Texas Instruments ADC108S022CIMT

Overview

ADC108S022 from Texas Instruments is a low-power, 8-channel, 10-bit successive-approximation ADC with 50–200 ksps throughput, independent analog/digital supplies (VA = 2.7–5.25 V, VD = 2.7–VA), and SPI/QSPI/MICROWIRE-compatible serial interface - used for precision sensor data acquisition in automotive navigation and portable medical instrumentation.

For engineers reviewing the ADC108S022 datasheet, ADC108S022 pinout, ADC108S022 application, or ADC108S022 equivalent, this page delivers verified electrical specs, validated TSSOP-16 pin functions, real-world timing behavior (13-cycle conversion + 3-cycle acquisition), and two confirmed alternative parts with documented functional trade-offs.

Technical Context

The ADC108S022 employs a charge-redistribution DAC architecture with internal track-and-hold, enabling full-resolution acquisition in the first conversion after power-up without dummy cycles. Its 8-channel multiplexer supports channel selection via 3-bit address (ADD2–ADD0) loaded on DIN during CS assertion.

Serial communication uses MSB-first straight-binary output synchronized to SCLK falling edges: 4 leading zeros, 10-bit result (bits 5–14), then 2 trailing zeros per 16-cycle frame. Power-down is activated by high CS, reducing consumption to 0.09 µW at 3 V.

Key Specifications

Pinout & Package

ADC108S022 is housed in a 16-lead TSSOP (Package Number PW), with separate analog (AGND) and digital (DGND) ground pins, independent VA/VD supplies, and 8 single-ended analog inputs (IN0–IN7).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-channel, 10-bit SAR ADC applications.

Compared with ADS7822U and MAX11100ETE+, the ADC108S022 uniquely combines 200 ksps throughput, dual-supply isolation, VA-as-reference flexibility, and guaranteed −40°C to +105°C operation - making it optimal for ruggedized embedded data loggers requiring long-term stability without recalibration.

Availability

ADC108S022 is available at Aetrix Electronics and suitable for automotive navigation systems, portable medical instrumentation, and industrial process control modules requiring stable component supply across extended temperature ranges and multi-year production cycles.

Supply support for ADC108S022 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 over 50 years of innovation in precision data converters and industrial-grade ICs.

The ADC108S022 belongs to TI's precision SAR ADC product line, designed specifically for low-power, multi-channel sensor interface applications in harsh environments - emphasizing robustness, supply flexibility, and guaranteed performance from −40°C to +105°C.

FAQ

What is the minimum SCLK frequency required for reliable operation of the ADC108S022?

The ADC108S022 requires a minimum SCLK frequency of 0.8 MHz for guaranteed timing compliance across −40°C to +105°C. At lower frequencies, acquisition time (3 SCLK cycles) and conversion time (13 SCLK cycles) may exceed specification limits, risking incomplete sampling or data corruption. The ADC108S022 datasheet specifies 0.8 MHz as the absolute minimum under all operating conditions - not just room temperature.

Does the ADC108S022 require an external reference voltage, or can it operate using VA as reference?

The ADC108S022 uses VA as its internal reference voltage and does not require an external reference. The full-scale range is 0 to VA, with LSB = VA / 1024. This eliminates need for precision external REF components and simplifies layout - but mandates strict VA supply cleanliness (1 µF + 0.1 µF local bypass) to maintain ±0.3 LSB INL performance.

How is channel selection implemented on the ADC108S022, and what happens during power-up?

Channel selection is controlled by the 3-bit ADD2–ADD0 field loaded into the ADC108S022's control register via DIN on the first 3 rising SCLK edges after CS falls. At power-up, the ADC108S022 defaults to IN0 without requiring initialization - the first valid conversion result is always from IN0, enabling immediate data acquisition in boot-critical systems.

What is the purpose of the DONTC bits in the ADC108S022 control register, and can they be left unconnected?

The DONTC bits (positions 7,6,2,1,0) in the ADC108S022 control register are "don't care" - their values have no effect on operation. They must still be driven (typically held low or high) during DIN transmission, but logic state is irrelevant. Leaving them floating is unsafe; tie them to GND or VD to ensure deterministic serial framing and avoid metastability on the shift register.

Can the ADC108S022 operate with VA = 5.0 V and VD = 3.3 V, and what are the implications?

Yes - the ADC108S022 supports VD as low as 2.7 V and up to VA, so VA = 5.0 V and VD = 3.3 V is a valid configuration. This separates noisy digital logic (3.3 V) from sensitive analog core (5.0 V reference), improving PSRR. However, DOUT output high level becomes VD − 0.5 V = 2.8 V min, requiring level-shifting if interfacing with 5 V microcontrollers.