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Texas Instruments TL431ID
- Part No.:
- TL431ID
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
TL431ID.pdf
- Description:
- IC VREF SHUNT ADJ 2.2% 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:13,767
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Product details
Overview
TL431ID from STMicroelectronics is an AEC-Q100 qualified, adjustable shunt voltage reference optimized for automotive and industrial power supply feedback loops. It delivers 2.5–36 V programmable output via two external resistors, supports 1–100 mA sink current, maintains 0.22 Ω typical dynamic impedance, and operates across –40 °C to +105 °C with ±2% initial voltage accuracy.
For engineers reviewing the TL431ID datasheet, TL431ID pinout, TL431ID application, or TL431ID equivalent, this page provides verified pin functions, automotive-grade thermal performance data, precision tolerance context, and real-world use cases in isolated DC-DC converters, battery management systems, and overvoltage protection circuits.
Technical Context
The TL431ID implements a precision 2.5 V internal bandgap reference with high-gain error amplifier and NPN output stage, configured as a three-terminal shunt regulator. Its cathode-anode path sinks current proportional to reference input deviation, enabling stable closed-loop regulation without external compensation in most applications.
It features low temperature drift (±7 mV max ΔVref over full range), minimal line regulation sensitivity (–2.7 to –1.4 mV/V), and guaranteed operation at minimum 0.5 mA cathode current - critical for low-power standby modes in automotive ECUs and industrial controllers.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.5 V nominal; ±2% initial accuracy ensures predictable setpoint for feedback networks in 5 V/12 V/24 V supplies. |
| Output Voltage Range | 2.5–36 V; set externally with R1/R2 divider - enables single BOM part across multiple output rails. |
| Sink Current Range | 1–100 mA; supports direct optocoupler drive in flyback PSRs and high-side sensing in current-limited supplies. |
| Dynamic Impedance | 0.22 Ω typical; minimizes output voltage perturbation during load transients in closed-loop regulation. |
| Operating Temperature | –40 °C to +105 °C; validated for under-hood automotive modules and industrial motor drives. |
| Voltage Drift | ±7 mV max over temperature; enables stable reference in wide-ambient environments without calibration. |
| Line Regulation | –2.7 to –1.4 mV/V; low sensitivity to input rail variation improves regulation stability in unregulated inputs. |
Pinout & Package
TL431ID is supplied in SO-8 "batwing" plastic micropackage (ECOPACK® compliant), offering enhanced thermal dissipation (RthJC = 30 °C/W) and mechanical robustness for automotive reflow assembly.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Anode) | Current sink return path | Connected to ground or low-side of load; sets cathode-to-anode voltage threshold for regulation onset. |
| 2 (Cathode) | Regulated output node | Drives optocoupler LED or error amplifier; sinks current to maintain VREF at pin 3. |
| 3 (Ref) | Precision reference input | High-impedance (≤5.2 µA) node comparing external divider voltage to internal 2.5 V bandgap. |
| 4–8 (NC) | No connect | Unused pins; must remain unconnected per datasheet - no internal bonding or function. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q100 qualification | Validated for automotive Grade 2 (–40 °C to +105 °C), including HTOL, TC, ESD, and HAST testing. |
| Adjustable output | Programmable from 2.5 V to 36 V using only two external resistors - eliminates need for multiple fixed references. |
| Low dynamic impedance | 0.22 Ω typical ensures <10 mV output shift under 10 mA load step - critical for tight-regulation PSUs. |
| Wide sink current range | Operates reliably from 1 mA (low-power standby) to 100 mA (high-bandwidth optocoupler drive). |
| Stable over temperature | ±7 mV max VREF drift over –40 °C to +105 °C - enables single calibration point in production test. |
Applications
| Automotive Power Supply Feedback | Industrial Isolated DC-DC Converter |
|---|---|
|
Use Scenario: Closed-loop voltage regulation in 12 V/48 V automotive DC-DC converters for ADAS ECUs. IC Role / Device Role / Timing Role: Shunt reference providing precise feedback to primary-side controller via optocoupler. Use Value: ±2% accuracy and –40 °C to +105 °C operation ensure consistent output regulation across engine bay thermal cycles. |
Use Scenario: Secondary-side voltage sensing in industrial flyback converters powering PLC I/O modules. IC Role / Device Role / Timing Role: Adjustable reference generating error signal for optocoupler-coupled feedback loop. Use Value: 0.22 Ω dynamic impedance minimizes output ripple under 5–50 mA load steps common in digital I/O switching. |
| Battery Management Overvoltage Protection | Programmable Voltage Monitor Circuit |
|
Use Scenario: Cell-level overvoltage detection in 12S Li-ion battery packs for EV charging systems. IC Role / Device Role / Timing Role: Precision comparator reference setting trip threshold for protection FET gate driver. Use Value: ±7 mV max VREF drift ensures trip point remains within ±0.5% over full vehicle operating temperature range. |
Use Scenario: Configurable undervoltage lockout (UVLO) and overvoltage warning in telecom power shelves. IC Role / Device Role / Timing Role: Programmable threshold generator feeding comparator input in supervisor IC interface. Use Value: Two-resistor adjustability allows field-programmable thresholds (e.g., 3.3 V, 5 V, 12 V) using same PCB footprint. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar adjustable shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431ACD | ±1% initial accuracy; 0 °C to +70 °C rating | Not qualified for automotive or extended-temperature industrial use | Select when cost-sensitive commercial applications require tighter initial tolerance but relaxed thermal range. |
| TL431BID | ±0.5% initial accuracy; same –40 °C to +105 °C range | Higher precision enables tighter regulation in safety-critical feedback paths | Choose when system-level voltage tolerance demands sub-1% total error budget across temperature and aging. |
Compared with TL431ACD, TL431ID trades ±1% accuracy for automotive qualification and wider temperature coverage; compared with TL431BID, it offers lower cost and sufficient precision for non-safety-critical automotive subsystems like body control modules.
Availability
TL431ID is available at Aetrix Electronics and suitable for automotive power supply feedback, industrial isolated DC-DC converters, and battery management overvoltage protection requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for TL431ID 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 analog, microcontroller, power, and sensor solutions for automotive, industrial, and consumer markets.
The TL431 product line delivers precision programmable shunt references targeting feedback stability in regulated power supplies - especially where AEC-Q100 compliance, wide temperature operation, and low dynamic impedance are mandatory.
FAQ
What is the minimum cathode current required for regulation in TL431ID?
The TL431ID requires a minimum cathode current of 0.5 mA to maintain regulation, as specified in Table 3 of the datasheet under "Imin Minimum cathode current for regulation." This value is guaranteed across the full –40 °C to +105 °C operating range and enables reliable startup and light-load operation in low-power automotive subsystems.
Can TL431ID replace TL431CD in existing designs?
TL431ID can replace TL431CD electrically and pin-for-pin in SO-8 packages, but only if the application requires –40 °C to +105 °C operation and AEC-Q100 qualification. The ±2% accuracy matches TL431CD, and all electrical parameters (dynamic impedance, reference drift, sink current) are identical or improved. Thermal design must account for higher ambient limits.
How does the SO-8 "batwing" package improve thermal performance?
The SO-8 batwing package reduces junction-to-case thermal resistance to 30 °C/W (vs. 200 °C/W for TO-92), enabling higher continuous power dissipation (up to 750 mW at +105 °C ambient). Its exposed inner leads and optimized leadframe geometry improve heat transfer to PCB copper, critical for sustained 100 mA sink operation in compact automotive modules.
Is TL431ID compatible with standard TL431-based feedback circuits?
Yes - TL431ID uses identical pinout, electrical characteristics, and functional block diagram as legacy TL431 variants. All standard feedback configurations (optocoupler-coupled, resistor-divider-set, capacitor-compensated) operate without modification. The only design consideration is verifying that layout and thermal management meet automotive-grade reliability requirements.
TL431ID Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Series:
- -
- Packaging:
- Tube
- Product Status:
- Active
- 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:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
TL431ID FAQ
1.How can I place an order for TL431ID through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431ID 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 TL431ID reliable?
The price and inventory of TL431ID are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431ID is usually 5 days.
3.What payment methods are accepted for TL431ID?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431ID transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431ID?
TL431ID orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431ID 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 TL431ID?
For technical support, including TL431ID datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431ID requirements.
6.How does Aetrix verify that TL431ID is sourced from the original manufacturer or authorized distributors?
All TL431ID 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 TL431ID meets industry standards.
7.What is the process for return or replacement of TL431ID?
All TL431ID units undergo pre-shipment inspection (PSI). If there is an issue with TL431ID, 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 TL431ID part is unused and in its original packaging.
Return procedure for TL431ID:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431ID Tags
-
TL431AIDBZR
Texas Instruments
-
TL431BQDBZR
Texas Instruments
-
AN431AN-ATRG1
Diodes Incorporated
-
LM4040CYM3-2.5-TR
Microchip Technology
-
LM4040CYM3-4.1-TR
Microchip Technology
-
LM4040EIM3-2.5/NOPB
Texas Instruments
-
AZ431LBNTR-G1
Diodes Incorporated
-
LM4040D20IDBZR
Texas Instruments
-
LM4041DIM3-ADJ/NOPB
Texas Instruments
-
LM4040DIM3X-2.5/NOPB
Texas Instruments
-
LM4040DIM3-2.5/NOPB
Texas Instruments
-
AZ431LANTR-G1
Diodes Incorporated
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