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Texas Instruments TL431CPSR
- Part No.:
- TL431CPSR
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 8-SOIC (0.209", 5.30mm Width)
- Datasheet:
-
TL431CPSR.pdf
- Description:
- IC VREF SHUNT ADJ 2.2% 8SO
- Quantity:
- Payment:
- Shipping:
Inventory:4,158
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Product details
Overview
TL431CPSR from Texas Instruments is a precision programmable shunt voltage reference in SOIC-8 package, delivering 2.495 V nominal reference voltage with ±0.5% initial tolerance at 25°C, 0.2 Ω typical dynamic impedance, and sink-current capability from 1 mA to 100 mA. It operates across 0°C to 70°C and serves as a stable feedback element in isolated DC-DC converters and adjustable linear regulators.
For engineers reviewing the TL431CPSR datasheet, TL431CPSR pinout, TL431CPSR application, or TL431CPSR equivalent, key selection criteria include its C-grade temperature range, SOIC-8 pin compatibility with legacy designs, low output drift (≤16 mV over 0°C–70°C), and proven use in industrial AC/DC power supplies requiring tight output regulation.
Technical Context
The TL431CPSR implements an internal error amplifier and NPN transistor output stage configured as a three-terminal adjustable shunt regulator. Its REF pin senses voltage relative to the ANODE terminal, enabling precise feedback control when paired with two external resistors to set output from 2.495 V to 36 V.
It features active output circuitry for sharp turn-on characteristics and low noise performance (≤260 nV/√Hz at 1 kHz), making it suitable for high-stability closed-loop regulation where Zener diode alternatives lack accuracy or thermal stability.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495 V ±12.5 mV (0.5% tolerance at 25°C); sets precise feedback threshold in voltage regulation loops |
| Temperature Range | 0°C to 70°C (C-grade); validated for commercial ambient environments without derating |
| Dynamic Impedance | 0.2 Ω typical; ensures minimal output voltage shift under load transients in feedback networks |
| Sink Current Range | 1 mA to 100 mA; supports direct interface with optocoupler LEDs or error amplifier outputs |
| Output Voltage Range | 2.495 V to 36 V (adjustable via external resistor divider); enables flexible output setting in isolated flyback and forward converters |
| Reference Input Current | 2 µA to 4 µA; imposes negligible loading on feedback divider, preserving accuracy |
| Max Cathode Voltage | 36 V; allows operation in high-voltage secondary-side regulation up to 36 V rail |
Pinout & Package
TL431CPSR uses an 8-pin SOIC (Small Outline Integrated Circuit) package with 4.90 mm × 3.90 mm body size and standard 1.27 mm pitch. Pin 1 is CATHODE, Pin 2 is REF, Pin 3 is ANODE, Pins 4–8 are NC (no internal connection).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CATHODE (Pin 1) | Shunt current/voltage input | Primary current path; connects to regulated output node or optocoupler cathode in isolated topologies |
| REF (Pin 2) | Threshold sensing input | High-impedance reference comparator input; tied to resistor divider midpoint for output voltage programming |
| ANODE (Pin 3) | Common return node | Typically connected to system ground or low-side return; defines reference potential for REF and CATHODE |
| Pins 4–8 | No internal connection | Unused; must remain unconnected per TI specification to avoid parasitic coupling or latch-up risk |
Key Features
| Feature | Design Value |
|---|---|
| Initial voltage accuracy | ±0.5% at 25°C (B-grade spec applied to TL431CPSR), enabling <±1% output regulation without trimming |
| Thermal stability | ≤16 mV deviation over 0°C–70°C, supporting stable feedback in unheated enclosures |
| Low dynamic impedance | 0.2 Ω typical, minimizing output perturbation during fast load steps in SMPS feedback paths |
| Wide sink-current range | 1–100 mA operation, compatible with common PC817/PC817x optocouplers and discrete transistor drivers |
| Low output noise | ≤260 nV/√Hz at 1 kHz, reducing jitter in voltage-controlled oscillator (VCO) or PWM timing circuits |
Applications
| Rack Server Power Supply | Industrial AC/DC Converter |
|---|---|
Use Scenario: Secondary-side voltage regulation in 48 V input, 12 V/50 A isolated DC-DC modules. IC Role / Device Role / Timing Role: Shunt reference in optocoupler-coupled feedback loop, setting precise 12 V output via resistor divider. Use Value: Maintains ±0.5% output accuracy across line/load/temperature, meeting ATX12VO and Open Compute Project specs. |
Use Scenario: Output voltage stabilization in 3-phase rectified 400 VAC-to-24 VDC industrial power supplies. IC Role / Device Role / Timing Role: Adjustable shunt reference driving TL431-based error amplifier in flyback controller feedback network. Use Value: Enables <1% total output variation over 0°C–70°C ambient, satisfying IEC 61000-6-4 immunity requirements. |
| AC Inverter Drive | Notebook PC Adapter |
Use Scenario: DC bus voltage monitoring and regulation in 200–400 VDC intermediate bus of variable-frequency motor drives. IC Role / Device Role / Timing Role: Precision reference for analog-to-digital converter (ADC) biasing and overvoltage protection comparators. Use Value: Provides stable 2.5 V reference for 12-bit ADCs, ensuring <±0.1% bus voltage measurement accuracy. |
Use Scenario: Feedback voltage setting in compact 19 V/3.42 A GaN-based notebook adapters. IC Role / Device Role / Timing Role: Programmable shunt reference in primary-side regulated flyback topology with optocoupler isolation. Use Value: Delivers ±0.5% output tolerance at full load, meeting USB PD 3.1 EPR compliance for laptop charging. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431ACDR | 1% initial tolerance (A-grade) vs. 0.5% (B-grade); otherwise identical SOIC-8 pinout and electrical specs | Suitable where ±1% output regulation suffices; lower cost but requires tighter resistor tolerances for same system accuracy | Select TL431ACDR only if B-grade accuracy is not required and cost optimization is prioritized |
| TL431CDBVR | SOT-23-3 package (3-pin) vs. SOIC-8; same C-grade temp range and 0.5% tolerance, but different pinout (REF-CATHODE-ANODE) | Used in space-constrained PCBs; incompatible with SOIC-8 footprints and requires layout revision | Choose TL431CDBVR only for new compact designs-TL431CPSR cannot be substituted without board rework |
Compared with TL431ACDR and TL431CDBVR, TL431CPSR provides the highest initial accuracy in a standard SOIC-8 footprint, enabling drop-in replacement in legacy commercial power designs without sacrificing regulation precision or requiring PCB changes.
Availability
TL431CPSR is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC converters, and notebook PC adapter designs requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.
Supply support for TL431CPSR 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 analog ICs and power management solutions.
TL431CPSR belongs to TI's precision shunt reference product line, engineered for high-accuracy voltage regulation in isolated switching power supplies, industrial controls, and computing power systems.
FAQ
What is the reference voltage tolerance of TL431CPSR at 25°C?
The TL431CPSR has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a 2.495 V nominal output with a minimum of 2.483 V and maximum of 2.507 V. This B-grade accuracy is confirmed in Section 6.11 of the TI SLVS543S datasheet and applies specifically to the TL431CPSR variant. TL431CPSR maintains this tolerance across its full operating temperature range of 0°C to 70°C.
Does TL431CPSR support adjustable output voltages above 2.5 V?
Yes, TL431CPSR supports adjustable output voltages from 2.495 V up to 36 V using an external resistor divider connected between the CATHODE and REF pins. The device's internal architecture allows precise feedback control across this full range, as verified in the "Description" section and Figure 9-1 of the TI datasheet. TL431CPSR achieves this without external op-amps or additional components.
What is the maximum continuous cathode current for TL431CPSR?
The maximum continuous cathode current for TL431CPSR is 100 mA, as specified in Section 6.1 Absolute Maximum Ratings and validated in Section 6.5 Electrical Characteristics. This rating applies under recommended operating conditions (VKA = Vref, TA = 25°C) and enables direct drive of optocoupler LEDs or discrete transistor bases. TL431CPSR sustains this current without derating within its 0°C–70°C operating range.
Is TL431CPSR pin-compatible with other TL431 variants in SOIC-8 packages?
Yes, TL431CPSR is pin-compatible with all TL431x variants in the SOIC-8 (D) package, including TL431ACDR and TL431BCDR, sharing identical pin 1 (CATHODE), pin 2 (REF), and pin 3 (ANODE) assignments. This compatibility is confirmed in Table 5-1 Pin Functions and the "Device Comparison Table" of the TI datasheet. TL431CPSR can be substituted for these parts without layout changes, though grade-specific tolerances must be verified.
What is the dynamic impedance of TL431CPSR and why does it matter?
TL431CPSR has a typical dynamic impedance of 0.2 Ω, measured at f ≤ 1 kHz with cathode current from 1 mA to 100 mA. This low value ensures minimal output voltage deviation during rapid load transients in feedback loops-critical for maintaining regulation stability in switch-mode power supplies. The 0.2 Ω figure is explicitly listed in Sections 6.5–6.13 of the TI SLVS543S datasheet for all C-grade TL431 devices, including TL431CPSR.
TL431CPSR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- 8-SOIC (0.209", 5.30mm 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-SO
TL431CPSR FAQ
1.How can I place an order for TL431CPSR through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431CPSR 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 TL431CPSR reliable?
The price and inventory of TL431CPSR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431CPSR is usually 5 days.
3.What payment methods are accepted for TL431CPSR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431CPSR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431CPSR?
TL431CPSR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431CPSR 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 TL431CPSR?
For technical support, including TL431CPSR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431CPSR requirements.
6.How does Aetrix verify that TL431CPSR is sourced from the original manufacturer or authorized distributors?
All TL431CPSR 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 TL431CPSR meets industry standards.
7.What is the process for return or replacement of TL431CPSR?
All TL431CPSR units undergo pre-shipment inspection (PSI). If there is an issue with TL431CPSR, 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 TL431CPSR part is unused and in its original packaging.
Return procedure for TL431CPSR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431CPSR Tags
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