STMicroelectronics TSU111IYCT

Overview

TSU111IYCT from STMicroelectronics is an automotive-grade, nanopower, rail-to-rail input/output operational amplifier optimized for ultra-low-power sensor signal conditioning and battery monitoring. It delivers 920 nA typical supply current at 25 °C, 150 µV max. input offset voltage at 25 °C, 4.6 µVpp low-frequency noise (0.1–10 Hz), 9 kHz gain bandwidth, and operates from 1.5 V to 5.5 V - enabling direct use with CR2032 coin cells in battery management systems.

For engineers reviewing the TSU111IYCT datasheet, TSU111IYCT pinout, TSU111IYCT application, or TSU111IYCT equivalent, key selection criteria include sub-microamp quiescent current, guaranteed accuracy over –40 to 125 °C, ESD robustness (4 kV HBM), rail-to-rail operation, and suitability for transimpedance amplification in energy-harvesting and wireless charging interfaces.

Technical Context

The TSU111IYCT employs complementary PMOS/NMOS input stages to achieve 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 supports stable operation down to 1.5 V supply.

It features a 9 kHz gain-bandwidth product with 70° phase margin and 30 dB gain margin, ensuring stability with capacitive loads up to 60 pF. Overload recovery times are specified at 420 µs (positive rail) and 880 µs (negative rail) across –40 to 125 °C, critical for wake-up detection in battery monitoring circuits.

Key Specifications

Pinout & Package

TSU111IYCT is supplied in SC70-5 package (2.0 × 1.25 mm, 0.65 mm pitch), optimized for space-constrained battery-powered PCBs. Pin mapping is validated per DS13616 Rev 5.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TSZ121ILT, TSU111IYCT trades 320 nA higher typical ICC for 250 µV lower max. offset over temperature and AEC-Q100 qualification; compared with OPA316IDBVR, it reduces supply current by 430× at the cost of 1.1 kHz GBW - making it optimal for always-on, ultra-low-power sensing rather than general-purpose amplification.

Availability

TSU111IYCT is available at Aetrix Electronics and suitable for battery management systems, energy harvesting nodes, wireless charging receivers, and on-board chargers requiring stable component supply with automotive-grade reliability and long-term lifecycle support.

Supply support for TSU111IYCT 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, microcontroller, power, and sensor solutions for automotive, industrial, and consumer markets.

The TSU111 series belongs to ST's nanopower precision op-amp product line, engineered specifically for ultra-low-power, high-accuracy signal conditioning in battery-critical applications such as BMS, wearables, and energy-harvesting systems.

FAQ

What is the maximum operating junction temperature for TSU111IYCT?

The TSU111IYCT has a maximum junction temperature of 150 °C, with guaranteed operation across –40 to 125 °C ambient. Thermal resistance (R_thJA) is 205 °C/W for the SC70-5 package. Designers must ensure power dissipation (P_D = V_CC × I_CC) remains low - e.g., at 5 V and 1.4 µA max., P_D ≈ 7 µW - making self-heating negligible in most layouts.

Can TSU111IYCT be used as a comparator?

Yes, TSU111IYCT can operate in open-loop comparator mode due to rail-to-rail output and saturation recovery behavior. However, its 9 kHz GBW and 420–880 µs overload recovery are slower than dedicated nanopower comparators like TS881. Use only when low-speed threshold detection suffices and op-amp functionality (e.g., programmable hysteresis via feedback) is needed.

Does TSU111IYCT require external compensation for stability?

No external compensation is required. The TSU111IYCT is unity-gain stable with ≥70° phase margin and 30 dB gain margin across 1.5–5.5 V supply and –40 to 125 °C. Stability is verified with 60 pF capacitive load; for heavier loads (>100 pF), a small series resistor (e.g., 10–100 Ω) at the output is recommended per Figure 37 in DS13616.

How does the guarding technique improve performance in nanopower designs?

Guarding surrounds high-impedance input traces (e.g., IN+, IN−) with a low-impedance conductor held at the same potential - eliminating leakage current through PCB surface contamination or moisture. This is critical for TSU111IYCT, where 10 pA input bias current can be swamped by board leakage. ST recommends implementing guard rings tied to output or reference voltage, as shown in Figure 41 of DS13616.