Texas Instruments ADC122S655CIMMX/NOPB

Overview

ADC122S655CIMMX/NOPB from Texas Instruments is a dual-channel, 12-bit, simultaneous-sampling SAR analog-to-digital converter with true differential inputs per channel, 200–500 kSPS throughput, ±1 LSB INL (max), and SPI/QSPI/MICROWIRE-compatible serial interface - used in motor control systems to preserve phase coherence between current and voltage sensing paths.

For engineers reviewing the ADC122S655CIMMX/NOPB datasheet, ADC122S655CIMMX/NOPB pinout, ADC122S655CIMMX/NOPB application, or ADC122S655CIMMX/NOPB equivalent, key selection criteria include simultaneous sampling integrity, differential input common-mode range (−VREF to +VREF), external reference flexibility (1.0 V to VA), low power consumption (11 mW at 500 kSPS), and industrial temperature operation (−40°C to +105°C).

Technical Context

The ADC122S655CIMMX/NOPB employs a successive-approximation register (SAR) architecture with dual independent track-and-hold circuits that sample CHA± and CHB± simultaneously on the fourth falling edge of SCLK after CS assertion - preserving inter-channel phase alignment critical for vector-controlled motor drives.

Its differential input structure maintains signal integrity from input pins through internal charge redistribution DACs, delivering −90 dB CMRR and −72 dBc THD (min) at 100 kHz input; the single serial DOUT outputs 4 null bits + 12-bit Channel A result + 4 null bits + 12-bit Channel B result, MSB-first, on SCLK falling edges.

Key Specifications

Pinout & Package

The ADC122S655CIMMX/NOPB is housed in a 10-lead VSSOP package (DGK suffix), 3.0 mm × 3.0 mm, 0.5 mm pitch, with exposed thermal pad (not electrically connected). Pin 1 is marked by beveled corner.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-channel, simultaneous-sampling ADC applications.

Compared with ADS8325IDGSR and AD7321BRUZ, the ADC122S655CIMMX/NOPB uniquely balances 12-bit accuracy, 500 kSPS simultaneous sampling, SPI compatibility, and ultra-small VSSOP-10 footprint - making it the optimal choice for cost-sensitive, size-constrained motor control and power monitoring modules.

Availability

ADC122S655CIMMX/NOPB is available at Aetrix Electronics and suitable for motor control systems, power meters/monitors, and multi-axis positioning equipment requiring stable component supply across extended product lifecycles.

Supply support for ADC122S655CIMMX/NOPB 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 signal chain solutions.

The ADC122S655CIMMX/NOPB belongs to TI's high-performance, low-power SAR ADC product line - engineered specifically for real-time, phase-critical acquisition in motor drives, energy metering, and automated test equipment.

FAQ

What is the maximum sample rate supported by the ADC122S655CIMMX/NOPB?

The ADC122S655CIMMX/NOPB supports a maximum sample rate of 500 kSPS per channel with true simultaneous sampling. This is achieved using an SCLK frequency of up to 16 MHz, with each conversion requiring exactly 32 clock cycles. At 500 kSPS, the device consumes 11 mW typical power with VA = 5 V and VREF = 2.5 V - verified across the full −40°C to +105°C operating range.

Does the ADC122S655CIMMX/NOPB require an external reference, and what voltage range is supported?

Yes, the ADC122S655CIMMX/NOPB requires an external reference applied to the VREF pin, supporting 1.0 V to VA (where VA is +4.5 V to +5.5 V). This allows flexible full-scale input ranges - e.g., 2.5 V reference yields ±2.5 V differential input - and direct interfacing to precision voltage references like REF5025. The reference current is ≤60 µA at 500 kSPS.

How does the ADC122S655CIMMX/NOPB handle simultaneous sampling across both channels?

The ADC122S655CIMMX/NOPB uses dual independent track-and-hold circuits that sample CHA± and CHB± on the same clock edge - specifically the fourth falling edge of SCLK after CS goes low. This architecture preserves relative phase information between channels to within <1° at 500 kSPS, enabling accurate vector calculations in motor control applications without software correction.

What serial interface standards is the ADC122S655CIMMX/NOPB compatible with?

The ADC122S655CIMMX/NOPB features a binary 2's complement serial output at DOUT compatible with SPI, QSPI, MICROWIRE, and common DSP interfaces. It uses standard 4-wire timing (CS, SCLK, DOUT, no DIN), with data valid on SCLK rising edges and output on falling edges - requiring no mode configuration or level-shifting for interoperability with TI C2000™, STM32, or NXP Kinetis microcontrollers.

What is the power consumption of the ADC122S655CIMMX/NOPB in power-down mode?

In power-down mode (CS high), the ADC122S655CIMMX/NOPB draws only 2.6–5.8 µW typical power with VA = 5.0 V and VREF = 2.5 V. This ultra-low standby current enables rapid wake-up (<1 µs) and extends battery life in portable instrumentation and condition-monitoring sensors - confirmed across the full industrial temperature range.