Texas Instruments ADS7822EC/2K5

Overview

ADS7822EC/2K5 from Texas Instruments is a 12-bit, pseudo-differential SAR analog-to-digital converter with 0.75 LSB integral linearity error, 200 kHz maximum throughput at 5 V, and microPower operation (1.6 mW at full rate). It features a synchronous 3-wire serial interface (CS/SHDN, DCLOCK, DOUT), operates from 2.7 V to 5.25 V, and is optimized for battery-powered remote data acquisition systems.

For engineers reviewing the ADS7822EC/2K5 datasheet, ADS7822EC/2K5 pinout, ADS7822EC/2K5 application, or ADS7822EC/2K5 equivalent, key selection criteria include its MSOP-8 package, ±0.75 LSB INL/DNL performance grade, 25 pF analog input capacitance, power-down current ≤3 μA, and support for external reference voltages from 50 mV to VCC.

Technical Context

The ADS7822EC/2K5 implements a capacitive redistribution successive approximation register (SAR) architecture on a 0.6 μm CMOS process, integrating sample-and-hold functionality. Conversion is initiated by CS falling edge, with sampling occurring over 1.5–2.0 clock cycles and fixed 12-cycle conversion time.

It uses a pseudo-differential input structure where +In and –In are sampled simultaneously onto an internal capacitor array; –In is limited to –0.2 V to +1.0 V and serves as a remote ground sense point-not a fully differential input. Data output is straight binary, MSB-first, synchronized to DCLOCK falling edges.

Key Specifications

Pinout & Package

ADS7822EC/2K5 is housed in an MSOP-8 package (DGK designation), 3.0 mm × 3.0 mm × 1.0 mm body, 0.65 mm lead pitch, exposed thermal pad (not electrically connected).

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7822U/2K5 and ADS7822EB/2K5, the ADS7822EC/2K5 delivers the highest linearity (±0.75 LSB), making it optimal for applications where code-edge accuracy directly impacts measurement validity-such as calibrated sensor interfaces or closed-loop feedback control.

Availability

ADS7822EC/2K5 is available at Aetrix Electronics and suitable for battery-operated systems, remote data acquisition, isolated analog input modules, and portable medical instrumentation requiring stable component supply and long-term manufacturability.

Supply support for ADS7822EC/2K5 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 low-power signal chain solutions.

The ADS7822 product line was designed for ultra-low-power, space-constrained applications demanding 12-bit accuracy-targeting portable instrumentation, remote sensing, and isolated industrial I/O where microPower and small footprint are critical.

FAQ

What is the guaranteed integral linearity error for ADS7822EC/2K5 across temperature?

The ADS7822EC/2K5 guarantees ±0.75 LSB integral linearity error over the full operating temperature range of –40°C to +85°C, as specified in the Electrical Characteristics table under ADS7822C grade conditions. This value is measured at VCC = 2.7 V, VREF = 2.5 V, and fSAMPLE = 75 kHz, and reflects worst-case deviation from ideal transfer function across all 4096 codes.

Can ADS7822EC/2K5 operate with a 2.0 V supply voltage?

ADS7822EC/2K5 supports VCC down to 2.0 V per Absolute Maximum Ratings, but specified performance-including 200 kHz throughput and ±0.75 LSB linearity-is only guaranteed from 2.7 V to 5.25 V. At 2.0 V, maximum sample rate drops below 7.5 kHz, and parameters like INL, DNL, and noise are not characterized; TI recommends staying within the 2.7–5.25 V range for full-spec operation.

How does the pseudo-differential input of ADS7822EC/2K5 differ from a true differential input?

The ADS7822EC/2K5 pseudo-differential input samples +In and –In simultaneously onto a single capacitor array-unlike true differential SAR ADCs that use two independent sampling paths. The –In pin is restricted to –0.2 V to +1.0 V and functions primarily as a remote ground reference, not a symmetrical signal input. It cannot reject large common-mode signals or support bipolar input ranges.

What is the minimum clock frequency required for reliable operation of ADS7822EC/2K5?

The minimum DCLOCK frequency for ADS7822EC/2K5 is determined by internal capacitor leakage and varies with supply voltage: ≥10 kHz (625 Hz throughput) at VCC = 2.7–3.6 V, and ≥10 kHz at VCC = 4.75–5.25 V. However, stable 12-bit acquisition requires sufficient time for 25 pF input capacitance to settle-TI recommends ≥100 kHz for robust performance across temperature and reference conditions.

Does ADS7822EC/2K5 support daisy-chained serial output configurations?

ADS7822EC/2K5 does not natively support daisy-chaining-the DOUT pin is a standard CMOS output that goes high-impedance when CS is high, and outputs only its own 12-bit result. To implement multi-device serial readout, external multiplexing (e.g., analog switch or FPGA-controlled CS sequencing) is required; each ADS7822EC/2K5 must be individually selected via its dedicated CS/SHDN line.