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Texas Instruments TL431CPS
- Part No.:
- TL431CPS
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 8-SOIC (0.209", 5.30mm Width)
- Datasheet:
-
TL431CPS.pdf
- Description:
- IC VREF SHUNT ADJ 2% 8SO
- Quantity:
- Payment:
- Shipping:
Inventory:9,006
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Product details
Overview
TL431CPS from Texas Instruments is a precision programmable shunt voltage reference IC in SOIC-8 package, delivering 2.495 V nominal reference voltage with ±0.5% initial tolerance (B grade), 0.2 Ω typical dynamic impedance, and adjustable output from 2.5 V to 36 V. It operates across 0°C to 70°C and serves as a Zener diode replacement in feedback loops of isolated DC/DC converters and AC/DC power supplies.
For engineers reviewing the TL431CPS datasheet, TL431CPS pinout, TL431CPS application, or TL431CPS equivalent, key selection criteria include its 2.5–36 V programmable range, 0.2 Ω output impedance for stable regulation, low 2 µA reference input current, and SOIC-8 thermal performance (RθJA = 97°C/W) in industrial power designs.
Technical Context
The TL431CPS implements an internal error amplifier with high-gain transconductance stage driving a Darlington-connected output transistor, enabling sharp turn-on and precise regulation via external resistor divider on the REF pin. Its three-terminal shunt topology sinks cathode current (1–100 mA) proportional to deviation between REF voltage and internal 2.495 V bandgap reference.
Designed for closed-loop feedback in switching regulators, it features low 6 mV temperature drift (C-grade), 10 Hz–10 kHz input noise below 20 nV/√Hz, and stability-critical dynamic impedance specification validated at 1 mA–100 mA cathode current and ≤1 kHz frequency.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495 V ±0.5% at 25°C - sets accurate feedback threshold for output voltage programming |
| Adjustable Range | 2.5 V to 36 V - enables wide-output-power-supply designs using two external resistors |
| Dynamic Impedance | 0.2 Ω typical - ensures minimal output voltage shift under load transients in regulation loop |
| Cathode Current | 1 mA to 100 mA - defines usable sink-current window for stable feedback biasing |
| Temp Range | 0°C to 70°C - specifies commercial-grade operating envelope for non-automotive applications |
| Ref Input Current | 2 µA typical - minimizes resistor-divider power loss and voltage error in high-impedance networks |
| Temp Drift | 6 mV max over 0°C–70°C - guarantees <±25 ppm/°C stability for precision voltage setting |
Pinout & Package
TL431CPS is housed in an 8-pin SOIC (Small Outline Integrated Circuit) package measuring 4.90 mm × 3.90 mm, with standard JEDEC MS-012AC footprint and gull-wing leads. Thermal resistance is RθJA = 97°C/W, supporting moderate-power dissipation without forced airflow.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (CATHODE) | Shunt current output | Sinks regulated current to ground or return path; connects to transformer secondary or optocoupler anode in isolated flyback designs |
| 2 (ANODE) | Common reference node | Typically tied to system ground or power return; establishes reference potential for internal error amp |
| 3 (REF) | Feedback input | Compares external resistor-divider voltage against internal 2.495 V reference; determines regulation setpoint |
| 4–8 (NC) | No internal connection | Unused pins; electrically isolated and may be left unconnected or grounded per layout best practices |
Key Features
| Feature | Design Value |
|---|---|
| Zener diode replacement | Enables precise, low-drift voltage references without Zener's poor tempco and high impedance limitations |
| Low output impedance | 0.2 Ω dynamic impedance maintains regulation accuracy during fast load steps in SMPS feedback paths |
| Wide adjustment range | 2.5–36 V programmability supports single-part design across multiple output voltages in multi-rail systems |
| Low reference current | 2 µA input current reduces divider power loss and permits high-value resistors for low quiescent consumption |
| Stability-optimized architecture | Internally compensated error amplifier avoids external compensation in most isolated converter topologies |
Applications
| Rack Server Power | Industrial AC/DC |
|---|---|
Use Scenario: Secondary-side voltage sensing in 48 V input, 12 V/5 V/3.3 V isolated DC/DC modules for telecom servers. IC Role / Device Role / Timing Role: Shunt reference in optocoupler feedback loop to regulate output voltage with ±1% accuracy. Use Value: Enables tight output tolerance across line/load/temp while reducing component count vs discrete Zener + op-amp solutions. |
Use Scenario: Output voltage regulation in DIN-rail mounted 24 V/48 V industrial power supplies feeding PLCs and sensors. IC Role / Device Role / Timing Role: Precision shunt reference in primary-side controller feedback network for constant-voltage operation. Use Value: Delivers 0.5% initial accuracy and 6 mV temp drift-critical for meeting IEC 61000-4 immunity and long-term calibration stability. |
| AC Inverter Drives | Notebook PC Adapter |
Use Scenario: DC bus voltage monitoring and overvoltage protection circuitry in variable-frequency motor drives. IC Role / Device Role / Timing Role: Programmable threshold detector referenced to DC link voltage via resistor divider. Use Value: Adjustable 2.5–36 V range allows single BOM part to cover 300 V, 600 V, and 1000 V DC bus variants. |
Use Scenario: Feedback reference in 19 V, 65 W laptop AC adapters with QR flyback topology. IC Role / Device Role / Timing Role: Cathode-sink regulator controlling optocoupler LED current to maintain ±1% output regulation. Use Value: Low 2 µA reference current enables high-resistor-divider values, minimizing standby power and improving no-load efficiency. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431CDBVR | SOT-23-3 package (3-pin), same electrical specs but smaller footprint and higher RθJA (206°C/W) | Better suited for space-constrained PCBs; requires thermal derating above ~300 mW dissipation | Select when board area is critical and power dissipation remains below 150 mW |
| TLVH431ACDBVR | Lower 1.24 V reference voltage, 1% initial tolerance, 0.35 Ω impedance, SOT-23-3 | Enables lower-voltage feedback (e.g., 1.8 V, 2.5 V rails); not interchangeable for >2.5 V setpoints | Choose only when designing sub-2.5 V regulated outputs or needing reduced headroom |
Compared with TL431CPS, TL431CDBVR offers identical regulation performance in a miniature package but demands tighter thermal management, while TLVH431ACDBVR shifts the reference baseline downward-making it functionally distinct rather than drop-in compatible.
Availability
TL431CPS is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC, and notebook PC adapter designs requiring stable component supply, long-lifecycle support, and consistent parametric performance across production batches.
Supply support for TL431CPS 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.
The TL431 product line was engineered for high-accuracy, low-drift voltage referencing in isolated power conversion systems-targeting industrial, computing, and consumer power supply applications demanding reliability and design flexibility.
FAQ
What is the reference voltage tolerance of TL431CPS at 25°C?
The TL431CPS has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a 2.495 V nominal value with a range of 2.483 V to 2.507 V. This B-grade accuracy is confirmed in Section 6.11 of the TI datasheet (SLVS543S) and applies specifically to the TL431CPS variant under recommended operating conditions with 10 mA cathode current.
Can TL431CPS replace a Zener diode in feedback circuits?
Yes, TL431CPS is explicitly designed as a superior Zener diode replacement in feedback networks. Its 0.2 Ω dynamic impedance, sharp turn-on characteristic, and 2.5–36 V programmability provide significantly better regulation accuracy, temperature stability, and design flexibility than discrete Zeners-especially in isolated switch-mode power supplies where TL431CPS drives optocouplers.
What is the maximum cathode voltage rating for TL431CPS?
The absolute maximum cathode voltage (VK A) for TL431CPS is 37 V, as specified in Section 6.1 of the TI datasheet. For reliable operation, the recommended maximum cathode voltage is 36 V. Exceeding 37 V risks permanent damage, and operation near the limit requires careful thermal design due to power dissipation (P = VK A × IK A).
Does TL431CPS require external compensation components?
No, TL431CPS features internal frequency compensation optimized for stability in standard feedback configurations. The device is designed to operate reliably without external capacitors in typical optocoupler-based isolated converter topologies, though layout-dependent parasitics may necessitate minor RC snubbing in high-noise environments per Section 9.5 of the datasheet.
What is the operating temperature range of TL431CPS?
TL431CPS is characterized for operation from 0°C to 70°C (C-grade), as defined in Section 4 (Device Comparison Table) and Section 6.4 (Recommended Operating Conditions) of the TI datasheet. This commercial temperature range distinguishes it from TL431I (–40°C to 85°C) and TL431Q (–40°C to 125°C) variants.
TL431CPS Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- 8-SOIC (0.209", 5.30mm 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%
- 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
TL431CPS FAQ
1.How can I place an order for TL431CPS through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431CPS 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 TL431CPS reliable?
The price and inventory of TL431CPS are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431CPS is usually 5 days.
3.What payment methods are accepted for TL431CPS?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431CPS transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431CPS?
TL431CPS orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431CPS 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 TL431CPS?
For technical support, including TL431CPS datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431CPS requirements.
6.How does Aetrix verify that TL431CPS is sourced from the original manufacturer or authorized distributors?
All TL431CPS 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 TL431CPS meets industry standards.
7.What is the process for return or replacement of TL431CPS?
All TL431CPS units undergo pre-shipment inspection (PSI). If there is an issue with TL431CPS, 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 TL431CPS part is unused and in its original packaging.
Return procedure for TL431CPS:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431CPS Tags
-
TL431AIDBZR
Texas Instruments
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TL431BQDBZR
Texas Instruments
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AN431AN-ATRG1
Diodes Incorporated
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LM4040CYM3-2.5-TR
Microchip Technology
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LM4040CYM3-4.1-TR
Microchip Technology
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LM4040EIM3-2.5/NOPB
Texas Instruments
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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
-
AZ431LANTR-G1
Diodes Incorporated
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