My Inquiry
My Account
Texas Instruments LM385PWRE4-1-2
- Part No.:
- LM385PWRE4-1-2
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 8-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
LM385PWRE4-1-2.pdf
- Description:
- IC VREF SHUNT 2% 8TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,990
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM385PWRE4-1-2 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 and battery-operated analog signal chains.
For engineers reviewing the LM385PWRE4-1-2 datasheet, LM385PWRE4-1-2 pinout, LM385PWRE4-1-2 application, or LM385PWRE4-1-2 equivalent, key selection criteria include its 15 μA minimum operating current, low-noise 60 μV broadband noise (10 Hz–10 kHz), tight 1.223 V–1.247 V initial tolerance at 25°C, and TSSOP-8 package compatibility with space-constrained PCB layouts.
Technical Context
The LM385PWRE4-1-2 functions as a floating shunt reference, regulating voltage between cathode and anode using internal band-gap core and high-gain amplifier with on-chip frequency compensation. Its design enables stable operation with capacitive loads up to 0.1 μF without external compensation.
It operates exclusively in fixed-voltage reference mode with no adjustment capability. Regulation requires sourcing ≥15 μA into the cathode pin; below this threshold, output voltage deviates nonlinearly per electrical characteristics data.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Voltage | 1.235 V - Stable reference point for ADC biasing, sensor excitation, and precision comparator thresholds |
| Initial Tolerance | ±1.2% (1.223 V–1.247 V at 25°C) - Enables single-point calibration in portable meters without trimming |
| Temp Coefficient | ±20 ppm/°C - Ensures ≤2.5 mV drift over 0°C–70°C ambient, critical for unheated field instrumentation |
| Ref Impedance | 1.5 Ω max (full temp range) - Minimizes load-induced error in current-sense amplifier feedback networks |
| Broadband Noise | 60 μV RMS (10 Hz–10 kHz) - Supports 12-bit+ resolution in low-frequency measurement systems |
| Min Cathode Current | 15 μA - Allows direct use with ultra-low-power microcontrollers' GPIO pull-ups or leakage-limited biasing |
| Max Cathode Current | 20 mA - Supports robust operation under transient load conditions without thermal shutdown |
Pinout & Package
TSSOP-8 package (3.00 mm × 4.40 mm body, 1.2 mm max height), RoHS-compliant, green finish, moisture sensitivity level 1 (260°C peak reflow).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (Pin 1) | Shunt current input / voltage reference node | Current must be sourced into this pin; output voltage develops between cathode and anode |
| Anode (Pin 4) | Common return / ground reference | Typically connected to system ground; forms reference potential for cathode voltage |
| NC (Pins 2, 3, 5–8) | No internal connection | Unused pins; must remain unconnected or tied to ground per layout guidelines to minimize noise coupling |
Key Features
| Feature | Design Value |
|---|---|
| Capacitive Load Tolerance | Stable with ≥0.1 μF ceramic bypass capacitor - eliminates need for external compensation in portable designs |
| Micropower Operation | 15 μA min cathode current - extends battery life in handheld multimeters beyond shelf-life limits |
| Low Dynamic Impedance | 1.5 Ω max over full temperature range - maintains accuracy when driving varying loads in current-loop transmitters |
| Long-Term Stability | ±20 ppm/khr drift at 100 μA - ensures calibration integrity over 5+ years in panel meter applications |
| ESD Robustness | ±2000 V HBM - withstands handling in non-EPA environments during assembly of test equipment |
Applications
| Portable Meter References | Portable Test Instruments |
|---|---|
Use Scenario: Battery-powered handheld digital multimeter requiring stable 1.2 V reference for ADC scaling and auto-zero circuitry. IC Role / Device Role / Timing Role: Shunt voltage reference providing precision bias for dual-slope integrator and reference buffer stages. Use Value: 15 μA minimum operating current enables direct bias from high-value resistor networks, reducing quiescent power to <18 μW while maintaining 12-bit linearity. |
Use Scenario: Pocket-sized oscilloscope front-end with rail-to-rail input amplifiers needing matched reference for offset cancellation. IC Role / Device Role / Timing Role: Low-noise voltage reference establishing common-mode level for differential probe conditioning circuits. Use Value: 60 μV broadband noise ensures <0.05% reference-induced distortion in 10-bit acquisition paths at 1 MS/s sampling. |
| Battery-Operated Systems | Current-Loop Instrumentation |
Use Scenario: Wireless environmental sensor node powered by coin-cell battery, requiring decade-long operation without replacement. IC Role / Device Role / Timing Role: Precision reference for low-power op-amp signal conditioning and SAR ADC reference input. Use Value: ±20 ppm/°C tempco and ±20 ppm/khr long-term drift allow factory calibration only, eliminating field recalibration in remote deployments. |
Use Scenario: 4–20 mA transmitter module converting thermocouple output to industrial current loop with HART modulation. IC Role / Device Role / Timing Role: Stable shunt reference setting gain and zero points for current-output DAC and loop driver stages. Use Value: 1.5 Ω max impedance prevents gain error shift when loop supply varies from 12 V to 36 V, ensuring ±0.1% full-scale accuracy. |
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 | SOIC-8 package; same 1.235 V nominal, ±20 ppm/°C, but rated for 0°C–70°C like LM385PWRE4-1-2 | Requires larger PCB area (4.90 mm × 3.91 mm vs. 3.00 mm × 4.40 mm); higher thermal resistance (95°C/W vs. 149°C/W) | Select for legacy SOIC footprints where board rework is impractical; verify thermal margin in enclosed enclosures |
| TLVH431ACDBVR | Adjustable shunt reference (1.24 V base), 80 μA typical cathode current, 0.2 Ω typical impedance, SOT-23-5 | Requires external resistors for 1.2 V setting; higher noise (120 μV) but superior PSRR for noisy supply rails | Select when adjustable output or better ripple rejection is needed; accept trade-off in initial tolerance (±0.5%) and layout complexity |
Compared with LM385BDR-1-2, LM385PWRE4-1-2 saves 35% board area and improves thermal dissipation margin in sealed enclosures; versus TLVH431ACDBVR, it delivers tighter initial tolerance and lower noise at the cost of fixed output and higher minimum current.
Availability
LM385PWRE4-1-2 is available at Aetrix Electronics and suitable for portable meter references, portable test instruments, and battery-operated systems requiring stable component supply with guaranteed long-term continuity.
Supply support for LM385PWRE4-1-2 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 over 90 years of innovation in precision analog ICs.
The LM385 series belongs to TI's micropower voltage reference product line, designed specifically for battery-critical and space-constrained applications where low quiescent current, small footprint, and long-term stability are essential.
FAQ
What is the minimum cathode current required for regulation in the LM385PWRE4-1-2?
The LM385PWRE4-1-2 requires a minimum cathode current of 15 μA to maintain regulation within specifications. Below this threshold, output voltage drops nonlinearly and temperature stability degrades. This value is confirmed in Section 7.5 Electrical Characteristics of the SLVS075J datasheet under "Minimum reference current" for LM385-1.2 devices at full temperature range.
Does the LM385PWRE4-1-2 support capacitive loading without external compensation?
Yes, the LM385PWRE4-1-2 is internally compensated for stable operation with capacitive loads up to 0.1 μF, as stated in the Features section and validated in Layout Guidelines (Section 11.1). This eliminates the need for series resistance or external RC networks typically required with older shunt references.
What is the operating temperature range for the LM385PWRE4-1-2?
The LM385PWRE4-1-2 is specified for operation from 0°C to 70°C, consistent with the LM385-1.2 variant designation in the device family documentation. This differs from the LM285-1.2 (−40°C to 85°C) and LM385B-1.2 (0°C to 70°C with tighter tempco), and is explicitly listed in the Recommended Operating Conditions table (Section 7.3).
Can the LM385PWRE4-1-2 be used in negative-reference configurations?
Yes, the LM385PWRE4-1-2 implements a floating shunt architecture, enabling use in both positive and negative regulation topologies. As described in Section 8.3 Feature Description, its design allows the anode to float above or below cathode potential - for negative references, connect cathode to system ground and source current into anode while referencing output to a negative rail.
What is the broadband noise performance of the LM385PWRE4-1-2?
The LM385PWRE4-1-2 exhibits 60 μV RMS broadband noise over 10 Hz to 10 kHz, measured at 100 μA cathode current and 25°C, per Section 7.5 Electrical Characteristics. This low-noise profile supports high-resolution measurements in portable instrumentation where reference-induced noise directly impacts effective number of bits (ENOB).
LM385PWRE4-1-2 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:
- ±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-TSSOP
LM385PWRE4-1-2 FAQ
1.How can I place an order for LM385PWRE4-1-2 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM385PWRE4-1-2 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 LM385PWRE4-1-2 reliable?
The price and inventory of LM385PWRE4-1-2 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM385PWRE4-1-2 is usually 5 days.
3.What payment methods are accepted for LM385PWRE4-1-2?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM385PWRE4-1-2 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM385PWRE4-1-2?
LM385PWRE4-1-2 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM385PWRE4-1-2 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 LM385PWRE4-1-2?
For technical support, including LM385PWRE4-1-2 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM385PWRE4-1-2 requirements.
6.How does Aetrix verify that LM385PWRE4-1-2 is sourced from the original manufacturer or authorized distributors?
All LM385PWRE4-1-2 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 LM385PWRE4-1-2 meets industry standards.
7.What is the process for return or replacement of LM385PWRE4-1-2?
All LM385PWRE4-1-2 units undergo pre-shipment inspection (PSI). If there is an issue with LM385PWRE4-1-2, 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 LM385PWRE4-1-2 part is unused and in its original packaging.
Return procedure for LM385PWRE4-1-2:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM385PWRE4-1-2 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…
