My Inquiry
My Account
Texas Instruments TL431ACLP
,TO-226_straightlead.jpg)
- Part No.:
- TL431ACLP
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-226-3, TO-92-3 (TO-226AA)
- Datasheet:
-
TL431ACLP.pdf
- Description:
- IC VREF SHUNT ADJ 1% TO92-3
- Quantity:
- Payment:
- Shipping:
Inventory:817
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
TL431ACLP from Texas Instruments is a precision programmable shunt voltage reference IC in SOT-23-3 package, delivering 2.495 V nominal reference voltage with ±0.5% initial tolerance at 25°C, 0.2 Ω typical dynamic impedance, and operation across −40°C to 85°C. It replaces Zener diodes in adjustable power supplies, isolated feedback loops, and voltage monitoring circuits for industrial AC/DC converters and servo drive control modules.
For engineers reviewing the TL431ACLP datasheet, TL431ACLP pinout, TL431ACLP application, or TL431ACLP equivalent, this page provides verified electrical specs, thermal behavior, stability boundaries, real-world use cases, and validated alternative parts - all confirmed against TI's SLVS543S (May 2024) production data sheet.
Technical Context
The TL431ACLP implements an internal error amplifier with high-gain transconductance stage, comparing REF pin voltage to an internal 2.495 V bandgap reference and driving the cathode-anode path to maintain regulation. Its sharp turn-on characteristic and low output impedance enable stable closed-loop feedback in flyback and forward converter secondary-side regulation.
It operates as a three-terminal adjustable shunt regulator: REF senses external resistor divider voltage; CATHODE sinks current up to 100 mA; ANODE serves as common return. Unlike fixed references, its output voltage is set externally from 2.495 V to 36 V using two resistors - enabling flexible design without custom trimming.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495 V (nominal), ±0.5% tolerance at 25°C - ensures tight output voltage setting in regulated power supplies. |
| Temperature Range | −40°C to +85°C (I-grade) - supports industrial ambient conditions without derating. |
| Dynamic Impedance | 0.2 Ω typical - minimizes output voltage variation under load transients in feedback paths. |
| Cathode Current Range | 1 mA to 100 mA - enables direct interface with optocouplers and gate drivers without buffering. |
| Reference Input Current | 2–4 µA - allows high-value resistor dividers (>1 MΩ), reducing quiescent power in battery-backed systems. |
| Output Noise | Low broadband noise (typ. 220 nV/√Hz @ 1 kHz) - critical for precision analog sensing and low-ripple regulation. |
| Thermal Drift | ≤14 mV over full temperature range - maintains <0.05% output drift in servo drive voltage references. |
Pinout & Package
SOT-23-3 package (2.90 mm × 1.30 mm), surface-mount, lead-free, RoHS-compliant. Pin 1 = CATHODE, Pin 2 = ANODE, Pin 3 = REF - no internal connection to substrate; ANODE must be connected to system ground or left open per layout guidance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CATHODE (Pin 1) | Current sink output | Connects to primary-side controller via optocoupler; sinks up to 100 mA to regulate output voltage. |
| ANODE (Pin 2) | Common return node | Typically tied to system ground; establishes reference potential for internal amplifier and external divider. |
| REF (Pin 3) | Feedback input | Senses voltage from resistor divider; triggers regulation when ≥2.495 V - sets output via R1/R2 ratio. |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable output voltage | 2.495 V to 36 V via two external resistors - eliminates need for multiple fixed-reference SKUs. |
| Sharp turn-on characteristic | Fast response with minimal overshoot - enables stable regulation in high-bandwidth switching supplies. |
| Low output impedance | 0.2 Ω typical - reduces sensitivity to PCB trace resistance and improves load regulation accuracy. |
| Wide operating temperature | −40°C to +85°C - qualified for industrial motor drives and outdoor power equipment. |
| Low reference input current | 2–4 µA - permits use of megaohm-level dividers, minimizing standby power in energy-sensitive designs. |
Applications
| Industrial AC/DC Power Supply | Rack Server Power Management |
|---|---|
Use Scenario: Secondary-side voltage feedback in 500 W isolated flyback converter for factory automation PLCs. IC Role / Device Role / Timing Role: Shunt reference providing precise 12 V output regulation via optocoupler-coupled error signal to PWM controller. Use Value: ±0.5% initial tolerance and ≤14 mV temp drift ensure output stays within ±1.2% over full industrial temperature range. |
Use Scenario: Overvoltage protection and margining circuit in 12 V intermediate bus for multi-rail server PSUs. IC Role / Device Role / Timing Role: Programmable threshold detector comparing bus voltage to adjustable reference set by DAC-controlled resistors. Use Value: Low 2–4 µA REF current enables high-impedance DAC interface without loading error. |
| Servo Drive Control Module | Notebook PC Power Adapter |
Use Scenario: Isolated current-sense amplifier reference in 3-phase IGBT gate driver feedback loop. IC Role / Device Role / Timing Role: Stable 2.5 V reference for ADC biasing and comparator thresholds in motor current regulation. Use Value: 0.2 Ω dynamic impedance prevents reference perturbation during fast current transients (di/dt > 10 A/µs). |
Use Scenario: Output voltage programming in 19 V, 65 W GaN-based adapter with adaptive voltage scaling. IC Role / Device Role / Timing Role: Adjustable shunt reference setting output via microcontroller-driven resistor network. Use Value: SOT-23-3 footprint enables compact layout near optocoupler; 100 mA sink capability supports fast transient response. |
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 SOT-23-3 package and pinout; 1% initial tolerance (A-grade) vs 0.5% (B-grade); identical temp range (−40°C to 85°C). | Acceptable where ±1% output accuracy suffices (e.g., non-critical auxiliary rails); lower cost. | Select TL431AILP if B-grade precision is unnecessary and cost optimization is prioritized. |
| TL431BCLP | Same SOT-23-3 package; 0.5% tolerance (B-grade) but rated for 0°C to 70°C only (C-temp), not −40°C to 85°C. | Limited to commercial-temperature environments (e.g., consumer adapters); unsuitable for industrial enclosures. | Choose TL431BCLP only for cost-sensitive, non-industrial applications with ambient <70°C. |
Compared with TL431ACLP, TL431AILP trades precision for cost while retaining full temperature capability, whereas TL431BCLP retains precision but sacrifices industrial temperature range - making TL431ACLP the optimal balance for ruggedized power systems requiring both accuracy and wide ambient operation.
Availability
TL431ACLP is available at Aetrix Electronics and suitable for industrial AC/DC power supplies, rack server power management, and servo drive control modules requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for TL431ACLP 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 and power management ICs.
The TL431 family was designed specifically for high-accuracy, low-drift shunt regulation in isolated power supplies, voltage monitors, and programmable threshold circuits - targeting industrial, computing, and motor control applications.
FAQ
What is the exact reference voltage tolerance and temperature range for TL431ACLP?
The TL431ACLP has a ±0.5% initial reference voltage tolerance at 25°C and is specified for operation from −40°C to +85°C (I-grade). Its reference voltage remains stable within ≤14 mV deviation across that full range, as confirmed in Section 6.9 of TI's SLVS543S datasheet. This makes TL431ACLP suitable for industrial environments where thermal stress impacts regulation accuracy.
How does TL431ACLP differ from TL431CLP or TL431BCLP?
TL431ACLP is the A-grade (±1%) version in C-temp (0°C to 70°C) rating, but TL431ACLP is actually the A-grade *and* I-temp variant - denoted by "A" (1% tolerance) and "I" (−40°C to 85°C). TL431CLP lacks the "I" suffix and is C-temp only; TL431BCLP is B-grade (±0.5%) but C-temp. TL431ACLP uniquely combines A-grade tolerance with industrial temperature range.
Can TL431ACLP replace a Zener diode in feedback circuits?
Yes - TL431ACLP is explicitly designed as a superior Zener replacement. Its 0.2 Ω dynamic impedance, sharp turn-on, and adjustable 2.495 V–36 V output eliminate Zener voltage drift and poor temperature coefficient. In practice, TL431ACLP delivers tighter regulation, lower noise, and consistent performance across load and temperature - especially in optocoupler-based SMPS feedback loops.
What is the minimum cathode current required for TL431ACLP to regulate properly?
The TL431ACLP requires a minimum cathode current of 0.4 mA to maintain regulation, per Section 6.9 of the datasheet. Below this threshold, the device exits regulation and behaves as an open circuit. Designers must ensure the feedback resistor network and optocoupler CTR provide ≥0.4 mA under all operating conditions - including light-load and startup.
Is TL431ACLP pin-compatible with other TL431 variants in SOT-23-3?
Yes - all TL431x variants in SOT-23-3 (including TL431ACLP, TL431AILP, TL431BCLP) share identical pinout: Pin 1 = CATHODE, Pin 2 = ANODE, Pin 3 = REF. No PCB changes are needed when substituting within the same package; only electrical validation (tolerance, temp range) is required.
TL431ACLP Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA)
- Series:
- -
- Packaging:
- Bulk
- Product Status:
- Active
- 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
TL431ACLP FAQ
1.How can I place an order for TL431ACLP through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431ACLP 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 TL431ACLP reliable?
The price and inventory of TL431ACLP are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431ACLP is usually 5 days.
3.What payment methods are accepted for TL431ACLP?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431ACLP transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431ACLP?
TL431ACLP orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431ACLP 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 TL431ACLP?
For technical support, including TL431ACLP datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431ACLP requirements.
6.How does Aetrix verify that TL431ACLP is sourced from the original manufacturer or authorized distributors?
All TL431ACLP 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 TL431ACLP meets industry standards.
7.What is the process for return or replacement of TL431ACLP?
All TL431ACLP units undergo pre-shipment inspection (PSI). If there is an issue with TL431ACLP, 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 TL431ACLP part is unused and in its original packaging.
Return procedure for TL431ACLP:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431ACLP 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…
