Texas Instruments ADS8168IRHBT

Overview

ADS8168IRHBT from Texas Instruments is a 16-bit, 8-channel, 1-MSPS SAR ADC with integrated 4.096-V reference, programmable window comparator per channel, and enhanced-SPI interface. It operates from 3V–5.5V AVDD and –40°C to +125°C, enabling high-precision sensor data acquisition in compact industrial systems.

For engineers reviewing the ADS8168IRHBT datasheet, ADS8168IRHBT pinout, ADS8168IRHBT application, or ADS8168IRHBT equivalent, this page delivers verified specifications, real-world use cases, pin-level circuit roles, and validated alternative options for analog input subsystem design in safety-critical embedded instrumentation.

Technical Context

The ADS8168IRHBT implements a successive approximation register (SAR) architecture with on-chip multiplexer, reference buffer, REFby2 output (VREF/2), and per-channel digital window comparator. Its analog front-end supports single-ended and pseudo-differential inputs with extended settling time, reducing external driver complexity.

It features dual-mode SPI: backward-compatible 16-MHz SCLK mode and high-speed source-synchronous mode up to 70 MHz (SDR) or 35 MHz (DDR). Channel sequencing includes manual, on-the-fly, auto, and custom modes - enabling deterministic sampling across all eight inputs without host intervention.

Key Specifications

Pinout & Package

ADS8168IRHBT is housed in a 32-pin VQFN package (RHB), 5 mm × 5 mm, with exposed thermal pad connected to GND for thermal management in high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-precision, multi-channel SAR ADC applications.

Compared with ADS8167IRHBT and ADS8166IRHBT, the ADS8168IRHBT delivers 2× and 4× higher throughput respectively while maintaining identical pinout, register compatibility, and feature set - making it the performance-optimized variant within the ADS816x family for time-critical applications.

Availability

ADS8168IRHBT is available at Aetrix Electronics and suitable for chemistry analyzers, anesthesia delivery systems, mixed-function I/O modules, and intra-DC telemetry requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ADS8168IRHBT 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 converters and industrial-grade IC design.

The ADS816x product line was engineered for high-channel-count, low-power, high-accuracy sensor interface applications - targeting medical instrumentation, industrial process control, and test & measurement systems demanding robust operation from –40°C to +125°C.

FAQ

What is the maximum sampling rate supported by the ADS8168IRHBT?

The ADS8168IRHBT supports a maximum throughput of 1 million samples per second (1 MSPS) across all eight channels. This is confirmed in Section 5.6 of the datasheet under "Conversion Cycle" for the ADS8168 variant. The device achieves this rate using its internal clock and enhanced-SPI interface with up to 50-MHz SCLK, enabling real-time capture of fast analog signals without oversampling penalties. ADS8168IRHBT maintains full 16-bit resolution and specified INL/SNR performance at this rate.

Does the ADS8168IRHBT require an external reference voltage?

No, the ADS8168IRHBT does not require an external reference voltage. It integrates a precision 4.096-V internal reference with ±0.12% initial accuracy and 4–18 ppm/°C temperature drift. The REFIO pin functions as an output by default, and can be configured as an input only if an external 2.5–5-V reference is preferred. The internal reference eliminates BOM cost and layout sensitivity, and is explicitly validated for full-spec operation across –40°C to +125°C in the ADS8168IRHBT datasheet.

How does the per-channel window comparator work in the ADS8168IRHBT?

The ADS8168IRHBT includes a programmable digital window comparator for each of its eight analog input channels. Each channel has independently configurable high and low threshold registers and hysteresis settings. When enabled, the comparator continuously monitors converted results and asserts the ALERT pin (active-high) if any enabled channel exceeds its programmed bounds. This function operates autonomously without host intervention, reducing firmware overhead and enabling immediate hardware-triggered responses in safety-critical systems like anesthesia delivery.

What package type and dimensions does the ADS8168IRHBT use?

The ADS8168IRHBT uses a 32-pin VQFN package (RHB), measuring 5 mm × 5 mm with an exposed thermal pad. This is confirmed in the "Package Information" section and Figure 4-1 of the datasheet. The thermal pad must be soldered to a GND plane for optimal thermal performance. Pin functions are fully documented in Table 4-1, including dedicated analog inputs (AIN0–AIN7), dual SDO pins, ALERT, READY, and REFby2 - all mapped to specific physical locations on the RHB footprint.

Can the ADS8168IRHBT interface directly with a low-voltage microcontroller?

Yes, the ADS8168IRHBT supports direct interfacing with low-voltage microcontrollers via its DVDD supply, which operates from 1.65 V to 5.5 V. Its digital I/O pins (CS, SCLK, SDI, SDO-0, SDO-1/SEQSTS, ALERT, READY) are compatible with 1.8-V and 3.3-V logic levels when DVDD is set accordingly. Section 5.4 specifies VIH ≥ 0.7·DVDD and VIL ≤ 0.3·DVDD for 2.35–5.5-V DVDD, and relaxed thresholds for lower voltages - ensuring reliable communication with modern ultra-low-power MCUs without level shifters. ADS8168IRHBT's enhanced-SPI also supports DDR mode for efficient data transfer.