ADS7806P - 12-Bit 40kSPS SAR ADC | Texas Instruments
MPN: ADS7806P ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $18.95 | $18.95 |
| 10 | $17.06 | $170.60 |
| 100 | $15.16 | $1,516.00 |
| 500 | $13.65 | $6,825.00 |
| 1,000 | $12.13 | $12,130.00 |
ADS7806P Overview
Key headline specifications include ±1/2 LSB maximum INL and DNL, 72 dB minimum SINAD at 1 kHz input, 25 μs maximum acquisition+conversion time, 35 mW maximum power dissipation, and a power-down mode that drops quiescent draw to 50 μW. An internal 2.5V reference can be used or overridden with an external reference for ratiometric or absolute-accuracy applications.
A SAR ADC is a successive-approximation-register converter that uses an internal DAC and comparator to perform a binary search across N clock cycles to resolve a single conversion - this architecture is favored for multiplexed data-acquisition systems because it provides deterministic latency, low power consumption, no pipeline delay, and excellent DC accuracy. The ADS7806P belongs to TI's Burr-Brown ADC legacy family and is pin-compatible with the 16-bit ADS7807, allowing designers to migrate a 12-bit design to higher resolution later by simply swapping the part without changing the PCB layout.
Typical applications include industrial process control loops, multi-channel data-acquisition front-ends, factory-automation instrumentation, and test-and-measurement equipment requiring medium-resolution bipolar or unipolar conversion. The wide ±10V input range eliminates the need for external signal-conditioning op-amps in many PLC-style analog input modules.
When laying out a PCB for the ADS7806P, keep analog and digital grounds separated and joined only at the AGND/DGND pins of the IC; place the 10 μF bulk and 0.1 μF bypass capacitors as close to the supply pins as possible. Using the internal reference will save two external components but slightly degrades absolute accuracy and temperature drift versus a precision external reference - select based on whether your system needs ratiometric or absolute measurement quality.
Drop-in alternatives for ADS7806P — 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 ADS7806P (same form factor and footprint) — differing in SINAD, Acquisition + Conversion Time, Data Interface, Package, Reference.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ADS7807P
✅ Drop-In✓ In Stock
$10.65 / Unit
View Datasheet →ADS7805PB
✅ Drop-In✓ In Stock
$10.95 / Unit
View Datasheet →ADS7805PG4
✅ Drop-In✓ In Stock
$17.9 / Unit
View Datasheet →ADS7806P Maximum Ratings & Electrical Characteristics
| Resolution | 12 bits |
| Architecture | SAR (Successive Approximation Register) |
| Sampling Rate | 40 kSPS |
| Number of Input Channels | 1 |
| Input Voltage Ranges | ±10 V, 0 V to +5 V, 0 V to +4 V |
| Supply Voltage | +5 V single supply |
| Power Dissipation | 35 mW (max) |
| Power-Down Mode Current | 50 μW |
| Acquisition + Conversion Time | 25 μs (max) |
| INL (Integral Nonlinearity) | ±1/2 LSB (max) |
| DNL (Differential Nonlinearity) | ±1/2 LSB (max) |
| SINAD | 72 dB (min) at 1 kHz input |
| Data Output Interface | Parallel 12-bit or Serial |
| Output Coding | Binary two's complement or straight binary |
| Reference | Internal 2.5V or external |
| Package Type | 28-pin PDIP (0.300", 7.62 mm) |
ADS7806P Pin Configuration
| Pin 1 | VREF — Reference input/output (internal 2.5V or external override) |
| Pin 2 | AGND — Analog ground |
| Pin 3 | AIN — Analog input |
| Pin 4 | RANGE — Input range select |
| Pin 5 | DGND — Digital ground |
| Pin 6 | CS — Chip select (active low) |
| Pin 7 | R/C — Read/convert control |
| Pin 8 | BUSY — Conversion in progress (active high) |
| Pin 9 | HBEN — High-byte enable for parallel interface |
| Pin 10 | TAG — Serial data tag input |
| Pin 11 | SDATA — Serial data output |
| Pin 12 | SCLK — Serial data clock |
| Pin 13 | DB0 — Data bit 0 (LSB) |
| Pin 14 | DB1 — Data bit 1 |
| Pin 15 | DB2 — Data bit 2 |
| Pin 16 | DB3 — Data bit 3 |
| Pin 17 | DB4 — Data bit 4 |
| Pin 18 | DB5 — Data bit 5 |
| Pin 19 | DB6 — Data bit 6 |
| Pin 20 | DB7 — Data bit 7 |
| Pin 21 | DB8 — Data bit 8 |
| Pin 22 | DB9 — Data bit 9 |
| Pin 23 | DB10 — Data bit 10 |
| Pin 24 | DB11 — Data bit 11 (MSB) |
| Pin 25 | VANA — +5V analog supply |
| Pin 26 | VDIG — +5V digital supply |
| Pin 27 | PD — Power-down input |
| Pin 28 | CLKIN — External clock input |
Typical Applications
ADS7806P is suitable for 8 applications: Industrial Process Control Analog Input Module, Multichannel Data Acquisition System, Programmable Logic Controller (PLC) Analog Input Card, Test and Measurement Instrumentation, Medical Monitoring Front End, Audio and Signal-Analysis Equipment (Slow Signals), Battery Management and Energy Monitoring, Factory Automation Sensor Hub.
Industrial Process Control Analog Input Module
The ADS7806P's ±10V bipolar input range interfaces directly with industrial transducer signals from 4-20 mA current-loop resistors, thermocouple amplifiers, and strain-gauge bridges, eliminating front-end signal-conditioning op-amps in PLC analog input cards. The 12-bit resolution over a ±10V full-scale span yields 4.88 mV per LSB, sufficient for process-control loop stability and proportional-integral-derivative actuator feedback. The 72 dB minimum SINAD at 1 kHz input confirms clean digitization of slowly varying control signals, while the 35 mW dissipation allows 8- or 16-channel multiplexer-front-end designs to fit within a single backplane thermal envelope. Designers typically place the ADS7806P behind a low-leakage CMOS multiplexer such as the MUX36S08 and add a unity-gain buffer amplifier on its analog input to handle multiplexer charge injection and settling into the 25 μs acquisition window.
Recommended
Multichannel Data Acquisition System
In a multichannel data-acquisition system, the ADS7806P serves as the per-channel or shared ADC backend for sensors spanning 0-5V unipolar or ±10V bipolar output ranges. The 40 kSPS aggregate throughput, combined with an external analog multiplexer, scales to 8 channels at 5 kSPS each or 16 channels at 2.5 kSPS each - well matched to typical sensor-bandwidth signals in machinery health, vibration monitoring, or building-automation telemetry. The internal 2.5V reference simplifies ratiometric scans when the sensor excitation is also derived from the same reference, while an external REF5025 reference can be substituted for absolute-accuracy requirements where ppm-level drift matters. The DIP-28 package aids prototyping and rework, and the parallel interface avoids the bit-rate tax that serial ADCs impose on MCU sampling loops above 10 kSPS.
Recommended
Programmable Logic Controller (PLC) Analog Input Card
PLC analog input modules commonly deploy the ADS7806P for digitizing 4-20 mA loop currents sensed across a 250 ohm shunt resistor, yielding a 1-5V signal that maps cleanly into the 0-5V unipolar input range. The 12-bit resolution over the 1-5V span provides 0.98 mV per LSB at the converter input, equating to roughly 0.16 mA per LSB after scaling - sufficient resolution for proportional valve control and discrete set-point switching. The 50 μW power-down mode enables power-sequenced per-card shutdown under PLC supervision, and the single +5V supply rail simplifies isolated-DC-DC converter selection on each analog card. The DIP-28 mechanical package eases field replacement and rework on legacy industrial backplanes where through-hole assembly remains standard.
Recommended
Test and Measurement Instrumentation
Bench-top multimeters, oscilloscope auxiliary inputs, and laboratory data loggers use the ADS7806P for general-purpose 12-bit digitization thanks to its wide ±10V input range, which directly accepts standard 10V peak signals without external attenuators. The ±1/2 LSB maximum INL and DNL ensure monotonic acquisition, while the 72 dB SINAD floor provides roughly 12 effective bits for AC-input measurements such as THD analysis of audio-band signals. The internal 2.5V reference suffices for hand-held instrument accuracy budgets, and the parallel data interface simplifies capture into FPGA or CPLD measurement pipelines that drive displays and USB bridges. The 40 kSPS throughput is more than adequate for slow-DC parameter sweepers and battery-cycler test fixtures where signal bandwidth rarely exceeds 1 kHz.
Recommended
Medical Monitoring Front End
Patient-monitoring peripherals such as temperature probes, respiration sensors, and slow-electrophysiological amplifiers can use the ADS7806P as the digitizer stage because the 0-5V unipolar input range matches amplified biosensor outputs after signal conditioning. The ±1/2 LSB INL avoids code-edge noise that could otherwise appear as spurious transitions on slowly moving vital-sign waveforms displayed bedside. The single +5V supply rail is compatible with medical-grade isolated supplies, and the 35 mW power dissipation contributes negligibly to battery-powered portable monitor budgets. Designers must add medical-specific isolation and patient-leakage current barriers external to the ADS7806P; the ADC itself does not provide any inherent patient-protection isolation.
Recommended
Audio and Signal-Analysis Equipment (Slow Signals)
Although the ADS7806P's 40 kSPS rate cannot digitize broadband audio, it is well suited to sub-audio control-loop signals, VU-meter level-detection circuits, and transducer-bias feedback in professional audio equipment. The internal 2.5V reference yields DC-stability gains over external references when digitizing amplifier supply-rail monitor outputs, and the parallel interface cleanly latches into audio-DSP front ends such as the TAS series. The 72 dB SINAD floor matches the dynamic-range requirements of metering buses and clip-detector outputs far better than the 96 dB main audio path requires - reserving the high-resolution ADC for the actual audio path while keeping the ADS7806P for the supporting DC rails.
Recommended
Battery Management and Energy Monitoring
Battery-management systems use the ADS7806P for cell-voltage and pack-current telemetry where 12-bit resolution across a 0-5V or ±10V range is sufficient for state-of-charge estimation and coulomb-counting verification. The single +5V supply rail can be derived from the pack's 12V or 24V auxiliary rail via a low-dropout regulator, and the 50 μW power-down mode enables sleep-mode current sensing in idle monitor ICs. The SAR architecture provides deterministic conversion latency that simplifies synchronization with the BMS controller's supervisory loop. The internal reference is suitable for relative cell-balancing measurements, while an external REF5025 reference is preferred when absolute pack-voltage traceability to a calibration standard is required for warranty or regulatory reporting.
Recommended
Factory Automation Sensor Hub
Factory-automation hubs aggregate proximity sensors, photoelectric switches, and analog encoder outputs into a single backplane where the ADS7806P handles the medium-resolution analog inputs while leaving the high-speed logic signals to dedicated counters. The ±10V input range directly accepts legacy analog sensor outputs without range-shaping cards, dramatically simplifying backplane design. The 25 μs acquisition-plus-conversion time is well under typical factory scan-cycle budgets of 1-10 ms, leaving ample margin for multiplexer settling before the next channel read. The DIP-28 package also simplifies field service replacement when an individual ADC channel fails - a feature that matters for high-availability industrial lines where downtime is measured in dollars per minute.
Recommended
Recommended Products Summary
Engineering reference data for ADS7806P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ADS7807P | ADS7805PB | ADS7805PG4 |
|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 28-PDIP | 28-PDIP | 28-PDIP | 28-PDIP |
| Resolution | 12 bits | 16 bits | 16 bits | 16 bits |
| Sample Rate | 40 kSPS | 40 kSPS | 100 kSPS | 100 kSPS |
| INL (max) | ±1/2 LSB | ±1.5 LSB | ±1 LSB | ±1 LSB |
| DNL (max) | ±1/2 LSB | ±1 LSB | ±1 LSB | ±1 LSB |
| SINAD (min) | 72 dB @ 1 kHz | 86 dB @ 1 kHz | 86 dB @ 1 kHz | 86 dB @ 1 kHz |
| Power Dissipation (max) | 35 mW | 35 mW | 80 mW | 80 mW |
| Input Range | ±10V / 0-5V / 0-4V | ±10V / 0-5V / 0-4V | ±10V / 0-5V / 0-4V | ±10V / 0-5V / 0-4V |
Key Differentiators
- Three software-configurable input ranges on one pinout (vs ADS7805PB)
- 50 μW power-down mode for sleep-mode scanning (vs ADS7807P)
- Pin-compatible migration path to 16-bit ADS7807P (vs ADS7805PG4)
Design Notes
Keep analog and digital grounds separated and join them only at the ADS7806P AGND/DGND pins; this prevents digital-return currents from corrupting the analog-input reference node. Place the 10 μF bulk decoupling capacitor and a 0.1 μF ceramic bypass within 5 mm of the VANA and VDIG pins, with the smallest-value cap closest to the IC. Route parallel data bus traces away from the analog input trace and analog supply rail to minimize digital coupling into the input sample-and-hold. Estimated: assuming 5 nV/sqrt(Hz) digital noise density and 100 mA of switching return current, an ungrounded analog trace could pick up approximately 50 μV of digital crosstalk, which is significant at the 4.88 mV LSB scale of the ADS7806P.
Do not leave the RANGE pin floating - the ADS7806P requires a defined logic level to select between ±10V, 0-5V, and 0-4V input ranges, and a floating RANGE pin can produce unpredictable full-scale behavior. Drive PD low (normal operation) through a 10 kΩ pull-down rather than leaving it open, since a floating PD pin can intermittently enter power-down mode and interrupt conversions. Use the BUSY rising-edge to validate conversion completion - if CS is asserted while BUSY is high, the data bus will be invalid. These three pitfalls account for the majority of first-board bring-up failures with the ADS7806P legacy family.
Drive the ADS7806P analog input through a low-impedance buffer (e.g., OPA227 in unity gain) rather than directly from a high-impedance source; the 25 μs acquisition window requires settling to 12-bit accuracy (0.024% of 4.88 mV LSB) within roughly 10 μs, which implies a source impedance below 2 kΩ at the ADC's 8 pF sampling capacitor (Estimated: tau = RC, settling error ~Vstep * e^(-t/tau)). Add a 10 nF ceramic capacitor across AIN to AGND if your source impedance is between 5 kΩ and 50 kΩ, but do not exceed 100 nF because the leakage can degrade the ±1/2 LSB INL specification at elevated temperatures.
Compliance Information
RoHS and lead-free compliance inferred from TI product page; halogen-free status was not explicitly confirmed in the Verified Web Data and is marked unknown.
