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Texas Instruments LM385BDRG4-1-2
- Part No.:
- LM385BDRG4-1-2
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LM385BDRG4-1-2.pdf
- Description:
- IC VREF SHUNT 1% 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,500
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Product details
Overview
LM385BDRG4-1-2 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 serves as a precision shunt reference in portable test instruments, battery-operated systems, and current-loop instrumentation.
For engineers reviewing the LM385BDRG4-1-2 datasheet, LM385BDRG4-1-2 pinout, LM385BDRG4-1-2 application, or LM385BDRG4-1-2 equivalent, key selection criteria include initial voltage tolerance (±1%), long-term stability (±20 ppm/khr), low-noise operation (60 µV broadband), capacitive-load tolerance, and SOIC-8 packaging for surface-mount reliability in space-constrained analog designs.
Technical Context
The LM385BDRG4-1-2 implements a floating shunt topology with internal band-gap core and high-gain amplifier driving a shunt pass element, enabling stable regulation without external compensation. Its design supports both positive and negative regulation configurations via cathode-to-anode voltage reference placement.
It operates exclusively in fixed-voltage reference mode with no adjustment capability, requiring minimum cathode current (IZ,min = 15 μA) to activate internal regulation. Internal frequency compensation ensures stability under all capacitor loads, eliminating need for external phase compensation networks.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 1.235 V nominal at 25°C; tight 1% initial tolerance enables direct use in 12-bit ADC references without trimming. |
| Temperature Coefficient | ±20 ppm/°C over 0°C–70°C; ensures ≤2.5 mV drift across industrial ambient range. |
| Reference Impedance | 1.5 Ω max over full temperature range; maintains regulation accuracy under dynamic load transients. |
| Operating Current Range | 15 μA to 20 mA cathode current; supports ultra-low-power sleep modes and high-current precision sensing. |
| Broadband Noise | 60 μV RMS (10 Hz–10 kHz); suitable for high-resolution measurement front-ends without added filtering. |
| Long-Term Stability | ±20 ppm/khr at 25°C; guarantees <0.1% output drift over 10 years in sealed portable equipment. |
Pinout & Package
LM385BDRG4-1-2 is housed in an SOIC-8 package (4.90 mm × 3.91 mm body, 1.75 mm max height), RoHS-compliant with NiPdAu lead finish and moisture sensitivity level (MSL) 1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (Pin 2) | Shunt current/voltage input | Current-sink node where regulated 1.235 V appears relative to anode; requires external current source for operation. |
| Anode (Pin 1) | Common reference node | Typically connected to system ground; defines return path for cathode current and sets reference potential. |
| NC (Pins 3, 4, 5, 6, 7) | No internal connection | Unused pins; must remain unconnected per TI specification to avoid parasitic coupling or thermal imbalance. |
Key Features
| Feature | Design Value |
|---|---|
| Capacitive-load immunity | Stable with any value of bypass capacitor on cathode; eliminates need for series resistance or damping networks. |
| Low-power operation | 15 μA minimum operating current extends battery life in portable meters beyond shelf-life limits. |
| Tight initial tolerance | 1% factory-trimmed voltage accuracy reduces calibration overhead in production test fixtures. |
| Interchangeability | PIN-compatible with LM285-1.2 and LM385-1.2 in SOIC-8 footprint, enabling drop-in upgrades in legacy designs. |
Applications
| Portable Test Instruments | Battery-Operated Systems |
|---|---|
Use Scenario: Handheld multimeters and calibrators requiring stable, low-drift reference during intermittent use over multi-year field deployment. IC Role / Device Role / Timing Role: Shunt voltage reference establishing precise 1.235 V基准 for ADC conversion and analog front-end scaling. Use Value: ±20 ppm/°C TC and ±20 ppm/khr long-term stability ensure measurement accuracy remains within spec without recalibration. | Use Scenario: Wireless sensor nodes powered by coin-cell batteries with multi-year operational lifetime requirements. IC Role / Device Role / Timing Role: Micropower reference supplying excitation voltage to precision resistive sensors and biasing low-power op-amps. Use Value: 15 μA minimum current enables operation in deep-sleep states while maintaining reference integrity for wake-up measurements. |
| Current-Loop Instrumentation | Panel Meters |
Use Scenario: 4–20 mA transmitter modules in industrial process control where loop-powered operation demands minimal quiescent draw. IC Role / Device Role / Timing Role: Precision shunt reference setting current-sense threshold and DAC reference in loop driver circuitry. Use Value: 1.5 Ω max impedance ensures stable regulation despite supply rail variations caused by loop impedance changes. | Use Scenario: DIN-rail mounted digital panel meters used in energy monitoring and HVAC control panels with wide ambient temperature swings. IC Role / Device Role / Timing Role: Fixed-voltage reference for analog-to-digital conversion of scaled AC/DC input signals. Use Value: 0°C to 70°C operating range and ±20 ppm/°C TC guarantee consistent display accuracy across facility environments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM385DR-1-2 | 2% initial tolerance (vs. 1% for LM385BDRG4-1-2); same SOIC-8 package and 0°C–70°C temp range. | Suitable for cost-sensitive applications where ±2% reference error is acceptable in 8-bit systems. | Select when budget constraints outweigh need for 12-bit+ accuracy; identical layout and drive requirements. |
| TLVH431ACDBVR | Adjustable 1.24 V reference (2.5 V max), 2% tolerance, 0.3 Ω typical impedance, 80 µV noise, SOT-23-5 package. | Requires external resistor network for 1.235 V setup; not pin-compatible; better for space-constrained PCBs. | Choose for ultra-small footprint and lower impedance where adjustable configuration is acceptable and board area is critical. |
Compared with LM385DR-1-2, LM385BDRG4-1-2 delivers tighter initial accuracy for higher-resolution systems; versus TLVH431ACDBVR, it offers true pin-compatible replacement in SOIC-8 layouts but trades off adjustability and lower impedance for guaranteed 1% tolerance and proven long-term stability.
Availability
LM385BDRG4-1-2 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 traceable sourcing.
Supply support for LM385BDRG4-1-2 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.
LM385BDRG4-1-2 belongs to TI's micropower voltage reference product line, designed specifically for ultra-low-power, high-stability analog signal conditioning in portable and battery-critical applications.
FAQ
What is the operating temperature range for LM385BDRG4-1-2?
The LM385BDRG4-1-2 is specified for operation from 0°C to 70°C ambient temperature. This range is narrower than the LM285-1.2 (−40°C to 85°C) but optimized for commercial portable equipment where extended industrial range is unnecessary. The device maintains ±20 ppm/°C temperature coefficient and 1% initial tolerance across this full range, ensuring predictable performance in handheld and panel-mounted applications.
Does LM385BDRG4-1-2 require external capacitors for stability?
No, LM385BDRG4-1-2 does not require external capacitors for stability. Its internal frequency compensation provides unconditional stability with any capacitive load on the cathode pin, including standard 0.1 µF ceramic bypass capacitors. This eliminates risk of oscillation in high-impedance sensor interfaces and simplifies layout-TI explicitly confirms robustness against capacitive loading in the datasheet's Feature Description section.
What is the minimum cathode current required for regulation in LM385BDRG4-1-2?
The LM385BDRG4-1-2 requires a minimum cathode current (IZ,min) of 15 µA to achieve proper regulation. This value is confirmed in Section 7.5 Electrical Characteristics of the SLVS075J datasheet under "Minimum reference current" for the LM385B-1.2 variant. Supplying less than 15 µA may result in unstable or out-of-spec output voltage, especially at temperature extremes.
Is LM385BDRG4-1-2 pin-compatible with LM285-1.2 in SOIC-8 packages?
Yes, LM385BDRG4-1-2 is pin-compatible with LM285-1.2 in SOIC-8 packages (e.g., LM285DRG4-1-2). Both share identical pin 1 (anode) and pin 2 (cathode) assignments and NC pin locations. However, LM285-1.2 operates over −40°C to 85°C and has 10 µA minimum current, so thermal and current-source design must be verified for interchangeability in existing circuits.
What does the "G4" suffix indicate in LM385BDRG4-1-2?
The "G4" suffix in LM385BDRG4-1-2 denotes TI's green packaging standard: RoHS-compliant with no antimony or bromine-based flame retardants (≤1000 ppm halogen content), NiPdAu lead finish, and MSL Level-1 rating (unlimited floor life at ≤30°C/60% RH). It is functionally identical to non-G4 variants like LM385BDR-1-2 but meets stricter environmental compliance requirements for modern electronics manufacturing.
LM385BDRG4-1-2 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- 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-SOIC
LM385BDRG4-1-2 FAQ
1.How can I place an order for LM385BDRG4-1-2 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM385BDRG4-1-2 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 LM385BDRG4-1-2 reliable?
The price and inventory of LM385BDRG4-1-2 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM385BDRG4-1-2 is usually 5 days.
3.What payment methods are accepted for LM385BDRG4-1-2?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM385BDRG4-1-2 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM385BDRG4-1-2?
LM385BDRG4-1-2 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM385BDRG4-1-2 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 LM385BDRG4-1-2?
For technical support, including LM385BDRG4-1-2 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM385BDRG4-1-2 requirements.
6.How does Aetrix verify that LM385BDRG4-1-2 is sourced from the original manufacturer or authorized distributors?
All LM385BDRG4-1-2 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 LM385BDRG4-1-2 meets industry standards.
7.What is the process for return or replacement of LM385BDRG4-1-2?
All LM385BDRG4-1-2 units undergo pre-shipment inspection (PSI). If there is an issue with LM385BDRG4-1-2, 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 LM385BDRG4-1-2 part is unused and in its original packaging.
Return procedure for LM385BDRG4-1-2:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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