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Texas Instruments LM385LPR-1-2
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- Part No.:
- LM385LPR-1-2
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Datasheet:
-
LM385LPR-1-2.pdf
- Description:
- IC VREF SHUNT 2% TO92-3
- Quantity:
- Payment:
- Shipping:
Inventory:5,151
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Product details
Overview
LM385LPR-1-2 from Texas Instruments is a micropower, two-terminal, band-gap voltage reference IC operating over 15 μA to 20 mA cathode current, delivering 1.235 V nominal output with ±20 ppm/°C temperature coefficient and 1.5 Ω max reference impedance across full temperature range. It serves as a precision shunt reference in portable test instruments, battery-operated systems, and panel meters.
For engineers reviewing the LM385LPR-1-2 datasheet, LM385LPR-1-2 pinout, LM385LPR-1-2 application, or LM385LPR-1-2 equivalent, key selection criteria include its TO-92 package, 0 °C to 70 °C operating range, 15 μA minimum cathode current, low-noise 60 μV broadband output, and compatibility with capacitive loads up to 10 μF without instability.
Technical Context
The LM385LPR-1-2 implements a floating shunt topology using band-gap core regulation with on-chip trimming for initial tolerance control. Its internal high-gain amplifier and shunt pass element maintain stable voltage between anode and cathode terminals under varying load conditions.
Frequency compensation ensures loop stability across all capacitor loads, enabling direct use with bypass capacitors up to 10 μF. The device operates exclusively in fixed-voltage reference mode with no adjustment capability, requiring ≥15 μA cathode current for regulation at 25 °C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Reference Voltage | 1.235 V - precise shunt voltage setpoint for analog signal conditioning and ADC/DAC biasing |
| Initial Tolerance | ±2% - tight factory-trimmed accuracy enables calibration-free designs in portable instrumentation |
| Tempco (αVZ) | ±20 ppm/°C - low drift supports stable operation across 0 °C to 70 °C industrial temperature range |
| Reference Impedance | 1.5 Ω max - low dynamic impedance minimizes output voltage variation under changing load current |
| Min Cathode Current | 15 μA - ultra-low startup current extends battery life in micropower applications |
| Broadband Noise | 60 μV - low noise floor preserves signal integrity in high-resolution measurement circuits |
| Operating Temperature | 0 °C to 70 °C - specified performance range for commercial-grade embedded systems |
Pinout & Package
LM385LPR-1-2 uses a TO-92 (LP) 3-pin through-hole package with 4.30 mm × 4.30 mm body size and formed leads. Pin 1 is Anode, Pin 2 is Cathode, and Pin 3 is No Connection (NC).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Pin 1) | Shunt current return path | Connected to system ground or negative rail; completes current loop for reference operation |
| Cathode (Pin 2) | Reference voltage output node | Source of regulated 1.235 V; requires external current source (≥15 μA) for proper regulation |
| NC (Pin 3) | No internal connection | Unused terminal; must remain unconnected to avoid parasitic coupling or mechanical stress |
Key Features
| Feature | Design Value |
|---|---|
| Capacitive Load Tolerance | Stable with up to 10 μF bypass capacitance - eliminates need for external isolation resistors in battery-powered designs |
| Micropower Operation | 15 μA minimum cathode current - enables multi-year battery life in portable meters and remote sensors |
| Low Output Noise | 60 μV RMS (10 Hz–10 kHz) - preserves SNR in precision analog front-ends and sensor interfaces |
| Long-Term Stability | ±20 ppm/khr - minimal aging drift ensures calibration retention over product lifetime |
| ESD Robustness | ±2000 V HBM - withstands handling in standard assembly environments without special precautions |
Applications
| Portable Meter References | Portable Test Instruments |
|---|---|
Use Scenario: Handheld digital multimeters requiring stable, low-power voltage reference for ADC scaling and offset correction. IC Role / Device Role / Timing Role: Shunt voltage reference providing 1.235 V reference for 16-bit sigma-delta ADC conversion. Use Value: Enables <1 LSB error over 0–70 °C range due to ±20 ppm/°C tempco and 60 μV noise floor. | Use Scenario: Battery-powered oscilloscope probes needing accurate DC bias point generation. IC Role / Device Role / Timing Role: Precision shunt reference establishing calibrated zero-volt baseline for differential input stages. Use Value: Delivers ±2% initial accuracy and <30 mV total voltage shift across full current range (15 μA–20 mA), ensuring probe linearity. |
| Battery-Operated Systems | Current-Loop Instrumentation |
Use Scenario: Wireless sensor nodes powered by coin-cell batteries requiring multi-year operational life. IC Role / Device Role / Timing Role: Micropower reference for low-dropout regulator feedback and sensor excitation circuitry. Use Value: Draws only 15 μA minimum current, reducing quiescent power by >50% versus legacy references, extending shelf-life-equivalent runtime. | Use Scenario: 4–20 mA transmitter modules where reference stability directly impacts loop accuracy. IC Role / Device Role / Timing Role: Two-terminal shunt reference setting precise current-sense threshold in op-amp-based transmitters. Use Value: 1.5 Ω max impedance prevents gain error under varying loop load, maintaining ±0.1% current accuracy across temperature. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM385BLPR-1-2 | 1% initial tolerance (vs. 2%), same TO-92 package and 0–70 °C range | Higher-accuracy requirement in calibration-critical portable instruments | Select when tighter initial accuracy justifies cost premium; identical pinout and layout |
| TLVH431ACLP | Adjustable 1.24 V reference, 3-pin SOT-23, 100 μA min cathode current | Designs requiring programmable reference voltage or surface-mount footprint | Choose for flexibility in reference voltage selection or PCB space constraints; not drop-in compatible |
Compared with LM385LPR-1-2, LM385BLPR-1-2 offers improved initial accuracy but identical thermal and noise performance, while TLVH431ACLP trades fixed 1.235 V stability for adjustability and higher minimum current, requiring redesign of bias networks and layout.
Availability
LM385LPR-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 long-term lifecycle support.
Supply support for LM385LPR-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 power management solutions.
The LM385 family was designed specifically for micropower, two-terminal shunt voltage reference applications in portable and battery-constrained systems, emphasizing low current consumption and capacitive load immunity.
FAQ
What is the operating temperature range for LM385LPR-1-2?
The LM385LPR-1-2 is specified for operation from 0 °C to 70 °C. This commercial-grade temperature range is confirmed in the Electrical Characteristics table and Recommended Operating Conditions section of the SLVS075J datasheet. Performance parameters including reference voltage, tempco, and impedance are guaranteed only within this interval. The device may function outside this range but without specification guarantees.
Does LM385LPR-1-2 require an external capacitor for stability?
No, the LM385LPR-1-2 does not require an external capacitor for stability. Its internal frequency compensation provides loop stability with capacitive loads up to 10 μF, as stated in the Feature Description and Application Information sections. A 0.1 μF ceramic bypass capacitor on the cathode is recommended for noise reduction but is not needed for basic regulation stability.
What is the minimum cathode current required for LM385LPR-1-2 regulation?
The LM385LPR-1-2 requires a minimum cathode current of 15 μA at 25 °C to achieve proper regulation, as specified in the Electrical Characteristics table under IZ(min). This value increases slightly across temperature but remains ≤15 μA over the full 0 °C to 70 °C range. Supplying less than this current results in unregulated output voltage.
Can LM385LPR-1-2 be used in series with other components to generate higher reference voltages?
No, the LM385LPR-1-2 is a fixed 1.235 V shunt reference and cannot be configured to generate higher voltages. Its two-terminal architecture lacks an adjustment pin or feedback node. To obtain higher reference voltages, discrete resistor dividers or dedicated adjustable references like TLVH431 must be used - but these introduce additional error sources and power overhead not present in the LM385LPR-1-2 design.
Is LM385LPR-1-2 RoHS compliant and lead-free?
Yes, LM385LPR-1-2 is RoHS compliant and lead-free. The Package Option Addendum confirms "Pb-Free (RoHS)" eco plan and "SN" (tin) lead finish. It meets current EU RoHS requirements for all 10 restricted substances, with homogeneous material concentrations below 0.1% by weight. This compliance is verified in TI's official packaging documentation dated February 2020.
LM385LPR-1-2 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- 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
LM385LPR-1-2 FAQ
1.How can I place an order for LM385LPR-1-2 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM385LPR-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 LM385LPR-1-2 reliable?
The price and inventory of LM385LPR-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 LM385LPR-1-2 is usually 5 days.
3.What payment methods are accepted for LM385LPR-1-2?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM385LPR-1-2 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM385LPR-1-2?
LM385LPR-1-2 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM385LPR-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 LM385LPR-1-2?
For technical support, including LM385LPR-1-2 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM385LPR-1-2 requirements.
6.How does Aetrix verify that LM385LPR-1-2 is sourced from the original manufacturer or authorized distributors?
All LM385LPR-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 LM385LPR-1-2 meets industry standards.
7.What is the process for return or replacement of LM385LPR-1-2?
All LM385LPR-1-2 units undergo pre-shipment inspection (PSI). If there is an issue with LM385LPR-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 LM385LPR-1-2 part is unused and in its original packaging.
Return procedure for LM385LPR-1-2:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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