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Texas Instruments LM311H/NOPB
- Part No.:
- LM311H/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- Comparators
- Package:
- TO-99-8 Metal Can
- Datasheet:
-
LM311H/NOPB.pdf
- Description:
- IC COMPARATOR 1 GEN PUR TO99-8
- Quantity:
- Payment:
- Shipping:
Inventory:370
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Product details
Overview
LM311H/NOPB from Texas Instruments is a precision voltage comparator with open-collector output, designed for single-supply (5V) or dual-supply (±15V) operation. It delivers 200 ns response time, ±30V differential input range, and supports strobe-controlled output disable. Used in zero-crossing detection, relay drivers, and TTL/MOS interface circuits where rail-to-rail input swing and high-voltage load switching are required.
For engineers reviewing the LM311H/NOPB datasheet, LM311H/NOPB pinout, LM311H/NOPB application, or LM311H/NOPB equivalent, this page provides verified technical context, real-world design meaning of key specs, TO-99 package layout, confirmed alternatives, and supply support for industrial control and signal conditioning designs.
Technical Context
The LM311H/NOPB uses a bipolar input stage with 100 nA typical input bias current and 7.5 mV max input offset voltage at 25°C. Its open-collector output can sink up to 50 mA while driving loads referenced to ground, V+, or V− - enabling direct relay, lamp, or MOS logic interfacing without level-shifting circuitry.
Strobe functionality allows current-driven output disable (2–5 mA pulled from Pin 6), and offset nulling is supported via Pins 5 and 6. The device operates across 0°C to +70°C and tolerates ±30V differential input voltage, making it suitable for noisy industrial environments with wide common-mode swings.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Response Time | 200 ns - enables reliable detection of fast transitions in pulse-width modulation or clock edge sensing. |
| Differential Input Voltage Range | ±30 V - supports direct comparison of signals across wide voltage domains, e.g., AC line sensing or motor phase monitoring. |
| Output Sink Current | 50 mA - drives electromechanical relays or LEDs directly without external transistor buffering. |
| Input Offset Voltage (max) | 7.5 mV at 25°C - defines worst-case threshold error in precision level-detection applications like battery voltage monitoring. |
| Supply Voltage Range | Single 5V or dual ±15V - interoperates with both logic-level and analog signal chains without dedicated supply rails. |
| Strobe Enable Current | 2–5 mA - ensures clean output disable without grounding Pin 6, preventing latch-up or false triggering. |
| Operating Temperature | 0°C to +70°C - qualified for commercial-grade embedded systems including HVAC controllers and power supplies. |
Pinout & Package
LM311H/NOPB is housed in an 8-pin TO-99 metal can package (LMC outline), with hermetic sealing and through-hole mounting. Pin 1 is the output collector; Pin 2 is the inverting input; Pin 3 is the non-inverting input; Pin 4 is V−; Pin 5 and Pin 6 are offset null terminals; Pin 7 is V+; Pin 8 is strobe.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 | Output Collector | Open-collector node - must be pulled up externally to drive TTL/DTL/MOS loads or switch 50V-rated relays. |
| Pin 2 | Inverting Input (−) | High-impedance bipolar input - accepts signals up to ±15V relative to V−, used for reference or feedback paths. |
| Pin 3 | Non-Inverting Input (+) | High-impedance bipolar input - typically receives sensed signal; differential pair with Pin 2 sets comparison polarity. |
| Pin 4 | V− (Negative Supply) | Reference for internal circuitry - may be grounded in single-supply use; supports negative rail down to −15V. |
| Pin 5 / Pin 6 | Offset Null | Adjustable DC balance terminals - connected to potentiometer to trim input offset voltage below 2 mV. |
| Pin 7 | V+ (Positive Supply) | Main power rail - accepts 5V to +15V in single/dual configurations; powers internal differential pair and output stage. |
| Pin 8 | Strobe | Current-sink enable/disable - pulling 3–5 mA disables output; never grounded to avoid damage or erratic behavior. |
Key Features
| Feature | Design Value |
|---|---|
| Isolated Inputs & Outputs | Input and output stages electrically isolated from system ground - enables floating sensor interfaces and ground-referenced load switching. |
| Wire-OR Output Capability | Multiple LM311H/NOPB outputs can share one pull-up resistor - simplifies priority encoder or alarm bus architectures without external logic. |
| Strobe-Controlled Disable | Pin 8 current sink (2–5 mA) forces output high-impedance state - enables time-gated comparisons or synchronized sampling. |
| Wide Supply Flexibility | Operates from 5V single supply up to ±15V dual supply - eliminates need for separate analog/digital rails in mixed-signal PCBs. |
| High-Voltage Output Switching | Output withstands 40V to V− - directly controls solenoids, lamps, or optocouplers rated up to 40V without snubbers. |
Applications
| AC Line Monitoring | Relay Control Interface |
|---|---|
|
Use Scenario: Detecting zero-crossing points of 120/240 VAC mains for phase-controlled dimming or synchronous switching. IC Role / Device Role / Timing Role: Precision comparator comparing scaled AC waveform against ground reference with strobe-synchronized sampling. Use Value: 200 ns response ensures accurate timing alignment; ±30V input range accommodates peak AC voltages without attenuation networks. |
Use Scenario: Driving 24VDC industrial relays in PLC I/O modules where microcontroller GPIO cannot source sufficient current. IC Role / Device Role / Timing Role: Level-shifting and current-boosting interface between low-power MCU outputs and inductive relay coils. Use Value: 50 mA sink capability switches relays directly; open-collector output isolates MCU from inductive kickback transients. |
| Digital Signal Isolation | Peak Detection Circuit |
|
Use Scenario: Transmitting logic-level signals across isolation barriers using optocoupler-driven inputs and comparator-recovered outputs. IC Role / Device Role / Timing Role: Threshold detector reconstructing digital edges after optical isolation, rejecting noise on long traces. Use Value: Input hysteresis (via external feedback) suppresses noise-induced chatter; 200 ns propagation enables >1 MHz data rates. |
Use Scenario: Capturing positive voltage peaks from sensor outputs (e.g., piezoelectric transducers or RF envelope detectors). IC Role / Device Role / Timing Role: Comparator-based sample-and-hold front-end that triggers reset when input exceeds stored peak value. Use Value: Strobe pin disables output during hold phase; ±30V input range handles transient overloads without clipping. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar voltage comparator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM311N/NOPB | Same core comparator function but in 8-pin PDIP package; higher thermal resistance (100°C/W vs. TO-99's ~60°C/W); no metal-can EMI shielding. | Better suited for prototyping or low-volume PCBs where through-hole DIP sockets are preferred; less robust in EMI-heavy environments. | Select LM311N/NOPB when board space permits larger footprint and cost sensitivity outweighs shielding or thermal performance needs. |
| LM311MX/NOPB | SOIC-8 surface-mount variant; identical electrical specs; RoHS-compliant Sn finish; MSL Level-1 rating; 2500-piece tape-and-reel packaging. | Optimized for automated SMT assembly; requires reflow-compatible layout; lacks TO-99's hermetic seal and mechanical ruggedness. | Choose LM311MX/NOPB for high-volume production with pick-and-place lines and space-constrained layouts where thermal derating is managed. |
Compared with LM311H/NOPB, LM311N/NOPB trades metal-can EMI immunity and thermal efficiency for socket compatibility, while LM311MX/NOPB replaces hermetic sealing with SMT scalability - all maintain identical comparator functionality and 0°C to +70°C operation.
Availability
LM311H/NOPB is available at Aetrix Electronics and suitable for industrial control systems, power supply supervision, and analog signal conditioning requiring stable component supply across commercial temperature ranges.
Supply support for LM311H/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 specializing in analog and embedded processing technologies, with decades of expertise in precision signal chain components.
The LM311 series belongs to TI's legacy precision comparator product line, engineered for robust performance in industrial, instrumentation, and power management applications where reliability under wide voltage and temperature ranges is critical.
FAQ
What is the maximum differential input voltage the LM311H/NOPB can tolerate?
The LM311H/NOPB supports a differential input voltage range of ±30 V, as specified in its Absolute Maximum Ratings table. This allows direct comparison of signals with large voltage offsets - such as AC line sensing or motor phase monitoring - without external attenuation. Exceeding ±30 V risks permanent damage to the input stage. Always verify common-mode limits (±15 V with ±15 V supplies) alongside differential ratings when designing LM311H/NOPB circuits.
Can the LM311H/NOPB operate from a single 5V supply?
Yes, the LM311H/NOPB is explicitly rated for single 5V supply operation per its datasheet Features and Electrical Characteristics tables. With V− tied to ground and V+ at 5V, it maintains full functionality including 200 ns response time and 50 mA output sink capability. Input common-mode range extends to within 1.5 V of either rail, supporting direct interfacing with 3.3V or 5V logic sensors. The LM311H/NOPB does not require dual supplies unless negative input voltages or bipolar signal handling are needed.
How is the strobe pin (Pin 8) used on the LM311H/NOPB?
The strobe pin (Pin 8) on the LM311H/NOPB is a current-sink terminal: pulling 2–5 mA from it disables the output, forcing it into high-impedance state. It must never be grounded - doing so risks damage or unpredictable behavior. In practice, a microcontroller GPIO or logic gate drives a current source (e.g., NPN transistor or resistor to V+) to activate strobe. This feature enables time-gated comparisons, synchronized sampling, or multiplexed sensor readouts. The LM311H/NOPB datasheet specifies strict compliance with 3–5 mA for reliable disable.
What package type is the LM311H/NOPB supplied in?
The LM311H/NOPB is supplied in an 8-pin TO-99 metal can package (TI package code LMC), featuring hermetic sealing, through-hole mounting, and a height of ≤5.72 mm. This package provides superior EMI immunity and thermal performance compared to plastic DIP or SOIC variants. Pin 1 is the output collector; orientation follows standard TO-99 top-view numbering with Pin 1 adjacent to the tab. The "NOPB" suffix confirms lead-free (RoHS-compliant) finish, and the part marking reads "LM311H" on the can top.
Does the LM311H/NOPB support wire-OR output configurations?
Yes, the LM311H/NOPB's open-collector output architecture inherently supports wire-OR configurations. Multiple LM311H/NOPB outputs can share a single external pull-up resistor to V+ or another logic rail, enabling logical OR functions without discrete diodes or additional gates. This is commonly used in alarm consolidation, priority encoders, or fault-bus architectures. Ensure total sink current remains within safe limits (≤50 mA per device) and that pull-up strength matches downstream logic thresholds - especially for TTL or MOS interfaces driven by the LM311H/NOPB.
LM311H/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-99-8 Metal Can
- Series:
- -
- Packaging:
- Box
- 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):
- -
- 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
- :
- TO-99-8
LM311H/NOPB FAQ
1.How can I place an order for LM311H/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM311H/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 LM311H/NOPB reliable?
The price and inventory of LM311H/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM311H/NOPB is usually 5 days.
3.What payment methods are accepted for LM311H/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM311H/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM311H/NOPB?
LM311H/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM311H/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 LM311H/NOPB?
For technical support, including LM311H/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM311H/NOPB requirements.
6.How does Aetrix verify that LM311H/NOPB is sourced from the original manufacturer or authorized distributors?
All LM311H/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 LM311H/NOPB meets industry standards.
7.What is the process for return or replacement of LM311H/NOPB?
All LM311H/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM311H/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 LM311H/NOPB part is unused and in its original packaging.
Return procedure for LM311H/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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