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

STMicroelectronics LM319DT

Name: LM319DT
Brand: STMicroelectronics
SKU: LM319DT
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: LM319DT

Manufacturer:: STMicroelectronics

Category:: Comparators

Package:: 14-SOIC (0.154", 3.90mm Width)

Datasheet:: LM319DT.pdf

Description:: IC COMPARATOR 2 GEN PUR 14SO

Quantity:: RFQ Add To RFQ list

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Inventory:5,974

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Product details

Overview

LM319DT from STMicroelectronics is a high-speed dual comparator IC designed for precision threshold detection in mixed-signal systems operating from +5 V to ±15 V supplies. It delivers 80 ns typical response time at ±15 V, supports ±12 V common-mode input range, features open-collector outputs capable of sinking 25 mA, and maintains ≤1 µA max input bias current over 0 °C to +70 °C. It is used in relay driver circuits and window detectors requiring fast, rail-compatible comparison.

For engineers reviewing the LM319DT datasheet, LM319DT pinout, LM319DT application, or LM319DT equivalent, this page provides verified technical context, SO-14 package mapping, real-world timing behavior, TTL/relay interface capability, and validated alternatives for industrial control and logic-level signal conditioning.

Technical Context

The LM319DT integrates two independent comparators with fully differential inputs and open-collector NPN output stages. Its internal schematic includes matched transistor pairs and precision resistive networks enabling stable offset (≤10 mV) and low input bias current (≤1.2 µA) across temperature.

It operates with supply voltages ranging from single +5 V to bipolar ±15 V, supports common-mode input up to ±13 V, and achieves 80 ns propagation delay under 100 mV step with 5 mV overdrive - significantly faster than LM111 while consuming higher quiescent current (≤12.5 mA).

Key Specifications

Parameter	Value and Actual Design Meaning
Supply Voltage Range	+5 V to ±15 V - enables direct interfacing with TTL, CMOS, and analog rails without level-shifting.
Typical Response Time	80 ns at ±15 V - ensures reliable detection of fast edges in pulse-width modulation or overvoltage protection circuits.
Input Offset Voltage	≤10 mV max - defines minimum detectable voltage difference between inputs in precision threshold applications.
Input Bias Current	≤1.2 µA max - minimizes loading error on high-impedance sensor or reference sources.
Output Sink Current	25 mA - directly drives relays, LEDs, or TTL inputs without external buffer transistors.
Common-Mode Input Range	±13 V at +5 V supply - allows input signals referenced to system ground or floating supplies.
Operating Temperature	0 °C to +70 °C - qualified for commercial-grade embedded control and instrumentation environments.

Pinout & Package

LM319DT is supplied in a 14-pin SOIC (SO-14) plastic micropackage with standard 1.27 mm pitch, 8.55–8.75 mm body length, and ECOPACK® environmental compliance.

Pin/Terminal	Circuit Role	Design Meaning
1	Output 1	Open-collector NPN output - requires external pull-up to define logic HIGH level and sink up to 25 mA.
2	Inverting Input 1	Negative input of comparator 1 - accepts signals within common-mode range up to ±13 V.
3	Non-inverting Input 1	Positive input of comparator 1 - used for reference or signal comparison with matched input impedance.
4	Ground 1	Signal ground reference for comparator 1 - isolated from comparator 2's ground (pin 11) to reduce crosstalk.
5	Non-inverting Input 2	Positive input of comparator 2 - independently configurable for dual-threshold or window detection.
6	Inverting Input 2	Negative input of comparator 2 - paired with pin 5 to form second independent comparison channel.
7	Output 2	Open-collector NPN output - electrically isolated from Output 1 (pin 1), supports separate load connections.
8	VCC−	Negative supply rail - required for bipolar operation; tied to ground for single +5 V use.
9	N.C.	No connection - internally unconnected; must remain floating or grounded per layout guidelines.
10	N.C.	No connection - internally unconnected; no routing or termination required.
11	Ground 2	Signal ground reference for comparator 2 - physically separated from pin 4 to minimize inter-channel coupling.
12	N.C.	No connection - internally unconnected; leave unconnected.
13	N.C.	No connection - internally unconnected; leave unconnected.
14	VCC+	Positive supply rail - accepts +5 V to +18 V; powers both comparators and output stages.

Key Features

Feature	Design Value
Dual independent comparators	Two fully isolated comparison channels with separate ground pins (pins 4 and 11) reduce inter-channel interference in noise-sensitive designs.
Wide supply voltage range	Operates from +5 V single supply to ±15 V bipolar - eliminates need for dedicated voltage translators in mixed-rail systems.
80 ns propagation delay	Enables accurate timing capture in digital edge detection, PWM monitoring, and overcurrent trip circuits.
25 mA output sink capability	Directly interfaces with electromechanical relays, indicator LEDs, and TTL logic without external drivers.
≤1 µA input bias current	Preserves accuracy when comparing high-impedance sources such as thermistor dividers or photodiode amplifiers.

Applications

Relay Driver Circuit

Window Voltage Detector

Use Scenario: Driving a 12 V DC relay coil using a microcontroller GPIO that cannot source/sink sufficient current.

IC Role / Device Role: Dual comparator configured as high/low threshold detector with hysteresis, triggering relay activation only when input voltage falls outside defined bounds.

Use Value: Eliminates need for discrete transistors or optocouplers; open-collector outputs simplify interface to relay coil and flyback diode.

Use Scenario: Monitoring battery voltage in portable equipment to trigger low-battery warning and overvoltage shutdown.

IC Role / Device Role: One comparator monitors upper threshold (e.g., 4.3 V), the other lower threshold (e.g., 3.2 V); outputs combined via wired-OR logic.

Use Value: Provides precise, temperature-stable window detection with <10 mV offset error - critical for Li-ion battery management.

Pulse Width Modulation Monitor

TTL-Compatible Level Shifter

Use Scenario: Capturing rising/falling edges of PWM signals for duty-cycle measurement in motor control feedback loops.

IC Role / Device Role: Fast-response comparator converts analog PWM waveform into clean digital edge transitions synchronized to system clock.

Use Value: 80 ns delay ensures sub-microsecond timing resolution - essential for closed-loop servo accuracy and jitter reduction.

Use Scenario: Converting 3.3 V logic signals to 5 V TTL levels for legacy peripheral interfacing.

IC Role / Device Role: Comparator compares 3.3 V input against 1.4 V reference; open-collector output pulled to +5 V generates valid TTL HIGH/LOW.

Use Value: Achieves robust level translation without timing skew or shoot-through risk inherent in MOSFET-based solutions.

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed dual comparator applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
LM393DT	Slower response (1.3 µs), lower supply current (0.8 mA), no negative supply support - single +5 V only.	Suitable for low-power, non-critical timing applications where speed is not required.	Select when power budget is constrained and 80 ns timing is unnecessary; verify input common-mode range compatibility.
TL331IDBVR	Single comparator, 200 ns response, rail-to-rail input, 60 µA supply current - optimized for ultra-low power.	Requires two devices to replace dual functionality; lacks isolated grounds and high sink current.	Choose for space-constrained, battery-powered designs needing rail-to-rail input but accepting slower response and added component count.

Compared with LM319DT, LM393DT trades speed for power efficiency and simplicity, while TL331IDBVR offers rail-to-rail input at the cost of dual-channel integration and output drive strength - making LM319DT optimal for performance-critical, mixed-supply industrial sensing.

Availability

LM319DT is available at Aetrix Electronics and suitable for relay driver circuits, window voltage detectors, PWM monitoring systems, and TTL-compatible level shifters requiring stable component supply and guaranteed SO-14 packaging.

Supply support for LM319DT 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, MCU, power, and sensor solutions for industrial, automotive, and consumer markets.

The LM319 series belongs to ST's legacy precision analog comparators product line, engineered specifically for high-speed, wide-supply industrial signal conditioning and logic interfacing applications.

FAQ

What is the maximum output sink current for LM319DT?

The LM319DT output stage can sink up to 25 mA per channel when V_O ≤ 0.75 V at ±15 V supply and T_A = +25 °C. This rating holds across the full 0 °C to +70 °C operating range, enabling direct relay and LED driving without external buffers.

Can LM319DT operate from a single +5 V supply?

Yes - LM319DT is fully specified for single +5 V operation with V_CC+ = +5 V and V_CC− = 0 V. Input common-mode range extends to 1 V above ground, and output saturates near 0.4 V with 3.2 mA sink load, ensuring reliable TTL compatibility.

Why does LM319DT have two separate ground pins?

Pins 4 and 11 serve as independent signal grounds for comparator 1 and comparator 2 respectively. This physical separation reduces inter-channel coupling and improves noise immunity in dual-threshold applications like window detectors where one comparator's switching could affect the other.

How does LM319DT differ from LM393DT in timing performance?

LM319DT achieves 80 ns typical response time at ±15 V, whereas LM393DT requires 1.3 µs under identical conditions - a 16× speed advantage. This makes LM319DT suitable for PWM edge detection and fast overvoltage tripping where sub-microsecond latency is critical.

LM319DT Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Package/Case:: 14-SOIC (0.154", 3.90mm Width)

Series:: -

Packaging:: Tape & Reel (TR)

Product Status:: Active

Type:: General Purpose

Number of Elements:: 2

Output Type:: Open-Collector, Open-Emitter, TTL

Voltage - Supply, Single/Dual (±):: 5V ~ 30V, ±2.5V ~ 15V

:: 8mV @ ±15V

Voltage - Input Offset (Max):: 1µA @ ±15V

Current - Input Bias (Max):: -

Current - Output (Typ):: 12.5mA

Current - Quiescent (Max):: -

CMRR, PSRR (Typ):: -

Propagation Delay (Max):: -

Hysteresis:: 0°C ~ 70°C

Operating Temperature:: -

Grade:: -

Qualification:: Surface Mount

:: 14-SO

LM319DT FAQ

1.How can I place an order for LM319DT through Aetrix?

Please submit a Request for Quotation (RFQ) for LM319DT 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 LM319DT reliable?

The price and inventory of LM319DT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM319DT is usually 5 days.

3.What payment methods are accepted for LM319DT?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM319DT transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for LM319DT?

LM319DT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your LM319DT 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 LM319DT?

For technical support, including LM319DT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM319DT requirements.

6.How does Aetrix verify that LM319DT is sourced from the original manufacturer or authorized distributors?

All LM319DT 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 LM319DT meets industry standards.

7.What is the process for return or replacement of LM319DT?

All LM319DT units undergo pre-shipment inspection (PSI). If there is an issue with LM319DT, 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 LM319DT part is unused and in its original packaging.

Return procedure for LM319DT:

1.Submit a request within 90 days.

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

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