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Texas Instruments LM311DRG4
- Part No.:
- LM311DRG4
- Manufacturer:
- Texas Instruments
- Category:
- Comparators
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LM311DRG4.pdf
- Description:
- IC COMPARATOR 1 GEN PUR 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:8,217
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Product details
Overview
LM311DRG4 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 - used in zero-crossing detectors, peak detectors, and oscillator circuits.
For engineers reviewing the LM311DRG4 datasheet, LM311DRG4 pinout, LM311DRG4 application, or LM311DRG4 equivalent, key selection criteria include strobe-enabled disable capability, dual emitter/collector outputs, input offset voltage ≤7.5 mV (max), and operating temperature range of 0°C to +70°C - all critical for timing-critical analog interface designs.
Technical Context
The LM311DRG4 uses a PNP input stage enabling rail-to-rail common-mode input down to VCC−, followed by high-gain amplification and an isolated-emitter NPN open-collector output stage. Its BAL/STRB pin enables external offset trimming or logic-controlled output disable.
It operates across 3.5 V to 30 V total supply range, supports wire-OR output configurations, and isolates inputs/outputs from system ground - allowing load referencing to ground, VCC+, or VCC−. Strobe functionality forces high-impedance output when pulled low with −3 mA current.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Response time | 165 ns (high-to-low); enables fast edge detection in pulse-width modulation and clock recovery |
| Input offset voltage | ≤7.5 mV max (25°C); defines minimum detectable differential voltage before output switching |
| Supply voltage range | 3.5 V to 30 V total (VCC+–VCC−); supports single 5-V logic and dual ±15-V op-amp rails |
| Output drive capability | 40 V collector-to-emitter max, 50 mA sink current; directly switches relays, lamps, or MOSFET gates |
| Input bias current | ≤300 nA max; ensures minimal loading on high-impedance sensor or reference sources |
| Operating temperature | 0°C to +70°C; qualified for commercial-grade embedded control and instrumentation |
| Strobe input current | −3 mA to −5 mA required to disable output; prevents accidental short-to-ground activation |
Pinout & Package
LM311DRG4 is housed in an 8-pin SOIC (Small Outline Integrated Circuit) package measuring 4.90 mm × 3.91 mm, with gull-wing leads and surface-mount compatibility.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1: EMIT OUT | Emitter output terminal | Provides low-side switching path referenced to VCC−; used for grounded-load configurations |
| 2: IN+ | Noninverting input | Accepts reference or signal input; common-mode range extends to VCC− |
| 3: IN− | Inverting input | Accepts signal or threshold input; differential comparison determines output state |
| 4: VCC− | Negative supply rail | Reference for internal circuitry and emitter output; supports dual-supply or ground-referenced operation |
| 5: BALANCE | Offset null adjustment | Connects external potentiometer to trim input offset voltage; improves DC accuracy |
| 6: BAL/STRB | Strobe / balance select | Active-low enable: sinking −3 mA disables output; also used for offset balancing when unconnected |
| 7: COL OUT | Collector output terminal | Open-collector NPN output; requires external pullup to define logic-high level and drive capability |
| 8: VCC+ | Positive supply rail | Primary power input; sets upper limit for output voltage swing and internal biasing |
Key Features
| Feature | Design Value |
|---|---|
| Strobe-enabled output disable | Logic-controlled high-impedance state via BAL/STRB pin, eliminating need for external gate logic |
| Dual-output configuration | Separate EMIT OUT and COL OUT terminals allow flexible load referencing to VCC+, VCC−, or ground |
| Rail-to-rail input capability | Common-mode input range includes VCC−, enabling direct sensing of signals near negative rail |
| Wire-OR output compatibility | Open-collector COL OUT supports wired-logic summation with other comparators or digital outputs |
| High-voltage output switching | 40 V collector-to-emitter rating permits direct interfacing with industrial 24-V control systems |
Applications
| Zero-Crossing Detection | Oscillator Circuits |
|---|---|
Use Scenario: Detecting AC waveform polarity transitions in motor control or power supply feedback loops. IC Role / Device Role / Timing Role: Voltage comparator comparing sinusoidal input against 0-V reference to generate synchronized square-wave output. Use Value: 165 ns response ensures sub-microsecond timing accuracy; open-collector output interfaces directly with optocouplers or MCU interrupt pins. | Use Scenario: Generating stable square-wave clocks in relaxation oscillators or multivibrators. IC Role / Device Role / Timing Role: Core timing element using hysteresis feedback between COL OUT and IN+ to sustain oscillation. Use Value: Strobe pin allows external synchronization or duty-cycle modulation; wide supply range supports 5-V to ±15-V oscillator designs. |
| Peak Detection | TTL/MOS Level Translation |
Use Scenario: Capturing maximum amplitude of analog sensor outputs in data acquisition systems. IC Role / Device Role / Timing Role: Comparator driving sample-and-hold latch when input exceeds stored peak voltage. Use Value: Low input bias current (≤300 nA) prevents discharge of hold capacitor; 7.5 mV offset ensures <10 mV detection threshold error. | Use Scenario: Converting 3.3-V or 5-V logic signals to higher-voltage control levels for industrial I/O. IC Role / Device Role / Timing Role: Level-shifting interface with programmable output voltage via external pullup resistor. Use Value: 40-V output rating enables translation to 24-V PLC inputs; strobe pin adds enable/disable control without extra logic gates. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar voltage comparator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM311D | Same SOIC-8 package and pinout; identical electrical specs except LM311D rated for 0°C to +70°C (same as LM311DRG4) | No functional difference; both meet same commercial temperature grade and performance envelope | Select LM311DRG4 for RoHS-compliant, green packaging; LM311D for legacy non-green variant |
| LM211DR | Wider temperature range (−40°C to +85°C); otherwise identical pinout, function, and key specs (165 ns, 300 nA IB, 40 V output) | Suitable for extended-temperature industrial environments where LM311DRG4's 0°C lower limit is insufficient | Choose LM211DR when ambient operating temperature may fall below 0°C; otherwise LM311DRG4 remains optimal for cost-sensitive commercial designs |
Compared with LM311D, LM311DRG4 offers identical functionality with enhanced environmental compliance; versus LM211DR, it trades extended temperature range for lower cost and tighter qualification scope - making it ideal for fixed-temperature commercial instrumentation and power supplies.
Availability
LM311DRG4 is available at Aetrix Electronics and suitable for zero-crossing detection, oscillator circuits, peak detectors, and TTL/MOS level translation requiring stable component supply and long-term production continuity.
Supply support for LM311DRG4 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 for industrial, automotive, and consumer markets.
The LM311DRG4 belongs to TI's legacy high-speed comparator product line, engineered for precision analog signal comparison in cost-sensitive commercial applications with robust noise immunity and flexible power architecture.
FAQ
What is the maximum supply voltage for LM311DRG4?
The LM311DRG4 supports a total supply voltage (VCC+ – VCC−) up to 30 V, with individual rail limits of +18 V on VCC+ and –18 V on VCC−. This allows operation from ±15-V op-amp supplies or single 5-V logic rails. Exceeding these absolute maximum ratings risks permanent damage, per TI's SLCS007K datasheet Section 6.1.
Does LM311DRG4 have a built-in hysteresis feature?
No, the LM311DRG4 does not include internal hysteresis. Hysteresis must be added externally via positive feedback from COL OUT to IN+ using a resistor network. This design choice provides flexibility to tailor hysteresis voltage precisely to application needs - such as noise rejection in zero-crossing detectors - rather than fixing it at a factory-set value.
Can LM311DRG4 drive a relay directly?
Yes, the LM311DRG4 can directly drive small relays via its COL OUT pin, which supports up to 50 mA sink current and 40 V collector-to-emitter voltage. For reliable operation, connect the relay coil between VCC+ and COL OUT, with a flyback diode across the coil. Ensure strobe (BAL/STRB) is left open or held high to enable output switching.
What is the purpose of the BAL/STRB pin on LM311DRG4?
The BAL/STRB pin on LM311DRG4 serves dual functions: as a strobe input (active-low) to force high-impedance output state, or as a balance terminal for external offset nulling. When used as strobe, it must be driven with −3 mA to −5 mA current - not shorted to ground - to avoid damage. As balance, it connects to a potentiometer between VCC+ and VCC− to minimize input offset voltage.
Is LM311DRG4 compatible with single-supply operation?
Yes, LM311DRG4 supports true single-supply operation from as low as 3.5 V total supply (e.g., VCC+ = 5 V, VCC− = 0 V). Its PNP input stage enables common-mode input down to VCC−, allowing IN+ and IN− to operate near ground. Output remains functional with pullup to VCC+, and EMIT OUT can source current when VCC− is grounded - confirmed in TI's SLCS007K Section 8.1 and Figure 33.
LM311DRG4 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
LM311DRG4 FAQ
1.How can I place an order for LM311DRG4 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM311DRG4 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 LM311DRG4 reliable?
The price and inventory of LM311DRG4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM311DRG4 is usually 5 days.
3.What payment methods are accepted for LM311DRG4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM311DRG4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM311DRG4?
LM311DRG4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM311DRG4 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 LM311DRG4?
For technical support, including LM311DRG4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM311DRG4 requirements.
6.How does Aetrix verify that LM311DRG4 is sourced from the original manufacturer or authorized distributors?
All LM311DRG4 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 LM311DRG4 meets industry standards.
7.What is the process for return or replacement of LM311DRG4?
All LM311DRG4 units undergo pre-shipment inspection (PSI). If there is an issue with LM311DRG4, 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 LM311DRG4 part is unused and in its original packaging.
Return procedure for LM311DRG4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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