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Texas Instruments TL431CDBZRG4
- Part No.:
- TL431CDBZRG4
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
TL431CDBZRG4.pdf
- Description:
- IC VREF SHUNT ADJ 2.2% SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:1,274
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Product details
Overview
TL431CDBZRG4 from Texas Instruments is a precision programmable shunt voltage reference in SOT-23-3 package, delivering 2.495 V nominal reference voltage with ±0.5% initial tolerance at 25°C, 0.2 Ω typical dynamic impedance, and adjustable output from 2.495 V to 36 V via two external resistors. It operates across 0°C to 70°C and serves as a Zener diode replacement in feedback loops of isolated DC/DC converters and AC/DC power supplies.
For engineers reviewing the TL431CDBZRG4 datasheet, TL431CDBZRG4 pinout, TL431CDBZRG4 application, or TL431CDBZRG4 equivalent, key selection criteria include reference accuracy over temperature, cathode current sink capability (1–100 mA), low output noise, thermal drift (≤6 mV over 0°C–70°C), and SOT-23-3 footprint compatibility with space-constrained power regulation designs.
Technical Context
The TL431CDBZRG4 implements a bandgap-based error amplifier with internal reference and output stage, configured as a three-terminal adjustable shunt regulator. Its REF pin senses voltage relative to ANODE, triggering cathode current sink when input exceeds Vref - enabling precise closed-loop regulation without external op-amps.
It features active output circuitry for sharp turn-on, low 0.2 Ω dynamic impedance below 1 kHz, and stable operation with load capacitance up to 10 µF (per stability curves). The C-grade variant is characterized for 0°C to 70°C ambient, distinguishing it from I- and Q-grade versions rated for wider temperature ranges.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495 V (nominal); enables accurate 2.5 V–36 V adjustable output via resistor divider |
| Initial Tolerance | ±0.5% at 25°C (B-grade); ensures tight setpoint accuracy in factory-calibrated power supplies |
| Temp Range | 0°C to 70°C (C-grade); suitable for commercial-grade industrial and consumer power applications |
| Dynamic Impedance | 0.2 Ω typical (≤1 kHz); maintains stable regulation under fast load transients |
| Cathode Current | 1 mA to 100 mA sink range; supports direct feedback control in <10 W SMPS designs |
| Ref Input Current | 2–4 µA; minimizes divider resistor power loss and improves efficiency in high-impedance networks |
| Temp Drift | ≤6 mV over full 0°C–70°C range; guarantees ≤0.024% output variation for stable reference performance |
Pinout & Package
SOT-23-3 package (2.90 mm × 1.30 mm), surface-mount, lead-free, RoHS-compliant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1: REF | Reference Input | Senses voltage divider output; triggers regulation when input ≥ Vref (2.495 V) |
| Pin 2: CATHODE | Current Sink Output | Provides adjustable shunt path to ANODE; sinks 1–100 mA for feedback loop control |
| Pin 3: ANODE | Common Return | Acts as ground reference for REF and return path for cathode current; must be connected to system ground or lowest potential node |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable Output Range | 2.495 V to 36 V via two external resistors - eliminates need for multiple fixed-voltage references |
| Low Dynamic Impedance | 0.2 Ω typical - ensures minimal output voltage deviation during load steps in switching regulators |
| Sharp Turn-On Characteristic | Active output stage enables fast response (<1 µs rise time) - improves transient regulation in high-frequency SMPS |
| Low Reference Input Current | 2–4 µA - permits use of high-value divider resistors (e.g., 100 kΩ–1 MΩ), reducing quiescent power |
| Stability with Capacitive Loads | Compatible with up to 10 µF output capacitance (per Figure 6-16) - simplifies EMI filter integration without oscillation risk |
Applications
| Rack Server Power | Industrial AC/DC |
|---|---|
Use Scenario: Secondary-side voltage sensing in isolated 48 V–12 V DC/DC modules for telecom/datacom servers. IC Role / Device Role / Timing Role: Shunt reference in optocoupler feedback loop, setting precise 12 V output with ±1% total regulation. Use Value: Enables compliance with PMBus v1.3 voltage margining requirements using only two external resistors and no op-amp. | Use Scenario: Output voltage regulation in 300 W industrial AC/DC front-end with universal input (85–265 VAC). IC Role / Device Role / Timing Role: Precision reference for TL494 PWM controller feedback network, replacing discrete Zener + transistor solution. Use Value: Reduces component count by 3 parts while improving temperature stability (6 mV drift vs. >20 mV for Zener-based design). |
| AC Inverter & VF Drives | Notebook PC Power Adapter |
Use Scenario: DC bus voltage monitoring and overvoltage protection threshold in 3-phase motor drives. IC Role / Device Role / Timing Role: Adjustable shunt reference feeding comparator input to trigger shutdown at 420 V DC bus level. Use Value: Allows single BOM variant to support 380 V and 400 V nominal bus systems via resistor change - no PCB revision needed. | Use Scenario: Constant-voltage regulation in 65 W GaN-based USB-C adapter with 20 V output. IC Role / Device Role / Timing Role: Feedback reference for InnoSwitch3-Pro digital flyback controller, setting 20.0 V ±0.1 V output. Use Value: Achieves ±0.5% output accuracy over line/load/temperature - meets USB PD 3.0 specification without post-regulation LDO. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431ACDBZR | 1% initial tolerance (A-grade) vs. 0.5% (B-grade); otherwise identical electrical specs and SOT-23-3 package | Suitable where ±1% output accuracy suffices (e.g., non-critical bias rails), offering cost advantage | Select TL431ACDBZR only if system-level testing confirms ±1% regulation meets safety margins |
| TLVH431IDBZR | Lower 1.24 V reference voltage; 1.5% tolerance; 100 mA sink; same SOT-23-3 package but different pinout (REF/ANODE/CATHODE vs. REF/CATHODE/ANODE) | Enables sub-2.5 V regulation (e.g., 1.8 V LDO feedback), but requires PCB layout change due to reversed pinout | Choose TLVH431IDBZR only for new designs targeting <2.5 V outputs; not drop-in compatible |
Compared with TL431ACDBZR and TLVH431IDBZR, TL431CDBZRG4 provides the tightest initial accuracy (±0.5%) and matches the standard TL431 pinout, making it optimal for high-precision, drop-in-replacement scenarios in existing 2.5 V+ feedback networks without layout modification.
Availability
TL431CDBZRG4 is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC, and notebook PC power adapter designs requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.
Supply support for TL431CDBZRG4 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 and power control solutions.
The TL431 product line was designed for high-accuracy, low-cost voltage regulation in isolated and non-isolated power supplies - emphasizing simplicity, stability, and wide operating flexibility across commercial, industrial, and automotive applications.
FAQ
What is the reference voltage tolerance of TL431CDBZRG4 at 25°C?
The TL431CDBZRG4 has a ±0.5% initial reference voltage tolerance at 25°C, corresponding to a 2.495 V nominal value with a guaranteed range of 2.483 V to 2.507 V. This B-grade accuracy is confirmed in Section 6.11 of the TI datasheet (SLVS543S) and applies specifically to the C-temp (0°C to 70°C) variant. TL431CDBZRG4 maintains this tolerance without calibration or trimming.
Can TL431CDBZRG4 replace a Zener diode in feedback circuits?
Yes, TL431CDBZRG4 is explicitly designed as a superior Zener diode replacement in feedback circuits. Its active error amplifier delivers sharp turn-on, 0.2 Ω dynamic impedance, and adjustable 2.495 V–36 V output - unlike passive Zeners, which exhibit poor regulation, high impedance, and limited voltage options. TL431CDBZRG4 enables precise, stable regulation in SMPS feedback loops without additional components.
What is the maximum cathode current sink capability of TL431CDBZRG4?
The TL431CDBZRG4 supports a continuous cathode current sink range of 1 mA to 100 mA, as specified in Section 6.4 (Recommended Operating Conditions) and verified in Sections 6.5–6.13 of the datasheet. This allows direct interface with optocouplers (e.g., PC817) and PWM controllers (e.g., UC384x) without external transistors, provided power dissipation remains within thermal limits (PD ≤ (TJmax − TA)/θJA).
Does TL431CDBZRG4 require external compensation for stability?
No, TL431CDBZRG4 is internally compensated and stable with capacitive loads up to 10 µF when used per recommended configurations (Figure 6-16). Stability boundaries are documented in the datasheet - oscillation risk arises only outside defined IKA/CL regions. No external capacitor or resistor compensation is needed for standard feedback implementations in TL431CDBZRG4-based power supplies.
How does the pinout of TL431CDBZRG4 differ from TL432 devices?
TL431CDBZRG4 uses the standard TL431 pinout in SOT-23-3: Pin 1 = REF, Pin 2 = CATHODE, Pin 3 = ANODE. TL432 variants have reversed pinout (Pin 1 = CATHODE, Pin 2 = REF, Pin 3 = ANODE) - making them incompatible without PCB redesign. TL431CDBZRG4 is not pin-compatible with any TL432 part, including TL432CDBZR, due to this fundamental pin assignment difference.
TL431CDBZRG4 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:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
TL431CDBZRG4 FAQ
1.How can I place an order for TL431CDBZRG4 through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431CDBZRG4 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 TL431CDBZRG4 reliable?
The price and inventory of TL431CDBZRG4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431CDBZRG4 is usually 5 days.
3.What payment methods are accepted for TL431CDBZRG4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431CDBZRG4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431CDBZRG4?
TL431CDBZRG4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431CDBZRG4 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 TL431CDBZRG4?
For technical support, including TL431CDBZRG4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431CDBZRG4 requirements.
6.How does Aetrix verify that TL431CDBZRG4 is sourced from the original manufacturer or authorized distributors?
All TL431CDBZRG4 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 TL431CDBZRG4 meets industry standards.
7.What is the process for return or replacement of TL431CDBZRG4?
All TL431CDBZRG4 units undergo pre-shipment inspection (PSI). If there is an issue with TL431CDBZRG4, 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 TL431CDBZRG4 part is unused and in its original packaging.
Return procedure for TL431CDBZRG4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431CDBZRG4 Tags
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TL431AIDBZR
Texas Instruments
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TL431BQDBZR
Texas Instruments
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AN431AN-ATRG1
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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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LM4040DIM3-2.5/NOPB
Texas Instruments
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AZ431LANTR-G1
Diodes Incorporated
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