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Texas Instruments LM385BPWR-1-2
- Part No.:
- LM385BPWR-1-2
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 8-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
LM385BPWR-1-2.pdf
- Description:
- IC VREF SHUNT 1% 8TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,000
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Product details
Overview
LM385BPWR-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 (0°C to 70°C). It enables precision low-power analog circuitry in portable instrumentation and battery-operated systems.
For engineers reviewing the LM385BPWR-1-2 datasheet, LM385BPWR-1-2 pinout, LM385BPWR-1-2 application, or LM385BPWR-1-2 equivalent, key selection criteria include initial tolerance (1.223–1.247 V at 25°C), long-term stability (±20 ppm/khr), broadband noise (60 μV, 10 Hz–10 kHz), capacitive load tolerance, and TSSOP-8 package compatibility with space-constrained PCB layouts.
Technical Context
The LM385BPWR-1-2 implements a floating shunt topology using band-gap core regulation with on-chip trimming for tight initial accuracy. Its internal high-gain amplifier and shunt pass element maintain stable cathode-to-anode voltage independent of supply variations, requiring only minimum cathode current (15 μA) to initiate regulation.
Designed for capacitive loading resilience, it features internal frequency compensation enabling stable operation with bypass capacitors up to 10 μF. The device operates exclusively in fixed-voltage reference mode-no external adjustment or feedback is supported-and exhibits low-noise performance critical for precision ADC references and sensor signal conditioning.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 1.235 V nominal at 25°C; actual range 1.223–1.247 V ensures ≤1% initial error in precision analog circuits |
| Tempco | ±20 ppm/°C over 0°C–70°C; guarantees <±1.4 mV drift across full operating range for stable calibration |
| Ref Impedance | 1.5 Ω max over full temperature range; minimizes load-induced voltage error in varying-current applications |
| Operating Current | 15 μA to 20 mA cathode current; supports ultra-low-power sleep modes and high-current transient loads |
| Noise (10 Hz–10 kHz) | 60 μV RMS; enables use in 12-bit+ data acquisition without added filtering overhead |
| Long-Term Stability | ±20 ppm/khr at 100 μA; ensures <±0.1% output drift over 1000 hours for mission-critical references |
| Min Cathode Current | 15 μA; defines lowest power state before regulation loss-critical for battery life optimization |
Pinout & Package
TSSOP-8 package (3.00 mm × 4.40 mm, 1.2 mm max height), RoHS-compliant, moisture sensitivity level 1 (260°C peak reflow).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (Pin 1) | Shunt current/voltage input | Current-sink node where regulated 1.235 V appears relative to anode; must be driven by current source or resistor |
| Anode (Pin 6) | Common reference ground | Return path for cathode current; connects to system ground or negative rail in floating configurations |
| NC (Pins 2, 3, 4, 5, 7, 8) | No internal connection | Unused pins-must remain unconnected; no electrical function or thermal benefit from routing |
Key Features
| Feature | Design Value |
|---|---|
| Capacitive load immunity | Stable with ≥10 µF ceramic bypass-eliminates need for external compensation in portable meter designs |
| Low dynamic impedance | 1.5 Ω max over full temp range-reduces output voltage sag during fast load transients in current-loop transmitters |
| Micropower operation | 15 µA min cathode current-enables >10-year battery life in remote sensor nodes powered by coin cells |
| Band-gap core architecture | 60 µV broadband noise (10 Hz–10 kHz)-supports high-resolution ADCs without post-regulation filtering |
| On-chip trimming | 1.223–1.247 V tolerance at 25°C-reduces calibration steps in production test for panel meters and portable test gear |
Applications
| Portable Meter References | Portable Test Instruments |
|---|---|
Use Scenario: Handheld digital multimeters requiring stable 1.2 V reference for ADC scaling and auto-zero functions. IC Role / Device Role / Timing Role: Two-terminal shunt voltage reference providing precise, low-drift reference voltage for 16-bit sigma-delta ADC front-end. Use Value: Enables ±0.05% measurement accuracy over 0–50°C ambient with no warm-up delay or recalibration. |
Use Scenario: Battery-powered oscilloscope probes with integrated signal conditioning and offset correction. IC Role / Device Role / Timing Role: Fixed-voltage reference for op-amp biasing and DAC output scaling in compact probe electronics. Use Value: Delivers stable reference under variable load conditions while consuming <15 µA in standby-extending probe runtime per charge. |
| Battery-Operated Systems | Current-Loop Instrumentation |
Use Scenario: Wireless environmental sensors (temperature/humidity) transmitting via LoRaWAN with 10-year battery target. IC Role / Device Role / Timing Role: Precision reference for analog sensor excitation and ADC conversion in ultra-low-power microcontroller subsystems. Use Value: Maintains <±0.1% reference accuracy across -20°C to 60°C and 10-year shelf life-directly enabling long-term calibration validity. |
Use Scenario: 4–20 mA industrial transmitters converting RTD or thermocouple signals in hazardous locations. IC Role / Device Role / Timing Role: Stable shunt reference for current-sense amplifier gain setting and loop power monitoring circuitry. Use Value: 1.5 Ω impedance and ±20 ppm/°C tempco ensure <0.1% full-scale error across -40°C to 85°C ambient extremes. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM385BDR-1-2 | SOIC-8 package; identical electrical specs but larger footprint (4.90 × 3.91 mm vs. 3.00 × 4.40 mm) | Suitable for board space-constrained designs where TSSOP-8 reflow compatibility is required | Select LM385BPWR-1-2 when PCB real estate is limited or high-density layout demands finer pitch |
| REF3012AIDBZR | 1.2 V output, 50 ppm/°C tempco, 3.5 µA quiescent current, SOT23-3 package | Better tempco and lower IQ, but higher cost and different pinout-requires layout revision | Choose REF3012AIDBZR only if ±50 ppm/°C is insufficient and design allows SOT23-3 footprint change |
Compared with LM385BDR-1-2, LM385BPWR-1-2 saves 38% board area while maintaining identical reference performance; versus REF3012AIDBZR, it trades higher tempco for proven reliability, lower cost, and direct drop-in replacement in legacy TSSOP-8 footprints.
Availability
LM385BPWR-1-2 is available at Aetrix Electronics and suitable for portable meter references, battery-operated systems, and current-loop instrumentation requiring stable component supply across extended product lifecycles.
Supply support for LM385BPWR-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 decades of leadership in precision analog ICs and voltage references.
The LM385B series was designed specifically for micropower, high-stability voltage referencing in portable and industrial instrumentation-emphasizing low noise, capacitive load tolerance, and long-term drift control.
FAQ
What is the minimum cathode current required for regulation in the LM385BPWR-1-2?
The LM385BPWR-1-2 requires a minimum cathode current of 15 μA to establish and maintain regulation. Below this threshold, output voltage deviates from the specified 1.223–1.247 V range. This value is confirmed in the Electrical Characteristics table under "Minimum reference current" for LM385B-1.2 at full temperature range, and applies identically to the LM385BPWR-1-2 variant.
Does the LM385BPWR-1-2 support adjustable output voltage?
No, the LM385BPWR-1-2 operates exclusively as a fixed 1.235 V shunt reference and does not support external adjustment. Its two-terminal architecture lacks feedback or trim pins; regulation is achieved solely by sourcing current into the cathode and returning it through the anode. Any attempt to modify output voltage externally will disrupt regulation and violate recommended operating conditions.
Can the LM385BPWR-1-2 drive a 10 µF ceramic capacitor directly?
Yes, the LM385BPWR-1-2 is explicitly designed for capacitive load immunity and remains stable with ≥10 µF ceramic bypass capacitors on the cathode node. This capability is enabled by internal frequency compensation and is validated in the datasheet's Layout Guidelines and Typical Characteristics section-making it ideal for portable meters and battery-powered systems requiring robust decoupling without external components.
What is the maximum operating temperature range for the LM385BPWR-1-2?
The LM385BPWR-1-2 is rated for operation from 0°C to 70°C ambient temperature, as specified in the Recommended Operating Conditions table for LM385B-1.2 devices. This range is narrower than the LM285-1.2 (−40°C to 85°C) but sufficient for commercial-grade portable instrumentation and indoor industrial applications where thermal extremes are controlled.
How does the LM385BPWR-1-2 compare to the LM385-1.2 in terms of initial voltage tolerance?
The LM385BPWR-1-2 belongs to the LM385B-1.2 family and offers tighter initial voltage tolerance than standard LM385-1.2: 1.223–1.247 V (±1%) at 25°C versus 1.21–1.26 V (±2%). This improvement results from enhanced on-chip trimming and is documented in the Electrical Characteristics table-directly benefiting applications requiring higher absolute accuracy without post-production calibration.
LM385BPWR-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:
- ±1%
- 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
LM385BPWR-1-2 FAQ
1.How can I place an order for LM385BPWR-1-2 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM385BPWR-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 LM385BPWR-1-2 reliable?
The price and inventory of LM385BPWR-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 LM385BPWR-1-2 is usually 5 days.
3.What payment methods are accepted for LM385BPWR-1-2?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM385BPWR-1-2 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM385BPWR-1-2?
LM385BPWR-1-2 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM385BPWR-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 LM385BPWR-1-2?
For technical support, including LM385BPWR-1-2 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM385BPWR-1-2 requirements.
6.How does Aetrix verify that LM385BPWR-1-2 is sourced from the original manufacturer or authorized distributors?
All LM385BPWR-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 LM385BPWR-1-2 meets industry standards.
7.What is the process for return or replacement of LM385BPWR-1-2?
All LM385BPWR-1-2 units undergo pre-shipment inspection (PSI). If there is an issue with LM385BPWR-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 LM385BPWR-1-2 part is unused and in its original packaging.
Return procedure for LM385BPWR-1-2:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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