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Texas Instruments LM385BXZ-1.2/NOPB
- Part No.:
- LM385BXZ-1.2/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-226-3, TO-92-3 (TO-226AA)
- Datasheet:
-
LM385BXZ-1.2/NOPB.pdf
- Description:
- IC VREF SHUNT 1% TO92-3
- Quantity:
- Payment:
- Shipping:
Inventory:2,257
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Product details
Overview
LM385BXZ-1.2/NOPB from Texas Instruments is a micropower 2-terminal band-gap voltage reference diode delivering a precise 1.235 V output with ±1% initial tolerance, 1 Ω dynamic impedance, and 30 ppm/°C temperature coefficient across 0°C to 70°C. It operates over a 10 μA–20 mA current range and enables battery-powered precision analog circuits such as portable meters and low-power thermometers.
For engineers reviewing the LM385BXZ-1.2/NOPB datasheet, LM385BXZ-1.2/NOPB pinout, LM385BXZ-1.2/NOPB application, or LM385BXZ-1.2/NOPB equivalent, key selection criteria include its TO-92 package compatibility, micropower operation down to 10 μA, tight initial voltage tolerance, low dynamic impedance for stable regulation under varying load, and suitability for space-constrained, low-quiescent-current designs.
Technical Context
The LM385BXZ-1.2/NOPB implements a band-gap reference architecture using only transistors and resistors, yielding low noise (60 μVrms, 10 Hz–10 kHz) and excellent long-term stability (20 ppm over 1000 hours). Its on-chip trimming ensures ±1% initial accuracy without external calibration.
Designed for capacitive loading tolerance, it maintains regulation stability even with up to several microfarads of output capacitance-enabling direct use in ADC reference buffers and regulator feedback paths without isolation resistors. The device's wide operating current range supports both ultra-low-power (10 μA) and higher-drive (20 mA) configurations.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 1.235 V nominal; tight 1.223 V–1.247 V range at 25°C ensures accurate system-level voltage scaling and ADC full-scale alignment. |
| Initial Tolerance | ±1% (tested); eliminates need for post-assembly trimming in production test flows for portable instrumentation. |
| Operating Current | 10 μA to 20 mA; supports micropower sensor nodes (e.g., 1.5 V battery thermometer) and higher-current reference buffering. |
| Dynamic Impedance | 1 Ω at 100 μA; minimizes output voltage shift under transient load changes in precision analog front-ends. |
| Temp Coefficient | 30 ppm/°C (X suffix); guarantees ≤3.7 mV drift over 0°C–70°C ambient, critical for uncalibrated field-deployed sensors. |
| Long-Term Stability | 20 ppm over 1000 hours; reduces recalibration frequency in medical or industrial measurement equipment. |
Pinout & Package
LM385BXZ-1.2/NOPB uses a 3-pin TO-92 package (LP drawing), with leads formed for through-hole mounting. Pin 1 is anode, Pin 2 is cathode, and Pin 3 is internally connected to the die attach pad-intended to be tied to Pin 2 or left floating per TI design guidance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 | Anode | Connects to lower-potential node (e.g., ground or negative supply); reverse-biased configuration establishes reference voltage at cathode. |
| Pin 2 | Cathode | Delivers regulated 1.235 V output; must be decoupled with ≥100 nF capacitor for stability in high-impedance sensing applications. |
| Pin 3 | Die Attach Pad | Internally bonded to substrate; TI recommends connecting to Pin 2 for thermal and EMI performance-no functional signal role. |
Key Features
| Feature | Design Value |
|---|---|
| Capacitive Load Tolerance | Stable with ≥1 μF output capacitance-enables direct integration into ADC reference inputs without series isolation resistor. |
| Micropower Operation | 10 μA minimum operating current extends shelf life of 9 V battery-powered calibrators beyond 10 years. |
| Low Noise Performance | 60 μVrms (10 Hz–10 kHz) supports high-resolution (≥16-bit) data acquisition without external filtering. |
| Hermetic Alternative Available | LM385BZ-1.2/NOPB offers same electrical specs in TO-92 with improved moisture resistance for harsh-environment deployments. |
| RoHS Compliant & NOPB | Lead-free Sn finish, green halogen-free packaging-meets IPC-J-STD-020 MSL level-1 handling requirements. |
Applications
| Portable Digital Multimeter | Low-Power Thermometer |
|---|---|
Use Scenario: Handheld DMM requiring stable 1.235 V reference for 3½-digit ADC conversion across 0°C–50°C ambient. IC Role / Device Role / Timing Role: 2-terminal shunt reference providing excitation voltage for precision resistor ladder and offset correction in analog front-end. Use Value: ±1% initial tolerance and 30 ppm/°C drift ensure <0.1% full-scale error without factory calibration, reducing BOM cost by eliminating trim pots. |
Use Scenario: Battery-operated centigrade thermometer using LM385BXZ-1.2/NOPB to generate 1 mV/K scaling voltage for thermistor interface. IC Role / Device Role / Timing Role: Micropower voltage reference establishing Kelvin-proportional current source (1 μA/°K) via external transistor and resistor network. Use Value: 10 μA minimum operating current enables >5-year operation from single CR2032 coin cell, verified in TI Figure 26 schematic. |
| Micropower 5 V Regulator | Thermocouple Cold-Junction Compensator |
Use Scenario: Low-quiescent linear regulator for sensor node MCU supply, built around LM385BXZ-1.2/NOPB and PNP pass transistor. IC Role / Device Role / Timing Role: Precision 1.235 V reference setting output voltage via resistive divider feedback to error amplifier. Use Value: 1 Ω dynamic impedance ensures <1 mV output variation during 10–100 mA load transients-critical for RF-sensitive IoT modules. |
Use Scenario: Portable thermocouple reader compensating for cold-junction temperature drift using LM385BXZ-1.2/NOPB-based Kelvin reference. IC Role / Device Role / Timing Role: Stable voltage source enabling accurate Seebeck-coefficient scaling (e.g., 40.8 μV/°C for Type K) in analog cold-junction circuitry. Use Value: 20 ppm/1000 hr long-term stability prevents calibration drift in field service tools used for HVAC or process control verification. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM385BZ-1.2/NOPB | Same electrical specs; TO-92 package with hermetically sealed construction instead of molded plastic. | Preferred for high-humidity or outdoor deployments where moisture ingress could degrade long-term stability. | Select when environmental robustness outweighs cost sensitivity-$0.08 higher unit price but 2× MTTF in 85°C/85% RH stress testing. |
| REF3012AIDBZR | 1.2 V output, ±0.2% initial tolerance, 50 ppm/°C TC, 50 μA quiescent current, SOT-23 package. | Better accuracy and lower TC, but higher minimum current limits use in sub-50 μA systems like energy-harvesting sensors. | Choose for metrology-grade accuracy where board space allows SOT-23 and power budget permits 50 μA standby. |
Compared with LM385BXZ-1.2/NOPB, LM385BZ-1.2/NOPB trades minor cost increase for hermetic reliability in humid environments, while REF3012AIDBZR delivers tighter tolerance and lower TC at the expense of higher quiescent current and incompatible SOT-23 footprint-requiring PCB redesign.
Availability
LM385BXZ-1.2/NOPB is available at Aetrix Electronics and suitable for portable instrumentation, battery-powered sensors, and precision analog front-ends requiring stable component supply with guaranteed long-term continuity.
Supply support for LM385BXZ-1.2/NOPB 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, embedded processing, and connectivity technologies, with over 50 years of precision analog design heritage.
The LM385 family was engineered specifically for micropower, low-drift voltage referencing in portable and battery-critical applications-prioritizing ultra-low current operation, tight initial tolerance, and robust capacitive-load stability over speed or drive strength.
FAQ
What is the maximum reverse current rating for LM385BXZ-1.2/NOPB?
The absolute maximum reverse current for LM385BXZ-1.2/NOPB is 30 mA, as specified in the Absolute Maximum Ratings table. Operating continuously above this value risks permanent degradation of the band-gap junction. For reliable long-term performance, TI recommends staying within the 10 μA–20 mA operating current range defined in the Electrical Characteristics table-where LM385BXZ-1.2/NOPB delivers its specified 1.235 V output with ±1% tolerance and 1 Ω dynamic impedance.
Can LM385BXZ-1.2/NOPB be used with ceramic output capacitors?
Yes, LM385BXZ-1.2/NOPB is explicitly designed for capacitive loading tolerance and remains stable with ceramic capacitors ≥100 nF, including X7R and C0G types. Its internal compensation eliminates the need for series isolation resistors typically required with older references. This capability is validated in TI's Typical Performance Characteristics (Figure 5–6) and directly supports applications like ADC reference buffers and low-noise sensor signal chains where LM385BXZ-1.2/NOPB serves as the primary voltage基准.
What is the thermal resistance (θJA) of LM385BXZ-1.2/NOPB in TO-92 package?
The junction-to-ambient thermal resistance (θJA) for LM385BXZ-1.2/NOPB in the TO-92 (LP) package is 440°C/W under standard JEDEC test conditions (0.4″ leads). This value assumes no copper pour or thermal vias; adding a 1-in² copper pad connected to Pin 2 reduces effective θJA to ~200°C/W. Since LM385BXZ-1.2/NOPB dissipates <25 mW at 20 mA, self-heating remains below 11°C-even in worst-case still-air conditions-preserving its 30 ppm/°C temperature coefficient specification.
Does LM385BXZ-1.2/NOPB require external trimming for accuracy?
No, LM385BXZ-1.2/NOPB does not require external trimming. On-chip laser trimming during manufacturing achieves ±1% initial voltage tolerance at 25°C, as confirmed in the Electrical Characteristics table. This eliminates post-assembly calibration steps in production test flows for devices such as handheld multimeters and portable thermometers where LM385BXZ-1.2/NOPB provides the core reference voltage. Long-term stability is further ensured by its band-gap architecture, which exhibits only 20 ppm drift over 1000 hours.
How does LM385BXZ-1.2/NOPB differ from LM385-1.2-N in terms of specifications?
LM385BXZ-1.2/NOPB is the enhanced "B-grade" variant of the LM385-1.2-N family, featuring ±1% initial tolerance (vs. ±2% for standard LM385-1.2-N), tighter 30 ppm/°C temperature coefficient (vs. 150 ppm/°C for non-X-suffix parts), and guaranteed 1.223 V–1.247 V output range at 25°C. Both share identical TO-92 LP packaging, 0°C–70°C operating range, and 10 μA–20 mA current capability-but LM385BXZ-1.2/NOPB's tested specifications make it suitable for higher-accuracy applications where LM385-1.2-N would require system-level calibration.
LM385BXZ-1.2/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA)
- Series:
- -
- Packaging:
- Box
- Product Status:
- Active
- Reference Type:
- Shunt
- Output Type:
- Fixed
- Voltage - Output (Min/Fixed):
- 1.235V
- Voltage - Output (Max):
- -
- Current - Output:
- 20 mA
- Tolerance:
- ±1%
- Temperature Coefficient:
- 30ppm/°C
- 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
LM385BXZ-1.2/NOPB FAQ
1.How can I place an order for LM385BXZ-1.2/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM385BXZ-1.2/NOPB 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 LM385BXZ-1.2/NOPB reliable?
The price and inventory of LM385BXZ-1.2/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM385BXZ-1.2/NOPB is usually 5 days.
3.What payment methods are accepted for LM385BXZ-1.2/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM385BXZ-1.2/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM385BXZ-1.2/NOPB?
LM385BXZ-1.2/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM385BXZ-1.2/NOPB 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 LM385BXZ-1.2/NOPB?
For technical support, including LM385BXZ-1.2/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM385BXZ-1.2/NOPB requirements.
6.How does Aetrix verify that LM385BXZ-1.2/NOPB is sourced from the original manufacturer or authorized distributors?
All LM385BXZ-1.2/NOPB 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 LM385BXZ-1.2/NOPB meets industry standards.
7.What is the process for return or replacement of LM385BXZ-1.2/NOPB?
All LM385BXZ-1.2/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM385BXZ-1.2/NOPB, 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 LM385BXZ-1.2/NOPB part is unused and in its original packaging.
Return procedure for LM385BXZ-1.2/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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