STMicroelectronics TSM109AIDT

Overview

TSM109AIDT from STMicroelectronics is a dual comparator with integrated 2.5 V shunt voltage reference in SO-8 package. It delivers ±1 mV typical input offset voltage, 25 nA typical input bias current, and operates from ±1 V to ±18 V supply. Used in overvoltage protection circuits and power supply supervisory systems where space-constrained PCBs require combined reference and comparison functions.

For engineers reviewing the TSM109AIDT datasheet, TSM109AIDT pinout, TSM109AIDT application, or TSM109AIDT equivalent, key selection criteria include guaranteed 0.4% initial reference accuracy, rail-to-rail differential input range, ground-sensing common-mode capability, and low 250 mV output saturation voltage at 4 mA sink current.

Technical Context

The device integrates two independent comparators sharing a precision 2.5 V shunt reference. One comparator's inverting input is internally tied to the reference, enabling immediate threshold detection without external components. The PNP-input stage ensures constant 25 nA bias current flowing out of both inputs, eliminating charge injection during switching.

Each comparator supports input common-mode voltage down to ground and up to V_CC − 1.5 V, with differential input range equal to full supply voltage. Output stage provides open-collector sinking up to 20 mA and high-impedance sourcing, compatible with TTL/CMOS logic interfaces.

Key Specifications

Pinout & Package

SO-8 package (3.9 mm × 4.9 mm, 1.27 mm pitch), surface-mount, moisture sensitivity level 3. Thermal resistance θ_J-A = 175 °C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-comparator-with-reference applications.

Compared with TLV431AIDBVR and MAX9017EUT+T, TSM109AIDT uniquely combines dual comparators, 2.5 V reference, wide ±18 V operation, and ground-sensing inputs in one SO-8 package-enabling fully self-contained overvoltage/undervoltage supervision without external support components.

Availability

TSM109AIDT is available at Aetrix Electronics and suitable for power supply management, industrial sensor interfaces, and battery monitoring systems requiring stable component supply across extended temperature ranges.

Supply support for TSM109AIDT 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, designing and manufacturing analog, microcontroller, power, and MEMS products for industrial, automotive, and consumer markets.

The TSM109A series belongs to ST's precision analog comparators and references product line, engineered specifically for cost-sensitive, space-constrained power supervision and threshold-detection applications in harsh environments.

FAQ

Can TSM109AIDT operate from a single 3.3 V supply?

Yes. The device supports single-supply operation from 2 V to 36 V. At 3.3 V, the internal 2.5 V reference remains active and stable, and both comparators function with input common-mode range from 0 V to 1.8 V. Output saturation voltage stays below 400 mV at 4 mA sink, ensuring compatibility with 3.3 V logic thresholds.

How is the 2.5 V reference configured for regulation?

The V_REF pin (Pin 7) is the cathode of an internal shunt reference. To regulate, connect an external current-setting resistor between V_CC and V_REF. For 10 mA cathode current (optimal accuracy), use R = (V_CC − 2.5 V)/10 mA. Minimum cathode current is 0.5 mA; maximum is 100 mA per datasheet.

Are the two comparators electrically isolated from each other?

Yes. The two comparators share only the V_CC and GND supply rails and the internal reference node. Their input stages and output transistors are fully independent. Input offset voltage and response time parameters are specified separately for each channel, and crosstalk is not characterized - confirming functional isolation per design.

Does TSM109AIDT support hysteresis implementation?

Yes. Hysteresis can be added externally to either comparator by connecting a positive feedback resistor from its open-collector output to its inverting input. Since the outputs are open-collector, standard Schmitt-trigger configurations apply. No internal hysteresis is provided; all hysteresis must be implemented with external resistors per application requirements.