Texas Instruments ADS7851IRTET

Overview

ADS7851IRTET from Texas Instruments is a 14-bit, dual-channel, simultaneous-sampling analog-to-digital converter with independent internal voltage references (2.5 V ±5 mV), 1.5-MSPS throughput, and fully differential analog inputs. It features two SAR ADCs sharing a common serial interface, operates over –40°C to +125°C, and targets high-precision industrial motor control and power quality measurement systems.

For engineers reviewing the ADS7851IRTET datasheet, ADS7851IRTET pinout, ADS7851IRTET application, or ADS7851IRTET equivalent, this page delivers verified specifications, WQFN-16 package details, real-world use cases in protection relays and optical networking, and validated alternative parts for design continuity and sourcing flexibility.

Technical Context

The ADS7851IRTET implements two independent successive-approximation register (SAR) ADCs-ADC_A and ADC_B-each with its own internal reference (REFOUT_A/REFOUT_B), enabling true simultaneous sampling without inter-channel skew. Its analog input structure supports fully differential signals with common-mode voltage tied to the respective reference (VREF ±0.1 V), and full-scale range of ±VREF (0–2×VREF).

It uses a simple 4-wire SPI-compatible serial interface (CS, SCLK, SDO-A, SDO-B) with separate data outputs per channel, supporting daisy-chain or independent readout. Conversion timing is deterministic: tCONV = tSU_CSCK + 14×tCLK, with acquisition time of 90 ns at max clock frequency (27 MHz).

Key Specifications

Pinout & Package

ADS7851IRTET is housed in a thermally enhanced WQFN-16 (3 mm × 3 mm) package with exposed thermal pad. Pin 1 is REFOUT-A; pin 16 is AINM-A. The thermal pad must be soldered to PCB ground for optimal thermal performance (RθJB = 7.3°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7251IRTET and AD7380BCPZ-RL7, ADS7851IRTET uniquely balances 14-bit precision, guaranteed simultaneous sampling, integrated references, and industrial temperature support - making it optimal for protection relays and motor drives where channel correlation and long-term stability are non-negotiable.

Availability

ADS7851IRTET is available at Aetrix Electronics and suitable for motor control, protection relays, optical networking, and power quality measurement requiring stable component supply across extended temperature ranges and multi-year production cycles.

Supply support for ADS7851IRTET 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 industrial-grade signal chain solutions.

The ADS7x51 family-including ADS7851IRTET-is designed specifically for high-reliability industrial sensing applications demanding simultaneous dual-channel acquisition, internal reference integration, and extended temperature operation without performance degradation.

FAQ

What is the maximum sampling rate supported by the ADS7851IRTET?

The ADS7851IRTET supports a maximum sampling rate of 1.5 million samples per second (1.5 MSPS) under recommended operating conditions (AVDD = 5 V, fCLK = 27 MHz). This rate is guaranteed across the full industrial temperature range (–40°C to +125°C) and enables real-time capture of fast transients in protection relay and motor control applications. The ADS7851IRTET achieves this with a conversion time of tSU_CSCK + 14×tCLK.

Does the ADS7851IRTET require external reference components?

No, the ADS7851IRTET does not require external reference components. It integrates two independent 2.5-V internal voltage references (REFOUT_A and REFOUT_B), each specified at 2.495–2.505 V at +25°C with ±10 ppm/°C drift and ±1-mV matching between channels. Each reference requires only a 22-µF decoupling capacitor to its dedicated REFGND pin, eliminating external reference ICs and reducing system BOM and layout complexity.

How are the two ADC channels synchronized in the ADS7851IRTET?

The ADS7851IRTET guarantees true simultaneous sampling between ADC_A and ADC_B via hardware-level synchronization: both channels share the same sample-and-hold clock edge, achieving aperture delay matching of ≤40 ps. This eliminates time-skew-induced phase errors in vector-based calculations (e.g., Park transforms), unlike time-interleaved or multiplexed dual-ADC architectures. The simultaneous result is confirmed in the functional block diagram and timing specifications (tA match = 40 ps).

What package type and thermal characteristics does the ADS7851IRTET use?

The ADS7851IRTET uses a WQFN-16 (3 mm × 3 mm) package with an exposed thermal pad. Its thermal resistance values are RθJA = 33.3°C/W, RθJB = 7.3°C/W, and RθJC(bot) = 0.9°C/W. TI recommends soldering the thermal pad directly to PCB ground to achieve optimal junction-to-board conduction. This package enables compact placement in space-constrained industrial modules while maintaining reliable operation up to +125°C ambient.

Can the ADS7851IRTET operate with different analog and digital supply voltages?

Yes, the ADS7851IRTET supports independent analog and digital supplies: AVDD = 4.75–5.25 V (typical 5 V) and DVDD = 1.65–3.6 V (typical 3.3 V). This dual-supply architecture isolates analog noise from digital switching transients, preserving SNR and INL performance. The digital interface remains compatible with 1.8-V, 2.5-V, or 3.3-V host controllers, while the analog section maintains full 14-bit linearity and 83.5-dB SNR at 5-V AVDD.