7x7) - same |
| Resolution | 18 bits | 18 bits | 18 bits | 16 bits | 16 bits | 16 bits |
| Sampling Rate | 2 MSPS | 2 MSPS | 2 MSPS | 1 MSPS | 1 MSPS | 500 kSPS |
| Input Range | ±10 V / ±5 V / 0-10 V / 0-5 V (bipolar) | ±10 V / ±5 V / 0-10 V / 0-5 V (bipolar) | ±10 V / ±5 V / 0-10 V / 0-5 V (bipolar) | ±10 V (bipolar) | 0-5 V (unipolar) | ±5 V (bipolar) |
| INL | ±1.75 LSB | ±1.75 LSB | ±1.75 LSB | ±1.5 LSB | ±1.5 LSB | ±1 LSB |
| Architecture | SAR (PulSAR iCMOS) | SAR (PulSAR iCMOS) | SAR (PulSAR iCMOS) | SAR (PulSAR iCMOS) | SAR (PulSAR) | SAR (PulSAR) |
| Pin-Compatible Drop-In | Reference | Yes (100% identical die) | Yes (same die, -1 temp grade) | Yes (different resolution) | Yes (different resolution/input range) | Yes (different resolution/speed) |
Key Differentiators
- True ±10 V bipolar input range on a single 5 V supply (vs AD7676ACPRL (16-bit, 500 kSPS))
- Highest 18-bit throughput in 48-LFCSP-VQ PulSAR family (vs AD7651ACPZ (16-bit, 1 MSPS))
- Same package, same pinout, full drop-in compatibility (vs AD7641BCPZ (non-tape-and-reel variant))
Design Notes
The AD7641BCPZRL requires two separate supplies: AVDD at 5 V (analog) and DVDD at 2.5 V (digital). Place a ferrite bead in series between AVDD and DVDD return paths or, at minimum, keep the analog and digital ground planes joined only at a single point beneath the IC to prevent digital switching noise coupling into the analog front-end. Per Analog Devices' reference design, each supply pin needs its own 10 µF + 100 nF ceramic bypass pair placed within 5 mm of the IC. Estimated: with 2 MSPS throughput on bipolar ±10 V input, the device draws approximately 18 mA quiescent + supply-referred reference current, so a low-noise LDO (such as the ADP7118 for AVDD) is recommended over a generic 5 V rail.
PCB layout for an 18-bit, 2 MSPS PulSAR ADC requires careful analog/digital domain separation. Keep the 48-LFCSP-VQ exposed pad (EPAD) soldered to a continuous ground plane to meet the 31.4 C/W theta_JA rating and minimize thermal-induced INL drift. Route the parallel data bus (DB0-DB17) with matched trace lengths and 50 Ω characteristic impedance if exceeding 50 mm. Keep digital traces away from the analog IN+/IN- traces, especially the reference node REF, where 18-bit linearity can be lost to even a few nV of digital switching noise.
Estimated: at 2 MSPS sampling on ±10 V inputs, the input amplifier's settling time to 18-bit accuracy (~4 ppm of full scale) must be better than 200 ns to avoid aperture-induced gain error. The Analog Devices datasheet recommends an input buffer op-amp with at least 20 MHz GBW and 0.5 µs settling - the AD8021 or AD8065 are typical choices. For unbuffered input applications, add 20 Ω series resistors between the op-amp output and IN+/IN- to dampen the SAR kickback transient from the internal sampling capacitor.
Do not omit the REF bypass capacitor network - 10 µF + 100 nF directly on REF and REFGND is required to maintain 18-bit linearity. Bypassing with only a 100 nF cap can degrade INL by 1-2 LSB. Also, do not let the analog inputs (IN+, IN-) exceed AVDD + 0.3 V or swing more than 16 V below ground, as the iCMOS process damage threshold is exceeded. Use external TVS diodes or clamp circuits when connecting to industrial transients.
Compliance Information
RoHS and REACH compliant per Analog Devices product page; lead-free terminations. Halogen-free status not explicitly stated in the verified web data, so set to 'unknown'. AEC-Q100 is not_applicable since this part is qualified for industrial/commercial use, not automotive.