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Texas Instruments LM385BM/NOPB
- Part No.:
- LM385BM/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LM385BM/NOPB.pdf
- Description:
- IC VREF SHUNT ADJ 1% 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:368
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Product details
Overview
LM385BM/NOPB from Texas Instruments is a 3-terminal adjustable micropower band-gap voltage reference diode operating from 1.24 V to 5.30 V with 1% initial tolerance, 1 Ω dynamic impedance, and 30 ppm/°C max average temperature coefficient over 0°C to 70°C. It serves as a precision shunt reference in battery-powered meters, low-power regulators, and analog signal conditioning circuits.
For engineers reviewing the LM385BM/NOPB datasheet, LM385BM/NOPB pinout, LM385BM/NOPB application, or LM385BM/NOPB equivalent, key selection criteria include its 10 μA to 20 mA operating current range, low 50 μVRMS wideband noise at VREF, TO-92 and SOIC package options, and compatibility with capacitive loading without instability.
Technical Context
The LM385BM/NOPB implements a band-gap reference architecture using only transistors and resistors-no op-amps or active compensation-enabling low noise, excellent long-term stability (20 ppm typical drift over 1000 hours), and inherent tolerance to capacitive loading up to several microfarads. Its feedback current remains stable at ≤25 nA (max) across temperature and supply variations.
Designed for shunt-mode operation, it regulates output voltage by sinking variable current through an external resistor while maintaining precise VREF across its cathode-anode terminals. The SOIC-8 package supports surface-mount reliability and thermal performance with θJA = 170°C/W (0.125″ leads) and MSL Level-1 rating.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage Range | 1.24 V to 5.30 V - Adjustable via external resistor divider; enables flexible design of 2.5 V, 3.3 V, 5.0 V, or custom reference points. |
| Initial Tolerance | ±1% - Tight factory trimming ensures high accuracy without post-manufacture calibration in production systems. |
| Dynamic Impedance | 1 Ω - Low output impedance maintains stable reference voltage under load transients up to 20 mA. |
| Operating Current Range | 10 μA to 20 mA - Supports ultra-low-power sensor nodes (μA-level) and higher-current shunt regulator designs (mA-level). |
| Temperature Coefficient | 30 ppm/°C (max average) - Predictable drift over 0°C to 70°C enables reliable operation in commercial-grade embedded systems. |
| Wideband Noise | 50 μVRMS (10 Hz–10 kHz, VOUT = VREF) - Low noise preserves signal integrity in precision ADC references and analog front-ends. |
| Minimum Operating Current | 7 μA (max) - Ensures regulation starts reliably even with high-value biasing resistors in low-quiescent designs. |
Pinout & Package
LM385BM/NOPB is housed in an 8-pin SOIC (Small Outline Integrated Circuit) package per JEDEC MS-012, with gull-wing leads, RoHS-compliant CuSn finish, and moisture sensitivity level (MSL) 1 (unlimited floor life at <30°C/60% RH). Thermal resistance is θJA = 170°C/W (0.125″ leads).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Pin 1) | Current sink return path | Connected to system ground; completes shunt current loop; must be low-impedance for stable regulation. |
| Cathode (Pin 2) | Reference voltage output | Provides regulated VREF; connects to feedback node of external divider or load; requires minimal trace inductance. |
| No Connect (Pins 3–8) | Unused internal terminals | Internally unconnected; left floating per TI specification; no external tie required or recommended. |
Key Features
| Feature | Design Value |
|---|---|
| Capacitive load tolerance | Stable with ≥1 μF ceramic output capacitance-eliminates need for series isolation resistor in portable meter designs. |
| Low quiescent current | 10 μA minimum operating current enables >10-year battery life in remote sensor nodes powered by coin cells. |
| Tight initial accuracy | ±1% tolerance reduces or eliminates system-level calibration steps in production test for industrial instrumentation. |
| Band-gap core architecture | Transistor/resistor-only design delivers <20 ppm/1000 hr long-term stability-critical for unattended monitoring equipment. |
| SOIC-8 thermal performance | 170°C/W junction-to-ambient resistance allows continuous 20 mA operation at +70°C ambient without derating. |
Applications
| Portable Precision Multimeter | Battery-Powered Data Logger |
|---|---|
Use Scenario: Handheld digital multimeter requiring stable 2.5 V reference for 16-bit SAR ADC across 0°C–50°C ambient. IC Role / Device Role / Timing Role: Shunt voltage reference providing excitation and scaling reference for analog input channel and internal DAC. Use Value: 1% initial tolerance and 30 ppm/°C TC ensure <0.05% full-scale error drift over operating range without recalibration. | Use Scenario: Remote environmental sensor node logging temperature/humidity every 5 minutes using CR2032 coin cell. IC Role / Device Role / Timing Role: Micropower reference for low-dropout LDO feedback and ADC reference in sleep-active cycling architecture. Use Value: 10 μA minimum operating current enables >12 years of operation on single coin cell (225 mAh capacity, 10 μA avg. load). |
| Industrial 4–20 mA Transmitter | Programmable Power Supply Monitor |
Use Scenario: Loop-powered 4–20 mA transmitter with HART modulation, requiring stable 5.0 V rail derived from 24 V loop supply. IC Role / Device Role / Timing Role: Shunt regulator element setting precise 5.0 V reference for op-amp-based current loop driver and DAC interface. Use Value: 1 Ω dynamic impedance maintains <1 mV output shift during 20 mA loop current transients, preserving current accuracy. | Use Scenario: Embedded power management IC monitoring 3.3 V and 5 V rails in FPGA-based control system with fault reporting. IC Role / Device Role / Timing Role: Adjustable threshold detector (via resistor divider) triggering reset or alert when supply falls below 95% nominal. Use Value: Adjustable 1.24–5.30 V range allows exact trip point alignment to 3.135 V (95% of 3.3 V) and 4.75 V (95% of 5 V) with single BOM item. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar adjustable shunt voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TLVH431ACDBVR | 2.5 V fixed + adjustable (1.24–18 V); 0.5% initial tolerance; 0.2 Ω dynamic impedance; 80 μA typical IREF | Higher minimum current limits use in sub-50 μA systems; tighter tolerance suits metrology-grade designs | Select TLVH431ACDBVR when <0.5% accuracy or lower dynamic impedance is required, accepting higher quiescent current. |
| LM4040CIM3-ADJ | Adjustable (1.235–10 V); 0.5% tolerance; 0.5 Ω impedance; 60 μA typical IREF; SOIC-3 package | Smaller footprint but higher minimum current; not rated for >85°C ambient | Choose LM4040CIM3-ADJ for space-constrained PCBs where 60 μA minimum current is acceptable and temp range ≤85°C. |
Compared with TLVH431ACDBVR and LM4040CIM3-ADJ, LM385BM/NOPB offers the lowest operating current (10 μA min) and widest commercial temperature range (0°C to 70°C) in SOIC-8, making it optimal for ultra-low-power, cost-sensitive, and thermally moderate applications where ±1% accuracy suffices.
Availability
LM385BM/NOPB is available at Aetrix Electronics and suitable for portable instrumentation, battery-powered data loggers, industrial 4–20 mA transmitters, and programmable power supply monitors requiring stable component supply with consistent parametric performance across production lots.
Supply support for LM385BM/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 company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and personal electronics markets since 1930.
The LM385 series belongs to TI's precision voltage reference product line, designed specifically for low-power, cost-effective shunt reference applications in commercial-grade instrumentation and portable systems where micropower operation and stable regulation outweigh ultra-high accuracy requirements.
FAQ
What is the maximum operating temperature for LM385BM/NOPB?
The LM385BM/NOPB is rated for operation from 0°C to 70°C ambient temperature. Its maximum junction temperature is 100°C, as specified in Table 1 of the SNVS741F datasheet. This makes it suitable for commercial-grade applications but not extended industrial or automotive environments.
Does LM385BM/NOPB require an external capacitor for stability?
No, LM385BM/NOPB does not require an external capacitor for stability. Its band-gap core and internal design make it tolerant of capacitive loading-including ≥1 μF ceramic output capacitance-without oscillation or phase margin degradation, simplifying layout in portable and space-constrained designs.
Can LM385BM/NOPB be used as a 5.0 V reference?
Yes, LM385BM/NOPB can be configured as a precise 5.0 V reference using an external resistor divider network connected between cathode and anode. The device's 1.24 V to 5.30 V adjustment range fully covers 5.0 V, and its 1% initial tolerance ensures output accuracy within ±50 mV before trimming.
What is the pin configuration of LM385BM/NOPB in SOIC-8?
LM385BM/NOPB uses only Pins 1 (Anode) and 2 (Cathode) in its SOIC-8 package; Pins 3–8 are internally unconnected (NC) and must remain floating. This configuration is confirmed in TI's package drawing D and the "Connection Diagram" section of SNVS741F.
How does LM385BM/NOPB compare to LM385BXZ/NOPB?
LM385BM/NOPB (SOIC-8) and LM385BXZ/NOPB (TO-92) share identical electrical specifications-including 1% tolerance, 30 ppm/°C TC, and 10 μA–20 mA operating range-but differ in package, thermal performance, and board assembly. LM385BM/NOPB offers better thermal dissipation (θJA = 170°C/W vs. 440°C/W) and surface-mount compatibility, while LM385BXZ/NOPB provides through-hole robustness and lower cost per unit.
LM385BM/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Series:
- -
- Packaging:
- Tube
- Product Status:
- Active
- Reference Type:
- Shunt
- Output Type:
- Adjustable
- Voltage - Output (Min/Fixed):
- 1.24V
- Voltage - Output (Max):
- 5.3 V
- Current - Output:
- 20 mA
- Tolerance:
- ±1%
- Temperature Coefficient:
- 150ppm/°C
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- 50µVrms
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 55 µA
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
LM385BM/NOPB FAQ
1.How can I place an order for LM385BM/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM385BM/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 LM385BM/NOPB reliable?
The price and inventory of LM385BM/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM385BM/NOPB is usually 5 days.
3.What payment methods are accepted for LM385BM/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM385BM/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM385BM/NOPB?
LM385BM/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM385BM/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 LM385BM/NOPB?
For technical support, including LM385BM/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM385BM/NOPB requirements.
6.How does Aetrix verify that LM385BM/NOPB is sourced from the original manufacturer or authorized distributors?
All LM385BM/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 LM385BM/NOPB meets industry standards.
7.What is the process for return or replacement of LM385BM/NOPB?
All LM385BM/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM385BM/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 LM385BM/NOPB part is unused and in its original packaging.
Return procedure for LM385BM/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM385BM/NOPB Tags
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