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Texas Instruments TL431BCDRG4
- Part No.:
- TL431BCDRG4
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
TL431BCDRG4.pdf
- Description:
- IC VREF SHUNT ADJ 0.5% 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,337
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Product details
Overview
TL431BCDRG4 from Texas Instruments is a precision programmable shunt voltage reference IC with 0.5% initial tolerance at 25°C, adjustable output from 2.483 V to 36 V via two external resistors, and operation across −40°C to 125°C. It delivers 0.2 Ω typical dynamic impedance, 1–100 mA sink-current capability, and low 6 mV temperature drift (C-grade), serving as a high-stability replacement for Zener diodes in feedback loops of isolated DC/DC converters.
For engineers reviewing the TL431BCDRG4 datasheet, TL431BCDRG4 pinout, TL431BCDRG4 application, or TL431BCDRG4 equivalent, key selection criteria include reference accuracy over temperature, cathode current compliance, dynamic impedance stability under load transients, and compatibility with SOT-23-3 PCB footprints in space-constrained power management designs.
Technical Context
The TL431BCDRG4 implements an internal error amplifier with a precise 2.495 V bandgap reference, comparing REF pin voltage against Vref to control cathode current flow. Its active output stage provides sharp turn-on characteristics and stable regulation without external compensation in most configurations.
It operates as a three-terminal adjustable shunt regulator: REF senses voltage, ANODE serves as common return (typically grounded), and CATHODE sinks current into the regulated node. The device requires ≥0.4 mA minimum cathode current to maintain regulation and exhibits <0.5 µA off-state leakage at 36 V cathode voltage.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.483–2.507 V at 25°C (0.5% B-grade tolerance); sets feedback threshold for output regulation |
| Temp Range | −40°C to 125°C (Q-grade); validated for automotive and industrial ambient conditions |
| Dynamic Impedance | 0.2 Ω typical (≤0.5 Ω max); ensures minimal output voltage deviation during 1–100 mA load steps |
| Cathode Current | 1–100 mA continuous sink range; supports direct drive of optocoupler LEDs in isolated flyback controllers |
| Ref Input Current | 2–4 µA typical; enables high-impedance resistor-divider networks without significant loading error |
| Temp Drift (VI(dev)) | 14–34 mV over full range; quantifies worst-case reference voltage shift across operating temperature |
| Off-State Leakage | ≤0.5 µA at 36 V cathode voltage; minimizes standby power loss in always-on circuits |
Pinout & Package
SOT-23-3 package (2.90 mm × 1.30 mm), surface-mount, lead-free, RoHS-compliant. Pin 1 = CATHODE, Pin 2 = REF, Pin 3 = ANODE.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CATHODE (Pin 1) | Current sink output | Connects to regulated node or optocoupler anode; carries full load-adjustment current |
| REF (Pin 2) | Reference input | Senses divider voltage; triggers regulation when ≥2.495 V; draws only 2–4 µA |
| ANODE (Pin 3) | Common return | Typically tied to system ground or low-side return path; defines voltage reference point |
Key Features
| Feature | Design Value |
|---|---|
| 0.5% Initial Accuracy | Reduces need for post-manufacturing calibration in precision power supplies |
| Adjustable Output (2.483–36 V) | Enables single BOM part to support multiple output voltages using resistor scaling |
| 0.2 Ω Dynamic Impedance | Maintains tight regulation during rapid load changes in SMPS feedback paths |
| −40°C to 125°C Operation | Validated for under-hood automotive and industrial motor drive environments |
| Low 2–4 µA Reference Current | Permits use of >1 MΩ resistor dividers, minimizing quiescent current in battery-powered systems |
Applications
| AC/DC Power Supply Feedback | Rack Server VRM Monitoring |
|---|---|
Use Scenario: Secondary-side voltage sensing in isolated flyback or forward converters. IC Role / Device Role / Timing Role: Shunt reference providing error signal to optocoupler-driven primary controller. Use Value: 0.5% accuracy and 0.2 Ω impedance ensure ±1% output regulation across line/load/temperature. |
Use Scenario: Precision monitoring of 12 V or 5 V VRM outputs in multi-rail server PSUs. IC Role / Device Role / Timing Role: High-stability reference for ADC input scaling or comparator threshold setting. Use Value: 14–34 mV total drift over −40°C to 125°C enables reliable fault detection without software compensation. |
| Industrial Inverter Gate Drive Bias | Notebook Adapter Overvoltage Protection |
Use Scenario: Generating stable bias voltage for isolated IGBT gate driver ICs. IC Role / Device Role / Timing Role: Regulated shunt source for level-shifting and bootstrap capacitor charging circuits. Use Value: 1–100 mA sink capability supports direct drive of gate driver logic inputs without buffering. |
Use Scenario: OVP threshold reference in USB-C PD or proprietary notebook AC adapters. IC Role / Device Role / Timing Role: Precision trip point generator for secondary-side protection circuitry. Use Value: 0.5% tolerance eliminates need for trimming resistors, reducing BOM count and test time. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431BIDR | Same 0.5% accuracy and Q-temp grade, but in SOIC-8 package (4.90 mm × 3.90 mm) | Requires larger PCB area; better thermal dissipation (RθJA = 97°C/W vs 206°C/W) | Choose for higher-power designs (>500 mW) or legacy SOIC layouts |
| TLVH431BQDBVR | Lower 1.24 V reference, 0.5% accuracy, SOT-23-3, −40°C to 125°C, but 100 mA max sink | Not pin-compatible; requires redesign of resistor divider for 2.5 V setpoint | Choose only when lower reference voltage or improved noise performance (15 nV/√Hz) is required |
Compared with TL431BCDRG4, TL431BIDR offers superior thermal performance in larger packages while TLVH431BQDBVR enables lower-voltage regulation at the cost of circuit redesign - neither is pin-compatible, and both require validation of loop stability and layout parasitics.
Availability
TL431BCDRG4 is available at Aetrix Electronics and suitable for AC/DC power supplies, rack server VRMs, and industrial inverters requiring stable component supply with guaranteed long-term manufacturability.
Supply support for TL431BCDRG4 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 reference design and power management ICs.
The TL431 product line delivers programmable shunt references optimized for feedback-loop stability, low-drift operation, and wide-temperature reliability in industrial, automotive, and computing power systems.
FAQ
What is the reference voltage tolerance of TL431BCDRG4 at 25°C?
The TL431BCDRG4 has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a 2.483 V to 2.507 V range. This B-grade accuracy is specified in Section 6.11 of the TI datasheet and applies under recommended operating conditions with 10 mA cathode current. The TL431BCDRG4 maintains this tolerance without calibration or trimming.
Which package does TL431BCDRG4 use, and what are its dimensions?
The TL431BCDRG4 uses the SOT-23-3 package with nominal body size 2.90 mm × 1.30 mm. Pin 1 is CATHODE, Pin 2 is REF, and Pin 3 is ANODE - matching the standard TL431 DBZ pinout. This footprint is compatible with automated SMT assembly and supports thermal dissipation up to 350 mW at 25°C ambient.
Can TL431BCDRG4 replace a Zener diode in feedback circuits?
Yes, the TL431BCDRG4 is explicitly designed as a precision replacement for Zener diodes in feedback networks. Its 0.2 Ω dynamic impedance, sharp turn-on, and 0.5% tolerance provide superior regulation stability compared to discrete Zeners. The TL431BCDRG4 requires only two external resistors to set output voltage from 2.483 V to 36 V.
What is the minimum cathode current required for regulation in TL431BCDRG4?
The TL431BCDRG4 requires a minimum cathode current of 0.4 mA to maintain regulation, per Section 6.11 of the datasheet. Below this threshold, the device exits regulation and reference voltage collapses. This value is consistent across B-grade C/I/Q variants and must be ensured in all operating conditions, including light-load or standby modes.
Does TL431BCDRG4 support operation at 125°C ambient temperature?
Yes, the TL431BCDRG4 is rated for operation from −40°C to 125°C (Q-grade), with electrical characteristics fully specified across that range. Its VI(dev) parameter is 14–34 mV over temperature, confirming stable reference performance in automotive under-hood or industrial motor drive environments where ambient reaches 125°C.
TL431BCDRG4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Discontinued at Digi-Key
- Reference Type:
- Shunt
- Output Type:
- Adjustable
- Voltage - Output (Min/Fixed):
- 2.495V
- Voltage - Output (Max):
- 36 V
- Current - Output:
- 100 mA
- Tolerance:
- ±0.5%
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 600 µA
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
TL431BCDRG4 FAQ
1.How can I place an order for TL431BCDRG4 through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431BCDRG4 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 TL431BCDRG4 reliable?
The price and inventory of TL431BCDRG4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431BCDRG4 is usually 5 days.
3.What payment methods are accepted for TL431BCDRG4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431BCDRG4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431BCDRG4?
TL431BCDRG4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431BCDRG4 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 TL431BCDRG4?
For technical support, including TL431BCDRG4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431BCDRG4 requirements.
6.How does Aetrix verify that TL431BCDRG4 is sourced from the original manufacturer or authorized distributors?
All TL431BCDRG4 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 TL431BCDRG4 meets industry standards.
7.What is the process for return or replacement of TL431BCDRG4?
All TL431BCDRG4 units undergo pre-shipment inspection (PSI). If there is an issue with TL431BCDRG4, 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 TL431BCDRG4 part is unused and in its original packaging.
Return procedure for TL431BCDRG4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431BCDRG4 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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