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Texas Instruments TL431CPWE4
- Part No.:
- TL431CPWE4
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 8-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
TL431CPWE4.pdf
- Description:
- IC VREF SHUNT ADJ 2.2% 8TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,404
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Product details
Overview
TL431CPWE4 from Texas Instruments is a precision programmable shunt voltage reference IC with 1% initial tolerance at 25°C, adjustable output from 2.495 V to 36 V via two external resistors, 0.2 Ω typical dynamic impedance, sink-current capability of 1–100 mA, and operation across −40°C to 85°C. It serves as a Zener diode replacement in secondary-side regulation of flyback SMPSs.
For engineers reviewing the TL431CPWE4 datasheet, TL431CPWE4 pinout, TL431CPWE4 application, or TL431CPWE4 equivalent, key selection criteria include reference voltage accuracy over temperature, cathode current range, dynamic impedance, thermal drift (VI(dev) = 14 mV max), and SOT-23-3 package compatibility with space-constrained power supervision circuits.
Technical Context
The TL431CPWE4 implements a three-terminal adjustable shunt regulator architecture with an internal 2.495 V reference and high-gain error amplifier driving an NPN output stage. Its sharp turn-on characteristic and low output impedance enable stable closed-loop feedback in isolated DC/DC converters.
It operates as a voltage-controlled current sink: when the REF pin voltage exceeds 2.495 V, the cathode-anode path conducts, sinking current up to 100 mA. The device requires ≥0.4 mA minimum cathode current for regulation and exhibits <0.5 µA off-state leakage at 36 V cathode voltage.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Vref | 2.495 V ±1% at 25°C - sets precise threshold for feedback loop activation |
| VKA Range | 2.495 V to 36 V - enables wide-range adjustable output using resistor divider |
| IKA Range | 1 mA to 100 mA - supports robust current-sinking for error amplifier drive and load regulation |
| |zKA| | 0.2 Ω typical - ensures minimal output voltage deviation under dynamic load transients |
| VI(dev) | 14 mV max over −40°C to 85°C - guarantees ≤0.56% reference drift across full industrial temp range |
| Iref | 2–4 µA - ultra-low input bias current minimizes resistor-divider loading error |
| Imin | 0.4–0.7 mA - defines minimum cathode current needed to maintain regulation stability |
Pinout & Package
SOT-23-3 package (2.90 mm × 1.30 mm body), surface-mount, lead-free, RoHS-compliant. Pin 1: Cathode (current sink terminal); Pin 2: Anode (common return, typically grounded); Pin 3: REF (precision 2.495 V threshold input).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (Pin 1) | Current sink output | Connects to feedback node in SMPS; sinks current to adjust duty cycle when REF exceeds Vref |
| Anode (Pin 2) | Common reference node | Typically tied to system ground or low-side return; defines voltage reference point for REF and VKA |
| REF (Pin 3) | Precision voltage sense input | Monitors divided output voltage; triggers conduction when >2.495 V ±1% |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable reference range | 2.495 V to 36 V - eliminates need for multiple fixed-voltage Zeners in multi-output supplies |
| Low dynamic impedance | 0.2 Ω typical - maintains tight output regulation despite load or line variations |
| Industrial temperature range | −40°C to +85°C - qualified for use in automotive body electronics and industrial power modules |
| Zener replacement capability | Sharp turn-on with <100 ns response - enables fast transient correction in isolated feedback paths |
| Low reference input current | 2–4 µA - permits use of high-value resistor dividers without compromising accuracy |
Applications
| Switched-Mode Power Supply Feedback | Overvoltage Protection Circuit |
|---|---|
Use Scenario: Secondary-side voltage sensing in isolated flyback converter with optocoupler feedback. IC Role / Device Role / Timing Role: Shunt reference providing precise 2.495 V threshold to control optocoupler LED current and regulate primary-side PWM duty cycle. Use Value: Enables ±1% output voltage accuracy across line/load/temperature while reducing component count vs. discrete Zener + transistor solution. |
Use Scenario: Monitoring 12 V rail in automotive ECU to trigger shutdown if voltage exceeds 13.8 V. IC Role / Device Role / Timing Role: Adjustable comparator with integrated reference; REF pin biased to 13.8 V via resistor divider, cathode connected to MOSFET gate driver. Use Value: Delivers fast, accurate trip point without external op-amp or precision reference IC, minimizing BOM cost and board area. |
| Programmable Current Source | Linear Regulator Error Amplifier |
Use Scenario: Constant-current LED driver for signage requiring 350 mA across varying forward voltages. IC Role / Device Role / Timing Role: Shunt regulator configured with sense resistor between cathode and anode to fix current through load. Use Value: Achieves <±2% current accuracy over temperature using only one external resistor, eliminating need for dedicated current-sense IC. |
Use Scenario: Error amplifier in low-noise LDO where reference stability directly impacts PSRR and dropout performance. IC Role / Device Role / Timing Role: Precision reference source for LDO's internal error amp; REF pin tied to bandgap, cathode drives pass transistor gate. Use Value: 14 mV VI(dev) ensures <0.12% reference drift over −40°C to 85°C, preserving LDO output accuracy without trimming. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431CDBZR | SOT-23-3 package, same 1% grade (A), but C-temp grade (0°C to 70°C) vs. I-temp (−40°C to 85°C) of TL431CPWE4 | Limited to commercial ambient environments; unsuitable for under-hood or industrial enclosures | Select TL431CDBZR only for cost-sensitive consumer applications with controlled temperature profiles. |
| TL431BIDBZR | SOT-23-3 package, 0.5% grade (B), I-temp rated (−40°C to 85°C), VI(dev) = 14 mV same as TL431CPWE4 | Higher initial accuracy enables tighter output regulation in precision power supplies | Choose TL431BIDBZR when ±0.5% output tolerance is required and budget allows premium grade. |
Compared with TL431CDBZR, TL431CPWE4 offers extended temperature qualification critical for industrial deployment; compared with TL431BIDBZR, it trades 0.5% initial accuracy for lower unit cost while retaining identical thermal performance and package footprint.
Availability
TL431CPWE4 is available at Aetrix Electronics and suitable for switched-mode power supplies, overvoltage protection circuits, and programmable current sources requiring stable component supply with guaranteed long-term manufacturability.
Supply support for TL431CPWE4 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 power management, signal chain, and high-reliability components.
The TL431 product line delivers precision programmable shunt references for feedback, monitoring, and regulation in power conversion systems-designed for accuracy, stability, and ease of integration across automotive, industrial, and computing applications.
FAQ
What is the reference voltage tolerance of TL431CPWE4 at 25°C?
The TL431CPWE4 has a reference voltage tolerance of ±1% at 25°C, corresponding to the 'A' grade per TI's nomenclature. This means its Vref falls within 2.470 V to 2.520 V at room temperature under specified test conditions (VKA = Vref, IKA = 10 mA). This tolerance is confirmed in Section 7.8 of the SLVS543P datasheet for TL431AC devices.
Does TL431CPWE4 support operation at −40°C?
Yes, TL431CPWE4 is rated for operation from −40°C to +85°C (I-temp grade). Its VI(dev) specification is 14 mV maximum over this full range, ensuring reference stability in industrial and automotive under-hood environments. This is explicitly defined in the Device Comparison Table and Electrical Characteristics sections for TL431AI/TL432AI variants.
What package type is used by TL431CPWE4?
TL431CPWE4 uses the SOT-23-3 (DBZ) package, with nominal body dimensions of 2.90 mm × 1.30 mm. Pin configuration is Cathode (Pin 1), Anode (Pin 2), REF (Pin 3), as documented in the Pin Configuration and Functions section of the datasheet and confirmed in the Device Information table.
Can TL431CPWE4 replace a standard Zener diode?
Yes, TL431CPWE4 is explicitly designed as a Zener diode replacement. Its sharp turn-on, low dynamic impedance (0.2 Ω), and adjustable output (2.495 V to 36 V) allow it to emulate Zener behavior with superior accuracy, temperature stability, and current-handling capability-particularly valuable in onboard regulation and switching power supplies.
What is the minimum cathode current required for regulation in TL431CPWE4?
The TL431CPWE4 requires a minimum cathode current (Imin) of 0.4 mA to 0.7 mA to maintain regulation, depending on operating conditions. This value is specified in Sections 7.8–7.10 of the datasheet for TL431AC/AI/AQ variants and ensures stable reference operation when used in feedback networks with high-impedance dividers.
TL431CPWE4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- 8-TSSOP (0.173", 4.40mm Width)
- Series:
- -
- Packaging:
- Tube
- 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:
- ±2.2%
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 1 mA
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-TSSOP
TL431CPWE4 FAQ
1.How can I place an order for TL431CPWE4 through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431CPWE4 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 TL431CPWE4 reliable?
The price and inventory of TL431CPWE4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431CPWE4 is usually 5 days.
3.What payment methods are accepted for TL431CPWE4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431CPWE4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431CPWE4?
TL431CPWE4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431CPWE4 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 TL431CPWE4?
For technical support, including TL431CPWE4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431CPWE4 requirements.
6.How does Aetrix verify that TL431CPWE4 is sourced from the original manufacturer or authorized distributors?
All TL431CPWE4 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 TL431CPWE4 meets industry standards.
7.What is the process for return or replacement of TL431CPWE4?
All TL431CPWE4 units undergo pre-shipment inspection (PSI). If there is an issue with TL431CPWE4, 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 TL431CPWE4 part is unused and in its original packaging.
Return procedure for TL431CPWE4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431CPWE4 Tags
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TL431AIDBZR
Texas Instruments
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TL431BQDBZR
Texas Instruments
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AN431AN-ATRG1
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LM4040CYM3-2.5-TR
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LM4040CYM3-4.1-TR
Microchip Technology
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LM4040EIM3-2.5/NOPB
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AZ431LBNTR-G1
Diodes Incorporated
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LM4040D20IDBZR
Texas Instruments
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LM4041DIM3-ADJ/NOPB
Texas Instruments
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LM4040DIM3X-2.5/NOPB
Texas Instruments
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LM4040DIM3-2.5/NOPB
Texas Instruments
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AZ431LANTR-G1
Diodes Incorporated
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