STMicroelectronics TSM109IDT

Overview

TSM109IDT 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 detection and power supply sequencing circuits where space-constrained PCBs require combined reference and comparison functions.

For engineers reviewing the TSM109IDT datasheet, TSM109IDT pinout, TSM109IDT application, or TSM109IDT equivalent, key selection criteria include its rail-to-rail differential input range, ground-sensing capability, 250 mV typical low-level output saturation at 4 mA sink, and 0.4% initial reference accuracy over temperature.

Technical Context

The device integrates two independent comparators sharing a common 2.5 V precision shunt reference. Each comparator features PNP input stage enabling input common-mode voltage down to ground and differential input range equal to full supply voltage (±1 V to ±18 V).

Reference section provides 1–100 mA sink capability with 0.3 Ω dynamic impedance and ±13 ppm/°C temperature coefficient. Comparator outputs are open-collector, requiring external pull-up, and deliver 10–20 mA sink current with 250–700 mV saturation voltage across operating temperature.

Key Specifications

Pinout & Package

SO-8 package (3.9 mm × 4.9 mm, 1.27 mm pitch) with standard gull-wing leads and exposed pad not electrically connected.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV431AIDBVR and LM393DR, TSM109IDT uniquely combines matched comparator offsets, ground-sensing inputs, and factory-trimmed 2.5 V reference in one SO-8 package-reducing bill-of-materials, layout complexity, and calibration overhead in compact power supervision designs.

Availability

TSM109IDT is available at Aetrix Electronics and suitable for overvoltage protection circuits, DC-DC converter supervision, and battery cell monitoring requiring stable component supply across automotive, industrial, and medical power systems.

Supply support for TSM109IDT 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, MCU, power, and sensor solutions for industrial, automotive, and consumer markets.

The TSM109 belongs to ST's precision analog power management portfolio, engineered specifically for space-constrained power supervision tasks where integration of reference and comparison improves reliability and reduces system-level validation effort.

FAQ

Can TSM109IDT 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, both comparators function with input common-mode range from 0 V to 1.8 V and reference output remains stable at 2.5 V with ≥1 mA cathode current. Output saturation voltage stays below 400 mV at 4 mA sink, ensuring clean TTL/CMOS interfacing.

Is the internal voltage reference buffered or directly accessible?

The 2.5 V reference is implemented as a shunt regulator at Pin 7 (Vref). It is not buffered - users must sink current (1–100 mA) between Pin 7 and GND to maintain regulation. No internal buffer means output impedance is low (0.3 Ω), but it cannot source current or drive capacitive loads >100 pF without stability risk.

What is the maximum differential input voltage the comparators tolerate?

The differential input voltage range equals the supply voltage: ±1 V to ±18 V. For example, with ±15 V supplies, inputs may differ by up to 30 V. However, absolute input voltage on either pin must stay within −0.3 V to V_CC+ −1.5 V per datasheet limits - exceeding this risks latch-up or parametric degradation.

Does TSM109IDT support push-pull output configuration?

No. Both comparator outputs are open-collector. To achieve push-pull behavior, an external pull-up resistor plus a discrete N-channel MOSFET or transistor stage is required. The IC itself provides only active-low sinking capability (up to 20 mA), with no internal pull-up or sourcing capability.