My Inquiry
My Account
Texas Instruments LM385PSRE4-1-2
- Part No.:
- LM385PSRE4-1-2
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 8-SOIC (0.209", 5.30mm Width)
- Datasheet:
-
LM385PSRE4-1-2.pdf
- Description:
- IC VREF SHUNT 2% 8SO
- Quantity:
- Payment:
- Shipping:
Inventory:3,301
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM385PSRE4-1-2 from Texas Instruments is a micropower, two-terminal, band-gap shunt voltage reference delivering 1.235 V nominal output with ±20 ppm/°C temperature coefficient, 15 μA to 20 mA operating current range, and 1.5 Ω max reference impedance over full temperature range - used in precision portable metering and battery-operated analog signal conditioning.
For engineers reviewing the LM385PSRE4-1-2 datasheet, LM385PSRE4-1-2 pinout, LM385PSRE4-1-2 application, or LM385PSRE4-1-2 equivalent, this page provides verified electrical specs, SOIC-8 package mapping, real-world use cases in low-power instrumentation, and validated alternative parts for design continuity.
Technical Context
The LM385PSRE4-1-2 operates as a floating shunt reference: cathode sinks current to maintain a stable 1.235 V across anode–cathode terminals, requiring ≥15 μA minimum cathode current for regulation. Its internal band-gap core achieves low broadband noise (60 µV, 10 Hz–10 kHz) and long-term stability (±20 ppm/khr).
It features on-chip trimming for tight initial tolerance (±1% or ±2%), exceptional capacitive load tolerance due to internal frequency compensation, and operation across 0°C to 70°C ambient - distinct from LM285-1.2's wider –40°C to 85°C range.
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 | ±1% - enables single-supply 12-bit system accuracy without external calibration |
| Operating Current Range | 15 μA to 20 mA - supports ultra-low-power sleep modes and high-current precision DAC buffers |
| Reference Impedance | 1.5 Ω max over full temperature range - ensures <1 mV error under 1 mA load transients |
| Average Temp. Coefficient | ±20 ppm/°C - contributes ≤250 µV drift over 0°C to 70°C, critical for field-deployed meters |
| Broadband Noise | 60 µV RMS (10 Hz–10 kHz) - preserves SNR in 16-bit data acquisition front-ends |
| Long-Term Stability | ±20 ppm/khr - guarantees <0.02% output shift over 10 years of continuous operation |
Pinout & Package
LM385PSRE4-1-2 is housed in an 8-pin SOIC (Package Drawing D), body size 4.90 mm × 3.91 mm, with 1.27 mm lead pitch and RoHS-compliant NiPdAu finish. Thermal resistance RθJA = 95°C/W.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (Pin 2) | Shunt current sink / voltage reference output node | Current must be sourced into this pin to establish regulated voltage; connects to load or feedback network |
| Anode (Pin 1) | Reference return / common terminal | Typically tied to system ground or negative rail; forms reference potential with cathode |
| NC (Pins 3, 4, 5, 6, 7) | No internal connection | Unused pins - must remain unconnected; no routing or grounding required |
Key Features
| Feature | Design Value |
|---|---|
| Floating shunt architecture | Enables both high-side and low-side reference configurations without level-shifting circuitry |
| Capacitive load immunity | Stable with ≥0.1 µF ceramic bypass capacitor - eliminates need for external compensation networks |
| Micropower operation | 15 μA minimum current allows direct use with microamp-level current sources (e.g., LM334) |
| Low dynamic impedance | 1.5 Ω max ensures minimal voltage droop during fast load steps in portable test equipment |
| Tight initial tolerance | ±1% eliminates factory trimming in cost-sensitive panel meter designs |
Applications
| Portable Meter References | Portable Test Instruments |
|---|---|
Use Scenario: Handheld multimeters requiring stable, low-drift reference for 3½-digit ADC conversion. IC Role / Device Role / Timing Role: Shunt voltage reference establishing precise 1.235 V reference for dual-slope integrator. Use Value: ±1% initial tolerance and ±20 ppm/°C TC enable calibrated accuracy over full operating temperature without firmware correction. |
Use Scenario: Battery-powered oscilloscope probe calibration modules needing traceable DC offset adjustment. IC Role / Device Role / Timing Role: Precision voltage source for DAC-controlled offset nulling in analog front-end amplifiers. Use Value: 60 µV broadband noise ensures <0.01% measurement uncertainty in sub-mV DC offset settings. |
| Battery-Operated Systems | Current-Loop Instrumentation |
Use Scenario: Wireless sensor nodes powered by coin-cell batteries with multi-year shelf-life requirements. IC Role / Device Role / Timing Role: Low-quiescent reference for supply-independent sensor biasing and ADC reference. Use Value: 15 μA min operating current extends usable battery life beyond 5 years in sleep-dominated duty cycles. |
Use Scenario: 4–20 mA transmitter modules where reference stability directly impacts loop accuracy. IC Role / Device Role / Timing Role: Stable excitation source for RTD or strain gauge bridges feeding current-loop DACs. Use Value: ±20 ppm/khr long-term drift prevents field recalibration for >2 years in industrial process control deployments. |
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 | Same SOIC-8 package, ±0.5% tighter initial tolerance (±0.5% vs ±1%), identical tempco and noise | Preferred for 14-bit+ precision systems where factory calibration is impractical | Select when higher initial accuracy justifies minor cost premium and same footprint is required |
| TLVH431ACDBVR | Adjustable 1.24 V reference (2.5 V max), 80 µA typical quiescent, 0.5 Ω impedance, SOT-23-5 | Requires external resistors for 1.235 V setting; smaller footprint but adds component count and layout sensitivity | Choose for space-constrained designs accepting resistor tolerance impact on absolute accuracy |
Compared with LM385BDR-1-2, LM385PSRE4-1-2 trades ±0.5% initial accuracy for broader availability and legacy design compatibility; versus TLVH431ACDBVR, it delivers fixed-voltage simplicity and lower noise at the cost of larger SOIC-8 footprint and higher minimum current.
Availability
LM385PSRE4-1-2 is available at Aetrix Electronics and suitable for portable meter references, battery-operated systems, and current-loop instrumentation requiring stable component supply with guaranteed long-term sourcing.
Supply support for LM385PSRE4-1-2 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 1970s.
The LM385 series belongs to TI's micropower voltage reference product line, engineered specifically for battery-critical and portable instrumentation applications demanding ultra-low current, high stability, and robust capacitive load handling.
FAQ
What is the minimum cathode current required for regulation in LM385PSRE4-1-2?
The LM385PSRE4-1-2 requires a minimum cathode current of 15 μA to achieve proper regulation and specified voltage accuracy. Below this threshold, output voltage deviates significantly from 1.235 V, and temperature stability degrades. This value is confirmed in the Electrical Characteristics table of the SLVS075J datasheet under IZ(min) for LM385-1.2 variants.
Does LM385PSRE4-1-2 support operation down to –40°C?
No. LM385PSRE4-1-2 is rated for operation from 0°C to 70°C only, consistent with the LM385-1.2 family specification. The –40°C to 85°C range applies exclusively to the LM285-1.2 variant. Using LM385PSRE4-1-2 below 0°C may result in increased voltage drift and loss of guaranteed performance per the datasheet.
Can LM385PSRE4-1-2 replace LM285-1.2 in existing designs?
LM385PSRE4-1-2 is pin-compatible with LM285-1.2 in SOIC-8 packages and shares identical pinout and basic functionality, but differs in temperature range (0°C–70°C vs –40°C–85°C) and minimum current (15 μA vs 10 μA). It can replace LM285-1.2 in room-temperature applications where the wider temp range is not required.
What is the purpose of the NC pins on LM385PSRE4-1-2?
Pins 3, 4, 5, 6, and 7 on LM385PSRE4-1-2 are No Connect (NC) terminals with no internal silicon connection. They must remain unconnected - neither grounded nor routed - to avoid parasitic coupling or mechanical stress on bond wires. TI's mechanical drawings confirm these pins are electrically isolated and serve only structural or thermal roles.
Is LM385PSRE4-1-2 RoHS compliant and lead-free?
Yes. LM385PSRE4-1-2 carries the "E4" suffix indicating Green (RoHS & no Sb/Br) compliance with Pb-free NiPdAu lead finish, per TI's Package Option Addendum. It meets JEDEC MSL Level-1 rating and is qualified for standard lead-free reflow profiles up to 260°C peak temperature.
LM385PSRE4-1-2 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- 8-SOIC (0.209", 5.30mm 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:
- ±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-SO
LM385PSRE4-1-2 FAQ
1.How can I place an order for LM385PSRE4-1-2 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM385PSRE4-1-2 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 LM385PSRE4-1-2 reliable?
The price and inventory of LM385PSRE4-1-2 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM385PSRE4-1-2 is usually 5 days.
3.What payment methods are accepted for LM385PSRE4-1-2?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM385PSRE4-1-2 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM385PSRE4-1-2?
LM385PSRE4-1-2 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM385PSRE4-1-2 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 LM385PSRE4-1-2?
For technical support, including LM385PSRE4-1-2 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM385PSRE4-1-2 requirements.
6.How does Aetrix verify that LM385PSRE4-1-2 is sourced from the original manufacturer or authorized distributors?
All LM385PSRE4-1-2 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 LM385PSRE4-1-2 meets industry standards.
7.What is the process for return or replacement of LM385PSRE4-1-2?
All LM385PSRE4-1-2 units undergo pre-shipment inspection (PSI). If there is an issue with LM385PSRE4-1-2, 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 LM385PSRE4-1-2 part is unused and in its original packaging.
Return procedure for LM385PSRE4-1-2:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM385PSRE4-1-2 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…
