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Texas Instruments TL431ACLPRE3
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- Part No.:
- TL431ACLPRE3
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Datasheet:
-
TL431ACLPRE3.pdf
- Description:
- IC VREF SHUNT ADJ 1% TO92-3
- Quantity:
- Payment:
- Shipping:
Inventory:4,715
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Product details
Overview
TL431ACLPRE3 from Texas Instruments is a precision programmable shunt voltage reference IC with 1% initial tolerance at 25°C, adjustable output from 2.47 V to 36 V, and operation across −40°C to 85°C. It delivers 0.2 Ω typical dynamic impedance, 1–100 mA sink-current capability, and low 6 mV max temperature drift (I-grade), serving as a Zener diode replacement in feedback loops of isolated DC/DC converters and AC/DC power supplies.
For engineers reviewing the TL431ACLPRE3 datasheet, TL431ACLPRE3 pinout, TL431ACLPRE3 application, or TL431ACLPRE3 equivalent, key selection criteria include its A-grade accuracy, SOT-23-3 package footprint, cathode-anode-reference terminal configuration, thermal stability over industrial temperature range, and compatibility with optocoupler-based secondary-side regulation.
Technical Context
The TL431ACLPRE3 implements an internal bandgap reference and high-gain transconductance amplifier driving an NPN output stage. Its three-terminal shunt topology requires external resistive divider between cathode and reference pin to set output voltage, with anode tied to system ground or return path.
It operates in active regulation when cathode voltage exceeds reference threshold by ≥1 V, maintaining stable output via sharp turn-on characteristic and low 0.2 Ω dynamic impedance - enabling precise error amplification in switching power supply feedback networks without external compensation in many cases.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Vref tolerance @ 25°C | ±1% (A grade): ensures 24.7–25.2 V output setting accuracy at room temperature for mid-tier precision applications |
| Adjustable output range | 2.47 V to 36 V: supports wide-range feedback voltage programming using two external resistors |
| Operating temperature | −40°C to +85°C (I-grade): validated for industrial ambient conditions without derating |
| Dynamic impedance | 0.2 Ω typical: minimizes output voltage variation under load transients in closed-loop regulation |
| Sink current range | 1 mA to 100 mA: enables direct drive of optocoupler LEDs or small-signal transistors in isolated feedback paths |
| Reference input current | 2–4 µA: allows use of high-value resistor dividers (>1 MΩ) to reduce power loss in battery-sensitive designs |
| Temp drift (VI(dev)) | 14–34 mV over full range: quantifies worst-case reference voltage deviation across −40°C to +85°C |
Pinout & Package
TL431ACLPRE3 is housed in a 3-pin SOT-23-3 package (2.90 mm × 1.30 mm body size) with gull-wing leads and moisture sensitivity level 1. The package is RoHS-compliant and optimized for automated surface-mount assembly.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1: Cathode (K) | Shunt current output node | Connects to primary-side controller feedback input (e.g., UC384x COMP pin) or optocoupler anode; sinks regulated current |
| Pin 2: Anode (A) | Common reference return | Typically tied to system ground or power supply return; defines voltage reference point for internal comparator |
| Pin 3: Reference (REF) | Threshold input | Connected to resistor divider midpoint; triggers regulation when voltage reaches ~2.495 V; draws only 2–4 µA |
Key Features
| Feature | Design Value |
|---|---|
| Programmable reference voltage | Set precisely from 2.47 V to 36 V using two external resistors - eliminates need for multiple fixed-voltage references |
| Low dynamic impedance | 0.2 Ω typical ensures minimal output perturbation during fast load steps - critical for stable SMPS feedback loop response |
| Industrial temperature range | Rated for −40°C to +85°C operation without performance degradation - suitable for factory automation and motor drives |
| Low reference input current | 2–4 µA enables high-impedance voltage sensing - reduces divider power loss and improves efficiency in standby modes |
| Sharp turn-on characteristic | Enables clean transition into regulation with minimal hysteresis - avoids oscillation in marginally compensated feedback networks |
Applications
| Rack Server Power Supply | Industrial AC/DC Converter |
|---|---|
Use Scenario: Secondary-side voltage regulation in isolated 48 V input, 12 V/50 A output telecom rectifier modules. IC Role / Device Role / Timing Role: Precision shunt reference in optocoupler-coupled feedback loop, setting output voltage with ±1% accuracy across line/load/temperature. Use Value: Maintains tight output regulation (<±1.5%) under 10–90% load step while enabling fast transient recovery via low dynamic impedance. |
Use Scenario: Output voltage control in DIN-rail mounted 24 V/20 A industrial power supply for PLC I/O modules. IC Role / Device Role / Timing Role: Adjustable reference for TL494 or UC3845-based PWM controller feedback network. Use Value: Enables single-BOM flexibility across 12 V, 24 V, and 48 V output variants using same PCB layout and controller IC. |
| AC Inverter Drive | Servo Drive Control Module |
Use Scenario: DC bus voltage monitoring and overvoltage protection reference in 3-phase 400 V AC inverter for HVAC compressors. IC Role / Device Role / Timing Role: High-accuracy threshold detector feeding comparator input to trigger shutdown when bus exceeds 450 V. Use Value: Provides stable trip point over −40°C to +85°C with <15 mV drift - eliminates thermal hysteresis in protection circuitry. |
Use Scenario: Feedback reference for isolated gate driver bias supply in servo amplifier's IGBT half-bridge stage. IC Role / Device Role / Timing Role: Regulated 15 V auxiliary supply reference, powering isolated DC/DC converter for gate drive logic. Use Value: Ensures consistent gate driver voltage despite input ripple, improving IGBT switching consistency and reducing EMI. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431AILP | Same A-grade accuracy and I-temp range, but in SOIC-8 package (larger footprint, higher thermal resistance) | Better suited for through-hole prototyping or high-power dissipation scenarios where SOT-23 thermal limits are exceeded | Select TL431AILP when board space allows larger package and junction temperature must stay below 125°C under >50 mA continuous cathode current |
| TLVH431BIDBVR | Lower 0.5% B-grade accuracy, wider 1.24 V to 18 V range, lower 1.8 V minimum cathode voltage, SOT-23-3 | Optimized for low-voltage systems (e.g., 3.3 V or 5 V rails); not suitable for >18 V outputs or high-temperature industrial environments | Choose TLVH431BIDBVR only for cost-sensitive, low-voltage (<12 V) applications requiring tighter initial tolerance than TL431ACLPRE3 offers |
Compared with TL431ACLPRE3, TL431AILP trades compact SOT-23-3 size for better thermal handling in SOIC-8, while TLVH431BIDBVR sacrifices voltage range and temperature rating for improved accuracy at lower voltages - making TL431ACLPRE3 the balanced choice for industrial 24–48 V power systems.
Availability
TL431ACLPRE3 is available at Aetrix Electronics and suitable for rack server power supplies, industrial AC/DC converters, and servo drive control modules requiring stable component supply with guaranteed long-term manufacturability.
Supply support for TL431ACLPRE3 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 power management ICs.
The TL431 family was engineered as a drop-in Zener diode replacement for high-stability, programmable shunt regulation in power supply feedback, voltage monitoring, and error amplification applications across industrial, computing, and automotive markets.
FAQ
What is the reference voltage tolerance of TL431ACLPRE3 at 25°C?
The TL431ACLPRE3 has a reference voltage tolerance of ±1% at 25°C, corresponding to a nominal Vref of 2.495 V with a guaranteed range of 2.470 V to 2.520 V. This A-grade accuracy is specified in Section 6.8 of the TI datasheet SLVS543S and applies specifically to the TL431ACLPRE3 variant with I-temperature grading and SOT-23-3 packaging.
Can TL431ACLPRE3 be used in place of a Zener diode?
Yes, TL431ACLPRE3 functions as a superior alternative to discrete Zener diodes in most shunt regulation applications. Unlike Zeners, TL431ACLPRE3 provides sharp turn-on, low 0.2 Ω dynamic impedance, programmable output from 2.47 V to 36 V, and stable 1% accuracy across −40°C to +85°C - all in the same SOT-23-3 footprint as many Zener packages.
What is the maximum cathode voltage rating for TL431ACLPRE3?
The absolute maximum cathode-to-anode voltage (VKA) for TL431ACLPRE3 is 37 V, with recommended operating range from Vref up to 36 V. Exceeding 37 V risks permanent damage. This rating is defined in Section 6.1 (Absolute Maximum Ratings) of the TI datasheet and applies to all TL431x variants regardless of grade or package.
Does TL431ACLPRE3 require external compensation in feedback circuits?
TL431ACLPRE3 typically does not require external compensation when used with standard optocoupler-based feedback in flyback or forward converters, due to its inherent phase margin and low dynamic impedance. However, stability must be verified per application - Figure 6-16 and 6-18 in the datasheet provide load capacitance vs. cathode current stability boundaries specific to SOT-23-3 devices.
How does the temperature drift of TL431ACLPRE3 compare to the C-grade version?
TL431ACLPRE3 (I-grade) exhibits up to 34 mV total reference voltage deviation over −40°C to +85°C, whereas the C-grade TL431ACLPR has ≤25 mV drift over 0°C to +70°C. The I-grade's wider temperature range and higher drift reflect its industrial qualification - confirmed in Sections 6.5 (C-grade) and 6.9 (I-grade) of the datasheet.
TL431ACLPRE3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Reference Type:
- Shunt
- Output Type:
- Adjustable
- Voltage - Output (Min/Fixed):
- 2.495V
- Voltage - Output (Max):
- 36 V
- Current - Output:
- 100 mA
- Tolerance:
- ±1%
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 600 µA
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-92-3
TL431ACLPRE3 FAQ
1.How can I place an order for TL431ACLPRE3 through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431ACLPRE3 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 TL431ACLPRE3 reliable?
The price and inventory of TL431ACLPRE3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431ACLPRE3 is usually 5 days.
3.What payment methods are accepted for TL431ACLPRE3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431ACLPRE3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431ACLPRE3?
TL431ACLPRE3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431ACLPRE3 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 TL431ACLPRE3?
For technical support, including TL431ACLPRE3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431ACLPRE3 requirements.
6.How does Aetrix verify that TL431ACLPRE3 is sourced from the original manufacturer or authorized distributors?
All TL431ACLPRE3 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 TL431ACLPRE3 meets industry standards.
7.What is the process for return or replacement of TL431ACLPRE3?
All TL431ACLPRE3 units undergo pre-shipment inspection (PSI). If there is an issue with TL431ACLPRE3, 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 TL431ACLPRE3 part is unused and in its original packaging.
Return procedure for TL431ACLPRE3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431ACLPRE3 Tags
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TL431BQDBZR
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LM4040CYM3-4.1-TR
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LM4040EIM3-2.5/NOPB
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AZ431LBNTR-G1
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LM4041DIM3-ADJ/NOPB
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LM4040DIM3X-2.5/NOPB
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AZ431LANTR-G1
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