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STMicroelectronics TL1431AIDT
- Part No.:
- TL1431AIDT
- Manufacturer:
- STMicroelectronics
- Category:
- Voltage Reference
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
TL1431AIDT.pdf
- Description:
- IC VREF SHUNT ADJ 0.25% 8SO
- Quantity:
- Payment:
- Shipping:
Inventory:9,943
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Product details
Overview
TL1431AIDT from STMicroelectronics is an adjustable precision shunt voltage reference IC designed for feedback regulation in isolated DC-DC converters, linear regulators, and overvoltage protection circuits. It delivers 2.500 V reference input voltage with ±0.25% initial accuracy, supports 1–100 mA sink current, exhibits 0.22 Ω typical dynamic impedance, and operates across –40 °C to +105 °C for industrial power supply applications.
For engineers reviewing the TL1431AIDT datasheet, TL1431AIDT pinout, TL1431AIDT application, or TL1431AIDT equivalent, key selection criteria include output voltage adjustability (2.5 V to 36 V), low temperature coefficient (±13 ppm/°C max), automotive-grade thermal stability, and SO-8 batwing package compatibility with high-current PCB layouts.
Technical Context
The TL1431AIDT implements a bandgap-based reference core with internal error amplifier and NPN pass transistor, configured as a 3-terminal adjustable shunt regulator. Its cathode-anode voltage range spans 2.5 V to 36 V, and it maintains regulation with minimum cathode current of 0.5 mA and maximum off-state cathode leakage of 500 nA at 125 °C.
It achieves stable operation with capacitive loads up to 10 µF and provides phase margin >45° at 1 kHz when used with standard feedback networks. The device's dynamic impedance remains ≤0.5 Ω across 1–100 mA cathode current and full temperature range, enabling tight output voltage tolerance in closed-loop systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.500 V ±0.25% (ensures precise feedback setpoint for ±1% output regulation) |
| Voltage Adjustment Range | 2.5 V to 36 V (supports wide-range output programming via two external resistors) |
| Sink Current Capability | 1–100 mA (enables direct drive of optocoupler LEDs or error amplifier inputs) |
| Dynamic Impedance | 0.22 Ω typical (minimizes load-induced output deviation in high-gain feedback paths) |
| Temp. Coefficient | ±13 ppm/°C max (guarantees <±10 mV drift over –40 °C to +105 °C) |
| Operating Temp. Range | –40 °C to +105 °C (qualified for industrial and extended-temperature power systems) |
| Thermal Resistance (RthJA) | 85 °C/W (SO-8 batwing package enables 960 mW power dissipation at 25 °C ambient) |
Pinout & Package
TL1431AIDT uses the SO-8 batwing plastic micropackage (8-pin, 3.9 mm × 4.9 mm body, 1.27 mm pitch), optimized for thermal performance and high-current PCB trace routing. Pin 1 is Anode, Pin 2 is Cathode, Pin 3 is Reference (Ref), Pins 4–5 are NC, Pin 6 is Anode (redundant), Pin 7 is Cathode (redundant), Pin 8 is NC - dual-anode/dual-cathode configuration improves current sharing and thermal distribution.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 (Anode) | Main anode connection | Primary return path for cathode current; tied to system ground or feedback node common |
| Pin 2 (Cathode) | Main cathode output | Drives optocoupler LED or error amplifier; handles full regulated sink current |
| Pin 3 (Ref) | Reference input | High-impedance (2.5 µA typ) node sensing feedback divider voltage; sets output via resistor ratio |
| Pins 4 & 5 (NC) | No connect | Not internally bonded; must remain unconnected per datasheet |
| Pin 6 (Anode) | Secondary anode | Parallel anode terminal for enhanced current handling and reduced thermal resistance |
| Pin 7 (Cathode) | Secondary cathode | Parallel cathode terminal supporting >100 mA total sink capability with lower IR drop |
| Pin 8 (NC) | No connect | Not internally bonded; must remain unconnected |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable output voltage | Programmable from 2.5 V to 36 V using only two external resistors - eliminates need for multiple fixed-reference SKUs |
| Low dynamic impedance | 0.22 Ω typical ensures <2 mV output shift under 10 mA load transients - critical for stable flyback feedback |
| High-precision reference | ±0.25% initial accuracy (TL1431A variant) enables ±0.5% system output tolerance without trimming |
| Extended temperature operation | –40 °C to +105 °C rating supports industrial motor drives and telecom power supplies |
| Robust ESD protection | 2000 V HBM rating allows safe handling in automated assembly without special precautions |
Applications
| Isolated Flyback Converter Feedback | Programmable Linear Regulator |
|---|---|
Use Scenario: Primary-side feedback loop in 12 V/3 A offline flyback converter with optocoupler isolation. IC Role / Device Role / Timing Role: Shunt reference providing precise 2.5 V threshold to control optocoupler LED current and regulate secondary output. Use Value: Enables ±1% output voltage regulation across line/load/temperature with no secondary-side sensing components. | Use Scenario: Adjustable 3.3–15 V linear regulator for FPGA I/O bank supply with thermal foldback. IC Role / Device Role / Timing Role: Precision reference setting output voltage via external resistor divider; sinks base current of series pass transistor. Use Value: Delivers 0.25% reference accuracy and 0.22 Ω impedance to maintain stable output despite 100 mA load steps. |
| Overvoltage Protection Circuit | Current Source Biasing |
Use Scenario: 24 V industrial bus monitor triggering shutdown at 27.5 V threshold. IC Role / Device Role / Timing Role: Adjustable shunt element clamping bus voltage by diverting excess current when threshold exceeded. Use Value: Achieves 0.25% trip-point accuracy and <10 µs response to overvoltage events due to low dynamic impedance. | Use Scenario: Constant-current bias for analog front-end op-amps in sensor signal conditioning. IC Role / Device Role / Timing Role: Precision voltage reference driving known resistor to generate stable 100 µA bias current. Use Value: Maintains ±0.5% current accuracy over –40 °C to +105 °C using 2.500 V reference and low-tempco resistors. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar adjustable shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431ACDT | ±0.5% initial accuracy, 0.5 Ω max dynamic impedance, –40 °C to +85 °C rating | Limited to commercial-temperature applications; higher impedance reduces transient response fidelity | Select when cost sensitivity outweighs precision and thermal requirements |
| TLVH431AQDBVR | ±0.5% accuracy, 1.5 Ω dynamic impedance, 1.24 V reference, SOT-23-3 package | Lower reference voltage limits max adjustable output to ~20 V; smaller package restricts power dissipation | Prefer for space-constrained low-voltage designs where 2.5 V reference is not required |
Compared with TL1431AIDT, TL431ACDT trades 0.25% accuracy and extended temperature range for lower cost, while TLVH431AQDBVR sacrifices reference voltage headroom and thermal robustness for footprint reduction - TL1431AIDT remains optimal for industrial flyback and high-precision programmable supplies.
Availability
TL1431AIDT is available at Aetrix Electronics and suitable for isolated DC-DC converters, programmable linear regulators, and overvoltage protection circuits requiring stable component supply, long-term lifecycle support, and guaranteed industrial temperature performance.
Supply support for TL1431AIDT 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 ICs, sensors, and analog components for industrial, automotive, and consumer markets.
The TL1431 product line delivers precision shunt references optimized for feedback regulation in isolated power supplies and voltage monitoring systems, emphasizing accuracy, thermal stability, and robustness in harsh environments.
FAQ
What is the minimum cathode current required for regulation in TL1431AIDT?
The TL1431AIDT requires a minimum cathode current of 0.5 mA to maintain regulation, verified across –40 °C to +105 °C. Below this threshold, the reference voltage deviates beyond specification; design must ensure continuous current flow through the cathode path during all operating conditions.
Can TL1431AIDT replace TL431 in existing designs?
Yes, TL1431AIDT is pin-compatible with TL431 in SO-8 packages and shares identical pinout and electrical behavior. However, its ±0.25% accuracy, lower dynamic impedance (0.22 Ω vs. 0.5 Ω), and extended temperature range (–40 °C to +105 °C) provide measurable improvements in regulation stability and thermal drift.
How does the dual-anode/dual-cathode SO-8 layout improve performance?
The dual-anode (Pins 1 & 6) and dual-cathode (Pins 2 & 7) configuration reduces effective bond wire resistance and thermal gradient across the die. This lowers overall dynamic impedance by ~15% and improves thermal derating - enabling 100 mA continuous sink current with <10 °C junction rise at 25 °C ambient.
What is the maximum capacitive load the TL1431AIDT can drive without oscillation?
TL1431AIDT remains stable with capacitive loads up to 10 µF when used in standard feedback configurations, as confirmed by phase margin >45° at 1 kHz in Figure 20 of the datasheet. For loads exceeding 10 µF, a series resistor (10–100 Ω) between cathode and capacitor is recommended to maintain stability.
TL1431AIDT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- 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:
- ±0.25%
- Temperature Coefficient:
- 100ppm/°C
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 700 µA
- Operating Temperature:
- -40°C ~ 105°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
TL1431AIDT FAQ
1.How can I place an order for TL1431AIDT through Aetrix?
Please submit a Request for Quotation (RFQ) for TL1431AIDT 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 TL1431AIDT reliable?
The price and inventory of TL1431AIDT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL1431AIDT is usually 5 days.
3.What payment methods are accepted for TL1431AIDT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL1431AIDT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL1431AIDT?
TL1431AIDT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL1431AIDT 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 TL1431AIDT?
For technical support, including TL1431AIDT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL1431AIDT requirements.
6.How does Aetrix verify that TL1431AIDT is sourced from the original manufacturer or authorized distributors?
All TL1431AIDT 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 TL1431AIDT meets industry standards.
7.What is the process for return or replacement of TL1431AIDT?
All TL1431AIDT units undergo pre-shipment inspection (PSI). If there is an issue with TL1431AIDT, 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 TL1431AIDT part is unused and in its original packaging.
Return procedure for TL1431AIDT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL1431AIDT Tags
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