My Inquiry
My Account
Texas Instruments LM385BDG4-1-2
- Part No.:
- LM385BDG4-1-2
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LM385BDG4-1-2.pdf
- Description:
- IC VREF SHUNT 1% 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,225
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM385BDG4-1-2 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 LM385BDG4-1-2 datasheet, LM385BDG4-1-2 pinout, LM385BDG4-1-2 application, or LM385BDG4-1-2 equivalent, key selection criteria include initial tolerance (2%), long-term stability (±20 ppm/khr), low-noise operation (60 μV broadband), capacitive-load tolerance, and SOIC-8 package compatibility with standard PCB assembly processes.
Technical Context
The LM385BDG4-1-2 implements a floating shunt topology with internal band-gap core, high-gain amplifier, and frequency-compensated loop enabling stable regulation under all capacitor loads. Its design eliminates need for external compensation and supports both positive and negative regulation configurations.
It operates exclusively in fixed-voltage reference mode with no adjustability; regulation initiates only when cathode current exceeds 15 μA, and it maintains tight output accuracy across its specified 0°C to 70°C operating range without requiring external components.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Reference Voltage | 1.235 V - Stable shunt voltage at 25°C, used as precision bias or calibration point in analog signal chains. |
| Initial Tolerance | ±2% - Ensures output remains within 1.21–1.26 V at power-up without trimming. |
| Tempco (αVZ) | ±20 ppm/°C - Predictable drift of ≤25 μV/°C enables accurate operation across 0°C–70°C ambient. |
| Reference Impedance | 1.5 Ω max - Low dynamic impedance minimizes output voltage shift under varying load current. |
| Operating Current Range | 15 μA to 20 mA - Supports ultra-low-power portable designs and higher-current regulator feedback paths. |
| Broadband Noise | 60 μV - Measured from 10 Hz to 10 kHz; critical for high-resolution ADC references and low-noise amplifiers. |
| Long-Term Stability | ±20 ppm/khr - Drift less than 0.002% per 1000 hours ensures calibration integrity in field-deployed equipment. |
Pinout & Package
LM385BDG4-1-2 is housed in an 8-pin SOIC (Package Drawing D) with 4.90 mm × 3.91 mm body size and 1.75 mm max height. Pin 1 is cathode; Pin 2 is anode; Pins 3, 5, 6, 7 are NC; Pin 4 and Pin 8 are internally connected to cathode and anode respectively per functional mapping.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (Pin 1) | Shunt current input / voltage reference node | Current must be sourced into this pin to establish regulated 1.235 V between cathode and anode; connects to system ground or feedback node. |
| Anode (Pin 2) | Common reference return | Typically tied to ground; voltage at cathode is referenced to this terminal; forms two-terminal shunt configuration. |
| NC (Pins 3, 5, 6, 7) | No internal connection | Unused pins; may be left unconnected or tied to ground for mechanical stability-no electrical function. |
| Cathode (Pin 4) | Redundant cathode terminal | Internally bonded to Pin 1; improves current handling and thermal performance in high-reliability layouts. |
| Anode (Pin 8) | Redundant anode terminal | Internally bonded to Pin 2; provides additional solder joint reliability and lower parasitic inductance for ground return path. |
Key Features
| Feature | Design Value |
|---|---|
| Capacitive-load immunity | Stable with any value of bypass capacitor-eliminates need for series resistance or external compensation. |
| Low-power operation | 15 μA minimum operating current enables multi-year battery life in portable meters and IoT sensors. |
| Band-gap core architecture | Delivers inherent low noise (60 μV) and long-term stability (±20 ppm/khr) without laser trimming dependency. |
| Interchangeability | Pins and specs align with industry-standard LM285-1.2 and LM385-1.2-enables drop-in replacement in legacy designs. |
| ESD robustness | ±2000 V HBM rating ensures survivability during board handling and automated assembly. |
Applications
| Portable Test Instruments | Battery-Operated Systems |
|---|---|
Use Scenario: Handheld multimeters and calibrators requiring stable, low-drift reference for ADC front-end and autoranging circuits. IC Role / Device Role / Timing Role: Two-terminal shunt voltage reference providing 1.235 V基准 for precision scaling and offset correction. Use Value: Enables >4½-digit accuracy with <0.01% total error over temperature and time due to ±20 ppm/°C tempco and ±20 ppm/khr stability. | Use Scenario: Remote sensor nodes powered by coin cells or primary batteries needing minimal quiescent current. IC Role / Device Role / Timing Role: Micropower reference supplying excitation voltage to bridge sensors or biasing low-power op-amps. Use Value: 15 μA minimum current draw extends usable battery life to >5 years while maintaining 1.235 V accuracy within ±2%. |
| Current-Loop Instrumentation | Panel Meters |
Use Scenario: 4–20 mA transmitter modules where reference voltage sets loop current via precision resistor. IC Role / Device Role / Timing Role: Fixed shunt reference establishing exact voltage across sense resistor to define loop current. Use Value: 1.5 Ω max impedance prevents current-setting error under varying supply conditions; ±2% tolerance ensures factory calibration validity. | Use Scenario: Industrial panel-mounted digital displays requiring consistent reference for analog-to-digital conversion of process signals. IC Role / Device Role / Timing Role: Primary voltage reference for integrated ADCs and display drivers in DIN-rail mounted meters. Use Value: SOIC-8 package allows compact layout; ±20 ppm/°C tempco guarantees reading consistency across operating ambient (0°C–70°C). |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM385DG4-1-2 | 1% initial tolerance (vs. 2%); same SOIC-8 package, 0°C–70°C range, and 15 μA–20 mA operating current. | Suitable where tighter initial accuracy is required without changing layout or thermal design. | Select LM385DG4-1-2 if system-level calibration budget demands <1.2% total reference error at power-on. |
| LM385BDR-1-2 | Same 2% tolerance and specs, but supplied in tape-and-reel (2500 pcs) vs. tube (75 pcs) packaging. | Preferred for high-volume SMT production with automated pick-and-place. | Choose LM385BDR-1-2 for cost-efficient manufacturing runs requiring reel-fed assembly and traceable lot control. |
Compared with LM385DG4-1-2, the LM385BDG4-1-2 trades initial accuracy for cost and availability; compared with LM385BDR-1-2, it offers identical electrical performance in smaller-quantity tube packaging suited for prototyping and low-volume builds.
Availability
LM385BDG4-1-2 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 continuity.
Supply support for LM385BDG4-1-2 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 since the 1960s.
The LM385B series belongs to TI's micropower voltage reference product line, engineered specifically for battery-constrained and portable measurement applications demanding low drift, low noise, and wide operating current range.
FAQ
What is the operating temperature range for the LM385BDG4-1-2?
The LM385BDG4-1-2 is rated for operation from 0°C to 70°C ambient temperature. This range is defined in the Recommended Operating Conditions table and applies to all electrical characteristics including reference voltage, tempco, and impedance. Operation outside this range may result in parametric degradation or non-compliance with datasheet specifications.
Does the LM385BDG4-1-2 require external capacitors for stability?
No, the LM385BDG4-1-2 does not require external capacitors for stability. Its internal frequency compensation ensures loop stability across all capacitor values and types-including ceramic, tantalum, and electrolytic-making it inherently tolerant of capacitive loading without risk of oscillation.
What is the minimum cathode current needed for regulation in the LM385BDG4-1-2?
The LM385BDG4-1-2 requires a minimum cathode current of 15 μA to achieve proper regulation. Below this threshold, the device enters dropout and output voltage deviates significantly from 1.235 V. This value is specified in the Electrical Characteristics table under "Minimum reference current" for the LM385B-1.2 variant.
How does the LM385BDG4-1-2 differ from the LM285-1.2?
The LM385BDG4-1-2 differs from the LM285-1.2 in three key ways: (1) wider operating temperature range (0°C–70°C vs. −40°C–85°C), (2) higher minimum operating current (15 μA vs. 10 μA), and (3) tighter long-term stability (±20 ppm/khr vs. ±20 ppm/khr, same spec but validated over different test conditions). Both share identical pinout and basic functionality.
Is the LM385BDG4-1-2 RoHS compliant and lead-free?
Yes, the LM385BDG4-1-2 is RoHS compliant and lead-free. Per TI's Packaging Information, it carries a "Green (RoHS & no Sb/Br)" eco plan and "NIPDAU" lead finish, meeting EU RoHS Directive requirements for all 10 restricted substances with ≤0.1% by weight in homogeneous materials.
LM385BDG4-1-2 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Series:
- -
- Packaging:
- Tube
- 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
LM385BDG4-1-2 FAQ
1.How can I place an order for LM385BDG4-1-2 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM385BDG4-1-2 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 LM385BDG4-1-2 reliable?
The price and inventory of LM385BDG4-1-2 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM385BDG4-1-2 is usually 5 days.
3.What payment methods are accepted for LM385BDG4-1-2?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM385BDG4-1-2 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM385BDG4-1-2?
LM385BDG4-1-2 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM385BDG4-1-2 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 LM385BDG4-1-2?
For technical support, including LM385BDG4-1-2 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM385BDG4-1-2 requirements.
6.How does Aetrix verify that LM385BDG4-1-2 is sourced from the original manufacturer or authorized distributors?
All LM385BDG4-1-2 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 LM385BDG4-1-2 meets industry standards.
7.What is the process for return or replacement of LM385BDG4-1-2?
All LM385BDG4-1-2 units undergo pre-shipment inspection (PSI). If there is an issue with LM385BDG4-1-2, 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 LM385BDG4-1-2 part is unused and in its original packaging.
Return procedure for LM385BDG4-1-2:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM385BDG4-1-2 Tags
-
TL431AIDBZR
Texas Instruments
-
TL431BQDBZR
Texas Instruments
-
AN431AN-ATRG1
Diodes Incorporated
-
LM4040CYM3-2.5-TR
Microchip Technology
-
LM4040CYM3-4.1-TR
Microchip Technology
-
LM4040EIM3-2.5/NOPB
Texas Instruments
-
AZ431LBNTR-G1
Diodes Incorporated
-
LM4040D20IDBZR
Texas Instruments
-
LM4041DIM3-ADJ/NOPB
Texas Instruments
-
LM4040DIM3X-2.5/NOPB
Texas Instruments
-
LM4040DIM3-2.5/NOPB
Texas Instruments
-
AZ431LANTR-G1
Diodes Incorporated
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
