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Texas Instruments TL431CPWR
- Part No.:
- TL431CPWR
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 8-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
TL431CPWR.pdf
- Description:
- IC VREF SHUNT ADJ 2.2% 8TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,306
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Product details
Overview
TL431CPWR from Texas Instruments is a precision programmable shunt voltage reference in SOT-23-3 package, delivering 2.495 V nominal reference voltage with ±0.5% initial tolerance (B grade), 0.2 Ω typical dynamic impedance, and sink-current capability from 1 mA to 100 mA across −40°C to 85°C. It replaces Zener diodes in feedback loops of isolated DC/DC converters and AC/DC power supplies.
For engineers reviewing the TL431CPWR datasheet, TL431CPWR pinout, TL431CPWR application, or TL431CPWR equivalent, key selection criteria include reference accuracy at 25°C, temperature drift over industrial range, cathode current regulation stability, and compatibility with standard resistor-divider feedback networks in flyback and forward converter topologies.
Technical Context
The TL431CPWR implements an internal bandgap reference, error amplifier, and NPN output stage in a three-terminal adjustable shunt regulator architecture. Its sharp turn-on characteristic and low output impedance enable stable closed-loop regulation without external compensation in many power supply designs.
It operates as a voltage-controlled current sink: the REF pin senses a fraction of cathode-to-anode voltage via external resistors; when that fraction drops below 2.495 V, the cathode current increases to restore equilibrium. This mechanism supports precise output voltage setting from 2.5 V to 36 V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495 V nominal (B-grade), ±0.5% tolerance at 25°C - sets absolute accuracy baseline for feedback loop calibration |
| Temperature Range | −40°C to +85°C (I-grade) - validated for industrial ambient conditions without derating |
| Dynamic Impedance | 0.2 Ω typical at 1–100 mA cathode current - ensures minimal output voltage shift under load transients |
| Cathode Current Range | 1 mA to 100 mA - supports direct drive of optocoupler LEDs and high-gain error amplifiers |
| Reference Input Current | 2–4 µA - enables use with high-value feedback resistors (>1 MΩ) to minimize power loss |
| Output Noise | Low broadband noise (typ. 220 nV/√Hz @ 1 kHz) - critical for low-noise analog sensing and precision regulation |
| Max Cathode Voltage | 36 V - allows direct interface with 24 V and 32 V bus systems without external clamping |
Pinout & Package
SOT-23-3 package (2.90 mm × 1.30 mm body size), surface-mount, lead-free, RoHS-compliant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 (CATHODE) | Current Sink Output | Primary current path; connects to transformer secondary or optocoupler anode in isolated PSUs |
| Pin 2 (ANODE) | Common Reference Node | Typically tied to system ground or return path; defines voltage reference point for REF input |
| Pin 3 (REF) | Threshold Sense Input | High-impedance input comparing divided output voltage against internal 2.495 V reference |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable Output Voltage | 2.5 V to 36 V via two external resistors - eliminates need for multiple fixed-reference parts in BOM |
| Sharp Turn-On Characteristic | Fast response to reference deviation (<1 µs rise time) - prevents overshoot during line/load transients |
| Low Temperature Drift | 14 mV max deviation over −40°C to +85°C (I-grade) - maintains regulation accuracy without trimming |
| Low Output Noise | 220 nV/√Hz @ 1 kHz - preserves signal integrity in sensitive feedback paths and analog monitoring circuits |
| ESD Robustness | ±2000 V HBM - withstands handling and board assembly without protection circuitry |
Applications
| Rack Server Power | Industrial AC/DC Converter |
|---|---|
Use Scenario: Secondary-side voltage regulation in 48 V input, 12 V/50 A isolated DC/DC modules for telecom servers. IC Role / Device Role / Timing Role: Shunt reference in optocoupler-coupled feedback loop, setting precise 12.0 V ±1% output. Use Value: Enables tight output tolerance without post-regulation LDOs, reducing thermal overhead and bill-of-materials cost. |
Use Scenario: Output voltage stabilization in 3-phase rectified 380 VAC to 24 VDC industrial power supply. IC Role / Device Role / Timing Role: Adjustable shunt reference driving TL431-based error amplifier in flyback controller feedback network. Use Value: Maintains ±0.5% output accuracy across full temperature and load range, meeting IEC 61000-4-30 Class A compliance. |
| AC Inverter Drive | Servo Drive Control Module |
Use Scenario: Auxiliary 15 V rail regulation for gate driver ICs and current-sense amplifiers in 7.5 kW VFDs. IC Role / Device Role / Timing Role: Precision reference for isolated DC/DC bias supply feeding SiC MOSFET gate drivers. Use Value: Ensures consistent gate threshold margin across −25°C to +70°C cabinet temperatures, preventing shoot-through faults. |
Use Scenario: Feedback reference for dual-output 24 V/5 V isolated power module supplying servo motor control logic and analog interfaces. IC Role / Device Role / Timing Role: Dual-resistor-configured reference generating stable 5.00 V for ADC reference and microcontroller VDD. Use Value: Eliminates separate 5 V LDO, reducing component count while maintaining <1 LSB INL error in 16-bit position feedback ADCs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431IPWR | I-grade (−40°C to +85°C) with same 0.5% tolerance but higher VI(dev) (14 mV vs. 6 mV for C-grade); identical pinout and electrical behavior | Same functional role in industrial power supplies; requires no layout change | Select TL431IPWR when operating ambient exceeds 70°C but does not require automotive Q-grade temperature range |
| TLVH431QDBVRQ1 | AEC-Q100 qualified Q-grade (−40°C to +125°C), 0.5% tolerance, lower Iref (1.5 µA typ), higher cost; SOT-23-3 pin-compatible | Required for automotive infotainment power rails where extended temperature and qualification are mandatory | Choose TLVH431QDBVRQ1 only when AEC-Q100 certification and 125°C operation are contractually required |
Compared with TL431CPWR, TL431IPWR offers identical performance at higher ambient temperatures but with slightly increased reference drift, while TLVH431QDBVRQ1 adds automotive qualification and extended temperature range at premium cost and no electrical advantage in non-automotive settings.
Availability
TL431CPWR is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC converters, and servo drive control modules requiring stable component supply with guaranteed long-term continuity.
Supply support for TL431CPWR 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, embedded processing, and power management technologies, with decades of heritage in precision reference design.
The TL431 product line was engineered for high-accuracy, low-drift voltage regulation in isolated power supply feedback paths-targeting industrial, computing, and motor control applications demanding reliability and wide-temperature operation.
FAQ
What is the reference voltage tolerance of TL431CPWR at 25°C?
The TL431CPWR has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a nominal 2.495 V output with minimum 2.483 V and maximum 2.507 V under specified test conditions. This B-grade accuracy is confirmed in Section 6.11 of the TI SLVS543S datasheet and applies specifically to the CPWR variant with SOT-23-3 packaging and I-grade temperature rating.
Can TL431CPWR replace a Zener diode in a switching power supply feedback loop?
Yes, TL431CPWR is explicitly designed as a superior replacement for Zener diodes in feedback networks of flyback, forward, and push-pull converters. Its 0.2 Ω dynamic impedance, sharp turn-on, and adjustable 2.5–36 V output provide tighter regulation, lower temperature drift, and better transient response than discrete Zeners-verified in TI's Application Report SLVA245.
What is the maximum cathode voltage rating for TL431CPWR?
The absolute maximum cathode voltage (VKA) for TL431CPWR is 37 V, with recommended operating range up to 36 V referenced to the ANODE pin. Exceeding 36 V risks violating safe operating area limits and may cause irreversible degradation, as defined in Section 6.1 of the SLVS543S datasheet.
Does TL431CPWR require external capacitors for stability?
TL431CPWR can operate stably without external capacitors in many configurations, but stability depends on load capacitance and cathode current. Figure 6-18 shows oscillation boundaries: for VKA = 5–15 V and IKA = 1–100 mA, CL must remain below 0.1 µF unless series resistance is added. TI recommends verifying phase margin with actual PCB layout and parasitics.
How does the REF pin input current affect feedback resistor selection in TL431CPWR designs?
The REF pin draws only 2–4 µA (typical), enabling use of high-value feedback resistors (e.g., 100 kΩ–1 MΩ) to minimize power loss in high-voltage outputs. However, values above 1 MΩ increase susceptibility to noise and leakage; TI recommends keeping total divider current ≥10× Iref (i.e., ≥40 µA) for robust operation per Section 9.2 of SLVS543S.
TL431CPWR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- 8-TSSOP (0.173", 4.40mm Width)
- 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:
- ±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
TL431CPWR FAQ
1.How can I place an order for TL431CPWR through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431CPWR 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 TL431CPWR reliable?
The price and inventory of TL431CPWR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431CPWR is usually 5 days.
3.What payment methods are accepted for TL431CPWR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431CPWR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431CPWR?
TL431CPWR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431CPWR 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 TL431CPWR?
For technical support, including TL431CPWR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431CPWR requirements.
6.How does Aetrix verify that TL431CPWR is sourced from the original manufacturer or authorized distributors?
All TL431CPWR 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 TL431CPWR meets industry standards.
7.What is the process for return or replacement of TL431CPWR?
All TL431CPWR units undergo pre-shipment inspection (PSI). If there is an issue with TL431CPWR, 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 TL431CPWR part is unused and in its original packaging.
Return procedure for TL431CPWR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431CPWR 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
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