ADS8685
16-Bit, 500-kSPS, 1-Ch SAR ADC with programmable (±12/±10/±6/±5/±2.5V) input ranges on +5V supply
ADS8685
- 16-bit ADC with integrated analog front-end
- High speed:
- ADS8681: 1 MSPS
- ADS8685: 500 kSPS
- ADS8689: 100 kSPS
- Software programmable input ranges:
- Bipolar ranges: ±12.288 V, ±10.24 V, ±6.144 V, ±5.12 V, and ±2.56 V
- Unipolar ranges: 0 V–12.288 V, 0 V–10.24 V, 0 V–6.144 V, and 0 V–5.12 V
- 5-V analog supply: 1.65-V to 5-V I/O supply
- Constant resistive input impedance ≥ 1 MΩ
- Input overvoltage protection: Up to ±20 V
- On-chip, 4.096-V reference with low drift
- Excellent performance:
- DNL: ±0.4 LSB; INL: ±0.5 LSB
- SNR: 92 dB; THD: –107 dB
- ALARM → high, low threshold
- multiSPI™ interface with daisy-chain
- Extended industrial temperature range: –40°C to +125°C
The ADS8681, ADS8685, and ADS8689 belong to a family of integrated data acquisition system based on a successive approximation (SAR) analog-to-digital converter (ADC). The devices feature a high-speed, high-precision SAR ADC, integrated analog front-end (AFE) input driver circuit, overvoltage protection circuit up to ±20 V, and an on-chip 4.096-V reference with extremely low temperature drift.
The devices operate on a single 5-V analog supply, but support true bipolar input ranges of ±12.288 V, ±6.144 V, ±10.24 V, ±5.12 V, and ±2.56 V, as well as unipolar input ranges of 0 V to 12.288 V, 0 V to 10.24 V, 0 V to 6.144 V, and 0 V to 5.12 V. The gain and offset errors are accurately trimmed within the specified values for each input range to ensure high dc precision. The input range selection is done by software programming of the device internal registers. The devices offer a high resistive input impedance (≥ 1 MΩ) irrespective of the selected input range.
The multiSPI digital interface is backward-compatible to the traditional SPI protocol. Additionally, configurable features simplify interface to a wide range of host controllers.
Technical documentation
Type | Title | Date | ||
---|---|---|---|---|
* | Data sheet | ADS868x 16-Bit, High-Speed, Single-Supply, SAR ADC Data Acquisition System With Programmable, Bipolar Input Ranges datasheet (Rev. E) | PDF | HTML | 15 Aug 2022 |
Application brief | Precision ADCs in Servo Drives | PDF | HTML | 22 Aug 2024 | |
Circuit design | Input Protection for High-Voltage ADC Circuit with TVS Diode (Rev. A) | PDF | HTML | 02 May 2023 | |
Product overview | PLC Analog Input Front-End Architectures | PDF | HTML | 31 Jul 2022 | |
Application note | Cost-Optimized, High-Performance Front-End Design for Analog Input Modules | PDF | HTML | 22 Jun 2022 | |
Application note | Circuit for detecting input floating on ADS8681 ADC | PDF | HTML | 31 Mar 2021 | |
Application note | Extending Input Voltage Range and Understanding Associated Errors for ADC With I | 09 Nov 2018 | ||
White paper | Enabling Faster, Smarter, and More Robust Solutions for SAR ADSx With multiSPI | 08 Nov 2016 | ||
White paper | Voltage-reference impact on total harmonic distortion | 01 Aug 2016 |
Design & development
For additional terms or required resources, click any title below to view the detail page where available.
ANALOG-ENGINEER-CALC — PC software analog engineer's calculator
The analog engineer’s calculator is designed to speed up many of the repetitive calculations that analog circuit design engineers use on a regular basis. This PC-based tool provides a graphical interface with a list of various common calculations ranging from setting operational-amplifier (...)
Supported products & hardware
Products
Precision op amps (Vos<1mV)
General-purpose op amps
Audio op amps
Transimpedance amplifiers
High-speed op amps (GBW ≥ 50 MHz)
Power op amps
Video amplifiers
Line drivers
Transconductance amplifiers & laser drivers
Fully differential amplifiers
Precision ADCs
Biosensing AFEs
High-speed ADCs (≥10 MSPS)
Receivers
Touchscreen controllers
Difference amplifiers
Instrumentation amplifiers
Audio line receivers
Analog current-sense amplifiers
Digital power monitors
Analog current-sense amplifiers with integrated shunt resistor
Digital power monitors with integrated shunt resistor
Die & wafer services
PSPICE-FOR-TI — PSpice® for TI design and simulation tool
TINA-TI — SPICE-based analog simulation program
Package | Pins | CAD symbols, footprints & 3D models |
---|---|---|
TSSOP (PW) | 16 | Ultra Librarian |
Ordering & quality
- RoHS
- REACH
- Device marking
- Lead finish/Ball material
- MSL rating/Peak reflow
- MTBF/FIT estimates
- Material content
- Qualification summary
- Ongoing reliability monitoring
- Fab location
- Assembly location
Recommended products may have parameters, evaluation modules or reference designs related to this TI product.
Support & training
TI E2E™ forums with technical support from TI engineers
Content is provided "as is" by TI and community contributors and does not constitute TI specifications. See terms of use.
If you have questions about quality, packaging or ordering TI products, see TI support.