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Home > Products > Integrated Circuits (ICs) > Linear > Comparators

STMicroelectronics LM139APT

Name: LM139APT
Brand: STMicroelectronics
SKU: LM139APT
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: LM139APT

Manufacturer:: STMicroelectronics

Category:: Comparators

Package:: 14-TSSOP (0.173", 4.40mm Width)

Datasheet:: LM139APT.pdf

Description:: IC COMPARATOR 4 GEN PUR 14TSSOP

Quantity:: RFQ Add To RFQ list

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Inventory:1,166

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Product details

Overview

LM139APT from STMicroelectronics is a low-power quad voltage comparator in TSSOP-14 package, designed for single-supply operation from +2 V to +36 V (or ±1 V to ±18 V), featuring ±1 mV typical input offset voltage, 25 nA typical input bias current, and 250 mV typical output saturation voltage at 4 mA sink - used in precision threshold detection, level-shifting interfaces, and industrial sensor signal conditioning.

For engineers reviewing the LM139APT datasheet, LM139APT pinout, LM139APT application, or LM139APT equivalent, this page delivers verified electrical specs, real-world use cases, validated alternatives, and supply-chain-ready availability details - all grounded in ST's production-grade documentation (DocID2159 Rev 4, Aug 2014).

Technical Context

The LM139APT implements four independent open-collector comparators with PNP input stages enabling ground-sensing capability even under single-supply operation. Its input common-mode range extends from 0 V to (V_CC − 1.5 V), supporting direct interfacing with sensors referenced to system ground.

Each comparator delivers TTL/DTL/ECL/CMOS-compatible outputs with 6–16 mA sink current capability and 1.3 μs typical response time (100 mV step, 5 mV overdrive). Supply current remains stable at 1.1 mA across the full 2–36 V supply range, independent of load or temperature.

Key Specifications

Parameter	Value and Actual Design Meaning
Supply Voltage Range	+2 V to +36 V (single) or ±1 V to ±18 V (dual) - enables direct integration into 3.3 V, 5 V, 12 V, and 24 V industrial control rails.
Input Offset Voltage	±1 mV typ - ensures accurate threshold detection down to millivolt-level signal differentials without external trimming.
Input Bias Current	25 nA typ - minimizes loading on high-impedance sources like thermistors, RTDs, or photodiodes.
Output Sink Current	6–16 mA - directly drives LEDs, small relays, MOSFET gates, or logic inputs without external buffers.
Response Time	1.3 μs (100 mV step, 5 mV overdrive) - supports kHz-range window comparators and fast zero-crossing detection.
Common-Mode Input Range	0 V to (V_CC − 1.5 V) - allows input signals referenced to ground while operating from single positive supply.
Supply Current	1.1 mA (all four comparators, V_CC = 5 V) - enables battery-powered or energy-constrained applications with predictable quiescent draw.

Pinout & Package

TSSOP-14 (Thin Shrink Small Outline Package), 4.9 mm × 6.4 mm body, 0.65 mm pitch, lead-free and RoHS-compliant per ECOPACK® specifications.

Pin/Terminal	Circuit Role	Design Meaning
1	Inverting Input (Comparator 1)	Accepts reference or feedback signal; PNP input stage draws minimal reverse-biased current (25 nA typ).
2	Non-inverting Input (Comparator 1)	Accepts sensed signal; common-mode range includes ground, enabling direct connection to 0 V-referenced transducers.
3	Output (Comparator 1)	Open-collector NPN output; requires external pull-up to V_CC or logic rail; sinks up to 16 mA.
4	GND	Power and signal reference ground; shared return path for all four comparators and internal circuitry.
5	Inverting Input (Comparator 2)	Independent input channel; electrically isolated from other comparators; same bias and offset specs as Pin 1.
6	Non-inverting Input (Comparator 2)	Second sensing channel; supports differential or single-ended configurations with identical DC accuracy.
7	Output (Comparator 2)	Open-collector output; compatible with mixed-voltage systems via independent pull-up selection.
8	V_CC	Positive supply pin; accepts 2–36 V; supplies all four comparators; no separate negative rail required.
9	Inverting Input (Comparator 3)	Third independent comparator input; maintains ±1 mV offset and 25 nA bias across full temperature range.
10	Non-inverting Input (Comparator 3)	Supports multi-threshold monitoring (e.g., under/over-voltage, window detection) with matched performance.
11	Output (Comparator 3)	Drives discrete loads or logic; output saturation voltage ≤400 mV at 4 mA ensures clean low-state definition.
12	Inverting Input (Comparator 4)	Fourth channel; fully decoupled; enables simultaneous monitoring of four independent analog conditions.
13	Non-inverting Input (Comparator 4)	Enables complex logic functions (e.g., priority encoding, state machine triggers) using resistor networks.
14	Output (Comparator 4)	Final open-collector output; shares V_CC and GND; supports wired-OR bus configurations.

Key Features

Feature	Design Value
Ground-sensing input stage	PNP differential pair enables common-mode input down to 0 V - eliminates need for negative supply in single-rail systems.
Supply-current stability	1.1 mA typ across 2–36 V supply range - simplifies power budgeting and thermal design in wide-input applications.
Low input offset drift	±2 mV max over −55°C to +125°C - ensures consistent trip points in automotive and industrial environments.
Robust ESD protection	500 V HBM, 100 V MM, 1500 V CDM - reduces field failure risk during handling and PCB assembly.
Thermal resistance	R_thJA = 100 °C/W (TSSOP14) - supports continuous operation at ambient up to +85°C with standard PCB copper area.

Applications

Industrial Overvoltage Protection

Automotive Battery Monitoring

Use Scenario: Detecting battery voltage exceeding 14.8 V in 12 V vehicle systems to trigger warning LED or disable charging circuit.

IC Role / Device Role / Timing Role: Quad comparator configured as window detector with hysteresis; two channels monitor upper/lower thresholds, two enable status latching.

Use Value: Eliminates need for external op-amps or microcontroller ADC polling; operates reliably across −40°C to +105°C ambient.

Use Scenario: Monitoring alternator output and starter motor draw to detect regulator failure or parasitic drain.

IC Role / Device Role / Timing Role: Four independent comparators track V_BAT, engine RPM pulse, coolant temp voltage, and ignition status simultaneously.

Use Value: Single-package solution reduces BOM count and PCB area vs. discrete comparators; open-collector outputs interface directly with CAN transceiver enable pins.

Programmable Logic Controller (PLC) Input Module

Medical Patient Monitor Threshold Alarm

Use Scenario: Converting 4–20 mA current-loop sensor outputs into digital ON/OFF signals for PLC digital input cards.

IC Role / Device Role / Timing Role: Comparator 1–4 each condition one analog channel; outputs drive optocouplers tied to microcontroller GPIOs.

Use Value: Input bias current <30 nA prevents error in high-impedance shunt-based current sensing; wide supply range accommodates 24 V PLC backplane rails.

Use Scenario: Triggering audible/visual alarms when ECG amplitude exceeds 3 mV or SpO₂ saturation drops below 88%.

IC Role / Device Role / Timing Role: Precision comparator compares filtered analog sensor outputs against trimmed reference voltages; hysteresis prevents chatter near thresholds.

Use Value: ±1 mV offset ensures alarm activation within clinical tolerance; low power draw extends portable device battery life between charges.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
LM339APT	Same pinout and architecture, but rated for 0°C to +70°C (vs. LM139APT's −55°C to +125°C); offset voltage max 9 mV (vs. 4 mV).	Restricted to commercial-grade equipment; unsuitable for under-hood automotive or military-grade deployments.	Select LM339APT only for cost-sensitive, non-extended-temperature applications where ±9 mV offset is acceptable.
TLV331IPW	Single-channel, rail-to-rail input/output, 36 V supply capable, but 5 μA supply current (vs. 1.1 mA) and 3 mV offset max.	Requires four devices for quad functionality; superior for ultra-low-power designs but increases board area and component count.	Choose TLV331IPW when power budget is critical (<10 μA total) and space permits four separate packages.

Compared with LM339APT and TLV331IPW, LM139APT uniquely balances extended temperature operation, low offset, and quad integration in a single TSSOP-14 package - making it optimal for ruggedized industrial and automotive subsystems requiring deterministic analog decision-making.

Availability

LM139APT is available at Aetrix Electronics and suitable for industrial motor control, automotive battery management, and medical diagnostic equipment requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for LM139APT 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, specializing in automotive, industrial, power, and microcontroller solutions with vertical manufacturing and broad IP portfolio.

The LM139 series belongs to ST's precision analog comparators product line, engineered specifically for robust, low-drift threshold detection in harsh environments - emphasizing reliability, wide supply flexibility, and ground-referenced operation.

FAQ

Can LM139APT operate from a single 3.3 V supply?

Yes. The LM139APT supports single-supply operation from +2 V to +36 V, including 3.3 V. At 3.3 V, input common-mode range is 0 V to 1.8 V, output saturation voltage remains ≤400 mV at 4 mA sink, and supply current is ~1.1 mA - enabling direct interface with 3.3 V logic and low-voltage sensors without level shifters.

Does LM139APT require external pull-up resistors on its outputs?

Yes. All four outputs are open-collector NPN structures and must be pulled up to a voltage rail (V_CC or another logic-compatible voltage) via external resistors. Typical values range from 1 kΩ (for fast switching into heavy loads) to 10 kΩ (for low-power logic interfacing); pull-up voltage may differ from V_CC to enable mixed-voltage system interfacing.

What is the maximum input voltage allowed if V_CC = 0 V (unpowered)?

Per absolute maximum ratings, input voltage must remain between −0.3 V and +36 V regardless of V_CC state. With V_CC = 0 V, inputs may still be driven up to +36 V (e.g., hot-swap scenarios), but the −0.3 V lower limit applies strictly - violating this risks latch-up or permanent damage due to forward-biased ESD diode conduction.

How does LM139APT handle input signals exceeding the supply rail?

The LM139APT allows differential input voltage up to ±36 V and permits either input to swing up to +30 V even when V_CC = +5 V, provided the other input stays within the common-mode range (0 V to V_CC − 1.5 V). This enables overvoltage-tolerant sensing (e.g., detecting 24 V signals on a 5 V system) without external clamping, as long as the low-side input does not drop below −0.3 V.

LM139APT Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Package/Case:: 14-TSSOP (0.173", 4.40mm Width)

Series:: -

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Type:: General Purpose

Number of Elements:: 4

Output Type:: -

Voltage - Supply, Single/Dual (±):: 2V ~ 32V, ±1V ~ 16V

:: 2mV @ 30V

Voltage - Input Offset (Max):: 0.1µA @ 5V

Current - Input Bias (Max):: 16mA @ 5V

Current - Output (Typ):: 2mA

Current - Quiescent (Max):: -

CMRR, PSRR (Typ):: -

Propagation Delay (Max):: -

Hysteresis:: -55°C ~ 125°C

Operating Temperature:: -

Grade:: -

Qualification:: Surface Mount

:: 14-TSSOP

LM139APT FAQ

1.How can I place an order for LM139APT through Aetrix?

Please submit a Request for Quotation (RFQ) for LM139APT on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for LM139APT reliable?

The price and inventory of LM139APT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM139APT is usually 5 days.

3.What payment methods are accepted for LM139APT?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM139APT transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for LM139APT?

LM139APT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your LM139APT order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for LM139APT?

For technical support, including LM139APT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM139APT requirements.

6.How does Aetrix verify that LM139APT is sourced from the original manufacturer or authorized distributors?

All LM139APT products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that LM139APT meets industry standards.

7.What is the process for return or replacement of LM139APT?

All LM139APT units undergo pre-shipment inspection (PSI). If there is an issue with LM139APT, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The LM139APT part is unused and in its original packaging.

Return procedure for LM139APT:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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