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Texas Instruments LM385PWR-1-2
- Part No.:
- LM385PWR-1-2
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 8-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
LM385PWR-1-2.pdf
- Description:
- IC VREF SHUNT 2% 8TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,484
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Product details
Overview
LM385PWR-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 current-loop instrumentation.
For engineers reviewing the LM385PWR-1-2 datasheet, LM385PWR-1-2 pinout, LM385PWR-1-2 application, or LM385PWR-1-2 equivalent, key selection criteria include initial voltage tolerance (2%), low-noise operation (60 μV broadband), capacitive-load tolerance, long-term stability (±20 ppm/khr), and TSSOP-8 packaging for space-constrained analog designs.
Technical Context
The LM385PWR-1-2 implements a floating shunt topology with internal band-gap core and high-gain amplifier driving a shunt pass element, enabling stable regulation without external components. Its on-chip frequency compensation ensures stability with any capacitive load, including 0.1 μF ceramic bypass capacitors directly at the cathode node.
It operates exclusively in fixed-voltage reference mode with no adjustability; regulation requires sourcing ≥15 μA into the cathode terminal across 0°C to 70°C ambient, while maintaining reverse voltage compliance within absolute maximum ratings (30 mA IR, 150°C TJ).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Reference Voltage | 1.235 V at 25°C - defines precise bias point for ADC references and sensor excitation circuits |
| Initial Voltage Tolerance | ±2% - enables use without post-manufacturing calibration in cost-sensitive portable meters |
| Tempco (αVZ) | ±20 ppm/°C - ensures ≤0.15 mV drift over 0–70°C, critical for thermocouple cold-junction compensation |
| Reference Impedance | 1.5 Ω max over full temp range - minimizes load-induced error in precision current-sensing applications |
| Broadband Noise | 60 μV RMS (10 Hz–10 kHz) - supports low-noise signal conditioning without additional filtering |
| Min Cathode Current | 15 μA - allows ultra-low-power operation in energy-harvesting or shelf-life-critical battery systems |
| Long-Term Stability | ±20 ppm/khr - guarantees <0.2% output shift over 10 years, suitable for unattended field instrumentation |
Pinout & Package
TSSOP-8 package (3.00 mm × 4.40 mm, 1.2 mm max height), RoHS-compliant, green finish, moisture sensitivity level 1 (260°C peak reflow).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (Pin 1) | Shunt current input / voltage reference output | Current must be sourced into this pin to establish regulated 1.235 V between cathode and anode; connects to system ground or negative rail in floating configurations |
| Anode (Pin 8) | Common return / reference reference point | Typically connected to ground; voltage at cathode is referenced to this node; forms two-terminal shunt configuration |
| NC (Pins 2–7) | No internal connection | Unused pins; must remain unconnected per TI specification-no tie-to-ground or routing required |
Key Features
| Feature | Design Value |
|---|---|
| Capacitive-load immunity | Stable with ≥0.1 μF ceramic capacitor at cathode-eliminates need for series resistance or complex compensation networks |
| Low-power operation | 15 μA minimum cathode current enables >10-year battery life in portable test equipment using coin cells |
| Band-gap core architecture | Delivers low noise (60 μV) and long-term stability (±20 ppm/khr)-critical for metrology-grade analog front-ends |
| Wide dynamic current range | Operates from 15 μA to 20 mA-replaces legacy references while supporting both micropower and higher-current regulator feedback paths |
| Interchangeability | Pin- and function-compatible with LM285-1.2 and LM385-1.2-enables drop-in upgrade to tighter tolerance and improved tempco |
Applications
| Portable Test Instruments | Battery-Operated Systems |
|---|---|
Use Scenario: Handheld multimeters and calibrators requiring stable, low-drift reference for ADC conversion and display scaling. IC Role / Device Role / Timing Role: Two-terminal shunt voltage reference establishing 1.235 V reference for 16-bit SAR ADCs and digital display drivers. Use Value: ±2% initial tolerance and ±20 ppm/°C tempco ensure measurement accuracy remains within Class II specifications across operating temperature range. | Use Scenario: Wireless sensor nodes powered by CR2032 coin cells needing multi-year operational life without recalibration. IC Role / Device Role / Timing Role: Micropower shunt reference providing precision bias for op-amps and transducer interfaces in ultra-low-quiescent-current designs. Use Value: 15 μA minimum cathode current enables >10-year shelf-life-equivalent runtime; long-term stability prevents field drift-induced maintenance cycles. |
| Current-Loop Instrumentation | Thermocouple Cold-Junction Compensation |
Use Scenario: 4–20 mA transmitter modules where reference voltage sets loop current scaling and zero-point calibration. IC Role / Device Role / Timing Role: Precision shunt reference generating stable 1.235 V for DAC-based current-setting circuitry in industrial transmitters. Use Value: 1.5 Ω max reference impedance ensures <0.03% gain error contribution even under varying load conditions across temperature. | Use Scenario: Industrial temperature controllers using Type K thermocouples requiring accurate cold-junction compensation at sensor interface PCBs. IC Role / Device Role / Timing Role: Fixed-voltage reference feeding precision op-amp circuit that measures thermistor voltage to compute ambient temperature. Use Value: ±20 ppm/°C tempco matches thermistor characteristics, reducing cold-junction error to <0.5°C over 0–70°C ambient range. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM385BDR-1-2 | SOIC-8 package; same 1.235 V nominal, ±1% initial tolerance (tighter), identical tempco and noise specs | Requires larger PCB area; better suited for prototyping or non-space-constrained industrial control boards | Select when tighter initial tolerance is required and TSSOP assembly capability is unavailable |
| REF3012AIDBZR | 1.2 V output, ±0.2% initial tolerance, 50 ppm/°C tempco, 3.3 μA quiescent current, SOT23-3 package | Lower power but higher tempco; not interchangeable due to different pinout and topology (series vs shunt) | Select only for new designs prioritizing ultra-low IQ over long-term stability and noise performance |
Compared with LM385BDR-1-2, LM385PWR-1-2 trades ±1% tolerance for space savings and thermal performance in TSSOP; versus REF3012AIDBZR, it delivers superior tempco and noise at higher minimum current, making it optimal for precision analog systems where board area and long-term drift are primary constraints.
Availability
LM385PWR-1-2 is available at Aetrix Electronics and suitable for portable test instruments, battery-operated systems, and current-loop instrumentation requiring stable component supply with guaranteed long-term availability and consistent parametric performance.
Supply support for LM385PWR-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 LMx85-1.2 family was designed specifically for micropower, high-stability shunt voltage reference applications in portable, battery-powered, and industrial instrumentation systems where size, drift, and noise are critical.
FAQ
What is the operating temperature range for the LM385PWR-1-2?
The LM385PWR-1-2 is specified for operation from 0°C to 70°C ambient temperature. This range is confirmed in the Recommended Operating Conditions table of the SLVS075J datasheet and applies to all electrical characteristics including reference voltage, tempco, and impedance. Operation outside this range may result in parametric degradation or failure.
Does the LM385PWR-1-2 require external capacitors for stability?
No, the LM385PWR-1-2 does not require external capacitors for stability due to its internally compensated floating shunt architecture. However, TI recommends placing a 0.1 μF low-ESR ceramic capacitor directly at the cathode pin to reduce broadband noise and improve transient response-this is a design best practice, not a stability requirement.
Can the LM385PWR-1-2 be used in series (non-shunt) configurations?
No, the LM385PWR-1-2 is strictly a two-terminal shunt voltage reference and cannot operate in series (three-terminal) mode. Its pinout contains only Cathode and Anode terminals plus NC pins; there is no separate input, output, or ground pin required for series regulator topologies. Attempting series use will result in improper regulation or device damage.
What is the maximum cathode current rating for the LM385PWR-1-2?
The absolute maximum cathode current for the LM385PWR-1-2 is 30 mA, as defined in the Absolute Maximum Ratings table of the SLVS075J datasheet. Exceeding this value-even briefly-risks permanent damage. For reliable operation, cathode current should be maintained between 15 μA and 20 mA per Recommended Operating Conditions.
Is the LM385PWR-1-2 pin-compatible with the LM285-1.2 in TSSOP-8?
No-LM285-1.2 is not offered in TSSOP-8. The LM285-1.2 is available only in SOIC-8 and TO-92 packages. While LM385PWR-1-2 shares functional equivalence and pinout compatibility with LM385-1.2 variants in TSSOP-8, it is not a direct pin-for-pin replacement for LM285-1.2 due to differing package offerings and temperature range (LM285-1.2: –40°C to 85°C vs. LM385PWR-1-2: 0°C to 70°C).
LM385PWR-1-2 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- 8-TSSOP (0.173", 4.40mm Width)
- 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:
- Surface Mount
- Supplier Device Package:
- 8-TSSOP
LM385PWR-1-2 FAQ
1.How can I place an order for LM385PWR-1-2 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM385PWR-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 LM385PWR-1-2 reliable?
The price and inventory of LM385PWR-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 LM385PWR-1-2 is usually 5 days.
3.What payment methods are accepted for LM385PWR-1-2?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM385PWR-1-2 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM385PWR-1-2?
LM385PWR-1-2 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM385PWR-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 LM385PWR-1-2?
For technical support, including LM385PWR-1-2 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM385PWR-1-2 requirements.
6.How does Aetrix verify that LM385PWR-1-2 is sourced from the original manufacturer or authorized distributors?
All LM385PWR-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 LM385PWR-1-2 meets industry standards.
7.What is the process for return or replacement of LM385PWR-1-2?
All LM385PWR-1-2 units undergo pre-shipment inspection (PSI). If there is an issue with LM385PWR-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 LM385PWR-1-2 part is unused and in its original packaging.
Return procedure for LM385PWR-1-2:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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