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Texas Instruments LM311DRE4
- Part No.:
- LM311DRE4
- Manufacturer:
- Texas Instruments
- Category:
- Comparators
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LM311DRE4.pdf
- Description:
- IC COMPARATOR 1 GEN PUR 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,462
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Product details
Overview
LM311DRE4 from Texas Instruments is a single high-speed voltage comparator with open-collector output, designed for precision level detection in industrial and embedded systems. It delivers 165 ns response time, supports ±15 V or single 5-V supply operation, and features strobe and offset balance inputs. It drives loads up to 40 V at 50 mA and operates across 0°C to +70°C.
For engineers reviewing the LM311DRE4 datasheet, LM311DRE4 pinout, LM311DRE4 application, or LM311DRE4 equivalent, this page provides verified technical context, real-world use cases, validated alternatives, and supply-chain support tailored for analog signal conditioning, zero-crossing detection, and TTL/MOS interface design.
Technical Context
The LM311DRE4 uses a PNP input stage enabling input common-mode operation down to VCC−, and a high-gain differential amplifier followed by an isolated-emitter NPN open-collector output stage. Its strobe input (BAL/STRB) enables external current-driven gating (–3 mA to –5 mA), forcing output high-impedance regardless of input state.
Offset balancing is implemented via the BALANCE pin, allowing external trimming of input offset voltage (max 7.5 mV at 25°C). The device supports wire-OR outputs and load referencing to ground, VCC+, or VCC− - critical for level-shifting and relay/solenoid driver applications requiring isolation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Response time | 165 ns (high-to-low); enables fast edge detection in PWM, oscillator, and timing circuits |
| Input offset voltage | Max 7.5 mV at 25°C; defines minimum detectable voltage difference before trimming |
| Input bias current | Max 300 nA; ensures minimal loading on high-impedance sources like sensors or RC networks |
| Output voltage swing | Up to 40 V (collector-to-VCC−); supports direct driving of relays, lamps, and MOS logic |
| Supply range | 3.5 V to 30 V (VCC+ − VCC−); compatible with ±15 V op-amp rails and single 5-V logic supplies |
| Operating temperature | 0°C to +70°C; suitable for commercial-grade embedded control and instrumentation |
| Strobe current | –3 mA to –5 mA (sinking); enables precise external gating without pull-down resistors |
Pinout & Package
LM311DRE4 is housed in an 8-pin SOIC (Small Outline Integrated Circuit) package measuring 4.90 mm × 3.91 mm, with standard JEDEC MS-012AC footprint and gull-wing leads.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1: EMIT OUT | Emitter output terminal | Provides emitter-follower output referenced to VCC−; used for low-side switching or buffered reference |
| 2: IN+ | Noninverting input | Accepts reference or signal input; common-mode range extends to VCC− − 0.5 V |
| 3: IN− | Inverting input | Accepts threshold or feedback signal; differential comparison determines output state |
| 4: VCC− | Negative supply rail | Reference for internal circuitry and output stage; supports dual-supply or ground-referenced operation |
| 5: BALANCE | Offset null adjustment | Connects to external potentiometer for manual trimming of input offset voltage |
| 6: BAL/STRB | Strobe control input | Sinking current (–3 mA) forces output into high-impedance state; not logic-level compatible |
| 7: COL OUT | Collector output terminal | Open-collector NPN output; requires external pullup; drives TTL, MOS, relays, or lamps |
| 8: VCC+ | Positive supply rail | Power input for internal circuitry; supports up to +18 V relative to VCC− |
Key Features
| Feature | Design Value |
|---|---|
| Strobe capability | Current-sink gated disable (–3 mA) isolates output independently of input state |
| Wide supply range | 3.5 V to 30 V total supply; eliminates need for level translators in mixed-voltage systems |
| Isolated output stage | Emitter and collector outputs referenced separately to VCC−, enabling floating load connections |
| Low input bias current | ≤300 nA max; preserves accuracy in high-Z sensor interfaces and RC timing networks |
| Wire-OR compatibility | Open-collector output allows multiple LM311DRE4 devices to share one pullup and bus line |
Applications
| Zero-Crossing Detection | Oscillator & Multivibrator |
|---|---|
|
Use Scenario: Detecting AC waveform polarity transitions in power supplies and motor controllers. IC Role / Device Role / Timing Role: Voltage comparator comparing sinusoidal input against 0-V reference to generate clean digital edges. Use Value: 165 ns response ensures sub-microsecond timing resolution; open-collector output directly interfaces with optocouplers or microcontroller GPIOs. |
Use Scenario: Generating stable square-wave clocks in function generators and timing modules. IC Role / Device Role / Timing Role: Core comparator in hysteresis-based relaxation oscillator with RC timing network. Use Value: Strobe input enables external frequency modulation; wide supply range supports 5-V to ±15-V oscillator designs. |
| Relay & Solenoid Driver | TTL/MOS Level Shifting |
|
Use Scenario: Controlling 24-V industrial relays or 12-V solenoids from low-voltage logic signals. IC Role / Device Role / Timing Role: High-voltage interface buffer converting 3.3/5-V logic levels to 24-V switched loads. Use Value: COL OUT supports 40-V swing at 50 mA; isolated outputs prevent ground-loop interference in PLC I/O modules. |
Use Scenario: Translating between 3.3-V MCU outputs and 12-V or 24-V peripheral logic inputs. IC Role / Device Role / Timing Role: Bidirectional level shifter using open-collector output with programmable pullup voltage. Use Value: Load can be referenced to any rail (ground, VCC+, or VCC−); enables robust noise-immune communication in factory automation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar voltage comparator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM393DR | Dual comparator, lower speed (1.3 µs), no strobe or balance pins, 36-V supply max | Lacks strobe gating and offset trim; suited for cost-sensitive dual-threshold detection | Select when dual channels are needed and strobe/balance functions are unnecessary |
| TLV3011DBVR | Single comparator, rail-to-rail input, 200-ns response, 5.5-V max supply, no strobe | Higher precision (0.25-mV offset), but limited to low-voltage systems; no high-side drive capability | Choose for battery-powered sensors where rail-to-rail input and ultra-low offset matter more than 40-V output swing |
Compared with LM311DRE4, LM393DR offers dual-channel integration at lower speed and no strobe, while TLV3011DBVR delivers superior DC accuracy in low-voltage domains but sacrifices high-voltage output drive and strobe control - making LM311DRE4 uniquely suited for industrial-level-shifting and gated comparator applications.
Availability
LM311DRE4 is available at Aetrix Electronics and suitable for industrial control systems, power supply monitoring, and embedded signal conditioning requiring stable component supply across commercial temperature ranges.
Supply support for LM311DRE4 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 LM311DRE4 belongs to TI's legacy high-speed comparator family, engineered for robust performance in noisy environments, wide supply flexibility, and direct interface with electromechanical and logic loads.
FAQ
What is the maximum output voltage swing supported by the LM311DRE4?
The LM311DRE4 collector output (COL OUT) supports up to 40 V relative to VCC−, as specified in its Absolute Maximum Ratings. This enables direct driving of 24-V relays, lamps, or MOS logic without external transistors. The emitter output (EMIT OUT) is limited to 30 V relative to VCC−. Both outputs remain functional within the recommended operating supply range of 3.5 V to 30 V (VCC+ − VCC−).
Can the LM311DRE4 operate from a single 5-V supply?
Yes, the LM311DRE4 is explicitly rated for single 5-V supply operation per its datasheet Features and Recommended Operating Conditions. With VCC+ = 5 V and VCC− = 0 V, it maintains full functionality including input common-mode range (0.5 V to 3.5 V), 50 mA output sink capability, and 165 ns response time - making it ideal for interfacing with 5-V microcontrollers and logic families.
How does the BAL/STRB pin function in the LM311DRE4?
The BAL/STRB pin on the LM311DRE4 serves dual roles: as a strobe input (when driven with –3 mA to –5 mA sinking current) it forces the output into high-impedance state regardless of input differential, and as a balance control (when used with external resistor network) it adjusts input offset voltage. It must never be shorted to ground; instead, it requires active current sourcing/sinking for reliable strobe operation.
What is the purpose of the EMIT OUT pin on the LM311DRE4?
The EMIT OUT pin provides an emitter-follower output referenced to VCC−, delivering a buffered, low-impedance version of the internal comparator output node. Unlike COL OUT, EMIT OUT cannot sink current but offers faster rise times in certain configurations and enables level-shifting when VCC− is not ground. It is commonly used in precision reference buffers or cascode output stages.
Does the LM311DRE4 require external pullup resistors on its output?
Yes, the LM311DRE4's COL OUT pin is an open-collector NPN transistor and requires an external pullup resistor to define the high-state voltage level and provide sourcing current. Typical values range from 1 kΩ (for 5-V TTL) to 10 kΩ (for higher-voltage or low-power applications). No pullup is needed for EMIT OUT, which operates as an emitter follower with internal current path to VCC−.
LM311DRE4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- General Purpose
- Number of Elements:
- 1
- Output Type:
- MOS, Open-Collector, Open-Emitter, TTL
- Voltage - Supply, Single/Dual (±):
- 3.5V ~ 30V, ±1.75V ~ 15V
- :
- 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
LM311DRE4 FAQ
1.How can I place an order for LM311DRE4 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM311DRE4 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 LM311DRE4 reliable?
The price and inventory of LM311DRE4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM311DRE4 is usually 5 days.
3.What payment methods are accepted for LM311DRE4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM311DRE4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM311DRE4?
LM311DRE4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM311DRE4 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 LM311DRE4?
For technical support, including LM311DRE4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM311DRE4 requirements.
6.How does Aetrix verify that LM311DRE4 is sourced from the original manufacturer or authorized distributors?
All LM311DRE4 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 LM311DRE4 meets industry standards.
7.What is the process for return or replacement of LM311DRE4?
All LM311DRE4 units undergo pre-shipment inspection (PSI). If there is an issue with LM311DRE4, 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 LM311DRE4 part is unused and in its original packaging.
Return procedure for LM311DRE4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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