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Texas Instruments LM285LP-2-5
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- Part No.:
- LM285LP-2-5
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-226-3, TO-92-3 (TO-226AA)
- Datasheet:
-
LM285LP-2-5.pdf
- Description:
- IC VREF SHUNT 1.5% TO92-3
- Quantity:
- Payment:
- Shipping:
Inventory:1,495
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Product details
Overview
LM285LP-2-5 from Texas Instruments is a micropower, two-terminal, band-gap shunt voltage reference delivering a precise 2.5 V output with ±20 ppm/°C temperature coefficient, 20 μA to 20 mA operating current range, and 1.5 Ω maximum reference impedance over full temperature range. It serves as a stable voltage reference in portable battery-powered instrumentation requiring low quiescent current and high long-term stability.
For engineers reviewing the LM285LP-2-5 datasheet, LM285LP-2-5 pinout, LM285LP-2-5 application, or LM285LP-2-5 equivalent, this page provides verified technical context, TO-92 package details, real-world use cases in portable meters and thermocouple compensation, and validated alternative options for low-power analog reference design.
Technical Context
The LM285LP-2-5 operates as a floating shunt reference: cathode accepts current input while anode connects to ground (or system common), enabling both positive and negative regulation topologies. Its internal band-gap core and high-gain amplifier deliver 2.5 V with ±20 ppm/°C drift across –40°C to +85°C and maintain regulation down to 8 μA minimum cathode current.
Designed for capacitive load tolerance, it features internal frequency compensation and exhibits only 120 µV broadband noise (10 Hz–10 kHz) at 100 µA bias. Reference impedance remains ≤0.6 Ω at 25°C and ≤1.5 Ω over full temperature range, ensuring stable performance under varying load conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.462 V to 2.538 V at 25°C - tight 1.5% initial tolerance enables precision analog signal conditioning without external trimming. |
| Tempco | ±20 ppm/°C - ensures ≤1.25 mV total drift over –40°C to +85°C, critical for portable test equipment accuracy. |
| Operating Current | 20 μA to 20 mA - ultra-low minimum current extends battery life; wide range allows flexible biasing in diverse supply configurations. |
| Reference Impedance | ≤0.6 Ω at 25°C, ≤1.5 Ω over full temp - low dynamic impedance minimizes output voltage shift under load transients. |
| Noise (10 Hz–10 kHz) | 120 µV - low broadband noise supports high-resolution ADC references and sensitive sensor front-ends. |
| Long-Term Drift | ±20 ppm/khr - predictable aging behavior supports 10+ year calibration intervals in field-deployed instruments. |
Pinout & Package
LM285LP-2-5 uses a 3-pin TO-92 package (body size 4.30 mm × 4.30 mm) with axial lead configuration. The device is a two-terminal shunt reference: only ANODE and CATHODE are functional; Pin 2 (center lead) is NC (no internal connection).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| ANODE (Pin 1 or 3) | Common node / Ground reference | Typically connected to system ground; forms return path for cathode current and defines reference potential. |
| CATHODE (Pin 3 or 1) | Shunt current/voltage input | Current must be sourced into this terminal to establish 2.5 V across ANODE–CATHODE; regulates by sinking excess current. |
| NC (Pin 2) | No internal connection | Center lead is electrically isolated; must not be soldered to PCB trace or used for mechanical support. |
Key Features
| Feature | Design Value |
|---|---|
| Band-gap core with on-chip trimming | Delivers 2.5 V with 1.5% initial accuracy and ±20 ppm/°C tempco - eliminates need for external calibration in portable designs. |
| Floating shunt architecture | Enables use in both high-side and low-side reference configurations - supports negative supply rails and current-loop transmitters. |
| Capacitive load tolerance | Stable operation with ≥0.1 µF ceramic bypass on cathode - simplifies layout and avoids oscillation in space-constrained handheld devices. |
| Micropower operation | Functional down to 8 μA cathode current - extends shelf-life-equivalent battery operation in always-on monitoring systems. |
| Low-noise regulation | 120 µV RMS noise (10 Hz–10 kHz) - preserves SNR in 16-bit+ data acquisition paths without additional filtering. |
Applications
| Portable Meter References | Thermocouple Cold-Junction Compensation |
|---|---|
|
Use Scenario: Handheld digital multimeters and panel-mounted voltage/current meters powered by 9 V alkaline or lithium cells. IC Role / Device Role / Timing Role: Provides stable 2.5 V reference for ADC conversion and display scaling circuitry. Use Value: Enables >4½-digit accuracy with <1.25 mV total drift over operating temperature, extending recalibration intervals to 2 years. |
Use Scenario: Industrial temperature measurement systems using Type K thermocouples with ambient sensing. IC Role / Device Role / Timing Role: Generates precise 2.5 V reference for cold-junction compensation amplifier biasing and offset correction. Use Value: Maintains ≤0.5°C measurement error across –20°C to +70°C ambient, meeting ASTM E230 Class 2 requirements. |
| Battery-Operated Sensor Nodes | Current-Loop Instrumentation |
|
Use Scenario: Wireless environmental sensors (temperature/humidity/pressure) powered by coin-cell batteries. IC Role / Device Role / Timing Role: Supplies reference voltage for sensor excitation and signal conditioning in ultra-low-power sleep/wake cycles. Use Value: Draws only 8 μA minimum current, enabling >5-year battery life while maintaining 0.1% reference stability during wake periods. |
Use Scenario: 4–20 mA industrial transmitters converting analog sensor outputs for PLC interfacing. IC Role / Device Role / Timing Role: Sets precision 2.5 V reference for current-sense resistor feedback and DAC output scaling. Use Value: Ensures transmitter output accuracy within ±0.05% FSR over 15-year service life, meeting IEC 61000-4 immunity standards. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM385BLP-2-5 | Same TO-92 package, but rated for 0°C to +70°C only; 3% initial tolerance (vs. LM285LP-2-5's 1.5%) | Limited to commercial-temperature industrial controls; unsuitable for automotive or extended-range outdoor deployment | Select when cost sensitivity outweighs extended temperature range and tighter initial accuracy. |
| TLVH431AILP | Adjustable shunt reference (2.495 V typical), higher 80 μA min current, SO-8 package, ±50 ppm/°C tempco | Requires external resistors for 2.5 V setting; less stable over temperature than LM285LP-2-5 in battery-critical apps | Choose only if adjustable output or higher sink current (100 mA) is required; not a drop-in replacement. |
Compared with LM385BLP-2-5 and TLVH431AILP, the LM285LP-2-5 offers superior temperature range (–40°C to +85°C), tighter initial tolerance (1.5%), and lower minimum operating current (8 μA), making it optimal for long-life, wide-temperature portable instrumentation where reference stability directly impacts measurement validity.
Availability
LM285LP-2-5 is available at Aetrix Electronics and suitable for portable test instruments, battery-operated sensor nodes, and current-loop transmitters requiring stable component supply with guaranteed long-term availability and traceable sourcing.
Supply support for LM285LP-2-5 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 company specializing in analog and embedded processing technologies, with decades of leadership in precision voltage references and power management ICs.
The LMx85 series was designed specifically for micropower, high-stability analog reference applications in portable and battery-constrained systems - prioritizing low quiescent current, wide temperature operation, and robust capacitive-load immunity.
FAQ
What is the minimum cathode current required for regulation in the LM285LP-2-5?
The LM285LP-2-5 requires a minimum cathode current (IZ(MIN)) of 8 μA over its full operating temperature range (–40°C to +85°C) to maintain regulation. At 25°C, regulation is guaranteed down to 8 μA, and the device remains functional up to 20 mA. This ultra-low minimum current enables multi-year battery life in always-on portable instruments.
How does the LM285LP-2-5 differ from the LM385-2.5 in terms of temperature range and accuracy?
The LM285LP-2-5 is specified for –40°C to +85°C operation with 1.5% initial voltage tolerance, whereas the LM385-2.5 is limited to 0°C to +70°C and has 3% initial tolerance. Both share identical electrical characteristics at 25°C, but the LM285LP-2-5 delivers tighter accuracy and broader environmental resilience for industrial and automotive-adjacent applications.
Can the LM285LP-2-5 be used in a negative voltage reference configuration?
Yes - the LM285LP-2-5 is a floating shunt reference and can be configured for negative regulation by connecting its anode to the negative rail and sourcing current into the cathode. Its internal band-gap architecture and capacitive-load tolerance make it suitable for dual-supply systems and bipolar sensor interfaces without external level-shifting components.
What is the reference impedance of the LM285LP-2-5 and why does it matter?
The LM285LP-2-5 has a reference impedance of ≤0.6 Ω at 25°C and ≤1.5 Ω over –40°C to +85°C. Low impedance ensures minimal output voltage shift under dynamic load changes - critical for maintaining ADC reference stability during multiplexed sampling or fast-switching sensor excitation circuits.
Is a bypass capacitor required on the cathode pin of the LM285LP-2-5?
A 0.1 µF ceramic bypass capacitor on the cathode pin is optional but recommended for noise-sensitive applications. The LM285LP-2-5 is internally compensated and stable with capacitive loads up to 10 µF, so the capacitor improves high-frequency PSRR and reduces broadband noise coupling without risking instability.
LM285LP-2-5 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA)
- Series:
- -
- Packaging:
- Bulk
- Product Status:
- Active
- Reference Type:
- Shunt
- Output Type:
- Fixed
- Voltage - Output (Min/Fixed):
- 2.5V
- Voltage - Output (Max):
- -
- Current - Output:
- 20 mA
- Tolerance:
- ±1.5%
- Temperature Coefficient:
- 20ppm/°C Typical
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- 120µVrms
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 20 µA
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-92-3
LM285LP-2-5 FAQ
1.How can I place an order for LM285LP-2-5 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM285LP-2-5 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 LM285LP-2-5 reliable?
The price and inventory of LM285LP-2-5 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM285LP-2-5 is usually 5 days.
3.What payment methods are accepted for LM285LP-2-5?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM285LP-2-5 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM285LP-2-5?
LM285LP-2-5 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM285LP-2-5 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 LM285LP-2-5?
For technical support, including LM285LP-2-5 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM285LP-2-5 requirements.
6.How does Aetrix verify that LM285LP-2-5 is sourced from the original manufacturer or authorized distributors?
All LM285LP-2-5 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 LM285LP-2-5 meets industry standards.
7.What is the process for return or replacement of LM285LP-2-5?
All LM285LP-2-5 units undergo pre-shipment inspection (PSI). If there is an issue with LM285LP-2-5, 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 LM285LP-2-5 part is unused and in its original packaging.
Return procedure for LM285LP-2-5:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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