Texas Instruments INA819IDRGT

Overview

INA819IDRGT from Texas Instruments is a precision instrumentation amplifier optimized for low-power, high-accuracy signal conditioning in industrial and medical sensor interfaces. It delivers 35-µV max input offset voltage, 8-nV/√Hz input voltage noise, 2-MHz bandwidth at G = 1, ±60-V input overvoltage protection, and operates from 4.5 V single supply or ±2.25 V dual supply - enabling direct connection to strain gauges and ECG electrodes without external protection.

For engineers reviewing the INA819IDRGT datasheet, INA819IDRGT pinout, INA819IDRGT application, or INA819IDRGT equivalent, key selection criteria include gain-setting resistor configuration (RG pins 2 & 3), thermal pad handling in WSON package, RTI noise performance at target gain, common-mode rejection at DC and 60 Hz, and supply current vs temperature drift across –40°C to +125°C.

Technical Context

The INA819IDRGT uses super-beta input transistors to achieve ultra-low input bias current (0.15 nA typ) and sub-µV/°C input stage offset drift (0.35 µV/°C max), enabling stable DC-coupled measurements in high-impedance sensor front-ends. Its three-op-amp architecture separates gain-setting (via external RG between pins 2 and 3) from output buffering, preserving CMRR above 110 dB at G = 10 even with PCB layout imbalances.

Internal overvoltage protection circuitry clamps inputs to ±60 V independent of supply rails, allowing safe operation in noisy industrial environments where transient spikes exceed rail limits. The device maintains stability with up to 1-nF capacitive loads and supports reference pin (REF, pin 6) biasing for level-shifting output to match ADC input ranges.

Key Specifications

Pinout & Package

INA819IDRGT is housed in an 8-pin WSON package (3.0 mm × 3.0 mm) with exposed thermal pad internally connected to –VS. The thermal pad must be soldered to a PCB copper pour tied to the negative supply or left floating per layout guidelines.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar instrumentation amplifier applications.

Compared with INA821IDRGT and INA828IDRGT, the INA819IDRGT uniquely balances ultra-low offset (35 µV), industry-leading low power (385 µA), and robust ±60-V input protection - making it the preferred choice for portable medical devices and battery-constrained industrial sensors requiring DC accuracy and reliability.

Availability

INA819IDRGT is available at Aetrix Electronics and suitable for analog input modules, electrocardiogram (ECG) monitors, battery test systems, and process analytics equipment requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for INA819IDRGT 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 company specializing in analog and embedded processing technologies, with leadership in precision signal chain components and industrial-grade reliability.

The INA819IDRGT belongs to TI's high-precision instrumentation amplifier product line, designed specifically for demanding sensor interface applications requiring low noise, low drift, and robust overvoltage tolerance in harsh electrical environments.

FAQ

What is the maximum gain achievable with INA819IDRGT?

The INA819IDRGT supports gains from 1 V/V to 10,000 V/V using a single external resistor (RG) between pins 2 and 3, per the equation G = 1 + 50 kΩ / RG. At G = 10,000, RG = 5 Ω - requiring careful layout to minimize parasitic resistance. The INA819IDRGT maintains specified performance including CMRR and bandwidth down to G = 1, making it versatile across both unity-gain buffering and high-gain sensor amplification tasks.

Does INA819IDRGT require external capacitors for stability?

No, the INA819IDRGT is internally compensated and remains stable with purely resistive feedback and load capacitances up to 1 nF. This eliminates the need for external compensation capacitors in most applications, simplifying layout and reducing bill-of-materials count. However, for loads exceeding 1 nF or in high-EMI environments, a small series resistor (≤10 Ω) at the output may be added to isolate capacitive loading without affecting closed-loop performance.

How is the thermal pad on the INA819IDRGT WSON package connected?

The exposed thermal pad on the INA819IDRGT (WSON-8) is internally connected to the –VS pin (Pin 5). TI recommends soldering the pad to a PCB copper pour tied directly to the negative supply plane to maximize thermal dissipation and ensure reliable operation at full temperature range. Leaving the pad floating is permitted but degrades thermal performance - junction-to-board resistance increases from 28.6°C/W to >60°C/W, limiting maximum ambient temperature in high-power applications.

Can INA819IDRGT operate from a 3.3-V supply?

No, the INA819IDRGT requires a minimum supply of 4.5 V for single-supply operation, as specified in its Recommended Operating Conditions. Attempting to power it from 3.3 V will result in undefined behavior, including failure to meet offset, CMRR, and output swing specifications. For 3.3-V systems, consider the INA333 (1.8-V to 5.5-V supply range) or INA828 (4.5-V minimum, but higher offset tolerance), both of which maintain precision performance at lower voltages.

What is the purpose of the REF pin on INA819IDRGT?

The REF pin (Pin 6) on the INA819IDRGT provides a dedicated, low-impedance (40 kΩ) input for adding a DC offset to the output, with exact 1 V/V gain from REF to OUT. This enables level-shifting the amplified differential signal to match the input range of downstream ADCs - for example, shifting a ±2.5-V output to 0–5 V for a unipolar 5-V ADC. The REF pin must be driven by a low-impedance source; connecting it directly to a high-impedance voltage divider will degrade accuracy due to REF input current effects.