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Texas Instruments TL431ACPWR
- Part No.:
- TL431ACPWR
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 8-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
TL431ACPWR.pdf
- Description:
- IC VREF SHUNT ADJ 1% 8TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,000
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Product details
Overview
TL431ACPWR from Texas Instruments is a precision programmable shunt voltage reference IC in SOT-23-3 package, featuring 1% initial reference voltage tolerance at 25°C, adjustable output from 2.495 V to 36 V, and operation across −40°C to 85°C. It delivers 0.2 Ω typical dynamic impedance and supports 1–100 mA sink current, widely used in feedback loops of isolated DC/DC converters and AC/DC power supplies.
For engineers reviewing the TL431ACPWR datasheet, TL431ACPWR pinout, TL431ACPWR application, or TL431ACPWR equivalent, key selection criteria include reference accuracy grade (A = 1%), thermal drift performance (14 mV over −40°C to 85°C), cathode current capability, dynamic impedance stability, and SOT-23-3 footprint compatibility with space-constrained power control designs.
Technical Context
The TL431ACPWR implements a three-terminal adjustable shunt regulator architecture with an internal error amplifier, reference voltage cell, and NPN output transistor. Its REF pin senses voltage relative to ANODE, enabling precise regulation via external resistor dividers without requiring a ground-referenced output.
It operates as a high-gain, low-noise voltage-controlled current sink: when REF voltage exceeds 2.495 V, the cathode current increases sharply to maintain regulation; output impedance remains stable below 0.5 Ω up to 1 kHz, supporting fast transient response in switching power supply feedback paths.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.470–2.520 V at 25°C (1% A-grade tolerance; sets regulation threshold for feedback networks) |
| Temp Range | −40°C to +85°C (I-grade rating; ensures stable operation in industrial power environments) |
| Dynamic Impedance | 0.2 Ω typical (enables tight voltage regulation under varying load conditions in SMPS feedback) |
| Cathode Current | 1–100 mA (supports direct drive of optocoupler LEDs or error amplifier inputs without buffering) |
| Reference Input Current | 2–4 µA (low bias current minimizes divider resistor power loss and improves accuracy) |
| Output Noise | Low broadband noise (typ. 200 nV/√Hz at 1 kHz); critical for low-noise analog feedback paths) |
| Temperature Drift | 14 mV max over full range (ensures ≤0.05% output variation across operating temperature) |
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 = Reference (REF).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (Pin 1) | Shunt current output node | Connects to primary-side feedback network (e.g., optocoupler anode); sinks regulated current to maintain REF voltage |
| Anode (Pin 2) | Common reference and return path | Typically tied to system ground or converter output rail; serves as voltage reference point for REF input |
| REF (Pin 3) | High-impedance voltage sense input | Monitors divided output voltage; triggers regulation when >2.495 V; draws only 2–4 µA bias current |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable reference range | 2.495 V to 36 V via two external resistors - enables single-part support for multiple output voltages |
| Sharp turn-on characteristic | High open-loop gain (>60 dB) and fast response - eliminates need for Zener diodes in precision feedback |
| Low output impedance | 0.2 Ω typical - maintains regulation accuracy despite cathode current variations up to 100 mA |
| Low reference input current | 2–4 µA - reduces power loss and error in high-resistance feedback dividers |
| Thermal stability | 14 mV max deviation over −40°C to +85°C - ensures consistent regulation in industrial ambient conditions |
Applications
| AC/DC Power Adapter Feedback | Rack Server Primary-Side Regulation |
|---|---|
Use Scenario: Isolated flyback converter in notebook PC adapter delivering 19.5 V @ 3.33 A. IC Role / Device Role / Timing Role: TL431ACPWR acts as secondary-side voltage reference and error amplifier, driving optocoupler to regulate primary-side PWM controller. Use Value: 1% reference accuracy and low 0.2 Ω impedance ensure ±1.5% output voltage tolerance across line/load/temperature. |
Use Scenario: Multi-output 12 V/5 V/3.3 V server PSU with active OR-ing and PMBus monitoring. IC Role / Device Role / Timing Role: TL431ACPWR provides precise 5 V reference for ADC calibration and supervisor IC thresholds. Use Value: Stable 2.495 V reference with <14 mV drift enables accurate voltage margining and fault detection over full industrial temp range. |
| Industrial Inverter Voltage Sensing | Servo Drive Current Loop Reference |
Use Scenario: 3-phase AC inverter for HVAC compressors with DC bus voltage monitoring at 400 V. IC Role / Device Role / Timing Role: TL431ACPWR forms part of resistive divider and comparator circuit to detect overvoltage events. Use Value: Low input current (≤4 µA) prevents loading error in high-impedance sensing networks; 85°C rating matches inverter thermal profile. |
Use Scenario: Closed-loop current control in robotic servo drive using shunt-based sensing and op-amp amplification. IC Role / Device Role / Timing Role: TL431ACPWR supplies stable 2.495 V reference to instrumentation amplifier for offset calibration. Use Value: 0.2 Ω output impedance rejects noise coupling from motor switching transients, improving current measurement SNR. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431CDBZR | Same SOT-23-3 package, C-grade (0°C–70°C), 2% initial tolerance | Limited to commercial-temp applications; lower cost but reduced thermal stability | Select when ambient stays within 0–70°C and ±2% regulation suffices (e.g., consumer adapters) |
| TLVH431QDBVRQ1 | AEC-Q100 qualified, Q-grade (−40°C to 125°C), 0.5% B-grade accuracy, higher 1.24 V reference | Automotive-grade reliability; requires different resistor scaling due to 1.24 V reference | Choose for automotive power modules where extended temperature and qualification are mandatory |
Compared with TL431CDBZR, TL431ACPWR offers tighter 1% tolerance and wider −40°C to 85°C operation, making it suitable for industrial power; versus TLVH431QDBVRQ1, it lacks AEC-Q100 certification and uses a 2.495 V reference, simplifying redesign in non-automotive systems while maintaining robust thermal performance.
Availability
TL431ACPWR is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC, and servo drive control module applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for TL431ACPWR 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 focused on analog and embedded processing technologies, serving industrial, automotive, and communications markets with high-reliability components.
The TL431 family was designed as a precision programmable shunt reference for feedback regulation in isolated power supplies, replacing discrete Zener diodes with superior accuracy, stability, and design flexibility.
FAQ
What is the reference voltage tolerance of TL431ACPWR at 25°C?
The TL431ACPWR has a 1% initial reference voltage tolerance at 25°C, meaning its Vref is guaranteed between 2.470 V and 2.520 V under nominal conditions. This A-grade specification is confirmed in Section 6.8 of the TI datasheet (SLVS543S) and applies specifically to the TL431ACPWR variant with I-grade temperature rating.
Does TL431ACPWR support operation at −40°C?
Yes, TL431ACPWR is rated for operation from −40°C to +85°C (I-grade). Its electrical characteristics-including reference voltage deviation (max 14 mV), dynamic impedance (0.2 Ω typical), and cathode current range (1–100 mA)-are specified across this full industrial temperature range per Sections 6.6 and 6.9 of the official TI datasheet.
What package type does TL431ACPWR use?
TL431ACPWR uses the SOT-23-3 package (2.90 mm × 1.30 mm body size), with pinout: Pin 1 = Cathode, Pin 2 = Anode, Pin 3 = REF. This is explicitly listed in the Device Information table and confirmed in Figure 5-1 (DBZ package top view) of the TI SLVS543S datasheet.
Can TL431ACPWR replace a Zener diode in feedback circuits?
Yes, TL431ACPWR is engineered as a direct, high-performance replacement for Zener diodes in voltage regulation feedback paths. Its sharp turn-on, 0.2 Ω dynamic impedance, and adjustable 2.495–36 V range enable superior accuracy and stability-especially in isolated SMPS designs where TL431ACPWR drives optocouplers without additional buffering.
What is the maximum cathode current for TL431ACPWR?
The TL431ACPWR supports a continuous cathode current range of 1 mA to 100 mA, as specified in Section 6.4 (Recommended Operating Conditions) and verified across all I-grade electrical characteristics tables (Sections 6.6, 6.9, 6.12). Exceeding 100 mA risks thermal overload unless PCB layout provides adequate heat dissipation.
TL431ACPWR 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:
- ±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:
- Surface Mount
- Supplier Device Package:
- 8-TSSOP
TL431ACPWR FAQ
1.How can I place an order for TL431ACPWR through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431ACPWR 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 TL431ACPWR reliable?
The price and inventory of TL431ACPWR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431ACPWR is usually 5 days.
3.What payment methods are accepted for TL431ACPWR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431ACPWR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431ACPWR?
TL431ACPWR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431ACPWR 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 TL431ACPWR?
For technical support, including TL431ACPWR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431ACPWR requirements.
6.How does Aetrix verify that TL431ACPWR is sourced from the original manufacturer or authorized distributors?
All TL431ACPWR 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 TL431ACPWR meets industry standards.
7.What is the process for return or replacement of TL431ACPWR?
All TL431ACPWR units undergo pre-shipment inspection (PSI). If there is an issue with TL431ACPWR, 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 TL431ACPWR part is unused and in its original packaging.
Return procedure for TL431ACPWR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431ACPWR Tags
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TL431BQDBZR
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LM4040CYM3-2.5-TR
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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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LM4040DIM3-2.5/NOPB
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AZ431LANTR-G1
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