STMicroelectronics TS3121AIYLT

Overview

TS3121AIYLT from STMicroelectronics is a rail-to-rail input, open-drain single comparator qualified to AEC-Q100 Grade 1 (−40 °C to +125 °C), featuring 2 mV max input offset voltage at 25 °C, 70 μA typical supply current, and 60 ns propagation delay (high-to-low, 100 mV overdrive). It operates from 1.7 V to 5.5 V and supports overcurrent protection and industrial sensor interface applications.

For engineers reviewing the TS3121AIYLT datasheet, TS3121AIYLT pinout, TS3121AIYLT application, or TS3121AIYLT equivalent, this device delivers verified low-power high-speed comparison with rail-to-rail input, open-drain output, and guaranteed start-up time - critical for automotive body control modules, power tool motor controllers, and industrial overcurrent detection circuits.

Technical Context

The TS3121AIYLT implements a precision CMOS comparator core with built-in 1 mV hysteresis, enabling stable switching in noisy environments without external feedback. Its rail-to-rail input stage accepts common-mode voltages from −0.2 V to VCC+ + 0.2 V, while the open-drain output sinks up to 140 mA at 5 V and withstands voltages beyond VCC.

It guarantees 10–15 µs start-up time after VCC exceeds 1.5 V and maintains <20 µV/°C input offset drift across −40 °C to +125 °C. The device achieves 70 dB CMRR and 80 dB SVR at 5 V, supporting accurate threshold detection in varying supply and common-mode conditions.

Key Specifications

Pinout & Package

TS3121AIYLT is housed in a SC70-5 (SOT23-5 compatible) package, measuring 2.0 mm × 1.25 mm × 0.95 mm, optimized for space-constrained PCB layouts in automotive and portable industrial systems.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar comparator applications.

Compared with TS3121AIYLT, TS3021IYLT trades open-drain flexibility for faster switching and push-pull drive, while TS880IYLT sacrifices speed to achieve lower quiescent current - making TS3121AIYLT the optimal balance for automotive and industrial real-time protection where both speed and interface versatility matter.

Availability

TS3121AIYLT is available at Aetrix Electronics and suitable for automotive body electronics, industrial overcurrent protection, and power tool motor control requiring stable component supply across extended temperature and long product lifecycles.

Supply support for TS3121AIYLT 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 microcontrollers, analog ICs, power devices, and sensors for automotive, industrial, and consumer markets.

The TS3121 series belongs to ST's precision analog comparators product line, engineered specifically for high-reliability, low-power, high-speed sensing in harsh-environment applications including automotive subsystems and industrial safety-critical monitoring.

FAQ

What is the maximum output sink current for TS3121AIYLT at 5 V supply?

At VCC = 5 V and T = 25 °C, the TS3121AIYLT guarantees a minimum output sink current of 100 mA (typical 140 mA) before VOL exceeds 45 mV at 1 mA load. This enables direct driving of LEDs, small relays, or optocouplers without external buffers.

Does TS3121AIYLT require external hysteresis for stable operation?

No. The TS3121AIYLT integrates 1 mV of internal hysteresis, eliminating the need for external positive feedback resistors. This simplifies PCB layout and ensures consistent noise immunity across temperature and supply voltage variations.

Can TS3121AIYLT operate with a 1.8 V supply and still meet datasheet timing specs?

Yes. At VCC = 1.8 V, the TS3121AIYLT maintains tPHL ≤ 125 ns (100 mV overdrive) and tPLH ≤ 175 ns, with supply current remaining within 78–155 μA across temperature - fully supporting low-voltage IoT and wearables designs.

How does the open-drain output handle voltages exceeding VCC?

The OUT pin is rated to withstand up to 6 V regardless of VCC value, allowing safe connection to pull-up resistors tied to higher rails (e.g., 3.3 V or 5 V) while VCC is powered from 1.8 V - essential for level translation in mixed-supply systems.