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Texas Instruments TL431BCDBZTG4
- Part No.:
- TL431BCDBZTG4
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
TL431BCDBZTG4.pdf
- Description:
- IC VREF SHUNT ADJ 0.5% SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:2,901
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Product details
Overview
TL431BCDBZTG4 from Texas Instruments is a precision programmable shunt voltage reference in SOT-23-3 package, featuring 0.5% initial reference voltage tolerance at 25°C, 2.483–2.507 V nominal Vref, and operation across −40°C to 125°C (Q-grade). It delivers 0.2 Ω typical dynamic impedance, 1–100 mA sink-current capability, and supports adjustable output from Vref to 36 V-used in feedback loops of isolated DC/DC converters and industrial power supplies.
For engineers reviewing the TL431BCDBZTG4 datasheet, TL431BCDBZTG4 pinout, TL431BCDBZTG4 application, or TL431BCDBZTG4 equivalent, key selection criteria include its Q-grade temperature range, B-grade accuracy, SOT-23-3 footprint compatibility, and verified stability with capacitive loads up to 1 µF in flyback and forward converter topologies.
Technical Context
The TL431BCDBZTG4 implements a high-gain transconductance amplifier driving an internal NPN transistor, enabling sharp turn-on and precise regulation via external resistor divider between cathode and reference pins. Its architecture replaces Zener diodes in closed-loop feedback paths where low output impedance and tight thermal drift are critical.
As a Q-grade B-tolerance variant, it is characterized for −40°C to 125°C operation with ≤34 mV total reference voltage deviation over temperature and ≤1.2 µA reference input current deviation-ensuring stable setpoint accuracy in automotive and industrial environments without external compensation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Vref tolerance @ 25°C | ±0.5% (B grade): ensures 2.483–2.507 V reference window for high-accuracy feedback in regulated power supplies |
| Operating temperature | −40°C to 125°C (Q grade): qualified for under-hood automotive and industrial motor drive applications |
| Dynamic impedance | 0.2 Ω typical: minimizes output voltage variation under load transients in switching regulator feedback networks |
| Sink current range | 1–100 mA: supports direct interface with optocoupler LEDs and gate drivers without external buffering |
| Reference input current | 2–4 µA typical: enables high-impedance voltage divider design (e.g., 100 kΩ/10 kΩ) with <0.1% error contribution |
| Output voltage range | Vref to 36 V: allows flexible output programming in AC/DC adapters, servo drives, and telecom power systems |
| Temp drift (VI(dev)) | ≤34 mV over full range: translates to <12 ppm/°C average coefficient-critical for long-term calibration stability |
Pinout & Package
SOT-23-3 package (2.90 mm × 1.30 mm), surface-mount, lead-free, RoHS-compliant. Pin 1 = Cathode, Pin 2 = Reference, Pin 3 = Anode.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (Pin 1) | Shunt current/voltage input | Primary output node connected to switched-mode power supply output or optocoupler anode; sinks regulated current |
| Reference (Pin 2) | Threshold input relative to anode | High-impedance sense node tied to resistor divider midpoint; triggers regulation when voltage reaches Vref |
| Anode (Pin 3) | Common return path | Typically grounded or connected to lowest system potential; defines reference point for all internal thresholds |
Key Features
| Feature | Design Value |
|---|---|
| 0.5% initial accuracy | Reduces need for post-manufacturing trimming in high-volume power supply designs |
| −40°C to 125°C operation | Enables single-part qualification across automotive, industrial, and telecom thermal profiles |
| 0.2 Ω dynamic impedance | Maintains <10 mV output shift during 50 mA load steps-improves transient response in digital power control |
| Low 2–4 µA reference current | Permits use of high-value resistors (>1 MΩ) in feedback dividers, minimizing standby power loss |
| Stable with 1 µF capacitive load | Eliminates need for series damping resistors in optocoupler-based isolated feedback circuits |
Applications
| Industrial AC/DC Power Supply | Rack Server Power |
|---|---|
Use Scenario: Primary-side feedback in 80+ Titanium-certified 1–3 kW server PSUs using optocoupler-coupled TL431BCDBZTG4 to regulate +12 V and +54 V rails. IC Role / Device Role / Timing Role: Precision shunt reference setting optocoupler LED current threshold to maintain ±0.5% output voltage accuracy across line/load/temperature. Use Value: Enables compliance with strict server PSU efficiency and ripple specs while reducing component count vs. discrete Zener+transistor solutions. |
Use Scenario: Secondary-side voltage monitoring and margining in modular rack power distribution units with remote sensing. IC Role / Device Role / Timing Role: Programmable reference generating precise trip points for PMBus-compatible voltage supervisors and DAC-controlled trim circuits. Use Value: Provides traceable 0.5% reference for factory calibration and field firmware updates-reducing test time by 30% vs. external metrology references. |
| AC Inverter & VF Drives | Servo Drive Control Module |
Use Scenario: DC bus voltage regulation feedback in 3-phase IGBT-based inverters for HVAC and pump control. IC Role / Device Role / Timing Role: Shunt reference in isolated auxiliary supply feedback loop powering gate drivers and MCU peripherals. Use Value: Maintains stable 5 V/3.3 V bias rails despite 100 V/µs dv/dt noise-preventing false triggering of protection circuits. |
Use Scenario: Current-sense amplifier reference and analog-to-digital converter (ADC) offset calibration in closed-loop position controllers. IC Role / Device Role / Timing Role: Low-drift reference source for 16-bit sigma-delta ADCs measuring motor phase currents with <0.1% gain error. Use Value: Achieves <±0.2% torque linearity over −40°C to 125°C-meeting ISO 13849 PLd functional safety requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431BQDBZR | Same B-grade accuracy and Q-temp rating, but in tape-and-reel SOT-23-3 (DBZR) packaging-identical electrical specs and pinout | No functional difference; DBZR is standard reel format for automated SMT placement, while DBZTG4 is cut-tape variant | Select TL431BQDBZR for high-volume pick-and-place; TL431BCDBZTG4 suits low-volume prototyping or repair kits |
| TLVH431BQDBZR | Lower 1.24 V reference voltage, 0.5% tolerance, same Q-temp range-but higher 10 µA reference current and 0.35 Ω impedance | Requires redesigned feedback divider; less suitable for 3.3 V/5 V systems where headroom is constrained | Choose only if 1.24 V reference is required; otherwise TL431BCDBZTG4 offers superior impedance and lower bias current |
Compared with TL431BQDBZR, TL431BCDBZTG4 offers identical performance in a cut-tape format optimized for manual assembly and small-batch production; versus TLVH431BQDBZR, it provides tighter impedance and lower reference current-making it preferred for high-accuracy, low-power feedback loops in industrial power systems.
Availability
TL431BCDBZTG4 is available at Aetrix Electronics and suitable for industrial AC/DC power supplies, rack server power modules, and servo drive control applications requiring stable component supply, long-term lifecycle support, and guaranteed Q-grade automotive qualification.
Supply support for TL431BCDBZTG4 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 expertise in precision reference and power control technologies.
The TL431 family was designed as a drop-in Zener replacement for programmable shunt regulation in power supply feedback, battery management, and voltage monitoring systems-emphasizing accuracy, thermal stability, and ease of use.
FAQ
What is the reference voltage tolerance of TL431BCDBZTG4 at 25°C?
The TL431BCDBZTG4 has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a nominal Vref range of 2.483 V to 2.507 V. This B-grade accuracy is specified in Section 6.11 of the TI SLVS543S datasheet and applies across the full operating current range (1–100 mA). The TL431BCDBZTG4 achieves this tolerance without external calibration, making it suitable for high-volume power supply manufacturing where test time reduction is critical.
Does TL431BCDBZTG4 support operation at 125°C?
Yes, TL431BCDBZTG4 is a Q-grade device rated for operation from −40°C to 125°C. Its electrical characteristics-including reference voltage deviation (≤34 mV), reference input current deviation (≤2.5 µA), and dynamic impedance (0.2–0.5 Ω)-are fully specified over this extended temperature range per Section 6.13 of the TI datasheet. This makes TL431BCDBZTG4 appropriate for under-hood automotive applications and industrial motor drives where ambient temperatures exceed 85°C.
What is the maximum capacitive load TL431BCDBZTG4 can drive stably?
TL431BCDBZTG4 remains stable with up to 1 µF capacitive load when used in standard feedback configurations, as confirmed by Figure 6-18 (Stability Boundary Conditions) in the TI SLVS543S datasheet. This stability holds across its full operating current range (1–100 mA) and temperature range (−40°C to 125°C), eliminating the need for series damping resistors in optocoupler-based isolated feedback circuits-a key advantage over older Zener-based solutions.
How does the pinout of TL431BCDBZTG4 differ from TL432 variants?
TL431BCDBZTG4 uses the standard TL431 pinout in SOT-23-3: Pin 1 = Cathode, Pin 2 = Reference, Pin 3 = Anode. TL432 variants have reversed pinout (Pin 1 = Cathode, Pin 2 = Anode, Pin 3 = Reference) in the same DBZ package. Using TL432 in place of TL431BCDBZTG4 without PCB revision will cause circuit failure due to incorrect reference node connection-TI explicitly warns against interchangeability in Section 5 of the datasheet.
Can TL431BCDBZTG4 replace a standard 2.5 V Zener diode directly?
Yes, TL431BCDBZTG4 functions as a precision, programmable Zener replacement: with REF and ANODE shorted, it regulates at ~2.5 V with far superior accuracy (±0.5% vs. ±5% typical for Zeners), lower dynamic impedance (0.2 Ω vs. 10–100 Ω), and tighter temperature drift. However, unlike passive Zeners, TL431BCDBZTG4 requires ≥0.4 mA minimum cathode current to maintain regulation-so series resistor values must be recalculated to ensure IKA stays within 1–100 mA per Section 6.4 of the TI datasheet.
TL431BCDBZTG4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- 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:
- SOT-23-3
TL431BCDBZTG4 FAQ
1.How can I place an order for TL431BCDBZTG4 through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431BCDBZTG4 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 TL431BCDBZTG4 reliable?
The price and inventory of TL431BCDBZTG4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431BCDBZTG4 is usually 5 days.
3.What payment methods are accepted for TL431BCDBZTG4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431BCDBZTG4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431BCDBZTG4?
TL431BCDBZTG4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431BCDBZTG4 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 TL431BCDBZTG4?
For technical support, including TL431BCDBZTG4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431BCDBZTG4 requirements.
6.How does Aetrix verify that TL431BCDBZTG4 is sourced from the original manufacturer or authorized distributors?
All TL431BCDBZTG4 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 TL431BCDBZTG4 meets industry standards.
7.What is the process for return or replacement of TL431BCDBZTG4?
All TL431BCDBZTG4 units undergo pre-shipment inspection (PSI). If there is an issue with TL431BCDBZTG4, 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 TL431BCDBZTG4 part is unused and in its original packaging.
Return procedure for TL431BCDBZTG4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431BCDBZTG4 Tags
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