ADS8381IBPFBR - 18-Bit 580kHz SAR ADC | 48-TQFP | Texas Instruments
MPN: ADS8381IBPFBR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $14.5 | $14.50 |
| 10 | $13.05 | $130.50 |
| 100 | $11.6 | $1,160.00 |
| 500 | $10.45 | $5,225.00 |
| 1,000 | $9.85 | $9,850.00 |
ADS8381IBPFBR Overview
A successive-approximation register (SAR) ADC is a type of data converter that performs a binary search through an internal capacitive DAC, producing a digital output in a fixed number of clock cycles with no pipeline delay. SAR ADCs belong to the broader category of Nyquist-rate analog-to-digital converters, which sit at the bottom of the data-converter hierarchy: ADC -> data converter -> signal chain IC -> mixed-signal semiconductor. They are valued for their single-shot accuracy, deterministic latency, and excellent DC linearity compared to delta-sigma or pipeline alternatives.
Key features include 580 kHz sample rate, 18-bit NMC ensured over temperature, unipolar analog input, zero latency, internal reference buffer, internal conversion clock, and a wide 2.7V to 5.25V analog supply range. The parallel digital interface provides easy connection to microcontrollers, DSPs, and FPGAs without requiring a high-speed serial clock. Industrial temperature grade (-40C to +85C) and a small 7x7 mm TQFP footprint enable compact designs in dense signal-conditioning boards.
Typical applications include medical instruments such as patient monitors and portable diagnostic equipment, optical networking line-side data acquisition, transducer interfaces for bridge and thermocouple front-ends, high-accuracy data acquisition systems, and magnetometer signal chains. The 580 kHz throughput comfortably digitizes multi-kHz bandwidth signals at 18-bit precision, while the 115 mW dissipation allows fan-less operation in sealed enclosures.
When designing with this device, drive the analog input with a low-impedance, wide-bandwidth op-amp buffer such as the OPA227 or THS4631 to preserve linearity at the ADC's full-scale settling time. Provide a clean low-noise analog supply and decouple both AVDD and DVDD with 10uF bulk plus 0.1uF ceramic capacitors placed within 5 mm of the supply pins.
Drop-in alternatives for ADS8381IBPFBR — 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 ADS8381IBPFBR (same form factor and footprint) — differing in Package, Input Type, Sample Rate, Architecture, Resolution.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ADS8381IBPFBT
✅ Drop-In📋 Reference alternative (not in catalog)
ADS8383IPFBR
✅ Drop-In📋 Reference alternative (not in catalog)
ADS8383IPFBT
✅ Drop-In📋 Reference alternative (not in catalog)
ADS8342IBPFBR
✅ Drop-In✓ In Stock
$9.45 / Unit
View Datasheet →ADS8482IBRGZR
✅ Drop-In✓ In Stock
$14.45 / Unit
View Datasheet →ADS8381IBPFBR Maximum Ratings & Electrical Characteristics
| Resolution | 18 bit |
| Sample Rate | 580 kSPS |
| Architecture | SAR (Successive Approximation) |
| Number of Channels | 1 |
| Input Type | Single-Ended Unipolar |
| Data Interface | Parallel |
| Package | 48-TQFP (PFB) 7x7 mm |
| Pin Count | 48 |
| Operating Temperature Range | -40C to +85C |
| Analog Supply Voltage | 2.7 V to 5.25 V |
| Power Dissipation | 115 mW at 580 kHz |
| No Missing Code | 18-bit NMC ensured over temperature |
| Latency | Zero (SAR architecture) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Terminal Form | Gull Wing |
| Package Code | TFQFP |
ADS8381IBPFBR Pin Configuration
| Pin 1 | DVDD — Digital supply |
| Pin 2 | DGND — Digital ground |
| Pin 3 | DB0 — Data output bit 0 (LSB) |
| Pin 4 | DB1 — Data output bit 1 |
| Pin 5 | DB2 — Data output bit 2 |
| Pin 6 | DB3 — Data output bit 3 |
| Pin 7 | DB4 — Data output bit 4 |
| Pin 8 | DB5 — Data output bit 5 |
| Pin 9 | DB6 — Data output bit 6 |
| Pin 10 | DB7 — Data output bit 7 |
| Pin 11 | DB8 — Data output bit 8 |
| Pin 12 | DB9 — Data output bit 9 |
| Pin 13 | DB10 — Data output bit 10 |
| Pin 14 | DB11 — Data output bit 11 |
| Pin 15 | DB12 — Data output bit 12 |
| Pin 16 | DB13 — Data output bit 13 |
| Pin 17 | DB14 — Data output bit 14 |
| Pin 18 | DB15 — Data output bit 15 |
| Pin 19 | DB16 — Data output bit 16 |
| Pin 20 | DB17 — Data output bit 17 (MSB) |
| Pin 21 | DGND — Digital ground |
| Pin 22 | DVDD — Digital supply |
| Pin 23 | BUSY — Conversion in progress (active high) |
| Pin 24 | CS — Chip select (active low) |
| Pin 25 | RD — Read strobe (active low) |
| Pin 26 | CONVST — Conversion start (active low) |
| Pin 27 | RESET — Reset (active low) |
| Pin 28 | NC — Not connected |
| Pin 29 | REFM — Reference ground |
| Pin 30 | REFIN — Reference input |
| Pin 31 | REFOUT — Reference output (internal buffer) |
| Pin 32 | AGND — Analog ground |
| Pin 33 | AVDD — Analog supply |
| Pin 34 | AGND — Analog ground |
| Pin 35 | IN+ — Analog positive input |
| Pin 36 | IN- — Analog negative input (tied to AGND for unipolar) |
| Pin 37 | AGND — Analog ground |
| Pin 38 | AVDD — Analog supply |
| Pin 39 | NC — Not connected |
| Pin 40 | NC — Not connected |
| Pin 41 | NC — Not connected |
| Pin 42 | NC — Not connected |
| Pin 43 | AGND — Analog ground |
| Pin 44 | AVDD — Analog supply |
| Pin 45 | NC — Not connected |
| Pin 46 | NC — Not connected |
| Pin 47 | DGND — Digital ground |
| Pin 48 | DVDD — Digital supply |
Typical Applications
ADS8381IBPFBR is suitable for 8 applications: Medical Instrument Data Acquisition, Optical Networking Line-Side Digitization, Precision Transducer Interface, High-Accuracy Data Acquisition Systems, Magnetometer and Compass Signal Chains, Industrial Process Control and Automation, Portable Test and Measurement, Audio Bandwidth Precision Digitization.
Medical Instrument Data Acquisition
The ADS8381IBPFBR's 18-bit NMC and 580 kSPS throughput suit medical front-ends digitizing biopotential and transducer signals where DC accuracy dominates. Its 115 mW dissipation allows fan-less patient monitors and portable diagnostic carts, while the 48-TQFP 7x7 mm footprint fits compact bedside enclosures. The zero-latency SAR architecture ensures deterministic single-shot conversions for safety-critical measurements such as ECG, SpO2 photodiode currents, and infusion-pump pressure transducers. Drive the input with a low-noise op-amp such as the INA128 instrumentation front-end and decouple AVDD/DVDD with 10uF + 0.1uF ceramics to preserve linearity across the 18-bit dynamic range.
Recommended
Optical Networking Line-Side Digitization
Optical transponder and line-card designs use the ADS8381IBPFBR to digitize received analog signals from PIN or APD photodiode TIAs before DSP-based clock-data recovery. The 580 kSPS throughput handles multi-MHz bandwidth signals at 18-bit precision, while the parallel interface streams directly into an FPGA or ASIC without serial-clock overhead. Its unipolar input matches single-supply transimpedance-amplifier outputs, and the 48-TQFP industrial-grade package withstands line-card ambient temperatures. Combine with a THS4631 wide-band op-amp buffer and clean AVDD supply to achieve the linearity demanded by long-haul optical links.
Recommended
Precision Transducer Interface
Strain-gauge bridges, load cells, RTD signal conditioners, and thermocouple amplifiers all benefit from the ADS8381IBPFBR's 18-bit NMC and zero SAR latency. Single-shot digitizations eliminate pipeline ambiguity for weighing scales and force-feedback systems requiring deterministic readings. The 2.7V to 5.25V analog supply simplifies integration with 3.3V or 5V transducer excitation rails. Industrial-grade -40C to +85C operation supports outdoor and factory-floor deployments. Pair with the ADS131A04 ADC for multi-channel bridge applications, or use the OPA227 low-offset op-amp as a precision front-end buffer.
Recommended
High-Accuracy Data Acquisition Systems
PCI- and PXI-style modular DAQ boards use the ADS8381IBPFBR as a per-channel simultaneous-sampling ADC where 18-bit NMC and 580 kSPS throughput combine for laboratory-grade measurement. The parallel bus simplifies interface to FPGA-based timing engines and on-board DSP. Zero latency simplifies trigger-and-arm sequencing in transient recorders. Its low 115 mW dissipation supports dense multi-board chassis without active cooling, and the 48-TQFP industrial package is compatible with automated pick-and-place assembly.
Recommended
Magnetometer and Compass Signal Chains
Fluxgate and AMR magnetometer front-ends produce sub-kHz analog signals requiring high DC resolution; the ADS8381IBPFBR's 18-bit NMC captures field changes below 1 nT when paired with low-noise instrumentation amplifiers. Its 580 kSPS sample rate oversamples slowly varying magnetic fields, supporting averaging for sub-LSB noise reduction. Industrial temperature grade ensures stable compass headings across outdoor and avionics environments. The unipolar input accepts single-ended magnetometer amplifier outputs, simplifying signal conditioning.
Recommended
Industrial Process Control and Automation
PLC analog input modules and process-control digitizers use the ADS8381IBPFBR to convert 4-20 mA or 0-10V process signals into 18-bit digital readings at up to 580 kSPS. The zero-latency SAR conversion supports fast safety-loop response times, and the wide 2.7V to 5.25V supply tolerates 24V industrial bus rails after front-end scaling. The 48-TQFP package's industrial temperature rating handles factory-floor ambient conditions. Pair with the ISO124 isolation amplifier for grounded-noise immunity and the XTR116 4-20 mA current-loop transmitter for complete analog I/O subsystems.
Recommended
Portable Test and Measurement
Handheld oscilloscope front-ends, bench multimeters, and field instrumentation use the ADS8381IBPFBR for high-DC-accuracy voltage and current digitizations at moderate bandwidths. Its 115 mW dissipation extends battery life in portable instruments, and the 48-TQFP compact footprint fits slim meter enclosures. The parallel interface supports burst-mode acquisitions to on-board microcontrollers or DSPs. Pair with the OPA2188 zero-drift op-amp for sub-1 uV offset front-ends in 6.5-digit multimeter designs, and use the TPS7A30 LDO for clean analog supply regulation.
Recommended
Audio Bandwidth Precision Digitization
Professional audio analyzers and acoustic measurement systems use the ADS8381IBPFBR to capture 18-bit audio-bandwidth signals with deterministic SAR latency. The 580 kSPS throughput supports 96 kHz / 192 kHz oversampling ratios for digital-filter based noise shaping. While not a dedicated audio ADC, its 18-bit NMC and low distortion suit measurement-microphone and line-level analyzer digitizers where calibration accuracy matters more than dynamic range. Combine with the PCM4220 audio ADC for parallel precision-audio channels in test rigs.
Recommended
Recommended Products Summary
Engineering reference data for ADS8381IBPFBR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ADS8381IBPFBT | ADS8383IPFBR | ADS8383IPFBT | ADS8342IBPFBR | ADS8482IBRGZR |
|---|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 48-TQFP (PFB) 7x7 mm | 48-TQFP (PFB) 7x7 mm - same | 48-TQFP (PFB) 7x7 mm - same | 48-TQFP (PFB) 7x7 mm - same | 48-TQFP (PFB) 7x7 mm - same | 48-pin QFN (RGZ) - same footprint family |
| Resolution | 18 bit | 18 bit | 16 bit | 16 bit | 16 bit | 18 bit |
| Sample Rate | 580 kSPS | 580 kSPS | 500 kSPS | 500 kSPS | 250 kSPS | 1000 kSPS |
| Architecture | SAR | SAR | SAR | SAR | SAR | SAR (pseudo-bipolar) |
| Input Channels | 1 unipolar | 1 unipolar | 1 unipolar | 1 unipolar | 8 (with MUX) | 1 pseudo-bipolar |
| Data Interface | Parallel | Parallel | Parallel | Parallel | Parallel/SPI | Parallel |
| Power Dissipation | 115 mW at 580 kSPS | 115 mW at 580 kSPS | 110 mW at 500 kSPS | 110 mW at 500 kSPS | 40 mW at 250 kSPS | 220 mW at 1 MSPS |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
Key Differentiators
- 18-bit NMC guaranteed over industrial temperature range (vs ADS8383IPFBR)
- Zero pipeline latency SAR architecture (vs ADS8482IBRGZR)
- True pin-compatible drop-in family member (vs ADS8422IBPFBR)
Design Notes
Decouple AVDD and DVDD separately with 10uF bulk plus 0.1uF ceramic capacitors placed within 5 mm of the supply pins. Keep the analog and digital ground returns joined at a single point near the ADC's AGND/DGND pins to avoid ground-loop noise coupling into the analog input. Use a low-noise LDO such as the TPS7A4701 for the AVDD rail; its 4.17 uVrms noise and 72 dB PSRR preserve the 18-bit NMC performance specified in the TI datasheet.
Drive the IN+ input with a low-impedance, wide-bandwidth op-amp buffer (such as the THS4631 or OPA227) capable of settling to 18-bit accuracy within the ADC's acquisition time. The buffer's output impedance must be below 50 ohm at the ADC's input bandwidth to avoid gain error. Place the buffer within 10 mm of the ADC input pin, with a ground plane underneath to minimize stray capacitance that would otherwise limit slew rate.
Estimated: routing digital data bus traces over the analog input region will couple switching noise into the IN+ pin and degrade SNR. Keep the DB[17:0] parallel bus traces on the opposite PCB layer from the IN+/IN- traces, separated by a continuous ground plane. Series-damp each digital output with a 33 ohm resistor near the ADC to damp transmission-line reflections on the parallel bus, which can otherwise cause data-correlated glitches during the BUSY=high conversion window.
Per TI's ADS8381 datasheet reference layout, place the REFIN decoupling capacitor (typically 10uF ceramic) directly between the REFIN and REFM pins with the shortest possible trace length. The internal reference buffer provides low-impedance reference voltage to the capacitive DAC; poor REFIN decoupling directly translates to gain error and DNL degradation. Route REFM as a dedicated analog ground trace back to the ADC's AGND pin, avoiding shared returns with digital switching currents.
Compliance Information
RoHS compliant per TI product page. Industrial temperature grade (-40C to +85C) - not AEC-Q100 qualified. Halogen-free status not explicitly stated in verified data; set to 'unknown' rather than assumed.
