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Texas Instruments LM311DE4
- Part No.:
- LM311DE4
- Manufacturer:
- Texas Instruments
- Category:
- Comparators
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LM311DE4.pdf
- Description:
- IC COMPARATOR 1 GEN PUR 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,772
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Product details
Overview
LM311DE4 from Texas Instruments is a single high-speed voltage comparator with open-collector output, designed for precision level detection and signal conditioning in industrial and embedded systems. It delivers 165 ns response time, supports ±15 V or single 5-V supply operation, and drives loads up to 40 V at 50 mA - enabling direct interface with TTL, MOS, relays, and lamps.
For engineers reviewing the LM311DE4 datasheet, LM311DE4 pinout, LM311DE4 application, or LM311DE4 equivalent, this page provides verified technical context, real-world design meaning of key specs, validated pin functions, confirmed alternatives, and supply-chain support for production deployment.
Technical Context
The LM311DE4 uses a PNP input stage for rail-to-rail common-mode operation near VCC− and features an isolated-emitter NPN open-collector output stage, allowing flexible load referencing to ground, VCC+, or VCC−. Its strobe (BAL/STRB) and balance (BALANCE) pins enable external offset trimming and synchronous gating of comparison output.
It operates as a pure voltage comparator - not an amplifier - with differential input sensing, wire-ORable outputs, and no internal hysteresis. Input bias current is ≤300 nA max, input offset voltage is ≤7.5 mV max, and it maintains stable performance across 0°C to +70°C ambient temperature.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Response time | 165 ns high-to-low; enables fast edge detection in clock recovery or pulse-width measurement circuits |
| Supply voltage range | 3.5 V to 30 V total (±15 V or +5 V single supply); supports mixed-signal system integration without level shifters |
| Input offset voltage | ≤7.5 mV max at 25°C; defines minimum detectable voltage difference before output switching |
| Input bias current | ≤300 nA max; minimizes loading on high-impedance sources like sensor bridges or photodiode amplifiers |
| Output capability | Open-collector, 40 V max collector-to-emitter voltage, 50 mA sink current; directly drives optocouplers, small relays, or logic inputs |
| Common-mode range | –14.7 V to +13.8 V (with ±15 V supplies); allows input signals near either rail without invalid output behavior |
| Strobe current | –3 mA to –5 mA required at BAL/STRB pin; enables precise timing control of comparator enable/disable |
Pinout & Package
LM311DE4 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-impedance buffering or level-shifting applications |
| 2: IN+ | Noninverting input | Positive comparator input; accepts signals within common-mode range; high-impedance node (≤300 nA bias) |
| 3: IN− | Inverting input | Negative comparator input; differential pair input; same impedance and noise sensitivity as IN+ |
| 4: VCC− | Negative supply rail | Reference for internal circuitry and EMIT OUT; supports dual-supply operation or ground-referenced single-supply use |
| 5: BALANCE | Offset null adjustment | Connects to external potentiometer for manual input offset cancellation; improves DC accuracy in precision thresholding |
| 6: BAL/STRB | Strobe control input | Active-low enable: pulls output high-impedance when driven with –3 mA; enables synchronized sampling or gated comparison |
| 7: COL OUT | Collector output terminal | Open-collector NPN output; requires external pullup; sinks up to 50 mA; compatible with TTL/MOS logic families |
| 8: VCC+ | Positive supply rail | Primary power input; sets upper supply limit (max 18 V); powers internal gain stages and output transistor |
Key Features
| Feature | Design Value |
|---|---|
| Strobe capability | Enables precise timing control of comparator decision window via external current source on BAL/STRB pin |
| Isolated output stage | COL OUT and EMIT OUT are electrically isolated from VCC−, permitting load connection to any reference point |
| Wide supply flexibility | Operates from 3.5 V to 30 V total supply; eliminates need for dedicated comparator rails in multi-voltage systems |
| Wire-OR output compatibility | Multiple LM311DE4 outputs can be tied together with shared pullup for logical OR or priority encoding |
| High-voltage output drive | COL OUT supports up to 40 V collector-to-emitter voltage, enabling direct interface with industrial sensors and actuators |
Applications
| Zero-Crossing Detection | Oscillator & Timing Circuits |
|---|---|
|
Use Scenario: Detecting AC waveform polarity transitions in motor control feedback or power metering. IC Role / Device Role / Timing Role: Voltage comparator comparing sine wave input against 0 V reference to generate clean digital zero-cross pulses. Use Value: 165 ns response ensures sub-microsecond timing accuracy; open-collector output interfaces directly with microcontroller interrupt inputs. |
Use Scenario: Building free-running multivibrators or crystal-based oscillators for clock generation. IC Role / Device Role / Timing Role: Core comparator element in relaxation oscillator topology with RC timing network and hysteresis feedback. Use Value: Strobe pin allows external synchronization; wide supply range accommodates 5 V or ±15 V oscillator designs. |
| Peak Detector Interface | TTL/MOS Logic Level Translation |
|
Use Scenario: Capturing positive/negative peaks of analog sensor outputs for data acquisition systems. IC Role / Device Role / Timing Role: Comparator driving sample-and-hold latch; strobe pin gates capture window to avoid false triggers. Use Value: Low input bias current (≤300 nA) prevents discharge of hold capacitor; EMIT OUT provides buffered reference output. |
Use Scenario: Converting industrial 24 V or ±12 V signals to 3.3 V/5 V logic levels for MCU input protection. IC Role / Device Role / Timing Role: High-voltage comparator acting as level shifter with programmable threshold via resistor divider on IN+ or IN−. Use Value: 40 V output rating and rail-to-rail input range allow direct interface with unregulated fieldbus voltages. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar voltage comparator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM311DR | Same electrical specs and pinout; RoHS-compliant, lead-free SOIC package (no "E4" suffix) | No functional difference; identical thermal and timing behavior; suitable for new designs requiring modern compliance | Select LM311DR for new PCB layouts requiring lead-free assembly; LM311DE4 remains valid for legacy repair or obsolescence mitigation |
| LM211D | Same architecture but rated for –40°C to +85°C; higher input offset voltage (≤10 mV) and bias current (≤250 nA) | Better suited for automotive or extended-temperature industrial environments where LM311DE4's 0°C–70°C range is insufficient | Choose LM211D when operating outside 0°C–70°C; LM311DE4 remains optimal for cost-sensitive commercial-grade applications |
Compared with LM311DR, LM311DE4 offers identical functionality with legacy leaded packaging; versus LM211D, it trades extended temperature range for tighter DC specs and lower cost in commercial environments.
Availability
LM311DE4 is available at Aetrix Electronics and suitable for industrial automation, power supply monitoring, and test equipment requiring stable component supply with long-term lifecycle visibility.
Supply support for LM311DE4 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 LM311DE4 belongs to TI's legacy high-speed comparator family, engineered for robust voltage comparison in noisy industrial, instrumentation, and power-conversion systems where reliability and wide supply tolerance are critical.
FAQ
What is the maximum supply voltage for LM311DE4?
The LM311DE4 supports a total supply voltage (VCC+ to VCC−) of up to 30 V, with individual rail limits of +18 V on VCC+ and –18 V on VCC−. Exceeding these absolute maximum ratings may cause permanent damage. For reliable operation, TI recommends staying within 3.5 V to 30 V total supply range per the Recommended Operating Conditions table in the datasheet.
Can LM311DE4 operate from a single 5-V supply?
Yes, LM311DE4 can operate from a single 5-V supply with VCC− grounded. Its input common-mode range extends to within 1.5 V of either rail, and its output remains functional with pullup to 5 V. This configuration is explicitly supported in TI's datasheet and commonly used in digital interface and level-shifting applications.
What is the purpose of the BAL/STRB pin on LM311DE4?
The BAL/STRB pin on LM311DE4 serves dual functions: as a strobe input (active-low, –3 mA to –5 mA required) to force the output into high-impedance state, and as a balance control point when used with external resistors for offset nulling. It must never be shorted to ground - only current-driven - to avoid damaging the internal circuitry.
How does the EMIT OUT pin differ from COL OUT on LM311DE4?
EMIT OUT is the emitter-follower output of the internal NPN transistor, referenced to VCC−, providing low-impedance buffered voltage output. COL OUT is the open-collector drain of the same transistor, requiring external pullup and capable of sinking up to 50 mA. They serve complementary roles: EMIT OUT for analog buffering, COL OUT for digital logic interfacing or switching loads.
Is LM311DE4 pin-compatible with LM311P or LM311PW?
Yes, LM311DE4 (SOIC-8) shares identical pinout and function mapping with LM311P (PDIP-8) and LM311PW (TSSOP-8), as confirmed in TI's Pin Configuration and Functions section. All three packages route IN+, IN−, VCC−, VCC+, BALANCE, BAL/STRB, COL OUT, and EMIT OUT to the same pin numbers - enabling drop-in replacement across form factors.
LM311DE4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Series:
- -
- Packaging:
- Bulk
- 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
LM311DE4 FAQ
1.How can I place an order for LM311DE4 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM311DE4 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 LM311DE4 reliable?
The price and inventory of LM311DE4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM311DE4 is usually 5 days.
3.What payment methods are accepted for LM311DE4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM311DE4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM311DE4?
LM311DE4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM311DE4 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 LM311DE4?
For technical support, including LM311DE4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM311DE4 requirements.
6.How does Aetrix verify that LM311DE4 is sourced from the original manufacturer or authorized distributors?
All LM311DE4 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 LM311DE4 meets industry standards.
7.What is the process for return or replacement of LM311DE4?
All LM311DE4 units undergo pre-shipment inspection (PSI). If there is an issue with LM311DE4, 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 LM311DE4 part is unused and in its original packaging.
Return procedure for LM311DE4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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