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Texas Instruments LP311PSRE4
- Part No.:
- LP311PSRE4
- Manufacturer:
- Texas Instruments
- Category:
- Comparators
- Package:
- 8-SOIC (0.209", 5.30mm Width)
- Datasheet:
-
LP311PSRE4.pdf
- Description:
- IC COMPARATOR 1 DIFF 8SO
- Quantity:
- Payment:
- Shipping:
Inventory:3,643
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Product details
Overview
LP311PSRE4 from Texas Instruments is a low-power differential comparator with strobe capability, designed for precision voltage comparison in battery-powered and industrial sensing systems. It features 7.5 mV max input offset voltage at 25°C, 1.2 μs typical response time, ±15 V or single 3–30 V supply operation, and emitter-collector open-drain outputs capable of 25 mA sink current.
For engineers reviewing the LP311PSRE4 datasheet, LP311PSRE4 pinout, LP311PSRE4 application, or LP311PSRE4 equivalent, this device is selected for low-quiescent-current analog monitoring where strobe-controlled output gating, wide common-mode range (−14.5 V to 13.5 V), and compatibility with LM311-based designs are required.
Technical Context
The LP311PSRE4 implements a bipolar comparator core with ion-implanted resistor networks 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 pull-up configurations and rail-to-rail output swing below VCC−.
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 an external 3 kΩ potentiometer between BALANCE and BAL/STRB pins. The device operates across 0°C to 70°C ambient temperature.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage Range | Single 3–30 V or dual ±15 V - enables direct integration into 3.3 V microcontroller systems and legacy ±15 V industrial rails. |
| Input Offset Voltage | 7.5 mV max at 25°C - defines worst-case decision error in precision threshold detection circuits. |
| Response Time | 1.2 μs typical (100 mV step, 5 mV overdrive) - suitable for medium-speed level-crossing detection, not high-frequency PWM control. |
| Output Drive | 25 mA sink capability at emitter output - supports direct driving of LEDs, relays, or logic inputs without external buffers. |
| Input Bias Current | 15 nA typical - minimizes loading error on high-impedance sensor sources like thermistors or photodiodes. |
| Quiescent Power | 900 μW typical at 5 V - extends battery life in portable instrumentation and remote sensors. |
| Common-Mode Range | −14.5 V to 13.5 V with ±15 V supply - allows direct comparison of signals referenced to negative rails or ground-referenced inputs in mixed-supply systems. |
Pinout & Package
LP311PSRE4 is housed in an 8-pin SOIC (PS) package with 1.27 mm pitch, 3.9 mm width, and 1.75 mm max height per JEDEC MS-012 variation AA. Pin 1 identification is marked by a beveled corner and notch on the top surface.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - BALANCE | Offset null adjustment terminal | Connects to wiper of external 3 kΩ potentiometer to trim input offset voltage to ≤2 mV. |
| 2 - IN− | Inverting input | Accepts reference or feedback signal; high-impedance node (15 nA bias current) for minimal source loading. |
| 3 - IN+ | Non-inverting input | Accepts sensed signal; shares same input impedance and offset characteristics as IN−. |
| 4 - VCC− | Negative supply rail | Reference for emitter output swing; emitter can go ≤0.4 V below this rail under 1.6 mA load. |
| 5 - VCC+ | Positive supply rail | Supports single-supply (3–30 V) or split-supply (±15 V) operation; powers internal circuitry and collector output stage. |
| 6 - COL OUT | Collector output (open-drain) | Requires external pull-up; sinks up to 25 mA; used for TTL/CMOS-compatible logic interfacing. |
| 7 - BAL/STRB | Strobe and balance control | Pull low with 100–300 μA to disable output regardless of input state; also serves as second balance terminal when potentiometer is connected. |
| 8 - EMIT OUT | Emitter output (open-emitter) | Sinks current to VCC−; swings below VCC− by ≤0.4 V; ideal for sinking loads tied to positive rail. |
Key Features
| Feature | Design Value |
|---|---|
| Low-power operation | 900 μW typical at 5 V supply - reduces thermal load and extends runtime in energy-constrained applications. |
| Strobe-enabled output disable | Dedicated BAL/STRB pin accepts current-driven low signal (100–300 μA) to force output off-state independent of input voltages. |
| Wide supply flexibility | Operates from single 3 V up to ±15 V - eliminates need for level-shifting in multi-rail systems or battery-backed designs. |
| True open-collector + open-emitter outputs | Dual output terminals allow independent connection to different voltage domains - e.g., COL OUT to 5 V logic, EMIT OUT to −5 V reference. |
| LM311 pin compatibility | Identical 8-pin SOIC (PS), PDIP, and SOIC footprints - enables drop-in replacement in existing LM311 layouts without PCB revision. |
Applications
| Battery-Powered Threshold Detector | Industrial Level-Sensing Interface |
|---|---|
|
Use Scenario: Monitoring lithium-ion cell voltage during charging to trigger cutoff at 4.2 V. IC Role / Device Role / Timing Role: Precision comparator comparing cell voltage against stable reference; strobe used to gate output during calibration phase. Use Value: 7.5 mV offset ensures accurate 4.2 V trip point; 900 μW quiescent power preserves standby battery life for months. |
Use Scenario: Detecting fluid level in a tank using resistive float sensor with ±12 V supply. IC Role / Device Role / Timing Role: Differential comparator rejecting common-mode noise on long sensor cables; wide −14.5 V to 13.5 V input range accommodates sensor swing. Use Value: Open-emitter output directly drives 24 V PLC input; strobe disables output during maintenance mode to prevent false alarms. |
| Programmable Logic Input Conditioner | Legacy System Upgrade Module |
|
Use Scenario: Converting analog sensor output (0–10 V) to clean 3.3 V logic signal for FPGA I/O bank. IC Role / Device Role / Timing Role: Single-supply comparator operating from 3.3 V rail; COL OUT pulled up to 3.3 V for CMOS compatibility. Use Value: 15 nA input bias avoids loading high-impedance DAC outputs; 1.2 μs response meets FPGA setup timing for slow-control loops. |
Use Scenario: Replacing obsolete LM311 in field-installed HVAC controllers without board redesign. IC Role / Device Role / Timing Role: Pin-identical functional replacement; same SOIC-8 footprint and electrical interface. Use Value: 30× lower power reduces heat in sealed enclosures; identical strobe and balance functions preserve original firmware behavior. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar differential comparator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM311DR | Higher 5.5 mW typical power, faster 115 ns response, wider −15.5 V to 14.5 V common-mode range. | Preferred in high-speed switching or high-noise industrial environments where speed outweighs power savings. | Select LM311DR only if >10× speed improvement is required and thermal/power budget permits. |
| TL3017CDR | CMOS input (1 pA bias), rail-to-rail input, 1.5 V to 36 V supply, but no strobe function and 2.5 μs response. | Suitable for ultra-high-impedance sources (e.g., pH electrodes) where strobe gating is unnecessary. | Choose TL3017CDR when input bias must be <100 pA and strobe is unused; avoid if strobe or LM311 pinout is mandatory. |
Compared with LM311DR and TL3017CDR, LP311PSRE4 uniquely balances ultra-low power (900 μW), strobe control, and LM311 pin compatibility - making it optimal for retrofitting legacy systems and battery-operated devices where moderate speed suffices.
Availability
LP311PSRE4 is available at Aetrix Electronics and suitable for battery-powered instrumentation, industrial sensor interfaces, and legacy system upgrades requiring stable component supply and long-term obsolescence mitigation.
Supply support for LP311PSRE4 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 founded in 1930, delivering analog and embedded processing solutions across automotive, industrial, and personal electronics markets.
The LP311PSRE4 belongs to TI's legacy precision analog comparator family, engineered specifically for low-power, pin-compatible replacement of industry-standard LM311 in cost- and energy-sensitive applications.
FAQ
What is the operating temperature range for LP311PSRE4?
The LP311PSRE4 is characterized for operation from 0°C to 70°C ambient temperature. This commercial-grade rating aligns with its intended use in non-automotive industrial and consumer equipment. The device's thermal resistance (θJA = 95°C/W for PS package) ensures safe operation within this range under typical PCB layout conditions with moderate airflow.
Does LP311PSRE4 support single-supply operation?
Yes, LP311PSRE4 supports true single-supply operation from 3 V to 30 V. When used with a single 5 V rail, VCC− is connected to ground and VCC+ to 5 V; the emitter output can swing to within 0.4 V of ground, and the collector output pulls down to near ground when active - enabling direct interfacing with 3.3 V or 5 V logic families.
How is the strobe function implemented on LP311PSRE4?
The strobe function on LP311PSRE4 is controlled via the BAL/STRB pin (Pin 7). To disable the output, apply a current sink of 100–300 μA to this pin - typically achieved using a transistor switch or logic buffer. Direct grounding is prohibited; the datasheet specifies current-driven activation to prevent latch-up and ensure reliable output disable independent of input states.
Can LP311PSRE4 replace LM311 in existing designs without changes?
Yes, LP311PSRE4 is explicitly designed as a pin-compatible, functionally equivalent replacement for LM311 in SOIC-8 (PS) packages. It shares identical pinout, output structure, strobe and balance functionality, and mechanical footprint. No PCB layout changes are needed - though users should verify that the reduced 1.2 μs response time meets system timing requirements.
What is the maximum input voltage range relative to supply rails for LP311PSRE4?
With ±15 V supplies, LP311PSRE4 supports a common-mode input range of −14.5 V to 13.5 V - meaning either input (IN+ or IN−) may swing 0.5 V beyond the negative rail and 1.5 V below the positive rail. This tolerance prevents phase reversal and ensures correct operation even with large input transients or mismatched rail decoupling.
LP311PSRE4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- 8-SOIC (0.209", 5.30mm Width)
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- 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:
- Surface Mount
- :
- 8-SO
LP311PSRE4 FAQ
1.How can I place an order for LP311PSRE4 through Aetrix?
Please submit a Request for Quotation (RFQ) for LP311PSRE4 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 LP311PSRE4 reliable?
The price and inventory of LP311PSRE4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LP311PSRE4 is usually 5 days.
3.What payment methods are accepted for LP311PSRE4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LP311PSRE4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LP311PSRE4?
LP311PSRE4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LP311PSRE4 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 LP311PSRE4?
For technical support, including LP311PSRE4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LP311PSRE4 requirements.
6.How does Aetrix verify that LP311PSRE4 is sourced from the original manufacturer or authorized distributors?
All LP311PSRE4 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 LP311PSRE4 meets industry standards.
7.What is the process for return or replacement of LP311PSRE4?
All LP311PSRE4 units undergo pre-shipment inspection (PSI). If there is an issue with LP311PSRE4, 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 LP311PSRE4 part is unused and in its original packaging.
Return procedure for LP311PSRE4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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