STMicroelectronics TSZ122IST

Overview

TSZ122IST from STMicroelectronics is a dual high-precision chopper-stabilized operational amplifier optimized for ultra-low offset and near-zero drift in battery-powered sensor interfaces. It delivers 5 µV max input offset voltage at 25 °C, 8 µV over −40 °C to +125 °C, rail-to-rail I/O, 400 kHz gain bandwidth, and 40 µA max supply current per amplifier at 5 V - enabling precision signal conditioning in portable medical devices and low-power industrial sensors.

For engineers reviewing the TSZ122IST datasheet, TSZ122IST pinout, TSZ122IST application, or TSZ122IST equivalent, this page provides verified electrical specifications, package-specific terminal mapping (DFN8 2×2), real-world use cases in medical instrumentation and battery monitoring, and validated alternative options with documented functional trade-offs.

Technical Context

The TSZ122IST employs a 400 kHz chopper clock to continuously correct input offset and suppress 1/f noise, achieving <10 nV/°C drift and <0.8 µVpp low-frequency noise (0.1–10 Hz). Its CMOS input stage delivers pA-level bias current (200 pA typ. at 25 °C) and 115–136 dB CMRR across temperature.

It operates from 1.8 V to 5.5 V, supports rail-to-rail common-mode input (V_CC− − 0.1 V to V_CC+ + 0.1 V), and maintains stable unity-gain operation with ≥53° phase margin and 19 dB gain margin - confirmed across SC70-5, DFN8, and QFN16 packages.

Key Specifications

Pinout & Package

TSZ122IST is supplied in a 2 mm × 2 mm DFN8 package with exposed thermal pad (connected to V_CC− or left floating). Pin 1 is marked by a dot; the package is moisture-sensitive level 1 (MSL1).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD8628ARZ and OPA2333AIDR, TSZ122IST uniquely balances sub-5 µV offset, 40 µA power, 400 kHz bandwidth, and 91 dB 2.4 GHz EMI rejection - making it optimal for compact, battery-powered medical devices requiring robust RF immunity.

Availability

TSZ122IST is available at Aetrix Electronics and suitable for portable medical instrumentation, battery-powered sensor nodes, and industrial current-loop transmitters requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for TSZ122IST 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, Switzerland, designing and manufacturing analog, MCU, power, and sensor solutions for industrial, automotive, and consumer markets.

The TSZ12x series belongs to ST's precision analog portfolio, engineered specifically for zero-drift, micropower signal conditioning in space-constrained, battery-operated systems where calibration-free accuracy is mandatory.

FAQ

What is the maximum capacitive load the TSZ122IST can drive while maintaining stability?

The TSZ122IST remains stable with up to 100 pF capacitive load when configured as a unity-gain buffer with 10 kΩ series resistance at the output. Driving >100 pF requires external isolation resistor or compensation network - confirmed by Figure 29 (overshoot vs. load capacitance) and Figure 23 (open-loop gain/phase plots) in DS9216 Rev 11.

Does the DFN8 package require solder paste stencil aperture reduction for the exposed thermal pad?

Yes. For the DFN8 2×2 package, STMicroelectronics recommends a 50% area reduction (e.g., 1.2 mm × 1.2 mm aperture for a 2.0 mm × 2.0 mm pad) and 5–7 solder paste deposits to prevent voiding and ensure reliable thermal conduction - detailed in AN4923 "DFN Package Assembly Guidelines".

Can TSZ122IST be used in single-supply configurations with input signals near ground?

Yes. Its rail-to-rail input stage accepts common-mode voltages from V_CC− − 0.1 V to V_CC+ + 0.1 V, enabling direct interface with grounded sensors (e.g., thermistors, strain gauges) when V_CC− = 0 V. Output swings to within 30 mV of either rail, preserving dynamic range.

How does the chopper clock affect signal integrity in AC-coupled applications?

The 400 kHz chopper frequency introduces minimal in-band energy - its fundamental and harmonics fall outside typical sensor bandwidths (<10 kHz). Figure 27 shows input-referred noise remains flat at 37–60 nV/√Hz from 1–10 kHz, confirming negligible impact on ECG or audio-band signals.