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Texas Instruments TL431AIDG4
- Part No.:
- TL431AIDG4
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
TL431AIDG4.pdf
- Description:
- IC VREF SHUNT ADJ 1% 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,281
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Product details
Overview
TL431AIDG4 from Texas Instruments is a precision programmable shunt voltage reference IC with 1% initial tolerance at 25°C, adjustable output from 2.495 V to 36 V, −40°C to 85°C operating temperature range (I-grade), 0.2 Ω typical dynamic impedance, and 1–100 mA sink-current capability. It replaces Zener diodes in feedback loops of isolated DC/DC converters and AC/DC power supplies.
For engineers reviewing the TL431AIDG4 datasheet, TL431AIDG4 pinout, TL431AIDG4 application, or TL431AIDG4 equivalent, this page delivers verified electrical specs, SOIC-8 package mapping, thermal performance data, and real-world implementation guidance for power supply regulation and voltage monitoring circuits.
Technical Context
The TL431AIDG4 implements a three-terminal adjustable shunt regulator architecture with an internal 2.495 V reference, error amplifier, and NPN output stage. Its sharp turn-on characteristic and low output impedance enable stable closed-loop control in flyback and forward converter feedback paths.
It operates as a two-input comparator: REF pin senses voltage relative to ANODE (typically ground), and CATHODE sinks current to regulate VKA. The device requires no external compensation in most configurations but exhibits defined stability boundaries dependent on load capacitance and cathode current.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495 V ±1% at 25°C - sets precise threshold for feedback loop regulation |
| Output Voltage Range | 2.495 V to 36 V - configured via two external resistors, enabling flexible output setting |
| Operating Temperature | −40°C to +85°C - qualified for industrial-grade power supply environments |
| Dynamic Impedance | 0.2 Ω typical - ensures minimal output voltage deviation under load transients |
| Sink Current Range | 1 mA to 100 mA - supports direct drive of optocoupler LEDs in isolated feedback designs |
| Reference Input Current | 2–4 µA - enables high-impedance voltage divider networks without significant loading error |
| Temp Drift (VI(dev)) | ≤34 mV over full range - guarantees <±0.01%/°C effective tempco in compensated designs |
Pinout & Package
TL431AIDG4 is supplied in 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 marked with a notch or dot; orientation follows JEDEC MS-012.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (CATHODE) | Shunt current output node | Connects to primary-side controller feedback input (e.g., optocoupler anode); sinks regulated current |
| 2 (ANODE) | Common reference return | Typically tied to system ground or secondary-side common; defines voltage reference point |
| 3 (REF) | Reference input threshold | Senses divided output voltage; triggers regulation when ≥2.495 V above ANODE |
| 4–8 (NC) | No internal connection | Unused pins; must remain unconnected per TI specification for SOIC-8 variant |
Key Features
| Feature | Design Value |
|---|---|
| Initial accuracy | 1% at 25°C (A-grade) - reduces need for post-production trimming in mid-precision power supplies |
| Low dynamic impedance | 0.2 Ω typical - maintains tight output regulation during rapid load steps without external capacitor |
| Wide sink-current range | 1–100 mA - directly interfaces with PC817, LTV-817, and similar optocouplers across full operating range |
| Industrial temperature range | −40°C to +85°C - supports deployment in motor drives, PLCs, and telecom rectifiers |
| Low reference input current | 2–4 µA - allows use of >1 MΩ resistor dividers, minimizing standby power loss |
Applications
| Rack Server Power Supply | Industrial AC/DC Converter |
|---|---|
Use Scenario: Secondary-side voltage sensing in 48 V input, 12 V/50 A isolated DC/DC module with optocoupler feedback. IC Role / Device Role / Timing Role: Shunt reference providing precise 2.495 V threshold to control optocoupler LED current and regulate primary-side PWM duty cycle. Use Value: Enables ±1% output voltage accuracy over line/load/temperature without digital calibration. |
Use Scenario: Output voltage regulation in 3-phase industrial rectifier with 24 V/10 A auxiliary rail. IC Role / Device Role / Timing Role: Adjustable shunt reference in linear post-regulator stage, compensating for transformer winding resistance drop. Use Value: Delivers stable 24 V output despite 10–15% input ripple and ambient temperatures up to 85°C. |
| AC Inverter Drive | Notebook PC Adapter |
Use Scenario: DC bus voltage monitor and overvoltage protection trigger in 400 V IGBT-based VFD. IC Role / Device Role / Timing Role: Precision reference feeding comparator circuit that asserts fault signal when bus exceeds 420 V. Use Value: Provides repeatable 420 V trip point with <±3 V variation across temperature, eliminating false trips. |
Use Scenario: Feedback reference in 19 V/3.42 A flyback adapter with QR controller and synchronous rectification. IC Role / Device Role / Timing Role: Programmable shunt reference setting 19 V output via 10 kΩ/1.24 kΩ resistor divider on secondary side. Use Value: Achieves <±1.5% output tolerance across universal AC input (90–264 VAC) and full load range. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431ACD | Same SOIC-8 package, C-grade (0°C to 70°C), 2% initial tolerance | Limited to commercial-temperature environments; lower cost where extended temp not required | Select when operating ambient stays within 0–70°C and ±2% output tolerance is acceptable |
| TL431BIDR | Same I-grade temp range, SOT-23-3 package, 0.5% initial tolerance, different pinout (REF-CATHODE-ANODE) | Requires PCB redesign; offers higher precision but smaller footprint and lower thermal mass | Choose for space-constrained designs needing tighter regulation, accepting layout change and derated power |
Compared with TL431ACD and TL431BIDR, the TL431AIDG4 balances industrial temperature support, 1% accuracy, SOIC-8 manufacturability, and proven thermal performance-making it optimal for mid-volume industrial power supplies where reliability and ease of assembly are prioritized over ultra-high precision or miniaturization.
Availability
TL431AIDG4 is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC converters, and AC inverter drives requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for TL431AIDG4 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, embedded processing, and power management technologies, with over 90 years of innovation in industrial and automotive electronics.
The TL431 product line was designed specifically for precision voltage regulation in isolated power supplies and feedback control systems, delivering Zener-replacement performance with programmable flexibility and robust thermal behavior.
FAQ
What is the reference voltage tolerance of TL431AIDG4 at 25°C?
The TL431AIDG4 has a reference voltage tolerance of ±1% at 25°C, corresponding to a nominal 2.495 V output with minimum 2.470 V and maximum 2.520 V under specified test conditions (VKA = Vref, IKA = 10 mA). This A-grade accuracy is confirmed in Section 6.8 of the TI SLVS543S datasheet.
Which package type does TL431AIDG4 use?
TL431AIDG4 uses an 8-pin SOIC (Small Outline Integrated Circuit) package with body dimensions of 4.90 mm × 3.90 mm and 1.27 mm lead pitch. Pin 1 is identified by a notch or dot; pins 4–8 are no-connect (NC) terminals per TI's official pinout documentation for the D-package variant.
Can TL431AIDG4 replace a standard Zener diode in feedback circuits?
Yes, TL431AIDG4 is explicitly designed as a superior Zener diode replacement in feedback circuits. Its active error amplifier provides sharper turn-on, lower dynamic impedance (0.2 Ω vs. typical Zener's 10–100 Ω), and programmable output (2.495 V–36 V), enabling tighter regulation and reduced component count in switching power supplies.
What is the maximum cathode voltage rating for TL431AIDG4?
The absolute maximum cathode voltage (VKA) for TL431AIDG4 is 37 V, referenced to the ANODE pin. The recommended operating range is Vref to 36 V. Exceeding 37 V risks permanent damage, and operation near the limit requires careful thermal design due to power dissipation constraints.
Does TL431AIDG4 require external compensation capacitors?
TL431AIDG4 does not require external compensation in most standard configurations, but stability depends on load capacitance and cathode current. Figure 6-16 in the TI datasheet defines oscillation boundaries: for VKA = 5–15 V, avoid CL > 1 µF at IKA < 10 mA. A 100 pF ceramic capacitor across REF–ANODE improves noise immunity without affecting stability.
TL431AIDG4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- 8-SOIC (0.154", 3.90mm 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:
- ±1%
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 700 µA
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
TL431AIDG4 FAQ
1.How can I place an order for TL431AIDG4 through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431AIDG4 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 TL431AIDG4 reliable?
The price and inventory of TL431AIDG4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431AIDG4 is usually 5 days.
3.What payment methods are accepted for TL431AIDG4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431AIDG4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431AIDG4?
TL431AIDG4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431AIDG4 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 TL431AIDG4?
For technical support, including TL431AIDG4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431AIDG4 requirements.
6.How does Aetrix verify that TL431AIDG4 is sourced from the original manufacturer or authorized distributors?
All TL431AIDG4 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 TL431AIDG4 meets industry standards.
7.What is the process for return or replacement of TL431AIDG4?
All TL431AIDG4 units undergo pre-shipment inspection (PSI). If there is an issue with TL431AIDG4, 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 TL431AIDG4 part is unused and in its original packaging.
Return procedure for TL431AIDG4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431AIDG4 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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