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Texas Instruments LM311PG4
- Part No.:
- LM311PG4
- Manufacturer:
- Texas Instruments
- Category:
- Comparators
- Package:
- 8-DIP (0.300", 7.62mm)
- Datasheet:
-
LM311PG4.pdf
- Description:
- IC COMPARATOR 1 GEN PUR 8DIP
- Quantity:
- Payment:
- Shipping:
Inventory:1,060
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Product details
Overview
LM311PG4 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 features strobe control and offset balancing-enabling use in zero-crossing detectors, peak detectors, and oscillator circuits.
For engineers reviewing the LM311PG4 datasheet, LM311PG4 pinout, LM311PG4 application, or LM311PG4 equivalent, this page provides verified technical context, real-world design meaning of key specs, validated pin functions, application-specific implementation insights, and two confirmed alternative comparators with documented functional differences.
Technical Context
The LM311PG4 employs a PNP input stage enabling input common-mode range down to VCC− − 0.7 V, and a high-gain differential amplifier followed by an isolated-emitter NPN open-collector output stage. Its strobe (BAL/STRB) pin enables external current-driven gating (–3 mA to –5 mA), while BALANCE allows fine offset trimming via external resistor network.
Unlike standard open-drain comparators, the LM311PG4's emitter output (EMIT OUT) and collector output (COL OUT) are electrically isolated from VCC−, permitting flexible load referencing to ground, VCC+, or VCC−. Output wire-OR capability and TTL/MOS compatibility stem from its logic-level compatible saturation voltage and high-voltage switching (up to 40 V at 50 mA).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Response Time | 165 ns high-to-low; enables sub-6 MHz comparator-based oscillators and fast edge detection in timing-critical circuits. |
| Input Offset Voltage | Max 7.5 mV at 25°C; defines minimum detectable voltage difference before output transition-critical for precision threshold sensing. |
| Input Bias Current | Max 300 nA at full temperature range; ensures minimal loading on high-impedance sources like sensor bridges or photodiode amplifiers. |
| Output Voltage Range | COL OUT switches up to 40 V (vs. 50 V for LM111/LM211); supports direct interface to 24-V industrial loads without level-shifting. |
| Supply Voltage Range | 3.5 V to 30 V total (VCC+ − VCC−); permits operation from single 5-V logic rails or dual ±15-V op-amp supplies. |
| Common-Mode Input Range | –14.7 V to +13.8 V (at ±15 V supply); accommodates signals near supply rails-essential for rail-to-rail sensing in power monitoring. |
| Strobe Input Current | –3 mA to –5 mA required to disable output; mandates active-current sourcing (not simple grounding) for reliable gating. |
Pinout & Package
LM311PG4 is supplied in an 8-pin PDIP (Plastic Dual In-line Package) with 9.81 mm × 6.35 mm body size and through-hole mounting. Pin functions are validated per TI SLCS007K Rev K (March 2017) datasheet.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1: EMIT OUT | Emitter output terminal | Provides low-side switching path referenced to VCC−; used when load must be tied between VCC+ and output. |
| 2: IN+ | Noninverting input | Positive comparator input; accepts signals within common-mode range; high-impedance (≤300 nA bias current). |
| 3: IN− | Inverting input | Negative comparator input; differential comparison against IN+ determines output state. |
| 4: VCC− | Negative supply pin | Reference for internal circuitry and EMIT OUT; supports dual-supply (±15 V) or single-supply (0 V) configurations. |
| 5: BALANCE | Offset null adjustment | Connects to external potentiometer (typically 10 kΩ) between VCC+ and VCC− to trim input offset voltage. |
| 6: BAL/STRB | Strobe control input | Current-sink input: pulling –3 mA disables output regardless of input differential-used for synchronized sampling or blanking. |
| 7: COL OUT | Collector output terminal | Open-collector NPN output; requires external pullup; drives loads up to 40 V / 50 mA with VOL ≤ 0.75 V @ 50 mA. |
| 8: VCC+ | Positive supply pin | Primary power rail; sets upper limit for output swing and common-mode input range. |
Key Features
| Feature | Design Value |
|---|---|
| Strobe-enabled output gating | Active-low current-driven strobe (BAL/STRB) allows precise temporal blanking of comparator decisions-critical in multiplexed sensor systems. |
| Isolated emitter-collector outputs | EMIT OUT and COL OUT share no internal connection to VCC−, enabling load referencing to any rail-supports floating-load drivers and bidirectional switching. |
| Wide supply flexibility | Operates from 3.5 V to 30 V total supply; eliminates need for separate voltage regulators in mixed-supply systems (e.g., 5-V MCU + 24-V actuator). |
| Wire-OR output capability | Multiple LM311PG4 outputs can share a single pullup resistor, enabling priority encoding or OR logic without external gates. |
| Offset balancing via external resistor | BALANCE pin connects to a two-resistor divider across VCC+/VCC−, allowing <1-mV residual offset correction-vital for precision reference comparators. |
Applications
| Zero-Crossing Detection | Oscillator & Timing Circuits |
|---|---|
|
Use Scenario: Monitoring AC mains voltage to trigger triac firing or synchronize digital sampling at voltage polarity transitions. IC Role / Device Role / Timing Role: Voltage comparator detecting when input crosses 0 V relative to system ground, with hysteresis added externally. Use Value: 165 ns response ensures accurate zero-crossing capture even at 50/60 Hz with minimal phase error; open-collector output interfaces directly to opto-triac drivers. |
Use Scenario: Building free-running multivibrators, crystal oscillators, or relaxation oscillators for clock generation or PWM modulation. IC Role / Device Role / Timing Role: Core timing element comparing capacitor voltage against fixed or adjustable thresholds to generate periodic waveforms. Use Value: Strobe and balance pins enable frequency tuning and duty-cycle control; 40-V output swing supports direct drive of 24-V timing loads. |
| Peak Detection | TTL/MOS Level Translation |
|
Use Scenario: Capturing maximum amplitude of analog sensor signals (e.g., audio envelope, pulse height) for ADC input or alarm triggering. IC Role / Device Role / Timing Role: Comparator latching peak value via diode-capacitor hold circuit, with reset controlled by strobe or external logic. Use Value: Low input bias current (≤300 nA) prevents discharge of hold capacitor; wide common-mode range accommodates bipolar input signals. |
Use Scenario: Interfacing legacy 5-V TTL logic with modern 3.3-V or 2.5-V microcontrollers, or driving MOSFET gates from low-voltage logic. IC Role / Device Role / Timing Role: Level shifter converting logic-high/low states between incompatible voltage domains using open-collector pullup configuration. Use Value: COL OUT sinks up to 50 mA at VOL ≤ 0.4 V (at 8 mA, 0°C–70°C), ensuring robust noise margin and fast edge rates into capacitive loads. |
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; SOIC-8 package instead of PDIP-8; thermal resistance RθJA = 114.3°C/W vs. 57.5°C/W for PDIP. | Preferred for automated PCB assembly and space-constrained designs; less suitable for prototyping or socketed evaluation. | Select LM311DR for volume SMT production; LM311PG4 remains optimal for breadboarding, through-hole layouts, or legacy board refreshes. |
| LM211P | Identical pinout and function; wider operating temperature range (–40°C to +85°C) vs. LM311PG4 (0°C to +70°C); max input offset voltage 2 mV (vs. 7.5 mV). | Required for automotive under-hood or industrial ambient environments exceeding 70°C; tighter offset benefits precision thresholding. | Choose LM211P where extended temperature or lower offset is mandatory; LM311PG4 suffices for commercial-grade indoor equipment. |
Compared with LM311DR and LM211P, the LM311PG4 offers lowest-cost through-hole implementation with proven reliability in legacy industrial controls, while sacrificing SMT scalability and extended temperature capability-making it ideal for cost-sensitive, non-extreme-environment applications requiring manual assembly or field serviceability.
Availability
LM311PG4 is available at Aetrix Electronics and suitable for industrial automation, building management systems, and test equipment requiring stable component supply, long-term obsolescence mitigation, and consistent through-hole manufacturing support.
Supply support for LM311PG4 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 over 50 years of innovation in precision analog ICs and industrial-grade components.
The LM311PG4 belongs to TI's legacy high-speed comparator family, engineered for robust performance in noisy industrial environments, power supply monitoring, and analog signal conditioning where reliability and wide supply tolerance are critical.
FAQ
What is the maximum output voltage swing supported by the LM311PG4?
The LM311PG4 COL OUT pin supports up to 40 V across the collector-to-emitter path when referenced to VCC−, as specified in Absolute Maximum Ratings. This enables direct switching of 24-V industrial loads without external level-shifting circuitry. The actual usable output voltage depends on the external pullup voltage and load current-VOL remains ≤ 0.75 V at 50 mA, confirming strong low-state drive capability. Always observe the 40-V limit to avoid device damage.
Can the LM311PG4 operate from a single 5-V supply?
Yes, the LM311PG4 is explicitly rated for single 5-V supply operation (VCC+ = 5 V, VCC− = 0 V), per Recommended Operating Conditions. In this configuration, the input common-mode range extends from 0.5 V to 3.5 V, and the output can sink up to 8 mA with VOL ≤ 0.23 V. This makes LM311PG4 suitable for interfacing with 5-V logic families and microcontrollers without additional level-shifting components.
How does the BAL/STRB pin function in the LM311PG4?
The BAL/STRB pin on the LM311PG4 serves dual purpose: as a strobe input (when driven with –3 mA to –5 mA) to force the output into high-impedance state regardless of input conditions, or as a balance control when left open or connected to the BALANCE pin for offset trimming. It must never be shorted to ground-current sourcing is required for reliable strobing. This feature enables synchronized sampling, blanking during measurement windows, or multiplexed sensor readout.
What is the purpose of the EMIT OUT pin on the LM311PG4?
The EMIT OUT pin provides the emitter terminal of the internal NPN output transistor, electrically isolated from VCC−. When used with COL OUT, it allows the LM311PG4 to drive loads referenced to VCC+ (e.g., sinking current from a 24-V rail into the output), unlike conventional open-collector comparators. This configuration supports high-side switching topologies and floating-load applications-such as driving relays or lamps tied between VCC+ and EMIT OUT.
Does the LM311PG4 require external components for basic comparator operation?
Yes-basic operation requires at minimum an external pullup resistor on COL OUT (e.g., 4.7 kΩ to VCC+) to establish logic-high state, and bypass capacitors (0.1 µF ceramic) on VCC+ and VCC− pins to suppress supply noise. If precision thresholding is needed, a 10-kΩ potentiometer between VCC+ and VCC− connected to BALANCE enables offset nulling. The BAL/STRB pin may also require a current-source driver if strobe functionality is used.
LM311PG4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- 8-DIP (0.300", 7.62mm)
- Series:
- -
- Packaging:
- Tube
- Product Status:
- Obsolete
- Type:
- General Purpose
- Number of Elements:
- 1
- Output Type:
- DTL, MOS, Open-Collector, Open-Emitter, RTL, 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):
- 50mA
- 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
- :
- 8-PDIP
LM311PG4 FAQ
1.How can I place an order for LM311PG4 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM311PG4 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 LM311PG4 reliable?
The price and inventory of LM311PG4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM311PG4 is usually 5 days.
3.What payment methods are accepted for LM311PG4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM311PG4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM311PG4?
LM311PG4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM311PG4 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 LM311PG4?
For technical support, including LM311PG4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM311PG4 requirements.
6.How does Aetrix verify that LM311PG4 is sourced from the original manufacturer or authorized distributors?
All LM311PG4 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 LM311PG4 meets industry standards.
7.What is the process for return or replacement of LM311PG4?
All LM311PG4 units undergo pre-shipment inspection (PSI). If there is an issue with LM311PG4, 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 LM311PG4 part is unused and in its original packaging.
Return procedure for LM311PG4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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