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Texas Instruments TL431BILP
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- Part No.:
- TL431BILP
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-226-3, TO-92-3 (TO-226AA)
- Datasheet:
-
TL431BILP.pdf
- Description:
- IC VREF SHUNT ADJ 0.5% TO92-3
- Quantity:
- Payment:
- Shipping:
Inventory:223
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Product details
Overview
TL431BILP from Texas Instruments is a precision programmable shunt voltage reference IC with 0.5% initial tolerance at 25°C, adjustable output from 2.495 V to 36 V, and operation across −40°C to 125°C. It delivers 0.2 Ω typical dynamic impedance, 1–100 mA sink-current capability, and low 14 mV max reference voltage drift over temperature-used in feedback loops of isolated DC/DC converters and industrial power supplies.
For engineers reviewing the TL431BILP datasheet, TL431BILP pinout, TL431BILP application, or TL431BILP equivalent, key selection criteria include its Q-grade temperature range (−40°C to 125°C), B-grade accuracy (±0.5%), SOT-23-3 package footprint, and verified stability with capacitive loads up to 1 µF in flyback and forward converter topologies.
Technical Context
The TL431BILP implements a high-gain transconductance amplifier with internal 2.495 V reference, comparing REF pin voltage to VREF and driving the cathode to maintain regulation via external resistor divider. Its active output stage provides sharp turn-on and low output impedance, enabling direct replacement of Zener diodes in closed-loop regulation without additional compensation in many cases.
Designed for automotive-qualified applications, the "Q" suffix denotes −40°C to 125°C operation, while "B" specifies 0.5% reference tolerance at 25°C. The SOT-23-3 package (LP variant) uses standard anode-cathode-ref pinout, distinct from TL432 variants, and supports stable operation with load capacitances up to 1 µF per Figure 6-18.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495 V ±12 mV (0.5% tolerance at 25°C); sets precise feedback threshold in SMPS error amplifiers. |
| Temperature Range | −40°C to +125°C (Q-grade); enables use in under-hood automotive and industrial ambient environments. |
| Dynamic Impedance | 0.2 Ω typical; ensures minimal output voltage shift under varying load current in regulation circuits. |
| Sink Current Range | 1 mA to 100 mA; supports direct drive of optocoupler LEDs or secondary-side error amplifiers without buffering. |
| Reference Input Current | 2–4 µA; allows high-value feedback resistors (e.g., 1 MΩ) to minimize power loss in high-voltage dividers. |
| Output Noise | Low broadband noise (typ. 20 nV/√Hz @ 1 kHz); critical for low-noise analog references and precision ADC biasing. |
| Max Cathode Voltage | 36 V; permits use in 24 V industrial rails and 30 V DC bus monitoring with margin. |
Pinout & Package
SOT-23-3 (LP) package: 2.90 mm × 1.30 mm body, gull-wing leads, moisture sensitivity level 1, RoHS-compliant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1: Cathode | Current sink output | Connects to primary-side optocoupler anode or regulator feedback node; carries full error current. |
| Pin 2: Anode | Common return / ground reference | Typically tied to system ground or negative rail; defines voltage reference point for REF and Cathode. |
| Pin 3: REF | High-impedance reference input | Compares external resistor-divider voltage to internal 2.495 V; draws only 2–4 µA for minimal divider loading. |
Key Features
| Feature | Design Value |
|---|---|
| 0.5% initial reference accuracy | Reduces need for post-manufacturing calibration in power supply feedback paths. |
| −40°C to +125°C operation | Supports AEC-Q100 Grade 1 compliance in automotive engine control and battery management systems. |
| 0.2 Ω dynamic impedance | Maintains tight output regulation under fast transient load steps in isolated DC/DC converters. |
| 1–100 mA sink capability | Directly drives PC817/PC817x optocouplers across full CTR range without external transistor. |
| Stable with ≤1 µF capacitive load | Eliminates need for series damping resistors in secondary-side feedback networks. |
Applications
| Industrial AC/DC Power Supply | Rack Server PSU Feedback |
|---|---|
Use Scenario: Secondary-side voltage regulation in 500 W telecom rectifier with optocoupler isolation. IC Role / Device Role / Timing Role: Precision shunt reference generating error signal for TL3845 PWM controller via PC817 optocoupler. Use Value: 0.5% reference tolerance ensures ±0.5% output voltage accuracy across line/load/temperature; 125°C rating supports high-density board layout near heatsinks. |
Use Scenario: Multi-output DC/DC module regulating +12 V, +5 V, and +3.3 V rails in 1U server chassis. IC Role / Device Role / Timing Role: Primary reference for digital POL controllers; used in master-slave sequencing with DAC-adjustable setpoints. Use Value: Low 2–4 µA REF current enables high-resistance feedback dividers, reducing standby power by >15 mW per rail vs. standard Zener solutions. |
| AC Inverter Motor Drive | Servo Drive Control Module |
Use Scenario: DC bus voltage sensing and overvoltage protection in 15 kW VFD with IGBT gate drivers. IC Role / Device Role / Timing Role: Shunt reference in comparator-based OVLO circuit; triggers shutdown within 100 ns of fault detection. Use Value: 36 V max cathode rating accommodates 30 V DC link with 20% margin; 14 mV temp drift ensures trip point stability across motor thermal cycling. |
Use Scenario: Isolated analog feedback for position loop amplifier in robotic joint actuator with resolver interface. IC Role / Device Role / Timing Role: Reference source for 16-bit DAC generating precise current command signals to H-bridge driver. Use Value: Low 20 nV/√Hz noise prevents encoder jitter in sub-arcminute positioning; SOT-23-3 footprint saves space on compact servo PCBs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431BQDBVR | Same B-grade accuracy and Q-temp range; SOT-23-5 package with NC pin (Pin 2), different pinout than TL431BILP. | Requires PCB redesign due to 5-pin layout and relocated anode/cathode pins; not drop-in compatible. | Select when board layout allows SOT-23-5 and thermal performance requires lower RθJA (206°C/W vs. 206°C/W - identical for DBZ vs DBVR per datasheet Table 6.3). |
| MAX6008BEUR+T | Fixed 2.5 V output (not adjustable); 0.2% initial accuracy; 10 ppm/°C tempco; SOT-23-3 package. | Lacks adjustable voltage capability; unsuitable for designs requiring >2.5 V setpoint or resistor-programmable outputs. | Choose only for fixed 2.5 V reference needs where ultra-low tempco outweighs adjustability requirement. |
Compared with TL431BILP, TL431BQDBVR offers identical electrical specs but demands layout revision, while MAX6008BEUR+T trades adjustability for tighter initial accuracy and lower drift-making TL431BILP optimal for cost-sensitive, programmable industrial power applications requiring proven field reliability.
Availability
TL431BILP is available at Aetrix Electronics and suitable for industrial AC/DC power supplies, rack server PSUs, and servo drive control modules requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for TL431BILP 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 ICs, with decades of heritage in precision reference design.
The TL431 product line delivers programmable shunt references optimized for feedback regulation in isolated switch-mode power supplies, offering grade-specific accuracy and temperature robustness for industrial, automotive, and computing applications.
FAQ
What is the maximum cathode voltage rating for TL431BILP?
The TL431BILP has an absolute maximum cathode voltage (VK A) of 37 V, with recommended operating range from VREF (2.495 V) to 36 V. This allows safe use in 24 V and 30 V DC bus applications with sufficient margin, and aligns with industrial and automotive power rail requirements documented in Section 6.1 of the TI SLVS543S datasheet.
Does TL431BILP require an external capacitor for stability?
TL431BILP is stable with capacitive loads up to 1 µF without added series resistance, as confirmed in Figure 6-18 of the datasheet for Q-grade SOT-23-3 devices. Unlike older variants, it does not require mandatory output capacitance-enabling simpler, lower-BOM-count designs in isolated feedback networks.
How does the reference input current of TL431BILP affect feedback resistor selection?
TL431BILP draws only 2–4 µA into the REF pin, permitting use of high-value feedback resistors (e.g., 499 kΩ + 10 kΩ for 12 V output). This minimizes power loss in voltage dividers-critical for energy-efficient designs-and avoids loading errors that occur with higher-input-current references like LM4040.
Can TL431BILP replace a Zener diode in existing designs?
Yes, TL431BILP serves as a precision upgrade to Zener diodes in shunt regulation, offering 0.5% tolerance vs. typical 5% Zener tolerance, 0.2 Ω dynamic impedance vs. 10–100 Ω Zener impedance, and guaranteed operation from −40°C to 125°C. No circuit changes are needed beyond substituting the device and verifying resistor values for desired output voltage.
What is the temperature coefficient behavior of TL431BILP over its full operating range?
TL431BILP exhibits a maximum reference voltage deviation of 14 mV over −40°C to +125°C (Q-grade), corresponding to ~112 ppm/°C worst-case average drift. This is verified in Section 6.13 (TL431BQ characteristics) and Figure 6-1, making it suitable for applications where reference stability must hold across wide ambient and self-heating conditions.
TL431BILP Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA)
- Series:
- -
- Packaging:
- Bulk
- 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:
- ±0.5%
- 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:
- Through Hole
- Supplier Device Package:
- TO-92-3
TL431BILP FAQ
1.How can I place an order for TL431BILP through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431BILP 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 TL431BILP reliable?
The price and inventory of TL431BILP are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431BILP is usually 5 days.
3.What payment methods are accepted for TL431BILP?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431BILP transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431BILP?
TL431BILP orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431BILP 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 TL431BILP?
For technical support, including TL431BILP datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431BILP requirements.
6.How does Aetrix verify that TL431BILP is sourced from the original manufacturer or authorized distributors?
All TL431BILP 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 TL431BILP meets industry standards.
7.What is the process for return or replacement of TL431BILP?
All TL431BILP units undergo pre-shipment inspection (PSI). If there is an issue with TL431BILP, 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 TL431BILP part is unused and in its original packaging.
Return procedure for TL431BILP:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431BILP Tags
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