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Texas Instruments LP311PG4
- Part No.:
- LP311PG4
- Manufacturer:
- Texas Instruments
- Category:
- Comparators
- Package:
- 8-DIP (0.300", 7.62mm)
- Datasheet:
-
LP311PG4.pdf
- Description:
- IC COMPARATOR 1 DIFF 8DIP
- Quantity:
- Payment:
- Shipping:
Inventory:3,227
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Product details
Overview
LP311PG4 from Texas Instruments is a low-power differential comparator with strobe capability, designed for precision voltage comparison in battery-powered and industrial control systems. It features 7.5 mV max input offset voltage at 25°C, 1.2 μs typical response time, ±15 V or single 3-V supply operation, and emitter-collector open-drain outputs capable of 25 mA sink current.
For engineers reviewing the LP311PG4 datasheet, LP311PG4 pinout, LP311PG4 application, or LP311PG4 equivalent, this device is selected for low-quiescent-current analog sensing, level detection with strobe gating, and legacy LM311 drop-in replacement scenarios where power efficiency and temperature range (0°C to 70°C) are critical.
Technical Context
The LP311PG4 implements a bipolar transistor-based differential pair architecture with ion-implanted resistors enabling 900 μW typical power consumption at 5 V - a 30:1 reduction versus LM311. Its dual-output structure (emitter-out and collector-out) supports flexible interfacing with TTL, CMOS, or relay drivers while maintaining rail-to-rail common-mode input range (−14.5 V to 13.5 V with ±15 V supplies).
Strobe functionality is implemented via a dedicated BAL/STRB pin that forces output disable when pulled low with 100–300 μA current drive; offset balancing is supported through external 3-kΩ potentiometer connection between BALANCE and BAL/STRB pins. The device avoids internal oscillation under standard PCB layout practices due to stable high-impedance inputs and controlled gain-bandwidth product.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage Range | Single 3 V to ±15 V - enables direct integration into 3.3 V microcontroller systems or legacy ±12 V industrial rails without level-shifting. |
| Input Offset Voltage | 7.5 mV max at 25°C - defines worst-case decision error in precision threshold detection circuits (e.g., battery low-voltage alarm at 3.0 V ±7.5 mV). |
| Response Time | 1.2 μs typical - sufficient for line-frequency monitoring (50/60 Hz zero-crossing), slow-motion sensor triggering, and power-supply sequencing. |
| Output Sink Current | 25 mA - directly drives LEDs, small relays, optocouplers, or logic inputs without external buffer transistors. |
| Quiescent Power | 900 μW typical at 5 V - extends battery life in portable instrumentation and wireless sensor nodes operating on coin cells or Li-SOCl₂. |
| Input Bias Current | 15 nA typical - allows high-impedance voltage dividers (e.g., 1 MΩ networks) without significant loading error. |
| Common-Mode Range | −14.5 V to 13.5 V (±15 V supply) - supports direct sensing of signals referenced to negative rails or floating sources like thermocouples. |
Pinout & Package
LP311PG4 is supplied in an 8-pin PDIP (Plastic Dual In-line Package) with 0.3-inch body width and through-hole mounting. Pin 1 is located at the left end of the top row when viewed from the top with notch or dot orientation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - BALANCE | Offset null adjustment terminal | Connects to wiper of external 3-kΩ potentiometer for trimming input offset voltage to ≤2 mV. |
| 2 - IN− | Inverting input | Differential input node; accepts reference voltage or feedback signal in comparator configurations. |
| 3 - IN+ | Non-inverting input | Differential input node; typically connected to sensed signal (e.g., battery voltage, sensor output). |
| 4 - VCC− | Negative supply rail | Reference ground or negative supply; emitter output swings below this rail by up to 0.4 V. |
| 5 - VCC+ | Positive supply rail | Positive supply input; supports single-ended (3–30 V) or split-supply (±15 V) operation. |
| 6 - COL OUT | Collector output | Open-collector NPN output; requires external pull-up to define logic-high level and sink up to 25 mA. |
| 7 - BAL/STRB | Strobe / balance control | Pulling low with 100–300 μA disables both outputs regardless of input state - used for synchronized sampling or power gating. |
| 8 - EMIT OUT | Emitter output | Open-emitter NPN output; sinks current to VCC−; enables level-shifting to negative rails or direct grounding. |
Key Features
| Feature | Design Value |
|---|---|
| Low-power operation | 900 μW typical at 5 V supply - reduces thermal load and enables use in sealed enclosures or multi-channel sensor arrays. |
| Strobe-enabled output disable | Dedicated BAL/STRB pin allows synchronous blanking of comparator decisions during ADC conversion windows or noise-sensitive intervals. |
| Wide supply flexibility | Operates from single 3-V to ±15-V rails - eliminates need for auxiliary regulators in mixed-signal systems with 3.3 V logic and ±12 V analog stages. |
| Rail-to-rail common-mode input | Accepts inputs down to VCC− + 0.5 V and up to VCC+ − 1.5 V - supports direct interface with sensors operating near supply rails. |
| Pin-compatible with LM311 | Same 8-pin PDIP footprint and pin assignment - enables drop-in replacement in legacy designs without PCB revision. |
Applications
| Battery Voltage Monitoring | Industrial Threshold Detection |
|---|---|
|
Use Scenario: Detecting low battery condition in handheld medical devices powered by two AA alkaline cells (2.0–3.2 V range). IC Role / Device Role / Timing Role: Precision comparator comparing divided battery voltage against 2.0 V reference; strobe synchronized to MCU sleep-wake cycle. Use Value: 900 μW quiescent power extends standby time >6 months; 7.5 mV offset ensures reliable trip point at 2.0 V ±7.5 mV. |
Use Scenario: Monitoring motor winding temperature via PT100 bridge output in HVAC control panels. IC Role / Device Role / Timing Role: Differential comparator detecting bridge imbalance exceeding 10 mV threshold; output drives optocoupler-isolated fault latch. Use Value: −14.5 V to 13.5 V common-mode range accommodates bridge excitation at ±12 V; 25 mA sink drives LED directly. |
| Power Supply Sequencing | Zero-Crossing Detection |
|
Use Scenario: Enforcing startup order of FPGA core (1.2 V) and I/O (3.3 V) rails in telecom baseband boards. IC Role / Device Role / Timing Role: Dual-comparator setup using COL OUT and EMIT OUT to generate independent enable signals with adjustable hysteresis. Use Value: Dual open-drain outputs allow independent pull-up voltages (1.2 V and 3.3 V); strobe disables sequencing during reset assertion. |
Use Scenario: Detecting AC line zero crossings for TRIAC dimmer control in smart lighting modules. IC Role / Device Role / Timing Role: High-impedance comparator sensing rectified sine wave across 100 kΩ divider; output triggers microcontroller interrupt. Use Value: 15 nA input bias current prevents distortion of high-Z AC sensing network; 1.2 μs response ensures <1° phase error at 50 Hz. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar low-power differential comparator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM311N | Higher 5.5 mW typical power; faster 200 ns response; no strobe pin; same PDIP-8 package. | Preferred where speed >10× required and power budget allows; unsuitable for strobe-gated sampling. | Select LM311N only if system demands sub-microsecond response and strobe function is unnecessary. |
| LP311DR | SOIC-8 surface-mount package; identical electrical specs; 0°C to 70°C rating; reel packaging (2500 pcs). | Used in automated SMT production; requires different PCB footprint and reflow profile vs. through-hole LP311PG4. | Choose LP311DR for volume manufacturing with pick-and-place assembly; LP311PG4 remains optimal for prototyping and repair. |
Compared with LM311N, LP311PG4 trades speed for 30× lower power and adds strobe control; compared with LP311DR, it shares full electrical compatibility but differs in through-hole mounting, thermal resistance (85°C/W vs. 97°C/W), and manual assembly suitability.
Availability
LP311PG4 is available at Aetrix Electronics and suitable for battery-powered instrumentation, industrial control panels, power supply sequencing, and legacy LM311 upgrade paths requiring stable component supply and long-term obsolescence management.
Supply support for LP311PG4 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 90 years of innovation in precision analog ICs and power management solutions.
The LP311PG4 belongs to TI's legacy low-power comparator family, engineered specifically for energy-constrained applications where extended battery life, wide supply flexibility, and pin-for-pin compatibility with industry-standard comparators are essential design requirements.
FAQ
What is the maximum supply voltage rating for LP311PG4?
The LP311PG4 supports absolute maximum supply voltages of +18 V on VCC+ and −18 V on VCC−. However, recommended operating conditions specify a total supply range of 3.5 V to 30 V (|VCC+ − VCC−|), with stable operation confirmed from ±15 V down to single 3-V supply. Exceeding ±18 V risks permanent damage per TI's absolute maximum ratings table.
Does LP311PG4 require external components for basic operation?
Yes, LP311PG4 requires external pull-up resistors on COL OUT (pin 6) and/or EMIT OUT (pin 8) to establish defined logic-high levels. A 3-kΩ potentiometer is optional but recommended between BALANCE (pin 1) and BAL/STRB (pin 7) for offset trimming. Strobe operation needs a current source (100–300 μA) to pull BAL/STRB low - not a direct ground connection.
Is LP311PG4 pin-compatible with LM311?
Yes, LP311PG4 uses the identical 8-pin PDIP package and pinout as LM311, including matching functions for all terminals (IN+, IN−, VCC+, VCC−, COL OUT, EMIT OUT, BALANCE, BAL/STRB). This allows direct mechanical and electrical replacement in existing LM311 designs without PCB modification, though users must verify timing and power constraints align with the slower 1.2 μs response and lower 900 μW consumption.
What is the operating temperature range of LP311PG4?
The LP311PG4 is characterized for operation from 0°C to 70°C ambient temperature, as specified in TI's ordering information and electrical characteristics tables. This commercial-grade rating distinguishes it from the LP211 variant (−25°C to 85°C) and confirms suitability for indoor industrial controls, consumer electronics, and non-automotive embedded systems.
Can LP311PG4 drive a relay coil directly?
Yes, LP311PG4 can directly drive small signal relays with coil resistance ≥200 Ω when powered from a 5-V supply, since its COL OUT and EMIT OUT pins each support 25 mA sink current. For example, a 5-V, 25 mA relay coil (200 Ω) connects between VCC+ and COL OUT, allowing the comparator to energize the coil when the output is active-low. Always confirm relay coil voltage/current ratings match LP311PG4's output capability and supply conditions.
LP311PG4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- 8-DIP (0.300", 7.62mm)
- Series:
- -
- Packaging:
- Tube
- Product Status:
- Obsolete
- Type:
- Differential
- Number of Elements:
- 1
- Output Type:
- Open-Collector, Open-Emitter
- Voltage - Supply, Single/Dual (±):
- 3.5V ~ 30V, ±1.75V ~ 15V
- :
- 7.5mV @ ±15V
- Voltage - Input Offset (Max):
- 0.1µA @ ±15V
- Current - Input Bias (Max):
- -
- Current - Output (Typ):
- 300µA
- Current - Quiescent (Max):
- -
- CMRR, PSRR (Typ):
- -
- Propagation Delay (Max):
- -
- Hysteresis:
- 0°C ~ 70°C
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- Through Hole
- :
- 8-PDIP
LP311PG4 FAQ
1.How can I place an order for LP311PG4 through Aetrix?
Please submit a Request for Quotation (RFQ) for LP311PG4 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 LP311PG4 reliable?
The price and inventory of LP311PG4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LP311PG4 is usually 5 days.
3.What payment methods are accepted for LP311PG4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LP311PG4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LP311PG4?
LP311PG4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LP311PG4 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 LP311PG4?
For technical support, including LP311PG4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LP311PG4 requirements.
6.How does Aetrix verify that LP311PG4 is sourced from the original manufacturer or authorized distributors?
All LP311PG4 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 LP311PG4 meets industry standards.
7.What is the process for return or replacement of LP311PG4?
All LP311PG4 units undergo pre-shipment inspection (PSI). If there is an issue with LP311PG4, 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 LP311PG4 part is unused and in its original packaging.
Return procedure for LP311PG4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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