Texas Instruments ADS8318IDGSR

Overview

ADS8318IDGSR from Texas Instruments is a 16-bit, 500-kSPS successive approximation register (SAR) analog-to-digital converter with unipolar differential input (–V_REF to +V_REF), SPI-compatible serial interface, and zero-latency operation at full speed. It operates from 2.048 V to 5.5 V external reference and consumes only 18 mW typical at 500 kSPS, making it suitable for precision data acquisition in battery-powered instrumentation.

For engineers reviewing the ADS8318IDGSR datasheet, ADS8318IDGSR pinout, ADS8318IDGSR application, or ADS8318IDGSR equivalent, key selection considerations include its 95.2 dB SNR at 10 kHz, ±1.0 LSB max INL, 10-pin MSOP package, daisy-chain-capable SPI interface, and power-down current of 0.25 µW - critical for low-noise, low-power embedded measurement systems.

Technical Context

The ADS8318IDGSR implements a capacitor-based SAR architecture with inherent sample-and-hold, enabling true zero-latency conversion at 500 kSPS. Its internal charge redistribution circuitry samples the differential input on rising CONVST and completes conversion in a fixed 1400 ns using an internal clock - independent of SCLK timing.

Digital interface flexibility includes 3-wire or 4-wire CS mode and daisy-chain mode, selectable via SDI logic level at CONVST rise. A programmable busy indicator bit (prepending 16-bit data) simplifies host synchronization without requiring external timing signals or polling.

Key Specifications

Pinout & Package

ADS8318IDGSR is housed in a 10-pin MSOP (DGS) package with exposed thermal pad, rated MSL-2 per JSTD-020. Pin functions are validated per TI SLAS568A datasheet Figure 1 (MSOP top view) and Terminal Functions table.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 16-bit SAR ADC applications.

Compared with ADS8318IDGSR, ADS8320IDRCT offers higher speed but sacrifices interface flexibility and ultra-low power scaling, while AD7682BRMZ provides comparable resolution in a simpler interface at reduced throughput - making ADS8318IDGSR optimal for battery-constrained, multi-device, precision measurement systems requiring deterministic timing and minimal layout overhead.

Availability

ADS8318IDGSR is available at Aetrix Electronics and suitable for portable data loggers, industrial process monitors, medical patient monitors, and optical network transceivers requiring stable component supply, long-term lifecycle support, and guaranteed authentic sourcing.

Supply support for ADS8318IDGSR 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, embedded processing, and connectivity technologies, with decades of expertise in precision data converters and industrial-grade IC design.

The ADS8318IDGSR belongs to TI's precision SAR ADC product line, engineered for high-resolution, low-power, and interface-flexible data acquisition in space-, power-, and noise-constrained applications such as portable instrumentation and distributed sensing.

FAQ

What is the maximum sampling rate supported by the ADS8318IDGSR?

The ADS8318IDGSR supports a maximum sampling rate of 500 kSPS with full 16-bit accuracy and zero latency. This is achieved via a fixed 1400 ns internal conversion time, independent of external clock frequency. At this rate, the device consumes 18 mW typical power with +VA = 5 V and +VBD = 5 V. Lower rates reduce power linearly - e.g., 100 kSPS draws ~3.6 mW - enabling precise power-performance tradeoffs in ADS8318IDGSR-based designs.

Does the ADS8318IDGSR require an external clock for conversion?

No, the ADS8318IDGSR uses an internal clock for SAR conversion and does not require an external clock to perform sampling or digitization. The SCLK signal is used solely for serial data transfer after conversion completes. This eliminates clock jitter sensitivity in the conversion process and ensures deterministic 1400 ns conversion time regardless of SCLK frequency - a key advantage of ADS8318IDGSR over externally clocked ADCs.

How does the daisy-chain interface mode work on the ADS8318IDGSR?

The ADS8318IDGSR enters daisy-chain mode when SDI is low at the rising edge of CONVST. In this mode, multiple ADS8318IDGSR devices can be connected serially: SDO of one device connects to SDI of the next, sharing SCLK and CONVST. A single 16-bit read cycle retrieves data from all devices in sequence - reducing GPIO count and PCB routing complexity. This mode is confirmed in the ADS8318IDGSR datasheet Figure 54 and functional description section.

What is the input voltage range specification for the ADS8318IDGSR?

The ADS8318IDGSR has a unipolar differential input range of –V_REF to +V_REF, with a fixed input common-mode voltage of +V_REF/2. For example, with a 4.096 V reference, the full-scale differential swing is ±4.096 V (–4.096 V to +4.096 V), centered at 2.048 V. This is explicitly defined in the "ANALOG INPUT" section of the ADS8318IDGSR datasheet under "Full-scale input span" and "Input common-mode range" parameters.

Can the ADS8318IDGSR operate with a 3.3 V digital supply while using a 5 V analog supply?

Yes, the ADS8318IDGSR supports independent analog and digital supplies: +VA may be 4.5–5.5 V while +VBD operates from 2.375–5.5 V, including 3.3 V. This allows interfacing with 3.3 V microcontrollers or FPGAs while maintaining high-precision analog performance. The datasheet specifies separate absolute maximum ratings and recommended operating conditions for each rail, confirming safe mixed-supply operation for ADS8318IDGSR.