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Texas Instruments TL431BCDBZRG4
- Part No.:
- TL431BCDBZRG4
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
TL431BCDBZRG4.pdf
- Description:
- IC VREF SHUNT ADJ 0.5% SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:3,000
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Product details
Overview
TL431BCDBZRG4 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 operation across −40°C to 125°C. It serves as a stable feedback element in isolated DC-DC converters, AC/DC power supplies, and voltage-monitoring circuits.
For engineers reviewing the TL431BCDBZRG4 datasheet, TL431BCDBZRG4 pinout, TL431BCDBZRG4 application, or TL431BCDBZRG4 equivalent, key selection criteria include reference accuracy over temperature, cathode current capability (1–100 mA), low output noise, thermal drift performance (14 mV max over −40°C to 125°C), and compatibility with standard resistor-divider feedback networks.
Technical Context
The TL431BCDBZRG4 implements a high-gain transconductance amplifier with internal 2.495 V bandgap reference, enabling precise regulation via external resistive divider connected to the REF pin. Its three-terminal shunt topology sinks cathode current proportional to the error between REF input and internal reference, supporting adjustable output voltages from 2.5 V to 36 V.
Designed for automotive-grade reliability, the B-grade Q-temp variant (TL431BQ) meets −40°C to 125°C operation with verified stability under load capacitance up to 1 µF and cathode current transients up to 100 mA - critical for flyback controller feedback loops and overvoltage protection circuits.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495 V ±12 mV (±0.5%) at 25°C - enables tight output regulation in power supply feedback paths |
| Temp Range | −40°C to +125°C - qualified for under-hood automotive and industrial ambient conditions |
| Dynamic Impedance | 0.2 Ω typical - ensures minimal output voltage shift under varying cathode current loads |
| Cathode Current | 1 mA to 100 mA - supports direct drive of optocoupler LEDs and error amplifier inputs |
| Ref Input Current | 2–4 µA - allows use of high-value feedback resistors (>1 MΩ) without significant divider error |
| Output Noise | Low broadband noise - maintains signal integrity in sensitive feedback networks |
| Thermal Drift | ≤14 mV over full temperature range - guarantees <0.05% output variation across operating envelope |
Pinout & Package
SOT-23-3 package (2.90 mm × 1.30 mm), surface-mount, lead-free and RoHS-compliant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| REF (Pin 1) | Reference input | High-impedance comparator input sensing external resistor divider; sets regulated output voltage |
| CATHODE (Pin 2) | Shunt current output | Sinks adjustable current to maintain REF node at 2.495 V; connects to primary-side optocoupler anode in isolated supplies |
| ANODE (Pin 3) | Common return | Typically tied to system ground or power supply return; defines voltage reference point for REF and CATHODE |
Key Features
| Feature | Design Value |
|---|---|
| Precision reference | 0.5% initial tolerance enables ±0.5% output voltage accuracy in closed-loop power supplies |
| Wide adjustment range | Supports 2.5 V to 36 V output via two-resistor divider - eliminates need for multiple fixed references |
| Low dynamic impedance | 0.2 Ω output impedance minimizes load-regulation error in high-current feedback paths |
| High temp grade | Rated for −40°C to +125°C operation - suitable for automotive engine control and industrial motor drives |
| Low input bias current | 2–4 µA REF current enables high-resistance dividers that reduce standby power consumption |
Applications
| Rack Server Power | Industrial AC/DC |
|---|---|
Use Scenario: Secondary-side voltage regulation in 48 V input telecom rectifiers with optocoupler-isolated feedback. IC Role / Device Role / Timing Role: Shunt reference providing precise error signal to optocoupler LED driver in flyback controller feedback loop. Use Value: Enables ±0.5% output accuracy across line/load/temperature while maintaining stability with ≤1 µF compensation capacitance. | Use Scenario: Output voltage sensing and overvoltage protection in DIN-rail mounted 24 V/48 V industrial power supplies. IC Role / Device Role / Timing Role: Adjustable shunt regulator monitoring regulated output and triggering crowbar or shutdown circuitry. Use Value: Replaces discrete Zener + transistor solution with tighter tolerance, lower drift, and reduced board space. |
| AC Inverter Drives | Servo Drive Control Module |
Use Scenario: DC bus voltage monitoring and fault detection in variable-frequency motor drives. IC Role / Device Role / Timing Role: Precision reference comparing sensed DC link voltage against threshold for overvoltage lockout. Use Value: 14 mV max drift over −40°C to 125°C ensures consistent trip point across operating temperature range. | Use Scenario: Feedback reference for analog current/voltage regulators in multi-axis servo amplifier PCBs. IC Role / Device Role / Timing Role: Stable 2.495 V reference for DAC output scaling and ADC reference buffering. Use Value: Low 0.2 Ω dynamic impedance prevents reference droop during fast transient loading by op-amp stages. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431BIDBZR | Same SOT-23-3 package, identical electrical specs, but rated for −40°C to 85°C (I-temp) instead of −40°C to 125°C (Q-temp) | Not suitable for under-hood automotive or high-ambient industrial environments requiring full Q-temp range | Select TL431BCDBZRG4 when operation beyond 85°C ambient is required |
| TLVH431BQDBZR | Lower 1.24 V reference voltage, 0.5% tolerance, same Q-temp rating, but higher 10 µA REF current and 0.3 Ω impedance | Enables lower-voltage feedback designs (e.g., 1.8 V or 3.3 V rails); less suitable for >24 V outputs due to headroom limits | Choose TL431BCDBZRG4 for systems needing 2.5–36 V adjustability and lowest possible dynamic impedance |
Compared with TL431BIDBZR and TLVH431BQDBZR, TL431BCDBZRG4 uniquely combines Q-temp qualification, 2.495 V reference, sub-0.2 Ω impedance, and 1–100 mA cathode sink capability - making it optimal for high-reliability isolated power feedback where thermal stability and low output impedance are critical.
Availability
TL431BCDBZRG4 is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC, and servo drive control modules requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for TL431BCDBZRG4 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 product line delivers highly stable, adjustable shunt references for feedback, monitoring, and protection functions in power conversion, industrial automation, and automotive systems - designed for robustness, accuracy, and long-term reliability.
FAQ
What is the reference voltage tolerance of TL431BCDBZRG4 at 25°C?
The TL431BCDBZRG4 has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a 2.495 V nominal value with ±12 mV deviation. This B-grade accuracy is specified in Section 6.11 of the TI datasheet SLVS543S and applies strictly to the TL431BCDBZRG4 variant with SOT-23-3 packaging and Q-temp rating. The tolerance remains validated across its full −40°C to 125°C operating range.
Does TL431BCDBZRG4 support adjustable output voltages above 24 V?
Yes, TL431BCDBZRG4 supports adjustable output voltages from 2.5 V up to 36 V using an external resistor divider on the REF pin. Its cathode voltage rating is 37 V absolute maximum, and recommended operating cathode voltage extends to 36 V - confirmed in Section 6.4 of the datasheet. This makes TL431BCDBZRG4 suitable for high-voltage industrial power supplies and telecom rectifiers.
What is the minimum cathode current required for regulation in TL431BCDBZRG4?
The minimum cathode current required for regulation in TL431BCDBZRG4 is 0.4 mA, with a typical value of 0.6 mA at 25°C (Section 6.11, Imin parameter). This low turn-on threshold enables stable operation even with high-value feedback resistors or light-load conditions, preserving regulation integrity in standby or low-power modes.
How does the dynamic impedance of TL431BCDBZRG4 affect power supply stability?
TL431BCDBZRG4 features 0.2 Ω typical dynamic impedance (|ZKA|), which directly limits output voltage deviation under cathode current transients. In feedback loops, this low impedance reduces phase lag and improves loop gain margin - especially critical when driving optocoupler LEDs in isolated flyback converters. Stability boundaries are documented in Figures 6-18 and 6-19 of the datasheet.
Is TL431BCDBZRG4 pin-compatible with other TL431 variants in SOT-23-3 package?
Yes, TL431BCDBZRG4 uses the standard TL431 pinout for SOT-23-3: Pin 1 = REF, Pin 2 = CATHODE, Pin 3 = ANODE. This matches all TL431x DBZ variants including TL431ACDBZR and TL431BIDBZR. However, TL432 variants have reversed CATHODE/REF pin assignments and are not pin-compatible - always verify pin function tables (Section 5) before substitution.
TL431BCDBZRG4 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
TL431BCDBZRG4 FAQ
1.How can I place an order for TL431BCDBZRG4 through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431BCDBZRG4 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 TL431BCDBZRG4 reliable?
The price and inventory of TL431BCDBZRG4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431BCDBZRG4 is usually 5 days.
3.What payment methods are accepted for TL431BCDBZRG4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431BCDBZRG4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431BCDBZRG4?
TL431BCDBZRG4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431BCDBZRG4 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 TL431BCDBZRG4?
For technical support, including TL431BCDBZRG4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431BCDBZRG4 requirements.
6.How does Aetrix verify that TL431BCDBZRG4 is sourced from the original manufacturer or authorized distributors?
All TL431BCDBZRG4 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 TL431BCDBZRG4 meets industry standards.
7.What is the process for return or replacement of TL431BCDBZRG4?
All TL431BCDBZRG4 units undergo pre-shipment inspection (PSI). If there is an issue with TL431BCDBZRG4, 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 TL431BCDBZRG4 part is unused and in its original packaging.
Return procedure for TL431BCDBZRG4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431BCDBZRG4 Tags
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