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Texas Instruments LM385LPE3-1-2
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- Part No.:
- LM385LPE3-1-2
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-226-3, TO-92-3 (TO-226AA)
- Datasheet:
-
LM385LPE3-1-2.pdf
- Description:
- IC VREF SHUNT 2% TO92-3
- Quantity:
- Payment:
- Shipping:
Inventory:1,559
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Product details
Overview
LM385LPE3-1-2 from Texas Instruments is a micropower, two-terminal, band-gap voltage reference in TO-92 package, delivering 1.235 V nominal output with ±20 ppm/°C temperature coefficient, 15 μA to 20 mA operating current range, and 1.5 Ω max reference impedance over full temperature range. It serves as a precision shunt reference in portable battery-powered analog systems requiring long shelf-life-compatible power efficiency.
For engineers reviewing the LM385LPE3-1-2 datasheet, LM385LPE3-1-2 pinout, LM385LPE3-1-2 application, or LM385LPE3-1-2 equivalent, key selection criteria include initial voltage tolerance (±1%), low-noise operation (60 µV broadband), capacitive-load immunity, and compatibility with current-loop instrumentation and panel meter designs.
Technical Context
The LM385LPE3-1-2 operates as a floating shunt reference, regulating voltage between cathode and anode using internal band-gap core and high-gain amplifier. Regulation initiates only after minimum cathode current (15 μA) is supplied, and internal frequency compensation ensures stability across all capacitor loads.
Its design supports both positive and negative regulation topologies. The device exhibits low dynamic impedance (≤1.5 Ω) and tight long-term stability (±20 ppm/khr), enabling use in precision analog circuits where drift and noise must be minimized without external compensation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Reference Voltage | 1.235 V at 25°C - stable setpoint for analog calibration and ADC/DAC biasing |
| Initial Voltage Tolerance | ±1% - enables direct use in 12-bit systems without trimming |
| Temperature Coefficient | ±20 ppm/°C - limits drift to <±1.5 mV over 0°C to 70°C operating range |
| Operating Current Range | 15 μA to 20 mA - supports ultra-low-power sensor nodes and high-current reference buffering |
| Reference Impedance | 1.5 Ω max over full temperature range - ensures minimal load-induced error in varying current conditions |
| Broadband Noise | 60 µV RMS (10 Hz–10 kHz) - suitable for high-resolution measurement front-ends |
| Long-Term Stability | ±20 ppm/khr - maintains accuracy over years in unattended instrumentation |
Pinout & Package
LM385LPE3-1-2 uses a 3-pin TO-92 package (body size 4.30 mm × 4.30 mm, height ≤5.34 mm), with leads formed for through-hole mounting. Pin 1 is Anode, Pin 2 is Cathode, and Pin 3 is NC (no internal connection).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Pin 1) | Shunt current return path | Connected to system ground or low-impedance return; defines reference potential reference point |
| Cathode (Pin 2) | Shunt current input / voltage output node | Current sourced into this pin develops regulated 1.235 V relative to Anode; used as precision voltage source node |
| NC (Pin 3) | No internal connection | Not bonded; electrically isolated - must remain unconnected or grounded per layout best practice |
Key Features
| Feature | Design Value |
|---|---|
| Two-terminal shunt topology | Eliminates need for dedicated supply rail - simplifies design in floating or negative-regulation configurations |
| Capacitive-load immunity | Stable with any value of bypass capacitor on cathode - removes need for series resistance or complex compensation |
| Micropower operation | 15 μA minimum operating current enables multi-year battery life in portable meters and remote sensors |
| On-chip trimmed voltage | Guarantees ±1% initial accuracy without external calibration - reduces BOM count and test time |
| Low-noise band-gap core | 60 µV RMS noise supports 16-bit+ resolution in precision data acquisition systems |
Applications
| Portable Meter References | Portable Test Instruments |
|---|---|
Use Scenario: Handheld digital multimeters and clamp meters powered by alkaline or lithium coin cells. IC Role / Device Role / Timing Role: Shunt voltage reference establishing precise 1.235 V reference for ADC conversion and display scaling. Use Value: Enables >10-year battery life while maintaining ±0.1% measurement accuracy across temperature due to low 15 μA quiescent current and ±20 ppm/°C drift. | Use Scenario: Battery-operated oscilloscope probes and signal generators with integrated calibration references. IC Role / Device Role / Timing Role: Precision voltage source for internal DACs, offset trimming, and self-test circuitry. Use Value: Delivers stable 1.235 V with 60 µV noise floor, supporting sub-mV resolution in probe calibration and waveform fidelity verification. |
| Battery-Operated Systems | Current-Loop Instrumentation |
Use Scenario: Wireless sensor nodes and IoT edge devices with intermittent wake-up cycles and strict energy budgets. IC Role / Device Role / Timing Role: Low-power reference for analog front-end conditioning and microcontroller ADC reference input. Use Value: Draws only 15 μA minimum current, allowing operation from coin cells for >5 years in duty-cycled applications without voltage degradation. | Use Scenario: 4–20 mA industrial transmitters in process control systems with loop-powered architecture. IC Role / Device Role / Timing Role: Shunt reference providing accurate excitation voltage for RTD/thermocouple signal conditioning and current-sense amplifiers. Use Value: Maintains ±1% initial accuracy and <±1.5 mV total drift over 0°C–70°C, ensuring compliance with IEC 61000-4-5 surge immunity and long-term field calibration stability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM385LP-1-2 | Same TO-92 package and 1.235 V nominal output, but ±2% initial tolerance and 0°C–70°C temp range | Acceptable where cost sensitivity outweighs precision; not suitable for 12-bit+ systems requiring tighter initial accuracy | Select LM385LPE3-1-2 when ±1% tolerance and guaranteed RoHS-compliant SN lead finish are required. |
| TLVH431ACLP | Adjustable 3-terminal shunt regulator (1.24 V), higher 80 μA min current, 0.2 Ω typical impedance, SOIC-8 package | Requires external resistors for 1.235 V setting; better for programmable references but adds layout complexity and component count | Choose TLVH431ACLP only if adjustable output or lower impedance is prioritized over simplicity and micropower operation. |
Compared with LM385LP-1-2, LM385LPE3-1-2 provides tighter initial tolerance and Pb-free finish; compared with TLVH431ACLP, it offers lower quiescent current and simpler two-terminal implementation at the cost of fixed output voltage.
Availability
LM385LPE3-1-2 is available at Aetrix Electronics and suitable for portable meter references, battery-operated systems, and current-loop instrumentation requiring stable component supply with guaranteed RoHS compliance and traceable sourcing.
Supply support for LM385LPE3-1-2 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 leadership in precision analog ICs and industrial-grade components.
The LM385 family was designed specifically for micropower, high-stability shunt voltage reference applications in portable, battery-constrained, and industrial instrumentation systems.
FAQ
What is the operating temperature range for LM385LPE3-1-2?
The LM385LPE3-1-2 is specified for operation from 0°C to 70°C ambient temperature. This range is confirmed in the Electrical Characteristics table and Package Option Addendum, where its ordering information explicitly lists "Op Temp (°C): 0 to 70". Operation outside this range may result in degraded voltage accuracy and increased drift beyond ±20 ppm/°C.
Does LM385LPE3-1-2 require an external capacitor for stability?
No, LM385LPE3-1-2 does not require an external capacitor for stability. Its internal frequency compensation ensures stable operation with any value of bypass capacitor on the cathode pin, including 0.1 µF ceramic types commonly used for noise reduction. This eliminates the need for series resistance or additional compensation networks in most applications.
What is the minimum cathode current needed for regulation in LM385LPE3-1-2?
The minimum cathode current required for proper regulation in LM385LPE3-1-2 is 15 μA, as specified in the Electrical Characteristics table under "Minimum reference current" for LM385-1.2 devices. Supplying less than this current will result in loss of regulation and significant deviation from the nominal 1.235 V output.
Is LM385LPE3-1-2 pin-compatible with LM285LPE3-1-2?
No, LM385LPE3-1-2 is not pin-compatible with LM285LPE3-1-2 because the latter does not exist in TI's official orderable addendum. LM285-1.2 variants use TO-92 (LP) packaging but are rated for –40°C to 85°C and have different electrical specs (e.g., 10 μA min current, ±20 ppm/°C, but wider initial tolerance). Physical pinout matches, but thermal and current specifications differ - direct substitution requires validation.
What does the "E3" suffix indicate in LM385LPE3-1-2?
The "E3" suffix in LM385LPE3-1-2 denotes a Pb-Free (RoHS-compliant) lead finish with Sn (tin) plating, as documented in TI's Package Option Addendum. It confirms compliance with EU RoHS Directive 2011/65/EU and specifies N/A for MSL rating due to the TO-92 package type, distinguishing it from leaded or green-process variants.
LM385LPE3-1-2 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA)
- Series:
- -
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Reference Type:
- Shunt
- Output Type:
- Fixed
- Voltage - Output (Min/Fixed):
- 1.235V
- Voltage - Output (Max):
- -
- Current - Output:
- 20 mA
- Tolerance:
- ±2%
- Temperature Coefficient:
- 20ppm/°C Typical
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- 60µVrms
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 15 µA
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-92-3
LM385LPE3-1-2 FAQ
1.How can I place an order for LM385LPE3-1-2 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM385LPE3-1-2 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 LM385LPE3-1-2 reliable?
The price and inventory of LM385LPE3-1-2 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM385LPE3-1-2 is usually 5 days.
3.What payment methods are accepted for LM385LPE3-1-2?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM385LPE3-1-2 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM385LPE3-1-2?
LM385LPE3-1-2 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM385LPE3-1-2 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 LM385LPE3-1-2?
For technical support, including LM385LPE3-1-2 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM385LPE3-1-2 requirements.
6.How does Aetrix verify that LM385LPE3-1-2 is sourced from the original manufacturer or authorized distributors?
All LM385LPE3-1-2 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 LM385LPE3-1-2 meets industry standards.
7.What is the process for return or replacement of LM385LPE3-1-2?
All LM385LPE3-1-2 units undergo pre-shipment inspection (PSI). If there is an issue with LM385LPE3-1-2, 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 LM385LPE3-1-2 part is unused and in its original packaging.
Return procedure for LM385LPE3-1-2:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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