ADS1286U - 12-Bit 20kHz Micro Power ADC | Texas Instruments
MPN: ADS1286U ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.2 | $6.20 |
| 10 | $5.58 | $55.80 |
| 100 | $4.96 | $496.00 |
| 500 | $4.46 | $2,230.00 |
| 1,000 | $3.96 | $3,960.00 |
ADS1286U Overview
An analog-to-digital converter is a mixed-signal integrated circuit that converts a continuous-time, continuous-amplitude analog signal into a discrete digital code. The ADS1286 belongs to the successive-approximation-register (SAR) ADC product family within the broader signal-chain taxonomy that includes sigma-delta, pipeline, and flash converters. SAR ADCs are favored for low-power, single-shot, and multiplexed data-acquisition tasks because they offer deterministic latency, compact silicon area, and inherently low power consumption compared with higher-resolution delta-sigma parts.
Key specifications of the ADS1286U include 12-bit resolution, a 20 kHz maximum sampling rate, an integral non-linearity of +/-1 LSB (max), and a SINAD of 72 dB. The differential input stage accepts a +/-Vref full-scale range (typically 0 V to 5 V single- or 5 V differentially) and is preceded by a sample-and-hold that eliminates the need for an external front-end amplifier in most applications. The serial interface is clock-synchronized and supports two- or three-wire operation with an external serial clock rate up to 4 MHz, easing isolation between the converter and the host microcontroller.
Architecturally, the ADS1286 uses a charge-redistribution SAR core with a thin-film laser-trimmed input scaling network; this topology yields the very low 250 uA quiescent current while preserving 12-bit DC accuracy. The internal reference loop is designed for use with an external 2.5 V or 5 V reference, and the device does not include an on-chip reference. The wide-input-range CMOS input structure simplifies sensor-bridge and thermocouple front ends.
Typical end-use applications for the ADS1286U include battery-powered instrumentation, remote data loggers, isolated industrial sensors, portable medical devices, and handheld meters. Its tiny 8-pin SOIC footprint and 250 uA supply current make it especially attractive for loop-powered 4-20 mA transmitters and other energy-harvested nodes where every microamp matters.
A practical design consideration is the addition of an anti-aliasing RC filter ahead of the analog inputs: a 1 kohm/10 nF single-pole filter is sufficient for a 20 kHz Nyquist boundary. Decouple VDD with a 0.1 uF ceramic placed within 5 mm of the supply pin. This page synthesizes distributor pricing, verified drop-in alternatives, and practical layout notes not found on generic catalog summaries.
Drop-in alternatives for ADS1286U — 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 ADS1286U (same form factor and footprint) — differing in Package, Input Type, Architecture, Resolution, Data Interface.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ADS1286UA
✅ Drop-In📋 Reference alternative (not in catalog)
ADS1286UA/2K5
✅ Drop-In📋 Reference alternative (not in catalog)
ADS1286U/2K5
✅ Drop-In📋 Reference alternative (not in catalog)
ADS1286UCG4
✅ Drop-In📋 Reference alternative (not in catalog)
ADS1286U Maximum Ratings & Electrical Characteristics
| Resolution | 12 bits |
| Sampling Rate | 20 kHz |
| Architecture | SAR (Successive Approximation Register) |
| Number of Channels | 1 differential input |
| Supply Voltage | 4.5 V to 5.25 V (single supply) |
| Supply Current | 250 uA (typical) |
| Input Type | Differential with sample-and-hold |
| Integral Non-Linearity (INL) | +/-1 LSB (max) |
| Missing Codes | None (guaranteed) |
| SINAD | 72 dB |
| Serial Interface | SPI/SSI compatible, 2- or 3-wire |
| Maximum Serial Clock | 4 MHz |
| Operating Temperature | -40C to +85C |
| Package | 8-pin SOIC (U) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
ADS1286U Pin Configuration
| Pin 1 | VDD — Positive analog supply, 4.5 V to 5.25 V |
| Pin 2 | +VIN — Positive differential analog input |
| Pin 3 | -VIN — Negative differential analog input |
| Pin 4 | GND — Analog and digital ground |
| Pin 5 | DOUT/DRDY — Serial data output / data-ready indicator |
| Pin 6 | CS/SHDN — Chip-select / shutdown logic input |
| Pin 7 | SCLK — Serial clock input, up to 4 MHz |
| Pin 8 | VREF — External voltage reference input |
Typical Applications
ADS1286U is suitable for 7 applications: Battery-Powered Data Loggers, Isolated Industrial 4-20 mA Sensor Transmitters, Portable Medical Monitoring Devices, Remote Sensor and IoT Edge Nodes, Handheld Test and Measurement Meters, Strain-Gauge Bridge Digitizers, Automotive Sensor Interfaces (Non-Safety).
Battery-Powered Data Loggers
The ADS1286U's 250 uA typical supply current and 4.5-5.25 V single-supply operation make it ideal for battery-powered data loggers. With a quiescent draw under a milliamp, the ADC contributes negligible drain to the system budget, allowing lithium-coin or 4xAA cells to run multi-year deployments. The 12-bit resolution (1.22 mV LSB at 5 VFS) and 20 kHz sampling handle temperature, voltage, and pressure sensor capture with margin. The synchronous SPI interface simplifies isolation in higher-voltage logger designs.
Recommended
Isolated Industrial 4-20 mA Sensor Transmitters
In 4-20 mA current-loop transmitters, the ADS1286U provides 12-bit analog digitization on the field side while drawing only 250 uA. This leaves the bulk of the 4 mA error budget for signal conditioning and isolation. The differential input accepts bridge and thermocouple signals directly, the SPI interface crosses the digital isolator with only three lines, and the 8-pin SOIC footprint simplifies the field-side PCB. The 72 dB SINAD comfortably resolves 12-bit sensor drifts for process control.
Recommended
Portable Medical Monitoring Devices
The ADS1286U supports portable medical monitoring where its 250 uA draw extends battery runtime and its 12-bit resolution captures physiological signals at sample rates up to 20 kHz. The differential input rejects common-mode noise on-body, the SOIC-8 package fits handheld enclosure constraints, and the SPI interface connects to low-power MCUs without glue logic. It is particularly well suited to pulse-oximeter front-ends, ambulatory ECG channels, and infusion-pump pressure sensing.
Recommended
Remote Sensor and IoT Edge Nodes
The ADS1286U is well suited to remote IoT edge nodes where energy budgets are tight. It consumes only 250 uA typical while digitizing bridge sensors, thermistors, or 4-20 mA-vía-shunt signals at up to 20 kHz. Combined with a sub-gigahertz wireless MCU and a small lithium primary cell, the node can run for years unattended. The serial interface allows the host to power-gate the ADC between conversions for further energy savings.
Recommended
Handheld Test and Measurement Meters
The ADS1286U fits handheld DMMs, clamp meters, and insulation testers that require a 12-bit ADC front end. Its 20 kHz sample rate handles single-shot and slow-scan acquisition modes, while the SOIC-8 package keeps the BOM count low and the PCB small. The 250 uA supply current pairs well with low-power operational amplifiers drawing <1 mA per channel. The synchronous serial interface integrates with both LCD-driver MCUs and ARM Cortex hosts.
Recommended
Strain-Gauge Bridge Digitizers
The ADS1286U handles strain-gauge bridge digitizers where its differential input accepts the +/- output of a Wheatstone bridge directly. At 12-bit resolution (1.22 mV LSB) and 72 dB SINAD, the device captures full-scale bridge spans after a single-pole anti-alias filter. The micro-power consumption is critical for weight scales and force gauges powered by USB, coin cells, or harvested energy.
Recommended
Automotive Sensor Interfaces (Non-Safety)
For non-safety automotive body and chassis sensor modules - seat-position sensors, headlamp-leveling sensors, ambient sensors - the ADS1286U provides 12-bit conversion across -40C to +85C with a 250 uA micro-power footprint. It is not AEC-Q100 qualified so safety-critical applications such as airbag or stability control require a different part, but body electronics and climate control modules are well served by this converter.
Recommended
Recommended Products Summary
Engineering reference data for ADS1286U — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ADS1286UA | ADS1286UA/2K5 | ADS1286U/2K5 | ADS1286UCG4 |
|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 8-pin SOIC | 8-pin SOIC - same | 8-pin SOIC - same | 8-pin SOIC - same | 8-pin SOIC - same |
| Resolution | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits |
| Sampling Rate | 20 kHz | 20 kHz | 20 kHz | 20 kHz | 20 kHz |
| Supply Current | 250 uA | 250 uA | 250 uA | 250 uA | 250 uA |
| Supply Voltage | 4.5 V to 5.25 V | 4.5 V to 5.25 V | 4.5 V to 5.25 V | 4.5 V to 5.25 V | 4.5 V to 5.25 V |
| Interface | SPI/SSI 2- or 3-wire | SPI/SSI 2- or 3-wire | SPI/SSI 2- or 3-wire | SPI/SSI 2- or 3-wire | SPI/SSI 2- or 3-wire |
| Input Channels | 1 differential | 1 differential | 1 differential | 1 differential | 1 differential |
| Datasheet Revision | Original | Later (A) | Later (A), 2.5k reel | Original, 2.5k reel | G4 green tier |
Key Differentiators
- Micro-power 250 uA operation in an 8-pin SOIC (vs Generic 12-bit ADC at ~1 mA)
- 2- or 3-wire SPI/SSI serial interface with hardware shutdown (vs Generic 12-bit parallel-output ADC)
- Guaranteed no missing codes across -40C to +85C (vs Lower-cost 12-bit ADC with parametric drift)
Design Notes
Decouple VDD (pin 1) with a 0.1 uF X7R ceramic capacitor placed within 5 mm of the package and a 10 uF bulk capacitor at the regulator output. The reference input (pin 8, VREF) requires a similar 0.1 uF local decouple plus a 1-10 uF bulk cap; for ADC noise performance below the 12-bit LSB level, use a low-noise reference (such as REF02 or REF5040) rather than the 5 V supply rail.
Place a single-pole anti-aliasing RC filter directly at each analog input: a 1 kohm resistor in series with +VIN/-VIN (pin 2/3) and a 1 nF (to 10 nF) capacitor to ground. The differential pair traces to +VIN and -VIN should be routed together, length-matched, and guarded by a ground pour to maintain the 72 dB SINAD at the 20 kHz Nyquist boundary.
Do not leave the CS/SHDN pin (pin 6) floating: it has an internal pull-up but external noise can falsely trigger shutdown mode in 4-20 mA loops. Tie CS low to keep the ADC active, or pull CS high with a weak 100 kohm pull-up for shutdown. Tie any unused pin (such as analog ground noise sensing inputs if not used) per datasheet, never leave floating on the bench.
The serial interface SCLK (pin 7) and DOUT/DRDY (pin 5) run up to 4 MHz. Keep these traces short (<50 mm) and route them over a continuous ground reference. Series-terminate SCLK with 33 ohm if the trace exceeds 25 mm or crosses connectors. For opto-isolated layouts, place the isolator within 10 mm of the ADC to avoid ringing on the open-drain DOUT/DRDY output.
Compliance Information
RoHS and REACH compliant per TI ADS1286 product page. The ADS1286U is not AEC-Q100 qualified; for safety-critical automotive applications a different AEC-Q100 ADC must be selected.
