Texas Instruments ADC108S022CIMTX

Overview

ADC108S022 from Texas Instruments is a low-power, 8-channel, 10-bit successive-approximation ADC with 50–200 ksps throughput, independent analog (VA = 2.7–5.25 V) and digital (VD = 2.7–VA) supplies, SPI/QSPI/MICROWIRE-compatible serial interface, and operation across −40°C to +105°C - used for multi-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, TSSOP-16 pin mapping, real-world timing behavior, channel selection logic, and validated alternative parts - all grounded in TI's SNAS338F revision March 2013 datasheet.

Technical Context

The ADC108S022 employs a charge-redistribution DAC architecture with internal track-and-hold, acquiring input voltage over 3 SCLK cycles and completing conversion + serial output over 13 additional SCLK cycles (total 16 cycles per frame). It supports continuous mode with automatic re-entry into track mode after each 16-cycle boundary.

Serial communication uses MSB-first straight-binary format: leading zeros (SCLK falling edges 1–4), 10-bit result (edges 5–14), trailing zeros (edges 15–16). Input channel selection is controlled via 3-bit ADD[2:0] in the 8-bit control register loaded on DIN during the first 8 rising SCLK edges after CS fall.

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 and VD supplies, and dedicated serial I/O (CS, SCLK, DIN, DOUT) for noise isolation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7953SRHBT and MAX11100ETE+, the ADC108S022 uniquely balances 10-bit accuracy, true dual-supply isolation, industrial temperature range, and compact TSSOP-16 packaging - making it optimal for space-constrained, thermally demanding embedded systems requiring analog domain separation.

Availability

ADC108S022 is available at Aetrix Electronics and suitable for automotive navigation, portable medical instruments, and industrial process control requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

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 delivering analog, embedded processing, and connectivity solutions with deep expertise in precision data converters and industrial-grade reliability.

The ADC108S022 belongs to TI's precision SAR ADC product line, engineered for low-power, multi-channel data acquisition in harsh environments - targeting automotive, medical, and industrial applications where supply independence and temperature resilience are critical.

FAQ

What is the maximum clock frequency supported by ADC108S022 for reliable operation?

The ADC108S022 ensures correct operation with SCLK frequencies from 0.8 MHz to 3.2 MHz. While the absolute maximum clock rating is 16 MHz, TI specifies 3.2 MHz as the upper limit for guaranteed timing compliance, DNL/INL performance, and serial data validity per SNAS338F. Operating above 3.2 MHz may cause setup/hold violations on DIN/DOUT and degrade AC specifications like SINAD and SFDR. Always validate timing margins using tDS, tDH, tDACC, and tDHLD values from the datasheet when designing with ADC108S022.

How does the ADC108S022 handle channel selection during continuous conversion mode?

In continuous mode, the ADC108S022 loads the next channel address via the 3-bit ADD[2:0] field in its control register during the first 8 rising SCLK edges after each CS fall. The selected channel (IN0–IN7) is sampled in the subsequent conversion cycle. Because CS remains low across frames, channel selection is dynamically updated every 16 SCLK cycles - enabling programmable scan sequences without reasserting CS. This behavior is confirmed in Table 3 and Figure 2 of the ADC108S022 datasheet, and applies identically to ADC108S022 regardless of supply voltage or temperature.

Can ADC108S022 operate with VA = 3.3 V and VD = 1.8 V?

No - ADC108S022 requires VD to be between +2.7 V and VA, per the Operating Ratings table in SNAS338F. Setting VD = 1.8 V violates the minimum 2.7 V specification and will cause functional failure, including invalid DOUT levels and corrupted serial framing. If interfacing with a 1.8 V logic system, use a level translator on the DOUT line or select a different ADC (e.g., ADS7042) with native 1.8 V I/O compatibility. The ADC108S022's VD constraint is absolute and cannot be waived even for short-duration testing.

What is the aperture delay of ADC108S022 and how does it impact sampling accuracy?

The ADC108S022 has a typical aperture delay (tAD) of 4 ns, defined as the time between the fourth falling edge of SCLK and internal acquisition of the input signal. This fixed, low jitter delay ensures consistent sampling point alignment across all 8 channels - critical for coherent multi-channel measurements such as phase-difference analysis in motor control or ECG lead comparison. Because tAD is stable and specified over temperature, it can be compensated in firmware for time-of-flight or synchronization-critical applications. This value is measured and guaranteed per the ADC108S022 Electrical Characteristics table.

Does ADC108S022 require an external reference voltage?

No - ADC108S022 uses VA as its internal reference voltage; the full-scale input range is 0 V to VA. No external reference is needed or supported. This simplifies design and reduces BOM count, but means analog input accuracy directly tracks VA stability and noise. For highest precision, VA must be well-bypassed (1 µF + 0.1 µF ceramic capacitors within 1 cm) and sourced from a low-noise LDO - as demonstrated in Figure 39 of the ADC108S022 datasheet. Using a precision reference as VA is permissible and improves absolute accuracy, but VA remains both supply and reference.