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Texas Instruments LM311M/NOPB
- Part No.:
- LM311M/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- Comparators
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LM311M/NOPB.pdf
- Description:
- IC COMPARATOR 1 GEN PUR 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,369
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Product details
Overview
LM311M/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. It drives TTL/DTL/RTL loads and relays up to 50V/50mA, commonly used in zero-crossing detection, PWM generation, and relay control circuits.
For engineers reviewing the LM311M/NOPB datasheet, LM311M/NOPB pinout, LM311M/NOPB application, or LM311M/NOPB equivalent, key selection considerations include its 0°C to +70°C operating range, SOIC-8 package, strobe functionality, input bias current ≤250 nA at 25°C, and compatibility with logic-level and inductive loads without external level-shifting.
Technical Context
The LM311M/NOPB employs a bipolar input stage with trimmable offset via pins 5 and 6, enabling precise null adjustment. Its open-collector output allows wire-OR configuration and flexible pull-up to V+, ground, or intermediate rail - critical for interfacing across voltage domains.
Strobe functionality (pin 6) enables current-driven output disable (3–5 mA required), isolating the output without affecting input bias or common-mode behavior. The device avoids spurious oscillation through internal compensation and supports hysteresis implementation via external positive feedback to pin 5.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage Range | Single 5V or dual ±15V - supports direct interface with 5V logic and legacy op-amp rails. |
| Response Time | 200 ns - enables reliable comparison of signals up to ~500 kHz with 5 mV overdrive. |
| Differential Input Voltage | ±30V - permits direct sensing across high-voltage rails without external attenuators. |
| Input Bias Current | Max 250 nA at 25°C - ensures minimal loading on high-impedance sources like photodiodes or RC timing networks. |
| Output Drive Capability | 50V/50mA sink - directly switches relays, lamps, or MOSFET gates without buffer stages. |
| Operating Temperature | 0°C to +70°C - qualified for commercial-grade embedded and industrial control applications. |
| Strobe Current Range | 3–5 mA required to disable output - prevents accidental turn-off due to leakage or noise. |
Pinout & Package
LM311M/NOPB is housed in an 8-pin SOIC (D) package, 1.75 mm max height, RoHS-compliant with Sn lead finish and MSL Level-1 rating.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (OUT) | Open-collector output | Sinks current to ground or negative supply; requires external pull-up for logic-high state. |
| 2 (−IN) | Inverting input | High-impedance node accepting analog signals up to ±15V relative to supplies. |
| 3 (+IN) | Non-inverting input | High-impedance node; differential pair input referenced to same common-mode range as pin 2. |
| 4 (GND) | Ground reference | System ground connection; not required for operation if output load is referenced elsewhere. |
| 5 (BAL) | Offset null (positive) | Connects to one end of 5 kΩ potentiometer for trimming input offset voltage. |
| 6 (STROBE) | Output enable/disable control | Current-sink input: drawing 3–5 mA disables output; never ground directly. |
| 7 (V+) | Positive supply | Accepts 5V single supply or +15V in dual-supply mode; powers internal circuitry. |
| 8 (V−) | Negative supply | Accepts 0V (ground) in single-supply mode or −15V in dual-supply mode. |
Key Features
| Feature | Design Value |
|---|---|
| Isolated inputs and outputs | Input common-mode and output load references are independent - enables ground-loop-free signal conditioning in mixed-supply systems. |
| Strobe-controlled output disable | Pin 6 accepts 3–5 mA sink current to force output high-impedance, enabling time-multiplexed comparisons or power-gated operation. |
| Wire-OR compatible output | Open-collector topology allows multiple LM311M/NOPB outputs to share a single pull-up resistor - simplifies priority encoder or alarm bus designs. |
| Offset balancing terminals | Pins 5 and 6 support external 5 kΩ potentiometer to null input offset voltage down to <7.5 mV (max), improving DC accuracy in precision threshold detection. |
| Wide supply flexibility | Operates from 5V single supply up to ±15V - eliminates need for separate rail generators in hybrid analog-digital systems. |
Applications
| Zero-Crossing Detection | Relay Control Interface |
|---|---|
Use Scenario: Detecting AC line voltage polarity transitions for synchronous switching in SMPS or dimmer circuits. IC Role / Device Role / Timing Role: Comparator compares sinusoidal input against 0V reference; strobe disables output during noise-sensitive zero-crossing window. Use Value: 200 ns response ensures accurate edge timing; ±30V input range accommodates full-wave rectified inputs without attenuation. | Use Scenario: Driving electromagnetic relays in PLC I/O modules where load isolation and voltage translation are required. IC Role / Device Role / Timing Role: LM311M/NOPB acts as level-shifting interface between 3.3V/5V microcontroller GPIO and 24V relay coil. Use Value: 50V/50mA sink capability directly energizes standard industrial relays; open-collector output avoids shoot-through during coil de-energization. |
| PWM Signal Generation | Photodiode Signal Thresholding |
Use Scenario: Generating variable-duty-cycle square waves using triangle-wave and DC reference inputs in motor control feedback loops. IC Role / Device Role / Timing Role: Compares ramp waveform against adjustable threshold to produce clean digital PWM output with minimal jitter. Use Value: Low input bias current (<250 nA) prevents distortion of RC-generated ramps; strobe pin enables synchronized PWM blanking. | Use Scenario: Converting weak photocurrent from precision optical sensors into digital presence/absence signals in analytical instrumentation. IC Role / Device Role / Timing Role: Amplifies and compares photodiode current (via transimpedance stage) against calibrated reference voltage. Use Value: Input offset voltage ≤7.5 mV (max) ensures sub-millivolt threshold resolution; high CMRR rejects ambient light interference. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar voltage comparator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM393DR | Lower supply current (0.8 mA vs 6 mA), wider temp range (−40°C to +85°C), but slower response (1.3 µs) and no strobe function. | Suitable for battery-powered low-speed threshold detection; unsuitable for strobed or high-speed zero-crossing use. | Select LM393DR only when power efficiency and extended temperature range outweigh speed and strobe requirements. |
| TLV3011DBVR | Rail-to-rail input, 150 ns response, nano-power (1.2 µA), but open-drain output and no offset trim pins. | Better for ultra-low-power sensor interfaces; lacks strobe and offset adjustment needed in precision industrial comparators. | Choose TLV3011DBVR for portable devices with tight power budgets; retain LM311M/NOPB for strobe-critical or offset-calibrated designs. |
Compared with LM393DR and TLV3011DBVR, the LM311M/NOPB uniquely combines strobe control, offset trimming, 200 ns speed, and 50V output drive - making it irreplaceable in relay-driving, multiplexed comparator, and precision zero-crossing applications requiring deterministic disable and calibration.
Availability
LM311M/NOPB is available at Aetrix Electronics and suitable for industrial control systems, test equipment design, and embedded power management requiring stable component supply, long-term lifecycle continuity, and RoHS-compliant SOIC packaging.
Supply support for LM311M/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 and embedded processing solutions with emphasis on reliability, longevity, and broad application support.
The LM311 series belongs to TI's legacy precision analog comparator product line, engineered for robust performance in industrial, instrumentation, and power-conversion systems where speed, isolation, and configurability are essential.
FAQ
What is the maximum supply voltage for LM311M/NOPB?
The LM311M/NOPB supports a total supply voltage up to 36V, whether operated from a single 5V rail or dual ±15V supplies. Absolute maximum ratings specify VCC–VEE ≤ 36V; exceeding this risks permanent damage. For reliable operation at ±15V, ensure proper decoupling with 0.1 µF ceramic capacitors near pins 4 and 7.
Can LM311M/NOPB operate from a single 5V supply?
Yes, the LM311M/NOPB is fully specified for single 5V operation. Pin 4 (GND) serves as reference, pin 7 (V+) connects to +5V, and pin 8 (V−) connects to GND. Input common-mode range extends to within 1.5V of either rail, and output saturates to <0.4V with 8 mA sink - ensuring clean TTL-compatible logic levels.
How does the strobe function work on LM311M/NOPB?
The strobe pin (pin 6) disables the LM311M/NOPB output when 3–5 mA is actively sunk from it. This places the output transistor in high-impedance state without affecting input bias or offset. Never short pin 6 to ground - always drive it with a current source/sink. Strobing reduces system power during idle periods and enables time-division multiplexing of multiple comparators.
What is the purpose of pins 5 and 6 on LM311M/NOPB?
Pin 5 (BAL) and pin 6 (STROBE) serve distinct functions: pin 5 is the positive offset null terminal, used with an external 5 kΩ potentiometer to minimize input offset voltage; pin 6 is the strobe control, which disables the output when 3–5 mA is drawn. Though both are labeled "balance" in some schematics, they are electrically separate - pin 6 must never be used for offset trimming.
Does LM311M/NOPB require external pull-up resistors on its output?
Yes, the LM311M/NOPB features an open-collector output (pin 1) and requires an external pull-up resistor to define the logic-high voltage level. Typical values range from 1 kΩ (for fast rise times driving heavy loads) to 10 kΩ (for low-power logic interfacing). Pull-up may connect to V+, ground, or any intermediate rail - enabling level translation between incompatible logic families.
LM311M/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- 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):
- -
- Current - Output (Typ):
- 7.5mA
- Current - Quiescent (Max):
- -
- CMRR, PSRR (Typ):
- -
- Propagation Delay (Max):
- -
- Hysteresis:
- 0°C ~ 70°C
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- Surface Mount
- :
- 8-SOIC
LM311M/NOPB FAQ
1.How can I place an order for LM311M/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM311M/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 LM311M/NOPB reliable?
The price and inventory of LM311M/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM311M/NOPB is usually 5 days.
3.What payment methods are accepted for LM311M/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM311M/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM311M/NOPB?
LM311M/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM311M/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 LM311M/NOPB?
For technical support, including LM311M/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM311M/NOPB requirements.
6.How does Aetrix verify that LM311M/NOPB is sourced from the original manufacturer or authorized distributors?
All LM311M/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 LM311M/NOPB meets industry standards.
7.What is the process for return or replacement of LM311M/NOPB?
All LM311M/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM311M/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 LM311M/NOPB part is unused and in its original packaging.
Return procedure for LM311M/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM311M/NOPB Tags
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