Texas Instruments ADS8865IDGSR

Overview

ADS8865IDGSR from Texas Instruments is a 16-bit, 400-kSPS true-differential SAR analog-to-digital converter with no-latency output, SPI-compatible serial interface, and 96 dB SNR. It operates from 2.7 V to 3.6 V AVDD and 1.65 V to 3.6 V DVDD, supports –VREF to +VREF differential input range, and delivers 2.6 mW power dissipation at full speed. It is used in precision instrumentation requiring high linearity and low power.

For engineers reviewing the ADS8865IDGSR datasheet, ADS8865IDGSR pinout, ADS8865IDGSR application, or ADS8865IDGSR equivalent, key selection considerations include its true-differential input architecture with 90 dB CMRR, unipolar ±VREF full-scale range, 1200 ns full-scale settling time, and daisy-chain-capable SPI interface for multi-channel systems.

Technical Context

The ADS8865IDGSR employs a charge-redistribution SAR architecture with integrated sample-and-hold, enabling no-latency conversion output. Its internal clock drives conversion independent of external timing, and acquisition occurs during automatic power-down between conversions.

It features a unique common-mode voltage detection and rejection block allowing VCM anywhere from 0 V to VREF without performance degradation, unlike conventional differential SAR ADCs. Input sampling uses 55-pF capacitors per channel with 96-Ω series switch resistance, and reference switching dynamically loads the REF pin during conversion.

Key Specifications

Pinout & Package

ADS8865IDGSR is packaged in a 10-pin VSSOP (DGS) with exposed thermal pad. The package supports compact PCB layouts and requires decoupling: 1-μF on AVDD/DVDD, ≥10-μF on REF, and thermal pad connected to GND.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS8865IDGSR, ADS8864IDGSR trades 150 kSPS speed for marginally lower power at mid-range throughput, while ADS8867IDGSR sacrifices differential input capability and CMRR to reduce system BOM count in single-ended designs - neither offers pin compatibility or identical feature set.

Availability

ADS8865IDGSR is available at Aetrix Electronics and suitable for precision instrumentation, medical diagnostics, and automated test equipment requiring stable component supply, long-term manufacturability, and guaranteed traceability.

Supply support for ADS8865IDGSR 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 ADS8865IDGSR belongs to TI's high-performance SAR ADC family designed for applications demanding 16-bit accuracy, low power, and true-differential input flexibility in space-constrained, noise-sensitive environments.

FAQ

What is the maximum sample rate supported by the ADS8865IDGSR?

The ADS8865IDGSR supports a maximum throughput rate of 400 kSPS with no latency. This is achievable under specified conditions: TA = –40°C to +85°C, AVDD = 3 V, DVDD = 3 V, VREF = 5 V, and fSAMPLE = 400 kSPS. Conversion time is guaranteed between 500 ns and 1300 ns, and acquisition time is fixed at 1200 ns.

Does the ADS8865IDGSR require an external clock source for conversion?

No, the ADS8865IDGSR uses an internal clock for conversion and does not require an external clock input. The SCLK signal is used solely for the SPI serial interface to read conversion results. The internal conversion clock is optimized for low jitter (5 ps RMS aperture jitter) and enables consistent timing regardless of host processor clock stability.

Can the ADS8865IDGSR interface with a 1.8-V microcontroller?

Yes, the ADS8865IDGSR supports DVDD from 1.65 V to 3.6 V, making it fully compatible with 1.8-V logic systems. Digital input thresholds scale with DVDD (e.g., VIH = 0.7 × DVDD), and DOUT output levels comply with 1.8-V CMOS standards. No level-shifting circuitry is needed when DVDD = 1.8 V.

What is the recommended decoupling for the REF pin of the ADS8865IDGSR?

The ADS8865IDGSR REF pin requires a minimum 10-μF ceramic or tantalum decoupling capacitor placed as close as possible to the pin. TI specifies CREF = 10–22 μF, and the capacitor must have low ESR to handle dynamic switching currents during conversion. A series RC filter (RBUF_FLT + CBUF_FLT) is recommended for high-precision applications to further suppress reference noise.

Is the ADS8865IDGSR pin-compatible with other devices in the ADS88xx family?

The ADS8865IDGSR shares the same 10-pin VSSOP (DGS) package and pinout with ADS8864IDGSR and ADS8867IDGSR, enabling drop-in replacement within that subset. However, functional differences exist: ADS8864IDGSR is rated for 250 kSPS, and ADS8867IDGSR has single-ended input. Full electrical and timing compatibility requires validation per application requirements.