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Texas Instruments TL431QDBZTG4
- Part No.:
- TL431QDBZTG4
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
TL431QDBZTG4.pdf
- Description:
- IC VREF SHUNT ADJ 2.2% SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:3,481
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Product details
Overview
TL431QDBZTG4 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, −40°C to +125°C operating temperature range, and 0.2Ω typical dynamic impedance. It replaces Zener diodes in feedback loops of isolated DC/DC converters, AC/DC power supplies, and industrial motor drives requiring high thermal stability.
For engineers reviewing the TL431QDBZTG4 datasheet, TL431QDBZTG4 pinout, TL431QDBZTG4 application, or TL431QDBZTG4 equivalent, key selection criteria include its Q-grade automotive temperature rating, adjustable output (2.5 V to 36 V), low 14 mV max reference voltage drift over full temperature range, and sink-current capability up to 100 mA.
Technical Context
The TL431QDBZTG4 implements a three-terminal adjustable shunt regulator architecture with an internal precision op-amp and NPN transistor output stage. Its REF pin senses voltage relative to ANODE, enabling precise feedback control when used with two external resistors. The device operates as a voltage-controlled current sink, maintaining regulation by adjusting cathode current based on REF-to-ANODE differential.
Designed for automotive-grade reliability, the Q suffix denotes qualification across −40°C to +125°C, with specified thermal stability and 14 mV max reference voltage deviation over that range. Its SOT-23-3 pinout (REF–CATHODE–ANODE) differs from TL432 variants and requires correct PCB layout to avoid oscillation-especially with capacitive loads exceeding 10 nF without series resistance.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage (Vref) | 2.495 V typical (2.483–2.507 V for B-grade), enabling accurate 2.5 V–36 V programmable output via resistor divider. |
| Initial Tolerance | ±0.5% at 25°C (B grade), reducing closed-loop output error in precision power supply feedback paths. |
| Temp Range | −40°C to +125°C (Q grade), supporting under-hood automotive, industrial servo, and rack server applications. |
| Dynamic Impedance | 0.2 Ω typical, ensuring minimal output voltage shift under load transients in switching regulator compensation networks. |
| Sink Current Range | 1 mA to 100 mA, allowing direct interface with optocoupler LEDs or error amplifier outputs without buffering. |
| Ref Input Current | 2–4 µA typical, minimizing resistor-divider loading error and enabling high-impedance feedback networks. |
| Ref Voltage Drift | Max 14 mV over −40°C to +125°C, guaranteeing stable regulation in thermally demanding environments. |
Pinout & Package
SOT-23-3 package (2.90 mm × 1.30 mm body size), surface-mount, lead-free, RoHS-compliant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 (REF) | Reference input | Senses voltage relative to ANODE; sets regulation point via external resistor divider; high-impedance input (2–4 µA). |
| Pin 2 (CATHODE) | Current sink output | Carries regulated cathode current (1–100 mA); connects to primary-side controller feedback (e.g., optocoupler anode). |
| Pin 3 (ANODE) | Common reference node | Acts as circuit ground reference for REF and cathode; must be connected to system ground or return path. |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable output voltage | Programmable from 2.5 V to 36 V using two external resistors-enables single BOM for multiple output rails. |
| Low dynamic impedance | 0.2 Ω typical ensures <1 mV output shift under 10 mA load step-critical for stable loop response in SMPS. |
| Automotive temperature grade | Qualified for −40°C to +125°C operation, meeting AEC-Q100 stress test requirements for under-hood use. |
| Sharp turn-on characteristic | Fast internal op-amp and NPN output enable clean regulation onset-reduces startup overshoot in power supplies. |
| Low output noise | Sub-20 µVPP (0.1–10 Hz), minimizing jitter in precision analog feedback and voltage monitoring circuits. |
Applications
| Rack Server Power Supply | Industrial AC/DC Converter |
|---|---|
|
Use Scenario: Secondary-side voltage sensing in isolated 48 V–12 V DC/DC modules with optocoupler feedback. IC Role / Device Role / Timing Role: Precision shunt reference setting feedback threshold for primary-side PWM controller. Use Value: ±0.5% Vref tolerance and 14 mV max drift ensure <±1% output regulation across full thermal and load range. |
Use Scenario: Output voltage regulation in 3 kW industrial rectifier with active PFC front-end. IC Role / Device Role / Timing Role: Adjustable shunt reference in isolated flyback auxiliary supply powering gate drivers and sensors. Use Value: 100 mA sink current directly drives optocoupler LED without buffer, simplifying BOM and improving transient response. |
| AC Inverter Drive | Servo Drive Control Module |
|
Use Scenario: DC bus voltage monitoring and overvoltage protection threshold generation in 3-phase VFDs. IC Role / Device Role / Timing Role: Programmable reference for comparator-based fault detection circuit. Use Value: Stable 2.5 V reference with <14 mV drift enables reliable trip point accuracy across motor cabinet temperatures (−25°C to +85°C). |
Use Scenario: Feedback reference for isolated 24 V auxiliary supply powering position encoder interfaces and FPGA I/O banks. IC Role / Device Role / Timing Role: Shunt regulator providing stable bias for isolated communication isolators and ADC references. Use Value: Low 2–4 µA REF input current minimizes resistor-divider power loss and thermal drift in compact servo PCB layouts. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431CDBZR | Same SOT-23-3 package but C-grade (0°C to 70°C); ±0.5% tolerance; 6 mV max Vref drift. | Limited to commercial-temperature applications (e.g., consumer adapters); not qualified for automotive or extended industrial use. | Select TL431CDBZR only if ambient temperature stays within 0°C–70°C and cost is prioritized over thermal margin. |
| TLVH431QDBZR | Lower 1.24 V reference voltage; same Q-grade temp range; higher 10 µA REF current; 0.3 Ω impedance. | Enables lower-voltage feedback (e.g., 1.8 V, 3.3 V rails); less suitable for >12 V outputs due to headroom constraints. | Choose TLVH431QDBZR when designing sub-5 V regulated supplies where 2.5 V reference creates excessive divider loss. |
Compared with TL431CDBZR and TLVH431QDBZR, TL431QDBZTG4 uniquely balances automotive-grade temperature range, 2.5 V reference headroom for wide-output designs, and ultra-low dynamic impedance-making it optimal for high-reliability isolated power feedback where thermal stability and loop gain are critical.
Availability
TL431QDBZTG4 is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC converters, and servo drive control modules requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for TL431QDBZTG4 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 solutions.
The TL431 product line delivers cost-effective, high-stability shunt references for feedback, monitoring, and protection circuits in power conversion systems-designed specifically for automotive, industrial, and telecom infrastructure applications.
FAQ
What is the reference voltage tolerance of TL431QDBZTG4 at 25°C?
The TL431QDBZTG4 has a ±0.5% reference voltage tolerance at 25°C, corresponding to a 2.483 V–2.507 V range around the nominal 2.495 V. This B-grade accuracy is specified in TI's SLVS543S datasheet Section 6.13 and ensures tight output regulation in feedback networks without trimming.
Does TL431QDBZTG4 support operation beyond 125°C junction temperature?
No. TL431QDBZTG4 is rated for operation from −40°C to +125°C ambient (Q-grade), with absolute maximum junction temperature of 150°C. Exceeding 125°C ambient risks violating recommended operating conditions; thermal design must maintain TJ ≤ 150°C using the RθJA = 206°C/W (SOT-23-3) value from Section 6.3.
Can TL431QDBZTG4 replace a standard Zener diode in linear regulator designs?
Yes-TL431QDBZTG4 functions as a superior Zener replacement due to its sharp turn-on, 0.2 Ω dynamic impedance, and adjustable 2.5 V–36 V output. Unlike Zeners, it provides consistent regulation across current and temperature, making it ideal for precision shunt regulators and error amplifiers in linear and switching topologies.
What is the minimum cathode current required for regulation in TL431QDBZTG4?
The TL431QDBZTG4 requires a minimum cathode current (Imin) of 0.4 mA to maintain regulation, per Section 6.13 of the datasheet. Below this, the device exits regulation; design must ensure ≥0.4 mA flows through the cathode under all operating conditions-including light-load and startup.
How does the SOT-23-3 pinout of TL431QDBZTG4 differ from TL432 variants?
TL431QDBZTG4 uses REF–CATHODE–ANODE pinout (Pin 1–2–3), while TL432 variants use CATHODE–REF–ANODE. This difference is non-interchangeable: misrouting causes immediate functional failure. Always verify pin mapping against TI's Figure 5-1 (SOT-23-3 TL431) before PCB layout.
TL431QDBZTG4 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:
- ±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 ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
TL431QDBZTG4 FAQ
1.How can I place an order for TL431QDBZTG4 through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431QDBZTG4 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 TL431QDBZTG4 reliable?
The price and inventory of TL431QDBZTG4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431QDBZTG4 is usually 5 days.
3.What payment methods are accepted for TL431QDBZTG4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431QDBZTG4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431QDBZTG4?
TL431QDBZTG4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431QDBZTG4 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 TL431QDBZTG4?
For technical support, including TL431QDBZTG4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431QDBZTG4 requirements.
6.How does Aetrix verify that TL431QDBZTG4 is sourced from the original manufacturer or authorized distributors?
All TL431QDBZTG4 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 TL431QDBZTG4 meets industry standards.
7.What is the process for return or replacement of TL431QDBZTG4?
All TL431QDBZTG4 units undergo pre-shipment inspection (PSI). If there is an issue with TL431QDBZTG4, 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 TL431QDBZTG4 part is unused and in its original packaging.
Return procedure for TL431QDBZTG4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431QDBZTG4 Tags
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TL431AIDBZR
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TL431BQDBZR
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LM4040CYM3-2.5-TR
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LM4040CYM3-4.1-TR
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LM4040EIM3-2.5/NOPB
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AZ431LBNTR-G1
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LM4040D20IDBZR
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LM4041DIM3-ADJ/NOPB
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LM4040DIM3X-2.5/NOPB
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AZ431LANTR-G1
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