Texas Instruments OPA2145IDGKT

Overview

OPA2145IDGKT from Texas Instruments is a dual-channel, rail-to-rail output, JFET-input operational amplifier optimized for high-precision, low-noise signal conditioning. It delivers 5.5 MHz gain-bandwidth, 20 V/μs slew rate, and 475 µA maximum quiescent current per channel, with 150 µV max input offset voltage and 1 µV/°C max drift - enabling accurate amplification of microvolt-level sensor signals in single-supply systems up to 36 V.

For engineers reviewing the OPA2145IDGKT datasheet, OPA2145IDGKT pinout, OPA2145IDGKT application, or OPA2145IDGKT equivalent, this page provides verified specifications, validated dual-channel pin mapping for VSSOP-8, real-world use cases in precision DAQ and SMU systems, and two confirmed alternative parts with documented functional trade-offs.

Technical Context

The OPA2145IDGKT implements a fully differential JFET input stage with picoampere-level input bias current (2 pA typ) and ultra-low input voltage noise (7 nV/√Hz at 1 kHz), supporting high-impedance source interfacing without signal degradation. Its input common-mode range extends to the negative rail (V–), simplifying single-supply biasing while maintaining rail-to-rail output swing within 80 mV of either supply under 10 kΩ load.

Internally compensated for unity-gain stability, it achieves 114 dB typical open-loop gain (AOL) and 126 dB CMRR at ±18 V, with PSRR of ±0.3 µV/V across ±2.25 V to ±18 V supplies. Thermal performance is characterized for VSSOP-8 with R_θJA = 163.9 °C/W and R_θJC(top) = 53.4 °C/W.

Key Specifications

Pinout & Package

VSSOP-8 (DGK) package: 3.00 mm × 3.00 mm body, 0.65 mm lead pitch, exposed thermal pad (not electrically connected), RoHS-compliant matte tin lead finish.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar precision JFET op-amp applications.

Compared with OPA2140IDGKT, OPA2145IDGKT trades 110 µV offset for 5.5-MHz bandwidth and 20 V/μs slew rate - enabling faster settling in 16-bit DAQ. Compared with LTC6090IMS8E#PBF, OPA2145IDGKT offers tighter DC specs and lower quiescent current but lacks extended supply range and requires no layout change for existing VSSOP-8 footprints.

Availability

OPA2145IDGKT is available at Aetrix Electronics and suitable for semiconductor test equipment, lab instrumentation, and source measurement units requiring stable component supply with guaranteed long-term manufacturability and TI's 10-year product longevity commitment.

Supply support for OPA2145IDGKT 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 delivering analog and embedded processing solutions, with over 50 years of op-amp innovation and industry-standard reliability testing.

The OPAx145 family was designed specifically for high-precision, low-power signal conditioning in demanding environments - targeting applications where JFET input characteristics, rail-to-rail output, and low drift are mandatory, such as metrology-grade instrumentation and automated test equipment.

FAQ

What is the maximum operating temperature range for the OPA2145IDGKT?

The OPA2145IDGKT is fully specified from –40°C to +125°C ambient temperature, with electrical characteristics guaranteed across this range per TI's SBOS427F datasheet revision March 2021. At +125°C, parameters including input offset drift (±1 µV/°C max), quiescent current (655 µA max), and output swing (within 90 mV of rails) remain within published limits - making it suitable for under-hood automotive sensors and industrial motor control enclosures.

Does the OPA2145IDGKT support single-supply operation?

Yes, the OPA2145IDGKT supports true single-supply operation from 4.5 V to 36 V. Its input common-mode range extends to the negative rail (V–), and its rail-to-rail output swings within 80 mV of both supply rails under 10 kΩ load. This allows direct interfacing with unipolar sensors and 3.3-V or 5-V ADCs without level-shifting circuitry - a key advantage over older bipolar-input op-amps that require dual supplies for full-range signal handling.

What is the input bias current specification for OPA2145IDGKT at 85°C?

Per the SBOS427F datasheet Section 6.6, the OPA2145IDGKT input bias current is ±10 pA maximum at TA = 0°C to +85°C. At elevated temperatures, it rises to ±10 nA maximum over –40°C to +125°C - a known characteristic of JFET input stages. For designs operating near 85°C, this remains well below 100 pA, preserving accuracy in high-impedance applications like photodiode transimpedance amplifiers where leakage dominates error budget.

Can OPA2145IDGKT drive capacitive loads directly?

The OPA2145IDGKT is not optimized for direct capacitive load driving above 100 pF. Figure 6-27 shows increasing overshoot with capacitive loads >100 pF in unity-gain configuration. TI recommends adding a 50-Ω series resistor between the output and load to isolate capacitance - a proven method that preserves phase margin without degrading DC accuracy. This applies to OPA2145IDGKT in both SOIC and VSSOP packages, as stability behavior is process- and architecture-dependent, not package-dependent.

How does the OPA2145IDGKT compare to OPA2145IDR in terms of performance and packaging?

The OPA2145IDGKT (VSSOP-8) and OPA2145IDR (SOIC-8) share identical electrical specifications, including 5.5-MHz GBW, 20 V/μs slew rate, and 150 µV max offset. The only differences are mechanical: DGK uses a 3.00 mm × 3.00 mm VSSOP package with 0.65-mm pitch, while DR uses a larger 4.90 mm × 3.91 mm SOIC package with 1.27-mm pitch. Both are RoHS-compliant and pin-compatible - meaning OPA2145IDGKT can replace OPA2145IDR on existing layouts only if the PCB footprint matches VSSOP-8, not SOIC-8.