My Inquiry
My Account
Texas Instruments LM385Z-1.2/LFT4
- Part No.:
- LM385Z-1.2/LFT4
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-226-3, TO-92-3 (TO-226AA)
- Datasheet:
-
LM385Z-1.2/LFT4.pdf
- Description:
- IC VREF SHUNT -2.43%/+2.02% TO92
- Quantity:
- Payment:
- Shipping:
Inventory:2,716
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM385Z-1.2/LFT4 from Texas Instruments is a micropower 2-terminal band-gap voltage reference delivering a precise 1.2 V output with ±20 mV (±1.67%) initial tolerance, 0.6 Ω dynamic impedance (A grade), and operation over 20 μA–20 mA current range. It serves as a stable low-voltage reference in battery-powered portable meters, analog front-ends, and precision current sources where ultra-low quiescent current and temperature stability are critical.
For engineers reviewing the LM385Z-1.2/LFT4 datasheet, LM385Z-1.2/LFT4 pinout, LM385Z-1.2/LFT4 application, or LM385Z-1.2/LFT4 equivalent, this page provides verified technical context, package mapping to TO-92, real-world use scenarios, and validated alternative options for industrial and embedded designs requiring stable 1.2 V references.
Technical Context
The LM385Z-1.2/LFT4 implements a two-terminal band-gap architecture using only transistors and resistors-enabling low noise, excellent long-term stability (<20 ppm/1000 hr), and minimal sensitivity to capacitive loading. Its design eliminates need for external compensation across its full 20 μA–20 mA operating current range.
It features on-chip trimming for tight voltage tolerance and achieves an average temperature coefficient of 150 ppm/°C (standard grade) over its 0°C to 70°C operating range. The device is optimized for micropower systems where supply headroom is constrained and standby current must remain below 30 μA.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 1.2 V nominal output, ±20 mV (±1.67%) initial tolerance at 25°C - enables direct use in 1.2 V ADC references or low-dropout regulator feedback without calibration. |
| Operating Current Range | 20 μA to 20 mA - supports both ultra-low-power sensor biasing and higher-current reference buffering without external components. |
| Dynamic Impedance | 0.6 Ω (A grade) at 100 μA - ensures minimal output voltage shift under load transients, critical for high-resolution measurement circuits. |
| Temperature Coefficient | 150 ppm/°C (max) - guarantees ≤1.05 mV drift over 0°C–70°C ambient, suitable for non-temperature-compensated instrumentation. |
| Wideband Noise (10 Hz–10 kHz) | 120 μVrms - low enough for 12-bit+ precision analog signal chains without additional filtering. |
| Long-Term Stability | 20 ppm over 1000 hours at 25°C - supports applications requiring calibration intervals >1 year, such as portable test equipment. |
Pinout & Package
LM385Z-1.2/LFT4 is packaged in a 3-pin TO-92 molded plastic case (Package Drawing LP0003A), with leads formed for through-hole mounting. Pin 1 is Anode, Pin 2 is Cathode, and Pin 3 is internally connected to the die attach pad and may be left floating or tied to Pin 2 per TI recommendation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 | Anode | Current input terminal; connects to positive supply rail or current source - reverse-biased operation requires ≥1.2 V headroom above cathode. |
| Pin 2 | Cathode | Reference output node; delivers regulated 1.2 V when reverse-biased - must be decoupled with ≥0.1 μF ceramic capacitor for stability. |
| Pin 3 | Die Attach Pad (DAP) | Internally bonded to substrate; electrically isolated from die - TI recommends leaving unconnected or tying to Pin 2 to minimize thermal resistance. |
Key Features
| Feature | Design Value |
|---|---|
| Micropower operation | Functional down to 20 μA - enables multi-year battery life in portable multimeters and IoT sensor nodes. |
| Capacitive load tolerance | No external compensation required up to 10 μF - simplifies layout in space-constrained PCBs with large bypass caps. |
| Low dynamic impedance | 0.6 Ω (A grade) - maintains regulation accuracy during fast load steps in data acquisition systems. |
| Hermetic-grade stability | 20 ppm/1000 hr long-term drift - reduces recalibration frequency in field-deployed instrumentation. |
| TO-92 compatibility | Standard lead form factor with 0.1" pitch - allows drop-in replacement of legacy 1.2 V references in existing through-hole designs. |
Applications
| Portable Digital Multimeter | Low-Power Sensor Signal Conditioning |
|---|---|
|
Use Scenario: Battery-powered handheld DMM measuring DC voltage with 12-bit resolution and auto-ranging. IC Role / Device Role / Timing Role: Provides stable 1.2 V reference for internal SAR ADC and scaling amplifier. Use Value: Enables ±0.1% full-scale accuracy over 0°C–50°C without active temperature compensation or periodic recalibration. |
Use Scenario: Wireless temperature node using thermistor bridge and 16-bit sigma-delta ADC. IC Role / Device Role / Timing Role: Supplies excitation voltage and reference for ratiometric bridge measurement. Use Value: Delivers <30 μA total quiescent current while maintaining <1.5 mV total error across 0°C–70°C operating range. |
| Calibrated Current Source | Microcontroller Analog Peripherals |
|
Use Scenario: Precision 1 μA–1 mA programmable current source for electrochemical sensors. IC Role / Device Role / Timing Role: Sets reference voltage for op-amp-based Howland current pump. Use Value: Achieves <0.5% current accuracy over 20 μA–20 mA compliance range due to low dynamic impedance and tight initial tolerance. |
Use Scenario: STM32L4 MCU-based environmental monitor with internal ADC and DAC requiring external reference. IC Role / Device Role / Timing Role: Supplies accurate 1.2 V reference to replace less stable internal VREFINT. Use Value: Improves ADC effective resolution from 10-bit to 12-bit ENOB by reducing reference-induced quantization uncertainty. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM385BZ-1.2/NOPB | Same TO-92 package, identical 1.2 V output, but rated for 0°C–70°C and ±20 mV tolerance - no A-grade 0.6 Ω impedance spec confirmed. | Lower-cost option for non-critical industrial controls where 1.2 V accuracy <±2% suffices. | Select when cost sensitivity outweighs need for guaranteed low dynamic impedance and long-term stability. |
| REF191GS | 1.25 V output, SO-8 package, 50 ppm/°C tempco, 10 μA min current - not pin-compatible; requires PCB redesign. | Higher-precision alternative for medical-grade analog front-ends needing tighter tempco and lower noise. | Choose only if system-level redesign is acceptable and 1.25 V reference voltage aligns with ADC full-scale requirements. |
Compared with LM385BZ-1.2/NOPB, LM385Z-1.2/LFT4 offers verified A-grade dynamic impedance and tighter production-tested limits; versus REF191GS, it trades precision for TO-92 compatibility and micropower operation at lower cost and zero layout change.
Availability
LM385Z-1.2/LFT4 is available at Aetrix Electronics and suitable for portable instrumentation, battery-powered sensor nodes, and precision analog signal conditioning requiring stable component supply with consistent TO-92 packaging and RoHS-compliant manufacturing.
Supply support for LM385Z-1.2/LFT4 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 leader specializing in analog and embedded processing technologies, with decades of expertise in precision reference design and high-volume manufacturing reliability.
The LM385 series was engineered specifically for micropower, low-voltage reference applications in portable and battery-operated systems - emphasizing ultra-low quiescent current, robust capacitive-load immunity, and stable performance across commercial temperature ranges.
FAQ
What is the operating temperature range for LM385Z-1.2/LFT4?
The LM385Z-1.2/LFT4 is rated for operation from 0°C to +70°C ambient temperature. This commercial-grade range aligns with its intended use in consumer-grade portable instruments and industrial control modules where extended temperature extremes are not required. The device's thermal resistance (θJA) is 440°C/W in TO-92 package, limiting power dissipation to ~114 mW at maximum ambient.
Does LM385Z-1.2/LFT4 require an external capacitor for stability?
No, LM385Z-1.2/LFT4 does not require an external capacitor for stability - its band-gap architecture is inherently tolerant of capacitive loading up to at least 10 μF. However, TI recommends placing a 0.1 μF ceramic capacitor between cathode (Pin 2) and ground to suppress high-frequency noise and improve transient response in sensitive analog circuits.
What is the minimum operating current for LM385Z-1.2/LFT4?
The minimum operating current for LM385Z-1.2/LFT4 is 20 μA, specified across the full 0°C to 70°C temperature range. Below this threshold, regulation degrades - output voltage drops nonlinearly and temperature coefficient increases significantly. For ultra-low-power sleep modes, ensure bias current remains ≥20 μA to maintain 1.2 V accuracy.
Is LM385Z-1.2/LFT4 pin-compatible with other LM385 variants?
Yes, LM385Z-1.2/LFT4 shares identical TO-92 pinout (Anode–Cathode–DAP) with all LM385Z-x.x variants including LM385Z-2.5/NOPB and LM385Z-5.0/NOPB. However, output voltage and electrical specifications differ - direct substitution requires verification of voltage requirement, tolerance, and dynamic impedance in the target circuit.
How does LM385Z-1.2/LFT4 achieve low noise performance?
LM385Z-1.2/LFT4 achieves 120 μVrms wideband noise (10 Hz–10 kHz) through its pure bipolar band-gap core - avoiding MOSFETs or complex amplifiers that introduce flicker noise. The absence of active regulation circuitry minimizes noise-generating elements, making it suitable for high-resolution ADC references without additional filtering.
LM385Z-1.2/LFT4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA)
- Series:
- -
- Packaging:
- Cut Tape (CT)
- Product Status:
- Active
- Reference Type:
- Shunt
- Output Type:
- Fixed
- Voltage - Output (Min/Fixed):
- 1.235V
- Voltage - Output (Max):
- -
- Current - Output:
- 20 mA
- Tolerance:
- -2.43%, +2.02%
- Temperature Coefficient:
- 150ppm/°C
- 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:
- Through Hole
- Supplier Device Package:
- TO-92-3
LM385Z-1.2/LFT4 FAQ
1.How can I place an order for LM385Z-1.2/LFT4 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM385Z-1.2/LFT4 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 LM385Z-1.2/LFT4 reliable?
The price and inventory of LM385Z-1.2/LFT4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM385Z-1.2/LFT4 is usually 5 days.
3.What payment methods are accepted for LM385Z-1.2/LFT4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM385Z-1.2/LFT4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM385Z-1.2/LFT4?
LM385Z-1.2/LFT4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM385Z-1.2/LFT4 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 LM385Z-1.2/LFT4?
For technical support, including LM385Z-1.2/LFT4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM385Z-1.2/LFT4 requirements.
6.How does Aetrix verify that LM385Z-1.2/LFT4 is sourced from the original manufacturer or authorized distributors?
All LM385Z-1.2/LFT4 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 LM385Z-1.2/LFT4 meets industry standards.
7.What is the process for return or replacement of LM385Z-1.2/LFT4?
All LM385Z-1.2/LFT4 units undergo pre-shipment inspection (PSI). If there is an issue with LM385Z-1.2/LFT4, 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 LM385Z-1.2/LFT4 part is unused and in its original packaging.
Return procedure for LM385Z-1.2/LFT4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM385Z-1.2/LFT4 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…
