STMicroelectronics TSZ181IQ1T

Overview

TSZ181IQ1T from STMicroelectronics is a single-channel, chopper-stabilized precision operational amplifier designed for high-accuracy sensor signal conditioning in automotive and medical systems. It delivers 25 µV max input offset voltage at 25 °C, 35 µV over –40 °C to 125 °C, rail-to-rail input/output operation, 3 MHz gain bandwidth product, and 1 mA supply current at 5 V.

For engineers reviewing the TSZ181IQ1T datasheet, TSZ181IQ1T pinout, TSZ181IQ1T application, or TSZ181IQ1T equivalent, this device is selected for ultra-low-drift analog front-ends where calibration-free accuracy, EMI robustness (72 dB EMIRR at 1.8 GHz), and extended temperature stability are critical in current sensing, bridge amplification, and precision instrumentation.

Technical Context

The TSZ181IQ1T employs a 2.4 MHz chopper architecture that continuously corrects input offset and cancels 1/f noise in both time and frequency domains-modulating the input signal to suppress low-frequency errors, then demodulating and filtering to yield near-zero drift. Its CMOS input stage provides ultra-low bias current (200 pA typ. at 25 °C) and rail-to-rail common-mode range (V_CC– −0.1 V to V_CC+ +0.1 V).

It operates across 2.2–5.5 V supply, supports full-rail output swing (≤40 mV from rails into 10 kΩ), and maintains 108 dB CMRR and 123 dB SVR at 5 V. Stability is ensured up to 100 nF capacitive load with minimal external isolation resistance (e.g., 22 Ω at 1 µF), thanks to internal compensation optimized for unity-gain configurations.

Key Specifications

Pinout & Package

TSZ181IQ1T is packaged in SOT23-5 (5-pin plastic surface-mount), with exposed pad not connected internally and left floating per datasheet guidance. Pin functions are validated per DS11863 Rev 8 Figure 1 (SOT23-5 top view).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TSZ121 and TSV731, TSZ181IQ1T uniquely combines automotive-grade temperature range, 2.4 GHz EMI hardening, and 3 MHz bandwidth at 1 mA-making it the sole option for calibrated-free, high-speed precision sensing in safety-critical vehicular systems.

Availability

TSZ181IQ1T is available at Aetrix Electronics and suitable for automotive battery monitoring, medical ECG front-ends, and industrial pressure transducer signal conditioning requiring stable component supply across extended temperature and long production lifecycles.

Supply support for TSZ181IQ1T 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, specializing in automotive, industrial, and power management ICs with strong analog and precision signal-chain portfolios.

TSZ181IQ1T belongs to ST's TSZx zero-drift op-amp family, engineered specifically for calibration-free, high-accuracy analog signal acquisition in automotive and medical applications demanding AEC-Q100 compliance and sub-µV/°C thermal stability.

FAQ

What is the maximum capacitive load the TSZ181IQ1T can drive without external compensation?

The TSZ181IQ1T remains stable with up to 200 pF capacitive load in unity-gain configuration without any external components. For loads exceeding 200 pF, a series isolation resistor (e.g., 22 Ω for 1 µF) is required at the output to maintain ≥47° phase margin and prevent overshoot, as verified in DS11863 Figure 51–53.

Does the TSZ181IQ1T require external clocking or configuration pins for chopper operation?

No. The chopper modulation runs autonomously at a fixed 2.4 MHz internal clock; no external timing components, configuration pins, or user-accessible control signals are needed. The architecture is fully integrated and transparent to the user-only standard op-amp connections (V+, V–, IN+, IN–, OUT) are required.

Can the exposed pad on the SOT23-5 package be soldered to ground for thermal improvement?

No. Per DS11863 Rev 8 page 2, the exposed pad of the SOT23-5 variant (unlike the DFN8) is not electrically connected to any internal node and must be left floating or optionally tied to PCB copper for mechanical anchoring only-not for thermal or electrical purposes. Thermal resistance is specified at 250 °C/W with pad unconnected.

How does the TSZ181IQ1T handle input overvoltage conditions beyond the supply rails?

The device includes ESD diodes from each input to V_CC+ and V_CC–. If input voltage exceeds either rail by >0.5 V, these diodes conduct. To prevent damage, input current must be limited to ≤10 mA via an external series resistor, as shown in DS11863 Figure 50-failure to do so risks latch-up or permanent degradation of input MOSFETs.