Texas Instruments ADS7822UBG4

Overview

ADS7822UBG4 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 200kHz). It features ±2 LSB integral linearity error, 2.7V–5.25V supply range, and SO-8 package-designed for battery-powered remote data acquisition where low power and small size are critical.

For engineers reviewing the ADS7822UBG4 datasheet, ADS7822UBG4 pinout, ADS7822UBG4 application, or ADS7822UBG4 equivalent, key selection considerations include its 12-bit resolution with guaranteed no missing codes, 3μA max power-down current, pseudo-differential input architecture enabling remote ground sensing, and compatibility with 2.7–5.25V logic and reference voltages down to 50mV.

Technical Context

The ADS7822UBG4 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 after acquisition (1.5–2.0 cycles), with data output synchronized to DCLOCK falling edges and MSB-first serial format on DOUT.

It operates with an external reference voltage (50mV to VCC), where LSB weight equals VREF/4096. The pseudo-differential input (+In/–In) captures voltage difference during hold mode without resampling –In later; –In is limited to –0.2V to +1.0V, making it suitable for remote ground sensing but not full differential rejection.

Key Specifications

Pinout & Package

ADS7822UBG4 is housed in an SO-8 (D package) surface-mount package with standard 150-mil width and 1.27mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7822U, ADS7822UBG4 delivers tighter ±1 LSB integral linearity for precision sensor interfaces, while MCP3201-I/P trades pseudo-differential input and 200kSPS speed for lower unit cost in less demanding applications-making ADS7822UBG4 optimal for isolated, battery-powered measurement systems requiring both accuracy and flexibility.

Availability

ADS7822UBG4 is available at Aetrix Electronics and suitable for battery-operated systems, remote data acquisition modules, and isolated industrial monitoring requiring stable component supply and long-term lifecycle support.

Supply support for ADS7822UBG4 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 design.

The ADS7822UBG4 belongs to TI's precision SAR ADC product line, engineered specifically for ultra-low-power, space-constrained measurement applications including portable medical devices, wireless sensors, and isolated industrial data acquisition.

FAQ

What is the maximum sampling rate supported by the ADS7822UBG4?

The ADS7822UBG4 supports a maximum sampling rate of 200kHz when operated at 5V supply with fCLK = 3.2MHz. At 2.7V, the maximum rate is 75kHz due to internal timing constraints. This rate is achievable only when CS is pulsed low for each conversion and DCLOCK meets minimum pulse width requirements (125ns high/low time at 5V).

Does the ADS7822UBG4 require an external reference voltage?

Yes, the ADS7822UBG4 requires an external reference voltage applied to the VREF pin. It accepts any voltage from 50mV to VCC, setting the full-scale input range. For example, with VREF = 2.5V, the LSB equals 0.61mV; with VREF = 50mV, LSB = 12.2μV. No internal reference is provided.

How does the pseudo-differential input of the ADS7822UBG4 differ from a true differential input?

The ADS7822UBG4's pseudo-differential input samples the voltage difference between +In and –In once at acquisition, then holds it-unlike true differential ADCs that continuously reject common-mode noise. The –In pin is limited to –0.2V to +1.0V and is intended for remote ground sensing, not full differential signal rejection.

Can the ADS7822UBG4 operate from a 3.3V supply?

Yes, the ADS7822UBG4 operates across 2.7V–5.25V, including 3.3V. At 3.3V, typical quiescent current is ~250μA at 75kHz sampling, and logic levels remain compatible with 3.3V MCUs. Ensure VREF does not exceed 3.3V, and maintain proper decoupling with ≥1μF ceramic capacitor.

What is the purpose of the CS/SHDN pin on the ADS7822UBG4?

The CS/SHDN pin serves dual functions: when pulled low, it initiates conversion and enables serial data output on DOUT; when high, it places the ADS7822UBG4 into full power-down mode drawing ≤3μA. This pin controls both device activation and ultra-low-power standby-critical for duty-cycled sensor systems.