STMicroelectronics TSU112IYST

Overview

TSU112IYST from STMicroelectronics is a dual-channel, AEC-Q100 qualified nanopower operational amplifier designed for ultra-low-power signal conditioning in battery-critical systems. It delivers 920 nA typical supply current per channel at 3.3 V, 150 µV max input offset voltage at 25 °C, rail-to-rail input/output operation across 1.5–5.5 V supply, and 9 kHz gain bandwidth - enabling precision sensing in energy-harvesting nodes and automotive battery management.

For engineers reviewing the TSU112IYST datasheet, TSU112IYST pinout, TSU112IYST application, or TSU112IYST equivalent, key selection criteria include sub-microamp quiescent current, guaranteed 400 µV offset over –40 to 125 °C, 4.6 µVpp low-frequency noise, 10 pA max input bias current, and DFN8 2×2 package compatibility with high-impedance sensor interfaces.

Technical Context

The TSU112IYST implements 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 and supports trans-impedance configurations for electrochemical and photodiode sensors.

It features a stable 9 kHz gain-bandwidth product with 70° phase margin and 30 dB gain margin across 1.5–5.5 V supply, ensuring predictable loop stability in low-frequency closed-loop designs. Overload recovery times are specified at 420 µs (positive rail) and 880 µs (negative rail) under 100 kΩ load and ±1 V differential input.

Key Specifications

Pinout & Package

TSU112IYST is housed in a wettable flank DFN8 2×2 mm package (pitch 0.5 mm), optimized for automated optical inspection (AOI) and high-reliability solder joint formation. The exposed thermal pad is electrically isolated and may be connected to VCC− or left floating per layout requirements.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TSU112IYLT, TSU112IYST offers superior manufacturability and thermal performance in space-constrained automotive modules; versus TSZ122IYST, it trades minimal current increase for guaranteed automotive qualification and tighter offset spec - making it the sole choice for safety-critical battery monitoring.

Availability

TSU112IYST is available at Aetrix Electronics and suitable for battery management systems, on-board chargers, and wireless charging receivers requiring stable component supply with AEC-Q100 compliance and long-lifecycle support.

Supply support for TSU112IYST 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, delivering intelligent power, sensing, and control solutions for automotive, industrial, and consumer markets.

The TSU11x series belongs to ST's nanopower precision op-amp product line, engineered specifically for always-on, battery-operated systems where microamp-level current budget and sub-millivolt accuracy must coexist - such as automotive battery monitors and energy-harvesting sensor nodes.

FAQ

What is the maximum capacitive load the TSU112IYST can drive without instability?

The TSU112IYST is characterized for stable operation with up to 60 pF capacitive load when using 1 MΩ feedback resistance, as verified in Figure 30 of DS13616. For loads exceeding 60 pF, a series isolation resistor (R_iso) between output and capacitance is required - values are specified in Figure 37, e.g., 100 Ω for 100 pF. Driving >100 pF directly risks peaking or oscillation due to reduced phase margin.

Can TSU112IYST operate reliably at 1.5 V supply with full rail-to-rail input range?

Yes - the device guarantees rail-to-rail input operation from (VCC−) −0.1 V to (VCC+) +0.1 V across the entire 1.5–5.5 V supply range, including at 1.5 V. Electrical characteristics tables confirm functionality at 1.5 V, and Figure 22 validates absence of phase reversal even when inputs exceed rails by 100 mV at this voltage.

Does TSU112IYST support single-supply operation with ground-referenced inputs?

Yes - its rail-to-rail input stage allows direct connection of sensors referenced to VCC− (system ground) while maintaining full common-mode range. With VCC− = 0 V and VCC+ = 3.3 V, inputs function correctly from –0.1 V to +3.4 V, enabling ground-sensed thermistors or bridge outputs without level-shifting circuitry.

How does the 4.6 µVpp low-frequency noise impact DC measurement accuracy?

This peak-to-peak noise over 0.1–10 Hz defines the minimum resolvable DC step change: a 4.6 µVpp spread corresponds to ~1.5 µV RMS, limiting effective resolution to ≈18-bit for a 1 V full-scale measurement. It is measured under standard conditions (RL = 1 MΩ, Tamb = 25 °C) and remains stable across temperature, making it suitable for precision thermocouple or strain gauge amplification without chopper stabilization.