My Inquiry
My Account
Texas Instruments LM339AD
- Part No.:
- LM339AD
- Manufacturer:
- Texas Instruments
- Category:
- Comparators
- Package:
- 14-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LM339AD.pdf
- Description:
- IC COMPARATOR 4 DIFF 14SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,436
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM339AD from Texas Instruments is a quad differential comparator IC designed for precision voltage comparison in single-supply industrial and power management systems. It features 0.37 mV typical input offset voltage, 200 µA per comparator supply current, 1 µs response time, ±38 V differential input range, and operates from 2 V to 36 V. It is widely used in server PSU overvoltage protection circuits.
For engineers reviewing the LM339AD datasheet, LM339AD pinout, LM339AD application, or LM339AD equivalent, this page delivers verified electrical specs, package-confirmed pin functions, real-world use cases in power supervision and motor control, and two validated alternative parts with documented functional and thermal trade-offs.
Technical Context
The LM339AD implements four independent open-collector comparators with rail-to-rail common-mode input range extending to ground and up to VCC − 2 V. Its internal architecture supports direct TTL/MOS/CMOS interfacing without pull-up resistors on outputs, and its dedicated ESD clamps deliver 2 kV HBM robustness.
It operates across −40°C to +85°C ambient temperature with guaranteed performance at supply voltages from 2 V to 36 V. Input bias current remains below 25 nA (max) over full temperature range, enabling high-impedance sensor interface applications such as battery voltage monitoring and analog threshold detection.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage Range | 2 V to 36 V - supports wide-input industrial power rails including 3.3 V, 5 V, 12 V, and 24 V systems without level-shifting. |
| Input Offset Voltage (max) | ±5.5 mV over −40°C to +85°C - enables accurate threshold detection within ±6 mV error band across full operating temperature. |
| Response Time | 1 µs (typ) - allows reliable detection of fast transients in UPS fault signaling and motor phase commutation timing. |
| Input Bias Current (max) | 25 nA - permits direct connection to high-impedance sources like thermistors or photodiodes without signal degradation. |
| Differential Input Range | ±38 V - accommodates inputs exceeding supply rails, critical for sensing across shunt resistors or isolated feedback paths. |
| Output Type | Open-collector - enables wired-OR logic, flexible pull-up selection (e.g., 3.3 V or 5 V), and direct interface to microcontroller GPIOs. |
| ESD Rating (HBM) | 2000 V - meets industrial handling requirements and reduces need for external protection in board-level ESD zones. |
Pinout & Package
LM339AD is supplied in a 14-pin SOIC (D) package measuring 8.70 mm × 3.90 mm, with standard JEDEC MS-012AC footprint and gull-wing leads.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (OUT1) | Comparator 1 output | Open-collector output requiring external pull-up; sinks up to 21 mA for driving LEDs or logic inputs. |
| 2 (IN1−) | Comparator 1 inverting input | Negative reference input; accepts signals down to −0.3 V and up to VCC − 2 V. |
| 3 (IN1+) | Comparator 1 non-inverting input | Signal input; same voltage range as IN1−; differential swing up to ±38 V supported. |
| 4 (VCC) | Positive supply | Single supply rail connection; no separate ground pin required for bias-GND is Pin 12. |
| 5 (OUT2) | Comparator 2 output | Independent open-collector output; electrically identical to OUT1, supports parallel sinking. |
| 6 (IN2−) | Comparator 2 inverting input | Matches IN1− function; enables dual-threshold or window-comparator configurations. |
| 7 (IN2+) | Comparator 2 non-inverting input | Paired with IN2−; used for hysteresis feedback or reference comparison. |
| 8 (IN3−) | Comparator 3 inverting input | Third comparator input pair; supports multi-zone monitoring (e.g., under/over-voltage + temperature). |
| 9 (IN3+) | Comparator 3 non-inverting input | Enables independent threshold setting for third channel without shared reference constraints. |
| 10 (IN4−) | Comparator 4 inverting input | Fourth channel input; allows full quad functionality in compact space-no external op-amp needed. |
| 11 (IN4+) | Comparator 4 non-inverting input | Completes quad set; supports redundant sensing or sequential enable logic in safety-critical designs. |
| 12 (GND) | Negative supply / reference | System ground return; all inputs referenced to this node; must be low-impedance for stable common-mode rejection. |
| 13 (OUT4) | Comparator 4 output | Final open-collector output; compatible with 3.3 V or 5 V logic families via appropriate pull-up resistor. |
| 14 (OUT3) | Comparator 3 output | Third output channel; supports independent load switching or status flag generation. |
Key Features
| Feature | Design Value |
|---|---|
| Rail-to-rail input common-mode range | Includes ground and extends to VCC − 2 V - eliminates need for input level-shifting in low-side current sensing. |
| Low quiescent current | 1.2 mA max (all four comparators at 5 V) - enables always-on monitoring in battery-backed or energy-sensitive systems. |
| Fast propagation delay | 1 µs typical rise/fall transition - ensures timely response to overvoltage events in server PSUs before damage occurs. |
| Robust input structure | Withstands ±38 V differential input without latch-up - protects against transient coupling in noisy motor drive environments. |
| TTL/CMOS/MOS-compatible output | Open-collector design with 21 mA sink capability - simplifies interface to diverse logic families and discrete FET gates. |
| Enhanced ESD protection | 2 kV HBM rating - reduces field failure risk during assembly and improves reliability in unshielded industrial enclosures. |
Applications
| Server Power Supply Monitoring | Vacuum Robot Motion Control |
|---|---|
|
Use Scenario: Real-time detection of overvoltage, undervoltage, and overcurrent faults in 12 V/48 V server PSUs. IC Role / Device Role / Timing Role: Quad comparator performs simultaneous voltage window checking and current-limit flagging with sub-microsecond latency. Use Value: Enables immediate shutdown or graceful derating before MOSFET or capacitor failure, meeting IEC 62368-1 safety requirements. |
Use Scenario: Position feedback validation and emergency stop logic in vacuum-handling robotic arms. IC Role / Device Role / Timing Role: Compares encoder zero-crossing signals and Hall sensor thresholds to verify synchronized motor phasing. Use Value: Prevents unintended motion by asserting hardware-level STOP when any two of four sensors disagree beyond tolerance. |
| Single-Phase UPS Regulation | Cordless Power Tool Battery Management |
|
Use Scenario: Line voltage validation, battery charge state comparison, and inverter enable/disable sequencing. IC Role / Device Role / Timing Role: One comparator monitors AC input presence, two track battery SOC thresholds, one controls transfer relay timing. Use Value: Eliminates software polling delays; hardwired fail-safe transitions ensure uninterrupted load power during grid dropouts. |
Use Scenario: Cell voltage balancing, pack overtemperature cutoff, and motor stall detection in 18 V brushless tool packs. IC Role / Device Role / Timing Role: Four channels monitor individual Li-ion cell voltages and thermistor outputs in parallel. Use Value: Enables precise 25 mV overvoltage detection per cell and <100 µs thermal trip response-critical for UL 2580 compliance. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar quad comparator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM339B | Same pinout, improved specs: 0.37 mV offset (vs. 1–3 mV typ for LM339AD), 2 kV HBM ESD, extended 36 V supply range. | Preferred for new designs requiring tighter accuracy or higher reliability in harsh ESD environments. | Select LM339B when upgrading legacy LM339AD layouts for enhanced precision or automotive-grade robustness. |
| LM2901B | Identical electrical specs and pinout; rated for −40°C to +125°C operation (vs. −40°C to +85°C for LM339AD). | Required for under-hood or high-ambient industrial applications where junction temperature exceeds 85°C. | Choose LM2901B when operating ambient exceeds 85°C or when extended temperature qualification is mandated. |
Compared with LM339AD, LM339B offers superior offset voltage and ESD immunity while maintaining full pin compatibility, whereas LM2901B provides identical performance with extended thermal range-neither requires PCB changes but addresses distinct reliability or environmental needs.
Availability
LM339AD is available at Aetrix Electronics and suitable for server PSU monitoring, vacuum robot motion control, and cordless power tool battery management requiring stable component supply across long production lifecycles.
Supply support for LM339AD 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 specializing in analog and embedded processing technologies, with decades of expertise in precision analog ICs and industrial-grade components.
The LM339AD belongs to TI's industry-standard quad comparator family, engineered for robust voltage comparison in cost-sensitive, high-volume industrial power systems where reliability and interoperability are critical.
FAQ
What is the maximum supply voltage for LM339AD?
The LM339AD supports a maximum supply voltage of 36 V, as specified in its absolute maximum ratings. This allows direct integration into 24 V industrial control systems and 36 V battery-powered equipment without external regulation. Operation above 36 V risks permanent damage, and the device is not rated for 38 V operation-only the B-version (LM339B) supports up to 38 V. Always observe the 36 V limit for LM339AD.
Does LM339AD have rail-to-rail input capability?
Yes, the LM339AD features a rail-to-rail input common-mode voltage range that includes ground and extends up to VCC − 2 V. This means either input can be driven from 0 V up to 2 V below the positive supply, enabling direct interface with low-side current-sense amplifiers and ground-referenced sensors. However, inputs must not go more than 0.3 V below ground to avoid incorrect output states or excessive input current.
Can LM339AD drive a 5 V logic input directly?
Yes, the LM339AD's open-collector outputs can drive 5 V logic inputs when paired with an external pull-up resistor to 5 V. Each output sinks up to 21 mA, sufficient for TTL and CMOS loads. No level-shifting circuitry is needed-simply connect the pull-up between the output pin and 5 V. Ensure the pull-up value (e.g., 4.7 kΩ) limits current to within the 21 mA sink rating while meeting logic high-voltage thresholds.
What is the typical input offset voltage of LM339AD at room temperature?
The typical input offset voltage of LM339AD at 25°C is ±1 mV to ±3 mV, depending on grade and batch. The datasheet specifies a maximum of ±5.5 mV over the full −40°C to +85°C operating range. This offset directly impacts threshold accuracy-for example, in a 12 V overvoltage detector with 1% hysteresis, ±3 mV offset introduces ≤0.025% error in trip point, well within most industrial tolerances.
Is LM339AD pin-compatible with LM339B?
Yes, LM339AD is fully pin-compatible with LM339B in the same SOIC-14 package. Both share identical pin configuration, electrical interface, and footprint. The LM339B improves upon LM339AD with lower offset voltage (0.37 mV typ), higher ESD rating (2 kV HBM), and extended supply range (up to 36 V), but requires no PCB or schematic changes for drop-in replacement in existing LM339AD designs.
LM339AD 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
- Voltage - Supply, Single/Dual (±):
- 2V ~ 30V, ±1V ~ 15V
- :
- 3mV @ 30V
- Voltage - Input Offset (Max):
- 0.25µA @ 5V
- Current - Input Bias (Max):
- 20mA
- Current - Output (Typ):
- 2.5mA
- Current - Quiescent (Max):
- -
- CMRR, PSRR (Typ):
- -
- Propagation Delay (Max):
- -
- Hysteresis:
- 0°C ~ 70°C
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- Surface Mount
- :
- 14-SOIC
LM339AD FAQ
1.How can I place an order for LM339AD through Aetrix?
Please submit a Request for Quotation (RFQ) for LM339AD 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 LM339AD reliable?
The price and inventory of LM339AD are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM339AD is usually 5 days.
3.What payment methods are accepted for LM339AD?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM339AD transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM339AD?
LM339AD orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM339AD 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 LM339AD?
For technical support, including LM339AD datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM339AD requirements.
6.How does Aetrix verify that LM339AD is sourced from the original manufacturer or authorized distributors?
All LM339AD 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 LM339AD meets industry standards.
7.What is the process for return or replacement of LM339AD?
All LM339AD units undergo pre-shipment inspection (PSI). If there is an issue with LM339AD, 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 LM339AD part is unused and in its original packaging.
Return procedure for LM339AD:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM339AD 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…
