Texas Instruments ADS7822E/250G4

Overview

ADS7822E/250G4 from Texas Instruments is a 12-bit, 200kHz SAR analog-to-digital converter with pseudo-differential input, serial CMOS interface, and microPower operation (1.6mW at full rate). It features ±2 LSB integral linearity, 2.7V–5.25V supply range, and MSOP-8 package-designed for battery-powered remote data acquisition systems requiring low-noise, high-resolution sampling.

For engineers reviewing the ADS7822E/250G4 datasheet, ADS7822E/250G4 pinout, ADS7822E/250G4 application, or ADS7822E/250G4 equivalent, key selection considerations include its 200kHz throughput at 5V, 75kHz capability at 2.7V, power-down current ≤3μA, pseudo-differential input architecture, and compatibility with external references from 50mV to VCC.

Technical Context

The ADS7822E/250G4 implements a capacitive redistribution successive approximation register (SAR) architecture on a 0.6μm CMOS process, integrating sample-and-hold functionality. Its conversion cycle requires exactly 12 clock cycles, with 1.5–2.0 clock periods dedicated to analog input sampling before hold initiation.

It uses a synchronous 3-wire serial interface (CS/SHDN, DCLOCK, DOUT) where data is output MSB-first on the falling edge of DCLOCK, with no pipeline delay. The pseudo-differential input (+In/–In) captures voltage difference directly onto the internal capacitor array without resampling –In later in the cycle, limiting –In's absolute range to –0.2V to +1.0V while supporting remote ground sensing.

Key Specifications

Pinout & Package

ADS7822E/250G4 is housed in an MSOP-8 package (DGK marking, tape-and-reel quantity 250), with exposed pad not electrically connected. Pin functions are validated per TI SBAS062C datasheet Figure 1 (top view).

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7822E/250G4, ADS7823E/250 trades 2 bits of resolution for lower power and cost, while MCP3201-I/P offers identical resolution but reduced speed and incompatible DIP-8 footprint-neither is pin-compatible nor drop-in.

Availability

ADS7822E/250G4 is available at Aetrix Electronics and suitable for battery-operated systems, remote data acquisition, isolated data acquisition, and simultaneous sampling multichannel systems requiring stable component supply and long-term industrial availability.

Supply support for ADS7822E/250G4 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 precision data converter innovation.

The ADS7822E/250G4 belongs to TI's precision SAR ADC product line, engineered for ultra-low-power, high-resolution digitization in portable and isolated measurement systems where microPower efficiency and small MSOP-8 footprint are critical.

FAQ

What is the maximum sampling rate of the ADS7822E/250G4 and under what conditions?

The ADS7822E/250G4 achieves a maximum sampling rate of 200kHz when operated at VCC = 5V with fCLK = 3.2MHz. At VCC = 2.7V, the maximum rate drops to 75kHz due to internal timing constraints. These values are specified in the Electrical Characteristics tables of the SBAS062C datasheet and confirmed across the –40°C to +85°C temperature range.

Does the ADS7822E/250G4 support true differential input operation?

No, the ADS7822E/250G4 implements a pseudo-differential input architecture: it samples the voltage difference between +In and –In, but –In is not independently resampled and is limited to –0.2V to +1.0V. This supports remote ground sensing but does not provide full common-mode rejection like a true differential ADC. The ADS7822E/250G4 datasheet explicitly states this limitation in the Theory of Operation section.

What reference voltage range is supported by the ADS7822E/250G4?

The ADS7822E/250G4 supports an external reference voltage from 50mV to VCC, as verified in the Electrical Characteristics and Theory of Operation sections of SBAS062C. This allows LSB sizing from 12.2μV (at 50mV ref) to 1.22mV (at 5V ref), enabling flexible full-scale span configuration without external amplification.

How does the power-down mode function on the ADS7822E/250G4?

Power-down on the ADS7822E/250G4 is activated by driving CS/SHDN high, reducing supply current to ≤3μA. This fully shuts down both analog and digital sections. In contrast, after conversion completion with CS low, only the analog section powers down-the digital interface remains active, consuming significantly more current. This distinction is documented in the Power Dissipation section and Figure 26 of the ADS7822E/250G4 datasheet.

Can the ADS7822E/250G4 be interfaced with a 5V microcontroller while operating from a 3V supply?

Yes, the ADS7822E/250G4 digital inputs accept logic levels up to 6V regardless of VCC, allowing direct connection to 5V microcontrollers even when powered at 3V. However, its DOUT output swings 0V to VCC (3V), so level-shifting may be needed for reliable reception by 5V CMOS inputs-this behavior is specified in the Digital Interface section of the ADS7822E/250G4 datasheet.