Texas Instruments ADS8698IDBTR

Overview

ADS8698IDBTR from Texas Instruments is an 18-bit, 8-channel, single-supply SAR analog-to-digital converter with integrated analog front-end, 500-kSPS aggregate throughput, ±20-V input overvoltage protection, and software-programmable bipolar/unipolar input ranges (±10.24 V, ±5.12 V, ±2.56 V, 0–10.24 V, 0–5.12 V). It serves as a precision data acquisition system for industrial PLC analog input modules.

For engineers reviewing the ADS8698IDBTR datasheet, ADS8698IDBTR pinout, ADS8698IDBTR application, or ADS8698IDBTR equivalent, this page delivers verified electrical specs, TSSOP-38 package details, SPI/daisy-chain interface behavior, channel-independent PGA configuration, and real-world use cases in protection relays and power automation systems.

Technical Context

The ADS8698IDBTR implements a successive approximation register (SAR) ADC core with per-channel programmable gain amplifiers (PGA), 2nd-order low-pass filtering, and input overvoltage protection circuitry. Each of its eight single-ended analog inputs features a constant 1-MΩ resistive input impedance and independent software-selectable full-scale range.

It integrates a 4.096-V internal reference with ±10 ppm/°C drift, supports daisy-chained SPI communication up to 18 MHz, and operates across –40°C to +125°C with AVDD = 4.75–5.25 V and DVDD = 1.65–5.25 V. The device includes an auxiliary 16-bit ADC channel and ALARM output with per-channel high/low thresholds.

Key Specifications

Pinout & Package

TSSOP-38 package (9.7 mm × 4.4 mm), thermally enhanced with multiple AGND/DGND pins and dedicated REFGND/REFCAP for stable reference decoupling.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-precision multichannel ADC applications.

Compared with ADS8694IDBTR and AD7606C-18BSTZ, the ADS8698IDBTR uniquely balances 8-channel density, SPI simplicity, integrated reference, and industrial-grade OVP - making it optimal for space-constrained, cost-sensitive, and thermally demanding PLC and relay platforms.

Availability

ADS8698IDBTR is available at Aetrix Electronics and suitable for power automation, protection relays, and PLC analog input modules requiring stable component supply, long-term industrial lifecycle support, and guaranteed traceability.

Supply support for ADS8698IDBTR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog and embedded processing technologies, with decades of expertise in precision data conversion and industrial-grade IC design.

The ADS869x product line was engineered specifically for ruggedized industrial data acquisition - integrating front-end protection, flexible input scaling, and robust serial interfacing to replace discrete signal chains in PLCs, energy meters, and grid infrastructure equipment.

FAQ

What input voltage ranges does the ADS8698IDBTR support per channel?

The ADS8698IDBTR supports five software-selectable input ranges per channel: ±10.24 V, ±5.12 V, ±2.56 V, 0–10.24 V, and 0–5.12 V. These ranges are configured independently via SPI register writes, enabling mixed-signal acquisition without external hardware reconfiguration. The ADS8698IDBTR maintains a constant 1-MΩ input impedance across all ranges, ensuring consistent loading behavior regardless of selected scale.

Does the ADS8698IDBTR require an external reference voltage?

No, the ADS8698IDBTR includes a factory-trimmed 4.096-V internal reference with ±10 ppm/°C temperature drift and low output impedance (≤1 Ω). When REFSEL is driven low, REFIO becomes an output delivering this reference; no external reference is needed unless higher accuracy or different voltage is required. The ADS8698IDBTR's REFCAP pin must be decoupled with a 10–22 µF capacitor to ensure stability during conversion.

How does the daisy-chain SPI mode work on the ADS8698IDBTR?

In daisy-chain mode, multiple ADS8698IDBTR devices share a single SPI bus: CS and SCLK are common, while SDI of device N connects to SDO of device N−1, and DAISY enables internal data forwarding. The ADS8698IDBTR shifts out its 24-bit conversion result on SDO while simultaneously shifting in new configuration data on SDI. This allows synchronized readout of up to 16+ channels with minimal GPIO usage and deterministic timing alignment.

What is the purpose of the ALARM pin on the ADS8698IDBTR?

The ALARM pin on the ADS8698IDBTR is an open-drain digital output that asserts high when any enabled analog input channel exceeds its programmable high threshold or falls below its low threshold. Thresholds are set per channel via SPI registers, and ALARM provides immediate hardware-level notification - bypassing host polling - for time-critical events like overvoltage, overcurrent, or thermal fault detection in protection relay applications.

Can the ADS8698IDBTR operate with a 3.3-V digital supply while using a 5-V analog supply?

Yes, the ADS8698IDBTR supports independent analog and digital supplies: AVDD = 4.75–5.25 V and DVDD = 1.65–5.25 V. With DVDD = 3.3 V, all digital I/Os (CS, SCLK, SDI, SDO, DAISY, RST/PD, ALARM) meet CMOS logic thresholds, and SPI timing remains valid up to 18 MHz. This allows direct interfacing with 3.3-V microcontrollers or FPGAs while maintaining full 5-V analog performance - a key feature of the ADS8698IDBTR for mixed-voltage industrial systems.