STMicroelectronics TSU112IQ2T

Overview

TSU112IQ2T from STMicroelectronics is a dual-channel nanopower rail-to-rail input/output operational amplifier optimized for ultra-low-power sensor signal conditioning. It delivers 900 nA typical supply current per channel at 25 °C, 150 µV max input offset voltage at 25 °C, 3.6 µVpp low-frequency noise (0.1–10 Hz), 11.5 kHz gain bandwidth product at 5 V, and operates from 1.5 V to 5.5 V - enabling direct use with CR2032 coin cells in gas sensing and wearable energy harvesting systems.

For engineers reviewing the TSU112IQ2T datasheet, TSU112IQ2T pinout, TSU112IQ2T application, or TSU112IQ2T equivalent, key selection criteria include sub-microamp quiescent current, guaranteed 235 µV max offset over –40 to 85 °C, 10 pA max input bias current, rail-to-rail I/O, and ESD robustness (4 kV HBM) - all critical for battery lifetime and precision in electrochemical sensor front-ends.

Technical Context

The TSU112IQ2T employs complementary PMOS/NMOS input stages to achieve true rail-to-rail input common-mode range (VCC− − 0.1 V to VCC+ + 0.1 V) without phase reversal. Its CMOS architecture enables 10 pA max input bias current at 25 °C and 50 pA over temperature - essential for high-impedance trans-impedance configurations with electrochemical sensors.

It features a stable 60° phase margin and 7 dB gain margin at 3.3 V/5 V, supports overload recovery in ≤940 µs, and maintains ≥105 dB large-signal voltage gain across its full output swing (200 mV from rails). EMIRR reaches 79 dB at 900 MHz, validated under conductive-mode testing.

Key Specifications

Pinout & Package

TSU112IQ2T is housed in a 5-pin SC70 package (SOT-353), with exposed pad not present. Pin functions are electrically validated per DS11846 Rev 6 (p.2).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TSU102IYQ2T, TSU112IQ2T trades 7× higher ICC for 6× better offset and 3× higher GBP - making it optimal for responsive, uncalibrated gas sensing. Against TSZ122IYQ2T, it sacrifices 7.5× lower offset for 2× lower ICC and 1.5 V lower minimum supply - enabling CR2032 compatibility in space-constrained designs.

Availability

TSU112IQ2T is available at Aetrix Electronics and suitable for gas sensing systems, PIR motion alarms, energy-harvesting wearables, and battery current monitoring requiring stable component supply across industrial temperature ranges and long-lifecycle deployments.

Supply support for TSU112IQ2T 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, delivering innovative silicon solutions for automotive, industrial, and consumer applications with strong emphasis on power efficiency and reliability.

The TSU11x series belongs to ST's nanopower precision op-amp product line, engineered specifically for battery-constrained sensor interfaces where decades-long operation and sub-µV offset stability are mandatory design requirements.

FAQ

What is the maximum capacitive load the TSU112IQ2T can drive stably?

The TSU112IQ2T maintains stability with up to 60 pF capacitive load when configured with 1 MΩ feedback resistance, as verified in DS11846 Figure 24. For loads exceeding 60 pF, a series isolation resistor (Riso) between output and capacitance is required - values range from 10 Ω at 100 pF to 100 Ω at 1 nF per Figure 30. No external compensation capacitor is needed below 60 pF.

Can TSU112IQ2T operate from a 1.5 V alkaline cell?

Yes - TSU112IQ2T is fully specified from 1.5 V to 5.5 V supply, including guaranteed performance at 1.8 V, 3.3 V, and 5 V. At 1.5 V, supply current remains ≤1.48 µA over temperature, offset stays ≤235 µV, and rail-to-rail output swing is maintained with <40 mV saturation voltage into 10 kΩ, enabling direct use with single AA/AAA or zinc-carbon cells.

Does TSU112IQ2T require external ESD protection in handheld devices?

No - TSU112IQ2T integrates 4 kV HBM ESD protection on all pins per JEDEC JS-001, validated in production test. However, input voltages exceeding VCC+ or falling below VCC− must be current-limited to ≤10 mA using series resistors, as stated in Absolute Maximum Ratings Table 1. No external TVS diodes are needed for standard handling or board-level ESD immunity.

How does the guarding technique improve TSU112IQ2T performance in PCB layout?

Guarding surrounds high-impedance input traces (e.g., IN+) with a low-impedance conductor held at the same potential - typically the non-inverting input voltage via a unity-gain buffer. This eliminates leakage current across PCB surface contamination or moisture, preserving the 10 pA input bias spec. DS11846 Figure 35 shows implementation: guard ring width ≥2× trace spacing, connected directly to IN+ through low-impedance path.