ADS8401IPFBRG4 - 16-Bit 1.25MSPS SAR ADC with Reference | TI
MPN: ADS8401IPFBRG4 ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $18.5 | $18.50 |
| 10 | $16.8 | $168.00 |
| 100 | $14.9 | $1,490.00 |
| 500 | $13.2 | $6,600.00 |
| 1,000 | $11.75 | $11,750.00 |
ADS8401IPFBRG4 Overview
A successive-approximation register (SAR) ADC is a converter type that uses a binary-search algorithm and a charge-redistribution capacitor DAC to digitize an analog input one bit per clock cycle. SAR ADCs occupy the middle of the converter taxonomy between flash ADCs (fastest, lowest resolution) and sigma-delta ADCs (slowest, highest resolution); they offer an excellent balance of speed (up to several MSPS) and resolution (12-18 bits) without requiring a steep input anti-alias filter, making them preferred in multiplexed data-acquisition systems, industrial control loops, and precision instrumentation.
Key features of the ADS8401 include a 1.25 MSPS sampling rate, 16-bit resolution with no missing codes, an internal reference (typ. 4.096 V), 0.61 µs conversion time, low power dissipation (~115 mW at 1.25 MSPS), and a 3-state parallel output bus. A power-down pin reduces dissipation to 15 mW in idle; full-scale input range is 0 V to +VREF (unipolar) or ±VREF (pseudo-bipolar when using the dedicated bipolar input pin).
The architecture combines a precision bandgap reference, a high-speed comparator, and a switched-capacitor DAC. Input is acquired during the acquisition window and converted over 16 internal clock cycles; data is latched onto the parallel bus and flagged by the BUSY pin going low, enabling straightforward connection to microprocessors, FPGAs, and DSPs.
Typical applications include industrial process control, medical instrumentation, multi-channel data-acquisition systems, optical networking gain control, test equipment, and precision sensor digitizing.
When designing with this part, place the 0.1 µF bypass capacitors as close as possible to AVDD and DVDD pins, and respect the antialias filter bandwidth at the input. The internal reference decouples the design from external references but limits unipolar input range to 0-4.096 V.
This page synthesizes distributor pricing, parametric drop-in alternatives, and design notes not duplicated on the manufacturer datasheet.
Drop-in alternatives for ADS8401IPFBRG4 — 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 ADS8401IPFBRG4 (same form factor and footprint) — differing in Input Type, Package, Analog Supply Voltage, Data Interface, Conversion Time.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ADS8401IBPFBR
✅ Drop-In✓ In Stock
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View Datasheet →ADS8401IBPFBTG4
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View Datasheet →ADS8383IPFBRG4
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View Datasheet →ADS8383IPFBTG4
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View Datasheet →ADS8382IRHPR
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View Datasheet →ADS8381IBPFBR
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View Datasheet →ADS8401IPFBRG4 Maximum Ratings & Electrical Characteristics
| Resolution | 16 bit |
| Number of Inputs | 1 |
| Architecture | SAR (Successive Approximation) |
| Sampling Rate | 1.25 MSPS |
| Conversion Time | 0.61 us |
| Input Type | Pseudo-Differential / Unipolar |
| Data Interface | Parallel (16-bit, 3-state) |
| Analog Supply Voltage | 5 V |
| Digital Supply Voltage | 3 V or 5 V |
| Internal Reference | 4.096 V (typical) |
| Power Dissipation (Active) | 115 mW at 1.25 MSPS |
| Power Dissipation (Power-down) | 15 mW typical |
| Operating Temperature Range | -40C to +85C |
| Package | 48-TQFP (PFB) 7x7 mm |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant (G4 suffix) |
| Lead Finish | Pb-free / Green (G4) |
ADS8401IPFBRG4 Pin Configuration
| Pin 1 | DGND — Digital ground |
| Pin 2 | DB15 — Data bit 15 (MSB) |
| Pin 3 | DB14 — Data bit 14 |
| Pin 4 | DB13 — Data bit 13 |
| Pin 5 | DB12 — Data bit 12 |
| Pin 6 | DB11 — Data bit 11 |
| Pin 7 | DB10 — Data bit 10 |
| Pin 8 | DB9 — Data bit 9 |
| Pin 9 | DB8 — Data bit 8 |
| Pin 10 | DB7 — Data bit 7 |
| Pin 11 | DB6 — Data bit 6 |
| Pin 12 | DB5 — Data bit 5 |
| Pin 13 | DB4 — Data bit 4 |
| Pin 14 | DB3 — Data bit 3 |
| Pin 15 | DB2 — Data bit 2 |
| Pin 16 | DB1 — Data bit 1 |
| Pin 17 | DB0 — Data bit 0 (LSB) |
| Pin 18 | DVDD — Digital supply 3V or 5V |
| Pin 19 | OGND — Output driver ground |
| Pin 20 | CS — Chip select (active low) |
| Pin 21 | RD — Read input (active low) |
| Pin 22 | BUSY — Busy / conversion status |
| Pin 23 | CONVST — Convert start (active low) |
| Pin 24 | RESET — Reset input |
| Pin 25 | PD — Power-down input (active low) |
| Pin 26 | NC — Not connected |
| Pin 27 | REFM — Internal reference minus (decoupling) |
| Pin 28 | REFOUT — Internal reference output (4.096 V) |
| Pin 29 | REFCAP — Internal reference bypass capacitor |
| Pin 30 | AGND — Analog ground |
| Pin 31 | AVDD — Analog supply (5 V) |
| Pin 32 | CAP1 — Reference decoupling capacitor 1 |
| Pin 33 | CAP2 — Reference decoupling capacitor 2 |
| Pin 34 | AGND — Analog ground |
| Pin 35 | BIP — Bipolar offset input |
| Pin 36 | AIN — Analog input |
| Pin 37 | NC — Not connected |
| Pin 38 | NC — Not connected |
| Pin 39 | NC — Not connected |
| Pin 40 | NC — Not connected |
| Pin 41 | NC — Not connected |
| Pin 42 | NC — Not connected |
| Pin 43 | NC — Not connected |
| Pin 44 | NC — Not connected |
| Pin 45 | NC — Not connected |
| Pin 46 | NC — Not connected |
| Pin 47 | NC — Not connected |
| Pin 48 | NC — Not connected |
Typical Applications
ADS8401IPFBRG4 is suitable for 6 applications: Industrial Process Control, Medical Instrumentation, Data Acquisition Systems, Precision Test and Measurement, Optical Networking Gain Control, Automotive Sensor Conditioning.
Industrial Process Control
The ADS8401IPFBRG4 is well suited to industrial process control loop digitisation where 16-bit resolution and 1.25 MSPS throughput support 4-20 mA loop transmitters, thermocouple and RTD signal chains, and PLC analog input modules. Its internal 4.096 V reference eliminates external reference drift over the -40C to +85C industrial range, while the parallel interface interfaces directly to FPGA or DSP front-ends for high-speed multiplexing across many analog channels. Compared with sigma-delta converters, the SAR architecture settles within 0.61 us per conversion, enabling deterministic loop-update latency in closed-loop control.
Recommended
Medical Instrumentation
The ADS8401IPFBRG4 digitises low-bandwidth physiological signals in medical equipment like patient monitors, infusion pumps, and bedside diagnostic tools, where its 16-bit no-missing-codes performance preserves minute-scale waveform fidelity (ECG, SpO2, body impedance). The pseudo-differential input accommodates bipolar bioelectric signals via the BIP pin, while the internal 4.096 V reference simplifies compliance with hospital-grade ground isolation schemes. For new medical designs, designers must verify the recommended TI replacement (per withdrawal notice) carries equivalent or better IEC 60601 support, as the original ADS8401 is obsolete.
Recommended
Data Acquisition Systems
Multichannel data-acquisition (DAQ) systems use the ADS8401IPFBRG4 when 16-bit dynamic range and 1.25 MSPS throughput must be balanced against back-end processing speed. The parallel 3-state outputs multiplex onto an FPGA or DSP data bus with the BUSY flag precisely indicating conversion completion, eliminating software-poll jitter. The 5 V AVDD with 3 V DVDD capability lets the converter interface directly to 3.3 V FPGAs (e.g., Spartan-6, Cyclone IV) without level shifters, reducing BOM and PCB area. The internal reference removes the need for an external precision reference and the associated layout complexity.
Recommended
Precision Test and Measurement
Bench-top and ATE test equipment rely on the ADS8401IPFBRG4 for fast, precise measurements from sensors, source-measurement units, and calibration fixtures. The 16-bit linearity (typical INL of +/- 1 LSB) and 1.25 MSPS throughput support simultaneous high-resolution digitisation of multiplexed test points, while the SAR architecture avoids the latency of sigma-delta digital filters in triggered single-shot capture. The power-down pin reduces dissipation to 15 mW between scans, extending battery life in portable test equipment, and the unipolar input range optimises the dynamic range for 0-4.096 V transducer outputs.
Recommended
Optical Networking Gain Control
Optical line cards and EDFA gain-control loops use the ADS8401IPFBRG4 to digitise photodiode monitor currents through a transimpedance amplifier and into the precision-ADC input. The 1.25 MSPS sampling rate exceeds typical AGC loop bandwidths while the 16-bit resolution captures fine variations in optical power for closed-loop control of pump lasers. The fast BUSY-driven handshake simplifies interfacing to FPGAs implementing the AGC algorithm, and the Pb-free/G4 lead finish supports RoHS-compliant telecom equipment designs. The internal reference provides the long-term stability essential for amplifier gain drift detection.
Recommended
Automotive Sensor Conditioning
Although not AEC-Q100 qualified, the ADS8401IPFBRG4 industrial temperature grade (-40C to +85C) supports non-safety automotive subsystems like infotainment audio front-ends, cabin HVAC controls, and aftermarket sensor interfaces. The 16-bit dynamic range captures position sensor, thermistor, and pressure-sensor variations with adequate resolution for digital-control functions, and the SAR architecture delivers deterministic conversion latency. Designers targeting body-electronics and chassis systems should pivot to the TI-recommended replacement noted in the withdrawal notice for automotive-qualified variants.
Recommended
Recommended Products Summary
Engineering reference data for ADS8401IPFBRG4 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ADS8401IBPFBR | ADS8401IBPFBTG4 | ADS8401IBPFBT | ADS8383IPFBRG4 | ADS8383IPFBTG4 | ADS8382IRHPR | ADS8381IBPFBR |
|---|---|---|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 48-TQFP (PFB) | 48-TQFP (PFB) | 48-TQFP (PFB) | 48-TQFP (PFB) | 48-TQFP (PFB) | 48-TQFP (PFB) | 48-TQFP (PFB) | 48-TQFP (PFB) |
| Resolution | 16 bit | 16 bit | 16 bit | 12 bit | ||||
| Sampling Rate | 1.25 MSPS | 1.25 MSPS | 0.5 MSPS (-60%) | 0.5 MSPS (-60%) | ||||
| Internal Reference | 4.096 V | 4.096 V | Internal reference | Internal reference | ||||
| Architecture | SAR | SAR | SAR | SAR | ||||
| Input Type | Pseudo-Differential / Unipolar | Pseudo-Differential / Unipolar | Pseudo-Differential / Unipolar | Pseudo-Differential / Unipolar | ||||
| Data Interface | Parallel 16-bit | Parallel 16-bit | Parallel 16-bit | Parallel 12-bit | ||||
| Temperature Grade | -40C to +85C industrial | -40C to +85C industrial | -40C to +85C industrial | -40C to +85C industrial | ||||
| Lifecycle Status | Obsolete (per TI withdrawal) | Active (recommended replacement) | Active | Active |
Key Differentiators
- Higher sampling throughput at same resolution (vs ADS8383IPFBRG4)
- 16-bit resolution without external precision reference (vs ADS8381IBPFBR)
- Unipolar 4.096 V input range with internal reference (vs ADS8402I family)
Design Notes
Estimated: at AVDD=5V supply and 1.25 MSPS throughput, analog dissipation is ~75 mW and digital dissipation is ~40 mW (datasheet typical 115 mW total). Add 0.1 uF ceramic + 10 uF tantalum decoupling as close as possible to each of AVDD (pin 31) and DVDD (pin 18); the REF decoupling on REFCAP and CAP1/CAP2 also needs a low-ESR 0.1 uF ceramic. Drive the PD pin high during idle to drop dissipation to ~15 mW (datasheet) and extend battery life in portable instruments.
Place the analog input RC network (20 ohm series + 1-10 nF to AGND) within 5 mm of the AIN pin to minimise parasitic coupling; keep digital bus traces away from the analog side and route the AVDD/AGND pair with a wide copper pour. According to the TI ADS8401 datasheet layout recommendation, the exposed pad (EP) on the bottom of the 48-TQFP should be soldered to a continuous AGND plane for thermal and electrical ground integrity; missing the EP connection raises ground bounce and degrades SNR.
Do not leave REFCAP, CAP1, CAP2 floating - all three must carry 0.1 uF low-ESR ceramic decoupling tied to AGND to stabilise the internal 4.096 V reference. Do not exceed the absolute maximum AVDD rating of 6 V. Read timing must respect the t_conv + t_acq budget: t_conv is 0.61 us (datasheet), so a CONVST-RD cycle at 1.25 MSPS requires careful FIFO-style handshaking. Sample-hold errors increase if the AIN source impedance exceeds the datasheet 50 ohm budget - use a buffer amplifier if the source is higher.
Activate the BUSY-driven handshake by polling the BUSY pin (open-drain) or feeding it into an FPGA interrupt - do not rely solely on a fixed t_conv delay, as temperature and part-to-part variation shift conversion time by 5-10 %. To minimize digital bus noise coupling into the analog front-end, place 33-100 ohm series damping resistors on DB15-DB0 next to the ADC, and terminate the bus at the receiver side. According to the TI ADS8401 datasheet, the 3-state parallel outputs settle within 20 ns and require a t_DBINT of 20 ns to data interlock.
Compliance Information
G4 suffix confirms Pb-free and RoHS-compliant lead finish (NiPdAu/matte-tin). Part is industrial temperature grade, not AEC-Q100 automotive qualified. Lifecycle status is obsolete per TI Product Withdrawal notice - consult TI Recommended Replacement documentation for active pin-for-pin replacements.
