My Inquiry
My Account
Texas Instruments LM139AD
- Part No.:
- LM139AD
- Manufacturer:
- Texas Instruments
- Category:
- Comparators
- Package:
- 14-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LM139AD.pdf
- Description:
- IC COMPARATOR 4 DIFF 14SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,599
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM139AD from Texas Instruments is a quad differential comparator IC designed for precision voltage comparison in wide-supply industrial and aerospace systems. It operates from 2V to 30V, delivers ±9mV max input offset voltage (25°C), supports –55°C to +125°C temperature range, and features open-collector outputs compatible with TTL/MOS/CMOS logic - used in motor control feedback, power supply sequencing, and overvoltage protection circuits.
For engineers reviewing the LM139AD datasheet, LM139AD pinout, LM139AD application, or LM139AD equivalent, key selection criteria include its military-grade temperature range, low quiescent current (0.8–2 mA), rail-to-rail common-mode input capability down to ground, and compatibility with pull-up networks up to 30V.
Technical Context
The LM139AD implements four independent high-gain comparators with internal compensation, enabling fast decision-making without external hysteresis in most applications. Its input stage accepts common-mode voltages from V– to (V+) – 2V, allowing direct sensing of signals referenced to ground or near-rail conditions.
Each comparator features an open-collector output capable of sinking up to 16 mA at 1.5V saturation, with high-level leakage under 1 µA at 30V - supporting flexible interface design across logic families and mixed-voltage systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 2 V to 30 V - enables single-supply operation in battery-powered and industrial 24V systems |
| Input Offset Voltage (max) | ±9 mV at 25°C - ensures reliable detection of small differential signals without calibration |
| Operating Temperature | –55°C to +125°C - qualified for military, avionics, and harsh-environment embedded control |
| Quiescent Current | 0.8–2 mA per device - supports low-power monitoring while maintaining full-speed response |
| Output Sink Current | 6–16 mA - drives LEDs, relays, or logic inputs directly without external buffers |
| Common-Mode Range | V– to (V+) – 2 V - allows ground-referenced inputs and high-side sensing in unipolar supplies |
| Response Time | 1.3 µs (100 mV step) - suitable for real-time fault detection in power converters and motor drives |
Pinout & Package
LM139AD is packaged in a 14-pin SOIC (D) package measuring 8.70 mm × 3.90 mm, with standard JEDEC outline and surface-mount compatibility.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (OUT1) | Comparator 1 output | Open-collector output requiring external pull-up; sinks current when IN1– > IN1+ |
| 2 (IN1–) | Comparator 1 inverting input | Differential input node; accepts voltage down to V– – 0.3 V without damage |
| 3 (IN1+) | Comparator 1 non-inverting input | Differential input node; supports common-mode range up to V+ – 2 V |
| 4 (VCC) | Positive supply | Single positive rail connection; no separate ground pin required for biasing |
| 5 (OUT2) | Comparator 2 output | Independent open-collector output; electrically isolated from OUT1 |
| 6 (IN2–) | Comparator 2 inverting input | Matches IN1– electrical behavior; supports same voltage and current limits |
| 7 (IN2+) | Comparator 2 non-inverting input | Matches IN1+ electrical behavior; shares same common-mode specification |
| 8 (GND) | Negative supply / reference | System ground return; all inputs and outputs referenced to this node |
| 9 (OUT3) | Comparator 3 output | Third independent open-collector output; identical sink capability to OUT1/OUT2 |
| 10 (IN3–) | Comparator 3 inverting input | Third differential pair input; fully decoupled from other channels |
| 11 (IN3+) | Comparator 3 non-inverting input | Third differential pair input; matches performance of IN1+/IN2+ |
| 12 (OUT4) | Comparator 4 output | Fourth open-collector output; enables multi-threshold monitoring in one IC |
| 13 (IN4–) | Comparator 4 inverting input | Final differential input; supports full common-mode and overvoltage robustness |
| 14 (IN4+) | Comparator 4 non-inverting input | Final differential input; completes quad-channel functional independence |
Key Features
| Feature | Design Value |
|---|---|
| Rail-to-rail input common-mode range | Operates with inputs at ground potential - eliminates need for level-shifting in low-side sensing |
| Open-collector outputs | Enable wired-OR logic, mixed-voltage interfacing, and direct drive of loads up to 30V |
| Wide supply voltage range | 2V–30V operation supports both low-power microcontroller domains and industrial 24V rails |
| Military temperature qualification | –55°C to +125°C rating ensures reliability in avionics, defense, and downhole equipment |
| Low input bias current | Max ±300 nA enables high-impedance sensor interfacing without signal loading errors |
Applications
| Motor Drive Protection | Industrial Power Sequencing |
|---|---|
Use Scenario: Monitoring phase currents and bus voltage in three-phase inverters to trigger shutdown during overcurrent or overvoltage events. IC Role / Device Role / Timing Role: Quad comparator performs simultaneous threshold comparisons on analog feedback signals, generating immediate digital fault flags. Use Value: Enables sub-microsecond response to critical faults, preventing IGBT destruction and improving system MTBF. | Use Scenario: Verifying correct ramp-up order of multiple DC rails (e.g., 12V, 5V, 3.3V) before enabling FPGA or processor core logic. IC Role / Device Role / Timing Role: Each comparator independently validates individual rail thresholds; outputs combined via external diodes or logic gates. Use Value: Prevents latch-up and configuration corruption by enforcing strict power-up sequence compliance. |
| Aerospace Sensor Interface | Overvoltage Crowbar Control |
Use Scenario: Converting analog outputs from radiation-hardened RTDs and pressure transducers into digital status signals for flight control computers. IC Role / Device Role / Timing Role: LM139AD compares sensor outputs against programmable reference voltages generated by precision DACs. Use Value: Maintains accuracy across extreme thermal cycles due to low drift and military-grade temp range. | Use Scenario: Detecting DC bus overvoltage in telecom rectifiers and triggering thyristor-based crowbar discharge to protect downstream loads. IC Role / Device Role / Timing Role: One comparator channel monitors bus voltage; output drives gate driver for SCR crowbar circuit. Use Value: Provides fail-safe hardware-level protection independent of software or microcontroller health. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar quad comparator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM339ADR | Commercial grade (0°C to 70°C), lower max offset (±4 mV), 2–30 V supply | Limited to benign environments; unsuitable for aerospace or extended-temp industrial use | Select when cost sensitivity outweighs temperature or reliability requirements |
| LM2901DR | Automotive grade (–40°C to +125°C), higher max offset (±15 mV), 2–32 V supply | Qualified for automotive AEC-Q100; lacks military temp range but offers wider voltage headroom | Prefer for automotive ECUs where extended voltage margin matters more than ultra-low offset |
Compared with LM139AD, LM339ADR trades military temperature range and long-term stability for lower cost and tighter offset in commercial settings, while LM2901DR provides automotive qualification and higher voltage tolerance at the expense of initial accuracy - making LM139AD the only choice for mission-critical, wide-temperature, high-reliability applications.
Availability
LM139AD is available at Aetrix Electronics and suitable for motor drive protection, industrial power sequencing, aerospace sensor interface, and overvoltage crowbar control requiring stable component supply across extended temperature and long product lifecycles.
Supply support for LM139AD 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
Texas Instruments is a global semiconductor leader delivering analog and embedded processing solutions for industrial, automotive, and aerospace markets.
The LM139AD belongs to TI's legacy precision comparator family, engineered specifically for high-reliability, wide-temperature applications where deterministic analog decision-making is essential - including defense systems, avionics, and space-grade electronics.
FAQ
What is the maximum supply voltage rating for LM139AD?
The LM139AD has an absolute maximum supply voltage of 36 V, but its recommended operating range is 2 V to 30 V. Operation above 30 V risks exceeding specified electrical characteristics and may impact long-term reliability. The datasheet explicitly defines 30 V as the upper limit for normal functional operation across the full –55°C to +125°C temperature range.
Does LM139AD support rail-to-rail input operation?
Yes, LM139AD supports rail-to-rail input common-mode operation down to the negative supply rail (V–), with an upper limit of (V+) – 2 V. This allows direct interfacing with ground-referenced sensors and signals without level-shifting circuitry, a key advantage in low-side current sensing and battery-monitoring applications.
What output configuration does LM139AD use?
LM139AD uses open-collector outputs on all four comparators. Each output requires an external pull-up resistor to a defined logic-high voltage, enabling wired-OR functionality, mixed-voltage interfacing (e.g., 3.3V logic driving a 24V load), and direct drive of LEDs or relay coils without additional buffering components.
Is LM139AD pin-compatible with other members of the LM339 family?
Yes, LM139AD shares identical pinout and footprint with LM339, LM239, LM2901, and LM339B in the 14-pin SOIC (D) package. However, differences in temperature range, offset voltage, and supply current mean functional substitution requires validation of timing, accuracy, and environmental requirements in the target application.
What is the typical response time of LM139AD?
The LM139AD exhibits a typical response time of 1.3 µs for a 100 mV input step with 5 mV overdrive, measured under standard test conditions (VCC = 5 V, RL = 5.1 kΩ, CL = 15 pF). This value remains consistent across its full operating temperature range and supply voltage span, ensuring predictable timing behavior in real-time protection circuits.
LM139AD Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- 14-SOIC (0.154", 3.90mm Width)
- Series:
- -
- Packaging:
- Tube
- Product Status:
- Obsolete
- Type:
- General Purpose
- Number of Elements:
- 4
- Output Type:
- Open-Collector, Open-Drain
- Voltage - Supply, Single/Dual (±):
- 2V ~ 30V, ±1V ~ 15V
- :
- 2mV @ 30V
- Voltage - Input Offset (Max):
- 0.1µA @ 5V
- Current - Input Bias (Max):
- 20mA
- 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-SOIC
LM139AD FAQ
1.How can I place an order for LM139AD through Aetrix?
Please submit a Request for Quotation (RFQ) for LM139AD 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 LM139AD reliable?
The price and inventory of LM139AD are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM139AD is usually 5 days.
3.What payment methods are accepted for LM139AD?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM139AD transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM139AD?
LM139AD orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM139AD 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 LM139AD?
For technical support, including LM139AD datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM139AD requirements.
6.How does Aetrix verify that LM139AD is sourced from the original manufacturer or authorized distributors?
All LM139AD 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 LM139AD meets industry standards.
7.What is the process for return or replacement of LM139AD?
All LM139AD units undergo pre-shipment inspection (PSI). If there is an issue with LM139AD, 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 LM139AD part is unused and in its original packaging.
Return procedure for LM139AD:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM139AD Tags
-
LM2903DR
Texas Instruments
-
LM339DR
Texas Instruments
-
LM339PWR
Texas Instruments
-
LM393DT
STMicroelectronics
-
LM2901PWR
Texas Instruments
-
LM2903DT
STMicroelectronics
-
LM393DR
Texas Instruments
-
LM239DR
Texas Instruments
-
LM339APWR
Texas Instruments
-
LM2903P
Texas Instruments
-
LM393ADR
Texas Instruments
-
NCX2200GMAZ
NXP Semiconductors
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
