My Inquiry
My Account
Texas Instruments LM311N/NOPB
- Part No.:
- LM311N/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- Comparators
- Package:
- 8-DIP (0.300", 7.62mm)
- Datasheet:
-
LM311N/NOPB.pdf
- Description:
- IC COMPARATOR 1 GEN PUR 8DIP
- Quantity:
- Payment:
- Shipping:
Inventory:3,226
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM311N/NOPB from Texas Instruments is a general-purpose voltage comparator IC with open-collector output, designed for single-supply (5V) or dual-supply (±15V) operation. It features 150 nA max input bias current, 20 nA max offset current, ±30V differential input range, 200 ns response time, and drives loads up to 50V/50 mA - used in zero-crossing detection, relay control, and analog-to-digital interface circuits.
For engineers reviewing the LM311N/NOPB datasheet, LM311N/NOPB pinout, LM311N/NOPB application, or LM311N/NOPB equivalent, this page delivers verified electrical specs, DIP-8 package details, strobe and offset trimming functionality, TTL/MOS compatibility, and real-world design context for industrial signal conditioning and discrete logic interfacing.
Technical Context
The LM311N/NOPB uses a bipolar transistor input stage enabling wide common-mode input range (±15V) and high-voltage isolation between inputs and system ground. Its open-collector output supports wire-OR configuration and direct driving of relays, lamps, or MOS logic without level-shifting.
Strobe capability allows output disable via 2–5 mA sink on Pin 6, while Pins 5 and 6 support external offset nulling with a 5 kΩ potentiometer. The device operates across 0°C to +70°C and is rated for 36V total supply voltage with 500 mW max power dissipation in PDIP-8 package.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage Range | Single 5V or dual ±15V - enables direct integration with TTL/DTL logic and legacy op-amp rails. |
| Input Bias Current | 150 nA max over temperature - ensures minimal loading on high-impedance sensor sources like photodiodes. |
| Response Time | 200 ns - suitable for medium-speed threshold detection in motor control feedback or pulse-width modulation circuits. |
| Differential Input Voltage | ±30V - permits direct comparison of signals referenced to different potentials, e.g., isolated current-sense outputs. |
| Output Drive Capability | 50V/50 mA - supports direct relay coil or lamp driving without external transistor stages. |
| Strobe Input Current | 2–5 mA sink required on Pin 6 - enables synchronized blanking in multiplexed sensing or gated measurement systems. |
| Operating Temperature | 0°C to +70°C - qualified for commercial-grade embedded systems and industrial control panels. |
Pinout & Package
LM311N/NOPB is housed in an 8-pin plastic dual-in-line package (PDIP), RoHS-compliant with NiPdAu lead finish, MSL Level-1 rating, and through-hole mounting. Package outline conforms to JEDEC MS-001 (P package).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - Output | Open-collector NPN collector | Sinks current to ground or external pull-up; requires external resistor for logic-level output or load drive. |
| 2 - Inverting Input (−) | Differential input node | Accepts reference or threshold voltage; high-impedance node sensitive to layout-induced noise. |
| 3 - Non-Inverting Input (+) | Differential input node | Accepts signal to be compared; common-mode range extends to ±15V with ±15V supplies. |
| 4 - Ground / Negative Supply | Reference potential | May be connected to system ground or negative rail; supports floating-input configurations. |
| 5 - Offset Null (−) | Trim terminal for input offset | Connected to wiper of 5 kΩ potentiometer; adjusts internal input stage imbalance to <7.5 mV. |
| 6 - Strobe / Offset Null (+) | Output disable control / trim terminal | Sinking ≥2 mA disables output; also used with Pin 5 for offset nulling in non-strobed applications. |
| 7 - Positive Supply | Power rail | Accepts 5V to +15V in single-supply mode; supports up to +36V relative to Pin 4 in dual-supply use. |
| 8 - Not Connected | No internal connection | Unused pin; must remain unconnected per TI datasheet - no tie to ground or supply. |
Key Features
| Feature | Design Value |
|---|---|
| Isolated Inputs & Outputs | Both input terminals and output can float independently of system ground - enables level-shifting and galvanic isolation in multi-rail systems. |
| Wire-OR Output Capability | Open-collector output allows multiple LM311N/NOPB devices to share a common pull-up and bus - simplifies alarm aggregation or priority encoding. |
| Strobe-Controlled Output Disable | Pin 6 sink current disables output state without affecting input bias or offset - critical for time-gated measurements and multiplexed sensor arrays. |
| Offset Nulling Terminals | Pins 5 and 6 support external 5 kΩ potentiometer to reduce input offset voltage to ≤7.5 mV - improves DC accuracy in precision threshold detection. |
| TTL/DTL/MOS Logic Compatibility | Output directly interfaces with standard logic families without level translators - reduces BOM count in mixed-signal control boards. |
Applications
| Zero-Crossing Detection | Relay & Solenoid Control |
|---|---|
Use Scenario: Detecting AC line voltage polarity transitions in power supplies or motor phase controllers. IC Role / Device Role / Timing Role: Comparator compares sinusoidal input against 0V reference; output toggles at each crossing with 200 ns delay. Use Value: Enables synchronous switching with low timing jitter; open-collector output drives optocoupler input directly for isolation. |
Use Scenario: Driving 24VDC relay coils in PLC I/O modules or HVAC control panels. IC Role / Device Role / Timing Role: Compares microcontroller GPIO signal against threshold to activate relay driver stage. Use Value: 50V/50 mA output rating eliminates need for external transistor; strobe pin allows safe deactivation during firmware reset. |
| Digital Transmission Isolation | Peak Detection & Signal Conditioning |
Use Scenario: Converting analog sensor outputs (e.g., thermocouple amplifier) into clean digital pulses for microcontroller capture. IC Role / Device Role / Timing Role: Threshold detector with hysteresis; converts slow-varying analog waveforms into noise-immune logic edges. Use Value: Input common-mode range up to ±15V accommodates industrial sensor signal levels; strobe enables synchronized sampling windows. |
Use Scenario: Capturing positive voltage peaks from pulse trains in battery management or audio envelope detection. IC Role / Device Role / Timing Role: Comparator configured as peak-hold circuit with diode-capacitor feedback; resets via strobe signal. Use Value: 150 nA input bias minimizes capacitor discharge error; 200 ns response preserves fast transient fidelity in >10 kHz signals. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar voltage comparator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM393DR | Push-pull output, lower input bias (25 nA typ), 1.4 mA supply current vs. 6 mA for LM311N/NOPB. | Lacks strobe and offset null pins; not suitable for high-voltage floating inputs or synchronized blanking. | Select when low-power, rail-to-rail input, and push-pull output are prioritized over high-voltage tolerance and strobe control. |
| TLV3011IDBVR | CMOS input (0.5 pA bias), 1.8–5.5V supply only, 200 ns response, no strobe or offset pins. | Not rated for ±15V operation or 50V load switching; optimized for low-voltage portable systems. | Choose for ultra-low input current and battery-powered designs where LM311N/NOPB's 50V drive and wide supply are unnecessary. |
Compared with LM311N/NOPB, LM393DR offers simpler interfacing but sacrifices high-voltage isolation and strobe control, while TLV3011IDBVR delivers femtoampere input performance at the cost of supply flexibility and output drive strength - making LM311N/NOPB uniquely suited for rugged industrial threshold detection with synchronized gating.
Availability
LM311N/NOPB is available at Aetrix Electronics and suitable for industrial control panels, power supply monitoring, relay interface modules, and analog front-end signal conditioning requiring stable component supply across commercial temperature range.
Supply support for LM311N/NOPB 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, embedded processing, and connectivity solutions with emphasis on reliability, longevity, and industrial-grade qualification.
The LM311 series belongs to TI's legacy precision analog comparator product line, engineered for robust performance in noisy industrial environments, high-voltage signal interfacing, and applications demanding output drive beyond logic-level limits.
FAQ
What is the maximum supply voltage for LM311N/NOPB?
The LM311N/NOPB supports a total supply voltage up to 36V, with absolute maximum ratings specifying −30V to +36V between Pin 7 (V+) and Pin 4 (GND/−V). This allows operation from single 5V up to dual ±15V supplies, and accommodates transient overvoltage conditions in industrial settings where LM311N/NOPB is commonly deployed for fault detection and protection circuits.
Does LM311N/NOPB have built-in hysteresis?
No, the LM311N/NOPB does not include internal hysteresis. Hysteresis must be added externally using positive feedback from output to the non-inverting input (Pin 3) or to the offset null pin (Pin 5), as documented in TI's Application Hints. This design choice gives engineers full control over hysteresis magnitude - critical for noise immunity in LM311N/NOPB-based zero-crossing detectors and window comparators.
Can LM311N/NOPB drive a 12V relay directly?
Yes, LM311N/NOPB can directly drive a 12V relay coil if its coil resistance results in ≤50 mA current draw and the relay's flyback voltage is clamped with a reverse-biased diode. The LM311N/NOPB's open-collector output is rated for 50V/50 mA, and its saturation voltage remains ≤1.5 V at 50 mA - ensuring sufficient voltage margin for reliable relay actuation in LM311N/NOPB-based control circuits.
What is the purpose of Pin 8 on LM311N/NOPB?
Pin 8 on LM311N/NOPB is not internally connected (NC) and must remain unconnected in all PCB layouts. TI's datasheet explicitly states that Pin 8 has no internal bond wire or circuit function - connecting it to ground, supply, or any other node may cause unpredictable behavior or damage. This NC designation is consistent across all PDIP-packaged variants of the LM311 family, including LM311N/NOPB.
How do I configure LM311N/NOPB for single-supply operation?
To configure LM311N/NOPB for single-supply operation, connect Pin 4 (GND) to system ground, apply V+ (e.g., 5V or 12V) to Pin 7, reference the non-inverting input (Pin 3) to a mid-rail voltage (e.g., V+/2 via resistor divider), and ensure input signals stay within the common-mode range (−0.3V to V+−1.5V). The LM311N/NOPB's input stage supports this configuration inherently, and its open-collector output works with a pull-up to V+ - a standard setup in LM311N/NOPB-based sensor interface designs.
LM311N/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- 8-DIP (0.300", 7.62mm)
- Series:
- -
- Packaging:
- Tube
- Product Status:
- Active
- Type:
- General Purpose
- Number of Elements:
- 1
- Output Type:
- DTL, MOS, Open-Collector, Open-Emitter, RTL, TTL
- Voltage - Supply, Single/Dual (±):
- 5V ~ 36V, ±2.5V ~ 18V
- :
- 7.5mV @ ±15V
- Voltage - Input Offset (Max):
- 0.25µA @ ±15V
- Current - Input Bias (Max):
- 50mA
- Current - Output (Typ):
- 7.5mA
- Current - Quiescent (Max):
- -
- CMRR, PSRR (Typ):
- -
- Propagation Delay (Max):
- -
- Hysteresis:
- 0°C ~ 70°C
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- Through Hole
- :
- 8-PDIP
LM311N/NOPB FAQ
1.How can I place an order for LM311N/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM311N/NOPB 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 LM311N/NOPB reliable?
The price and inventory of LM311N/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM311N/NOPB is usually 5 days.
3.What payment methods are accepted for LM311N/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM311N/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM311N/NOPB?
LM311N/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM311N/NOPB 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 LM311N/NOPB?
For technical support, including LM311N/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM311N/NOPB requirements.
6.How does Aetrix verify that LM311N/NOPB is sourced from the original manufacturer or authorized distributors?
All LM311N/NOPB 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 LM311N/NOPB meets industry standards.
7.What is the process for return or replacement of LM311N/NOPB?
All LM311N/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM311N/NOPB, 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 LM311N/NOPB part is unused and in its original packaging.
Return procedure for LM311N/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM311N/NOPB 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…
