Texas Instruments XTR101AG

Overview

XTR101AG from Texas Instruments is a precision 4–20mA two-wire transmitter IC integrating an instrumentation amplifier, voltage-controlled current source, and dual matched current references. It delivers ≤30µV offset, ≤0.75µV/°C drift, and ≤0.01% nonlinearity over −40°C to +85°C, operating from 11.6V to 40V supply. It is used in industrial pressure, temperature, and millivolt transmitters for remote signal conditioning of RTDs, thermocouples, and bridge sensors.

For engineers reviewing the XTR101AG datasheet, XTR101AG pinout, XTR101AG application, or XTR101AG equivalent, this page provides verified technical context, real-world design meaning of specifications, ceramic DIP-14 package details, application-specific implementation guidance, and validated alternative options for process control transmitter designs.

Technical Context

The XTR101AG implements a single-supply, two-wire architecture where power and 4–20mA signal share one wire pair via modulated loop current. Its input stage uses laser-trimmed instrumentation amplifier topology with differential input impedance ≥0.4GΩ and CMRR ≥90dB (DC), biased to operate with 4–6V common-mode voltage referenced to pin 7 (E).

Output current generation relies on internal feedback controlling a voltage-controlled current source, with span set by external resistor RS per IO = 4mA + (40/RS) × (e₂ − e₁). Dual 1mA matched current sources (pins 10/11) provide excitation for RTDs, bridges, and cold-junction compensation circuits, with ±0.014% match accuracy and ±15ppm/°C tracking error.

Key Specifications

Pinout & Package

Ceramic DIP-14 package (JD), 14-pin dual in-line with 0.3-inch body width and 0.1-inch pin pitch. Pin 1 index located at top-left corner when viewed from top with notch or dot oriented left.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 4–20mA two-wire transmitter applications.

Compared with XTR101AG, XTR101AP trades ceramic hermeticity for lower cost and plastic handling, while XTR105UA offers surface-mount compatibility and enhanced supply rejection-both retain identical functional architecture but differ in packaging, integration level, and environmental robustness.

Availability

XTR101AG is available at Aetrix Electronics and suitable for industrial process control, pressure transmitter manufacturing, and temperature monitoring systems requiring stable component supply across extended product lifecycles.

Supply support for XTR101AG 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 heritage in precision signal conditioning and industrial interface solutions.

The XTR101AG belongs to TI's XTR series of 4–20mA two-wire transmitters, designed specifically for high-accuracy, low-drift signal conditioning of millivolt-level industrial sensors in harsh environments.

FAQ

What is the maximum allowable input signal voltage for XTR101AG?

The XTR101AG supports a maximum differential input voltage (e₂ − e₁) of 1V when RS = ∞, decreasing proportionally as RS value reduces. For example, with RS = 278Ω (typical for 100mV full-scale), the maximum input is ~0.1V. Exceeding this risks saturation or violation of the 4–20mA output compliance range. Always ensure e₁ and e₂ remain within +4V to +6V relative to pin 7 for linear operation.

Can XTR101AG drive a 1kΩ load at 20mA output?

No-XTR101AG cannot reliably drive 1kΩ at 20mA. At VCC = 40V, the maximum supported load is 1400Ω, but at standard 24V supply, the absolute maximum is 600Ω (24V − 11.6V = 12.4V ÷ 20mA = 620Ω). Driving 1kΩ would drop >20V across the load, violating the 11.6V minimum compliance voltage requirement and causing output collapse or nonlinearity.

Does XTR101AG require external components for basic operation?

Yes-XTR101AG requires at minimum: (1) a 0.01µF bypass capacitor between pins 7 and 8, (2) an external span resistor RS between pins 5 and 6, and (3) biasing network (e.g., 2.5kΩ resistor) to establish 4–6V common-mode voltage on pins 3 and 4. Optional components include offset null potentiometer (pins 1/2/14) and bandwidth capacitor (pins 12/13).

How does the dual current source feature benefit RTD measurements with XTR101AG?

The dual 1mA matched current sources (pins 10/11) enable true 4-wire Kelvin RTD excitation: one source drives the RTD, the other biases the sense leads, eliminating lead-wire resistance error. Their ±0.014% matching ensures ratiometric accuracy, and their return to pin 7 maintains consistent reference for both excitation and measurement paths-critical for <0.1°C temperature resolution.

Is XTR101AG compatible with external NPN transistors for improved thermal performance?

Yes-XTR101AG supports optional external NPN transistors (e.g., 2N2222 or TIP29B) connected collector-to-pin 7, emitter-to-pin 8, and base-to-pin 11. This configuration shifts >90% of output-stage power dissipation away from the IC die, reducing self-heating-induced offset drift by up to 70% and improving long-term stability in high-accuracy transmitter designs.