Texas Instruments ADC128S022CIMTX

Overview

ADC128S022 from Texas Instruments is a 12-bit, 8-channel successive-approximation register (SAR) analog-to-digital converter with independent analog (VA) and digital (VD) supplies, 50–200 kSPS throughput, SPI/QSPI/MICROWIRE-compatible serial interface, and operation over −40°C to +105°C for industrial and automotive sensor data acquisition.

For engineers reviewing the ADC128S022 datasheet, ADC128S022 pinout, ADC128S022 application, or ADC128S022 equivalent, this page delivers verified technical context, real-world timing behavior, validated power management modes, confirmed TSSOP-16 package mapping, and two rigorously cross-checked alternative parts for multi-supply SAR ADC designs.

Technical Context

The ADC128S022 implements a charge-redistribution DAC-based SAR architecture with integrated track-and-hold: first 3 SCLK cycles in track mode acquire input voltage; next 13 cycles perform conversion and output 12-bit straight-binary data MSB-first. It supports continuous and burst conversion modes, with CS acting as both conversion trigger and output enable.

It features independent VA (2.7–5.25 V) and VD (2.7–VA) rails, enabling mixed-voltage system interfacing; VA serves as internal reference, while VD powers digital logic and DOUT. Channel selection is controlled via 3-bit ADD[2:0] in an 8-bit control register loaded on DIN during each frame's first 8 rising SCLK edges.

Key Specifications

Pinout & Package

Packaged in a 16-pin TSSOP (4.40 mm × 5.00 mm), the ADC128S022 uses a single-sided lead frame with 0.65 mm pitch and exposed thermal pad (not electrically connected). Layout requires separate AGND/DGND planes tied at single point near device, plus 1-µF + 0.1-µF ceramic decoupling on VA and 0.1-µF on VD within 1 cm of pins.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-channel, 12-bit SAR ADC applications.

Compared with ADS7953SRHBT and MAX11126ETE+, the ADC128S022 uniquely balances industrial temperature range, dual-supply independence, TSSOP-16 compatibility, and ultra-low shutdown power-making it optimal for cost-sensitive, thermally demanding, and mixed-rail embedded sensor hubs.

Availability

ADC128S022 is available at Aetrix Electronics and suitable for automotive navigation, portable medical instrumentation, and industrial motor control requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ADC128S022 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 signal chain solutions.

The ADC128S022 belongs to TI's general-purpose SAR ADC product line, designed specifically for cost-effective, low-power, multi-channel data acquisition in harsh-environment applications where reliability and supply-chain stability are critical.

FAQ

What is the absolute maximum clock frequency supported by the ADC128S022?

The ADC128S022 supports a maximum SCLK frequency of 3.2 MHz under recommended operating conditions (VA/VD = 2.7–5.25 V). Exceeding this limit may cause timing violations in the internal track-and-hold and conversion logic, resulting in invalid or missing codes. The minimum clock is 0.8 MHz; operation below this threshold risks incomplete acquisition or conversion cycles. Always verify timing margins using tCONVERT (13 SCLK cycles) and tACQ (3 SCLK cycles) from the datasheet.

Does the ADC128S022 require an external reference voltage?

No, the ADC128S022 does not require an external reference. Its analog supply voltage VA serves as the internal reference, defining the full-scale input range (0 to VA). This eliminates the need for a separate precision reference IC or resistor divider network. However, VA must be clean and well-bypassed (1-µF + 0.1-µF ceramics within 1 cm) to maintain ±1 LSB INL performance-especially critical in high-resolution sensor applications.

How does the ADC128S022 handle channel selection during continuous conversion mode?

In continuous conversion mode (CS held low), the ADC128S022 automatically sequences through channels based on the ADD[2:0] bits loaded into its control register during the previous frame's first 8 rising SCLK edges. Each 16-SCLK frame outputs one 12-bit result, and the next channel address is latched before the current conversion completes. No retransmission of address bits is needed between frames-enabling deterministic, jitter-free multi-channel sampling at up to 200 kSPS total throughput.

Can the ADC128S022 operate with VA = 3.3 V and VD = 1.8 V?

No, the ADC128S022 cannot operate with VD = 1.8 V when VA = 3.3 V. Per the datasheet, VD must be ≥2.7 V and ≤VA. Therefore, the valid VD range for VA = 3.3 V is 2.7 V to 3.3 V. Using VD = 1.8 V violates the absolute maximum rating and risks logic failure, DOUT malfunction, or permanent damage. For 1.8-V digital interfaces, use a level translator on the SCLK/DIN/DOUT lines while maintaining VD ≥2.7 V.

What is the significance of the "DONTC" bits in the ADC128S022 control register?

The DONTC (Don't Care) bits (positions 7, 6, 2, 1, 0) in the 8-bit ADC128S022 control register have no functional effect on device operation. They may be set to any logic level (0 or 1) during DIN loading without altering channel selection, power mode, or conversion behavior. Only ADD2–ADD0 (bits 5–3) determine the input channel (IN0–IN7); all other bits are ignored by the internal control logic-simplifying firmware register writes and improving noise immunity against bit errors.