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STMicroelectronics TL1431CL5T
- Part No.:
- TL1431CL5T
- Manufacturer:
- STMicroelectronics
- Category:
- Voltage Reference
- Package:
- SC-74A, SOT-753
- Datasheet:
-
TL1431CL5T.pdf
- Description:
- IC VREF SHUNT ADJ 0.4% SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:2,462
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Product details
Overview
TL1431CL5T from STMicroelectronics is an adjustable shunt voltage reference IC with 0.4% initial voltage precision, 2.5 V to 36 V programmable output via two external resistors, and guaranteed operation from –20 °C to +70 °C. It delivers 1–100 mA sink current with 0.22 Ω typical dynamic impedance and supports automotive-grade feedback loops in isolated DC-DC converters.
For engineers reviewing the TL1431CL5T datasheet, TL1431CL5T pinout, TL1431CL5T application, or TL1431CL5T equivalent, this page provides verified electrical specifications, SOT23-5L package terminal mapping, thermal performance data, and validated alternative parts for precision voltage regulation design.
Technical Context
The TL1431CL5T implements a bandgap-based reference core with internal error amplifier and NPN pass transistor, configured as a 3-terminal shunt regulator. Its cathode-anode voltage range spans 2.5 V to 36 V, and it maintains regulation across 1–100 mA cathode current with <0.5 Ω max dynamic impedance at 1 kHz.
It operates in closed-loop feedback configurations where the REF pin senses a resistor divider from cathode to ground, enabling precise output voltage setting. Temperature stability is ensured by ±90 ppm/°C max temperature coefficient and ≤20 mV total reference deviation over its industrial temperature range.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.500 V (typical), ±0.4% initial accuracy - sets absolute baseline for output voltage programming |
| Output Voltage Range | 2.5 V to 36 V - configurable via external R1/R2 divider without additional components |
| Sink Current Range | 1 mA to 100 mA - supports direct regulation of low-power supplies or drives optocoupler LEDs in flyback controllers |
| Dynamic Impedance | 0.22 Ω (typical) - ensures minimal output voltage perturbation under fast load transients |
| Temp. Coefficient | ±90 ppm/°C (max) - guarantees stable reference across –20 °C to +70 °C ambient |
| Voltage Deviation | ≤20 mV over full temp. range - enables high-accuracy feedback without calibration |
| Ref Input Current | 1.5–3.0 µA - imposes negligible loading on feedback divider, preserving ratio accuracy |
Pinout & Package
SOT23-5L plastic surface-mount package (5-pin, 1.9 mm × 1.3 mm footprint, 0.95 mm pitch), RoHS-compliant, ECOPACK® certified.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Pin 1) | Current return path | Connected to system ground or low-side return; carries full cathode current minus reference input current |
| Cathode (Pin 2) | Regulated output node | Delivers sink current to load; voltage at this pin is controlled relative to REF pin |
| REF (Pin 3) | Feedback sense input | High-impedance input (≤3 µA) that triggers regulation when voltage reaches 2.5 V |
| NC (Pin 4) | No connect | Internally unconnected; must be left floating or tied to ground per layout best practice |
| NC (Pin 5) | No connect | Internally unconnected; no electrical function; avoid routing signals nearby to prevent coupling |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable output via resistor divider | Enables single BOM part to support multiple output voltages (2.5–36 V) without redesigning reference network |
| Low dynamic impedance (0.22 Ω typ.) | Maintains tight output regulation during rapid load steps in SMPS feedback paths |
| 0.4% initial voltage precision | Reduces need for post-production trimming in cost-sensitive power supply designs |
| –20 °C to +70 °C operating range | Validated for industrial environments including motor drives and PLC I/O modules |
| ESD robustness (2000 V HBM) | Withstands handling and board assembly stresses without parameter shift or failure |
Applications
| Isolated Flyback Converter Feedback | Programmable Precision Reference |
|---|---|
Use Scenario: Used in secondary-side feedback loop of 12 V/5 W isolated flyback converter with PC817 optocoupler. IC Role / Device Role / Timing Role: Shunt reference providing stable 2.5 V threshold to drive optocoupler LED; regulates output voltage via duty cycle modulation. Use Value: Enables ±1.5% output accuracy over line/load/temp with no external op-amp or compensation components. | Use Scenario: Configured as 5.0 V reference in battery-powered sensor node ADC front-end. IC Role / Device Role / Timing Role: Adjustable shunt reference supplying precise bias to instrumentation amplifier and SAR ADC reference input. Use Value: Delivers 5.000 V ±20 mV over –20 °C to +70 °C using 1% resistors, eliminating need for trimming potentiometer. |
| Overvoltage Protection Circuit | Linear Regulator Error Amplifier |
Use Scenario: Monitors 24 V rail in industrial control cabinet; triggers shutdown if voltage exceeds 26.5 V. IC Role / Device Role / Timing Role: Programmable threshold detector using REF pin as comparator input; cathode drives MOSFET gate via pull-up. Use Value: Achieves 26.5 V trip point with ±0.1 V tolerance using 10 kΩ/10.5 kΩ divider, independent of supply ripple. | Use Scenario: Replaces discrete op-amp + Zener in LDO error amplifier stage for 3.3 V output. IC Role / Device Role / Timing Role: High-gain shunt reference acting as precision voltage comparator in series-pass transistor control loop. Use Value: Improves load regulation to ±0.5% and reduces dropout voltage sensitivity vs. standard Zener solutions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar adjustable shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431ACLPR | 0.25% initial accuracy, SO-8 package, higher 0.2 Ω typical impedance | Requires larger PCB area; better suited for through-hole prototyping or high-current (>100 mA) designs | Select when tighter initial tolerance outweighs SMT footprint constraints |
| TLVH431QDBVR | 1.24 V reference, SOT23-5L, 6 V max cathode-anode voltage, lower 0.35 Ω impedance | Limited to low-voltage outputs (<6 V); unsuitable for >12 V systems or flyback feedback | Choose only for sub-6 V references where ultra-low voltage headroom is critical |
Compared with TL431ACLPR and TLVH431QDBVR, TL1431CL5T uniquely balances SOT23-5L compactness, 36 V capability, and 0.4% accuracy-making it optimal for space-constrained industrial power supplies requiring wide output flexibility.
Availability
TL1431CL5T is available at Aetrix Electronics and suitable for isolated DC-DC converters, programmable voltage monitors, and linear regulator feedback circuits requiring stable component supply and long-term production continuity.
Supply support for TL1431CL5T 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
STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, power management ICs, analog chips, and MEMS sensors for industrial, automotive, and consumer markets.
The TL1431 belongs to ST's precision analog reference product line, engineered specifically for high-stability, low-cost voltage regulation in cost-sensitive power conversion and protection applications.
FAQ
What is the minimum cathode current required for regulation in TL1431CL5T?
The TL1431CL5T requires a minimum cathode current of 0.5 mA to maintain regulation, as specified in Table 4 of the datasheet. Below this threshold, the device exits regulation mode and cathode voltage rises toward the input rail. This value is confirmed across –20 °C to +70 °C and applies regardless of output voltage setting.
Can TL1431CL5T be used in place of TL431 in existing designs?
Yes, TL1431CL5T is functionally and pin-compatible with TL431 in SOT23-5L footprint, sharing identical pinout (Anode, Cathode, REF, NC, NC), electrical behavior, and reference voltage. However, verify thermal dissipation limits: TL1431CL5T has 790 mW max power rating in SOT23-5L versus 750 mW for TL431 variants.
Does TL1431CL5T support capacitive loads on the cathode node?
Yes, the TL1431CL5T remains stable with up to 10 nF capacitive load at the cathode, as shown in Figure 20 of the datasheet. For larger capacitances (e.g., bulk output caps), add a 1–10 Ω isolation resistor between cathode and capacitor to prevent oscillation in high-gain feedback configurations.
How does the REF pin input current affect resistor divider accuracy?
The REF pin draws 1.5–3.0 µA, introducing ≤0.03% gain error in a 10 kΩ/10 kΩ divider at 25 °C. At worst-case temperature (70 °C), ΔIref adds ≤1.2 µA, increasing error to ≤0.06% - well within 0.4% overall system tolerance when using 1% resistors.
TL1431CL5T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- SC-74A, SOT-753
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Reference Type:
- Shunt
- Output Type:
- Adjustable
- Voltage - Output (Min/Fixed):
- 2.5V
- Voltage - Output (Max):
- 36 V
- Current - Output:
- 100 mA
- Tolerance:
- ±0.4%
- Temperature Coefficient:
- 90ppm/°C
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 1 mA
- Operating Temperature:
- -20°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
TL1431CL5T FAQ
1.How can I place an order for TL1431CL5T through Aetrix?
Please submit a Request for Quotation (RFQ) for TL1431CL5T 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 TL1431CL5T reliable?
The price and inventory of TL1431CL5T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL1431CL5T is usually 5 days.
3.What payment methods are accepted for TL1431CL5T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL1431CL5T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL1431CL5T?
TL1431CL5T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL1431CL5T 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 TL1431CL5T?
For technical support, including TL1431CL5T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL1431CL5T requirements.
6.How does Aetrix verify that TL1431CL5T is sourced from the original manufacturer or authorized distributors?
All TL1431CL5T 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 TL1431CL5T meets industry standards.
7.What is the process for return or replacement of TL1431CL5T?
All TL1431CL5T units undergo pre-shipment inspection (PSI). If there is an issue with TL1431CL5T, 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 TL1431CL5T part is unused and in its original packaging.
Return procedure for TL1431CL5T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL1431CL5T Tags
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TL431AIDBZR
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TL431BQDBZR
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AN431AN-ATRG1
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LM4040CYM3-2.5-TR
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LM4040CYM3-4.1-TR
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LM4040EIM3-2.5/NOPB
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AZ431LBNTR-G1
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LM4040D20IDBZR
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LM4041DIM3-ADJ/NOPB
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LM4040DIM3X-2.5/NOPB
Texas Instruments
-
LM4040DIM3-2.5/NOPB
Texas Instruments
-
AZ431LANTR-G1
Diodes Incorporated
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