Texas Instruments ADS7822IDGKRQ1

Overview

ADS7822IDGKRQ1 from Texas Instruments is a 12-bit pseudo-differential SAR analog-to-digital converter optimized for automotive battery-powered data acquisition. It delivers 200-kHz throughput at 5 V, consumes only 1.6 mW at full rate, features a synchronous 3-wire serial interface (DOUT/DCLOCK/CS), and operates across –40°C to +85°C in an MSOP-8 package - enabling high-precision sensing in isolated or remote automotive sensor nodes.

For engineers reviewing the ADS7822IDGKRQ1 datasheet, ADS7822IDGKRQ1 pinout, ADS7822IDGKRQ1 application, or ADS7822IDGKRQ1 equivalent, key selection considerations include its micropower operation at variable sample rates (7.5–200 kHz), ±0.5 LSB integral linearity over temperature, 3 µA max power-down current, and support for external reference voltages from 50 mV to VCC - critical for low-noise, wide-dynamic-range automotive signal conditioning.

Technical Context

The ADS7822IDGKRQ1 implements a capacitive redistribution successive approximation register (SAR) architecture with integrated sample-and-hold, fabricated on a 0.6-µm CMOS process. Its conversion cycle requires exactly 12 clock cycles, with 1.5 cycles dedicated to analog input sampling - enabling deterministic timing and no pipeline delay.

It uses a synchronous 3-wire serial interface where DOUT outputs straight-binary data most-significant-bit first on the falling edge of DCLOCK, initiated by a falling CS edge. The pseudo-differential input (+In/–In) captures voltage difference during hold mode, with –In limited to –0.2 V to +1.0 V relative to GND - supporting remote ground sensing but not true differential rejection.

Key Specifications

Pinout & Package

ADS7822IDGKRQ1 is housed in an MSOP-8 (DGK) package - 3.0 mm × 3.0 mm, 0.65 mm pitch, exposed pad optional - suitable for space-constrained automotive PCBs with thermal constraints.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7822IDGKRQ1, the ADS7822IDGKRG4Q1 offers identical performance in a larger reel format for manufacturing scalability, while the ADS7822EVM provides hardware abstraction for rapid algorithm development - neither serves as a drop-in functional substitute, but both extend design flexibility within the same automotive-qualified family.

Availability

ADS7822IDGKRQ1 is available at Aetrix Electronics and suitable for automotive battery management, remote tire pressure sensing, isolated motor current monitoring, and chassis ground compensation requiring stable component supply across extended temperature and long product lifecycles.

Supply support for ADS7822IDGKRQ1 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 automotive qualification expertise and AEC-Q100-compliant manufacturing.

The ADS7822IDGKRQ1 belongs to TI's automotive-qualified precision SAR ADC product line, designed specifically for low-power, high-accuracy signal acquisition in harsh-temperature vehicle subsystems - including battery monitoring, motor control, and sensor fusion applications.

FAQ

What is the minimum external reference voltage supported by the ADS7822IDGKRQ1?

The ADS7822IDGKRQ1 supports an external reference voltage as low as 50 mV, which sets the full-scale input span. At this level, the LSB size is 12.2 µV (50 mV / 4096), increasing sensitivity to noise and offset errors. TI specifies performance down to 50 mV in the Electrical Characteristics tables, and the device remains functional across the full –40°C to +85°C range at this reference level. Designers must ensure clean layout, low-noise references, and adequate bypassing when operating below 100 mV to maintain effective resolution.

Does the ADS7822IDGKRQ1 require an external clock source, and what are the valid frequency ranges?

Yes, the ADS7822IDGKRQ1 requires an external DCLOCK signal. Valid frequencies range from 10 kHz (enabling 625 Hz throughput) to 3.2 MHz (supporting 200 kHz sampling). The clock duty cycle is not critical, but minimum high and low times depend on supply voltage: ≥400 ns each at 2.7–3.6 V, or ≥125 ns at 4.75–5.25 V. The ADS7822IDGKRQ1 does not contain an internal oscillator - all timing is slave-synchronized to DCLOCK, ensuring deterministic latency and eliminating jitter from internal RC sources.

How does the pseudo-differential input of the ADS7822IDGKRQ1 differ from a true differential input?

The ADS7822IDGKRQ1's pseudo-differential input samples the voltage difference between +In and –In only once, at the start of conversion, and holds it on the internal capacitor array - unlike true differential SAR ADCs that resample –In later in the cycle. The –In pin is restricted to –0.2 V to +1.0 V, limiting common-mode rejection to small offsets. This architecture is optimized for remote ground sensing (e.g., shunt resistor return path), not full differential signal acquisition. True differential alternatives like the ADS8860 require separate –IN and +IN pins with symmetric voltage ranges and higher CMRR.

Can the ADS7822IDGKRQ1 interface directly with a 5-V logic system while powered from a 3.3-V supply?

Yes. The ADS7822IDGKRQ1 digital inputs (CS/SHDN, DCLOCK) tolerate voltages up to 6 V regardless of VCC, allowing direct connection to 5-V microcontrollers or FPGAs even when VCC = 3.3 V. However, the DOUT output swings from 0 V to VCC (3.3 V), so interfacing with 5-V CMOS inputs may increase their supply current draw and slightly extend propagation delay - a level-shifter is recommended for robust 5-V receiver compatibility. The ADS7822IDGKRQ1 datasheet explicitly confirms this I/O voltage independence in the Digital Interface section.

What is the guaranteed integral linearity error (INL) specification for the ADS7822IDGKRQ1 over its full operating temperature range?

The ADS7822IDGKRQ1 guarantees ±0.5 LSB integral linearity error over the full –40°C to +85°C temperature range, as confirmed in the Electrical Characteristics tables for both 2.7-V and 5-V supply conditions. This corresponds to ±0.61 mV error at 2.5-V reference and ±1.22 mV at 5-V reference. The Typical Characteristics plots (Figures 1 and 9) show measured INL remains within ±0.3 LSB at 25°C, confirming margin beyond the guaranteed spec. This performance meets ASIL-B functional safety requirements for automotive voltage monitoring applications.