TL431CZT STMicroelectronics Integrated Circuit (Other) In Stock
The TL431CZT is an adjustable micropower shunt voltage reference with a nominal 2.495 V reference voltage and a programmable output range of 2.5 V to 36 V using two external resistors. It sinks up to 100 mA and is available in a TO-92-3 package. In stock with worldwide shipping.
- Manufacturer
- STMicroelectronics
- Package
- Other
- Pin Count
- 3
- Lifecycle
- ACTIVE
- Datasheet
- TL431CZT Datasheet PDF
- Category
- Integrated Circuit
- Price
- From $0.0576(MOQ 1)
- Temp Range
- ?°C to 70.0°C
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
Key Features
- Programmable output voltage from 2.5 V to 36 V set with two external resistors, enabling flexible reference or shunt regulator configurations
- 100 mA maximum cathode current with tight ±2.21% initial accuracy, providing reliable shunt regulation across a wide load range
- Compact TO-92-3 through-hole package supporting simple hand-soldering and easy prototyping in space-constrained or cost-sensitive designs
Applications
The TL431CZT is widely used as a precision voltage reference and shunt regulator in switch-mode power supply feedback networks, where it controls the output voltage via an optocoupler and PWM controller. It also serves in battery charger circuits, linear regulator feedback loops, and over-voltage protection circuits that require a stable reference between 2.5 V and 36 V. Additionally, it functions as a programmable comparator and error amplifier in low-cost industrial and consumer electronics designs.
Specifications
| Factory Lead Time | 10Weeks |
| YTEOL | 6.5 |
| Additional Feature | THE OUTPUT VOLTAGE MAY BE SET TO ANY VALUE BETWEEN 2.5V AND 36V WITH TWO EXTERNAL RESISTORS |
| Analog IC - Other Type | TWO TERMINAL VOLTAGE REFERENCE |
| JESD-30 Code | O-PBCY-T3 |
| JESD-609 Code | e3 |
| Number of Functions | 1 |
| Number of Outputs | 1 |
| Output Current-Max | 0.1A |
| Output Voltage-Max | 2.567V |
| Output Voltage-Min | 2.423V |
| Output Voltage-Nom | 2.495V |
| Package Body Material | PLASTIC/EPOXY |
| Package Equivalence Code | SIP3,.1,50 |
| Package Shape | ROUND |
| Package Style | CYLINDRICAL |
| Peak Reflow Temperature (Cel) | NOT SPECIFIED |
| Qualification Status | Not Qualified |
| Supply Current-Max (Isup) | 100mA |
| Surface Mount | NO |
| Technology | BIPOLAR |
| Temp Coef of Voltage-Max | 97.338ppm/°C |
| Temperature Grade | COMMERCIAL |
| Terminal Finish | Matte Tin (Sn) - annealed |
| Terminal Form | THROUGH-HOLE |
| Terminal Pitch | 1.27mm |
| Terminal Position | BOTTOM |
| Time@Peak Reflow Temperature-Max (s) | NOT SPECIFIED |
| Trim/Adjustable Output | YES |
| Package | Other |
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
| ECCN | EAR99 |
| HTS Code | 8542.39.00.60 |
| Country of Origin | Mainland China |
Alternate & Equivalent Parts
Compatible alternatives and drop-in replacements for TL431CZT:
Voltage Reference, 1 Output, 2.495V, Trim/Adjustable, BIPolar, PBCY3
Frequently Asked Questions
How is the output voltage of the TL431CZT programmed beyond its 2.495 V reference?
The TL431CZT's output voltage is set by connecting two external resistors in a voltage divider from the output (cathode) to the reference pin and to ground. Any voltage between 2.5 V and 36 V can be programmed using the formula Vout = Vref × (1 + R1/R2), where Vref is 2.495 V, giving designers fine-grained control over the regulation point without additional components.
In an SMPS feedback loop, how does the TL431CZT compare to a fixed reference like the LM385?
Unlike the LM385, which provides a fixed 1.2 V or 2.5 V reference, the TL431CZT offers a programmable range from 2.5 V to 36 V and includes an error amplifier with 0.5 V/µs slew rate. This makes TL431CZT directly suitable as an error amplifier in optocoupler-isolated flyback SMPS designs, eliminating an additional op-amp stage and reducing component count by 2 to 3 parts.
What is the maximum cathode current the TL431CZT can sink, and how does this affect heat dissipation?
The TL431CZT can sink up to 100 mA of cathode current. In a TO-92-3 package with a thermal resistance of approximately 200 °C/W junction-to-ambient, dissipating 100 mA at 10 V across the device produces 1 W of power, raising junction temperature by roughly 200 °C above ambient. Practical designs should keep power dissipation below 500 mW to stay within safe operating limits without a heatsink.
What initial voltage accuracy does the TL431CZT provide, and for which precision applications is it sufficient?
The TL431CZT offers an initial accuracy of ±2.21% on its 2.495 V reference, corresponding to a worst-case deviation of about ±55 mV. This accuracy is sufficient for power supply regulation, LED driver feedback, and battery protection circuits where tight absolute voltage is not critical, but is not recommended for precision metering or 12-bit ADC reference applications requiring better than ±0.5% accuracy.
Related Guides
How to Choose a BAS70 Schottky Diode for Signal Clamping: Selection Guide
A practical BAS70KFILM and BAS70-family Schottky diode selection guide for signal clamping, RF detection, leakage, and topology choices.
Jul 4, 2026
AMC1202DWVR Design Guide for Isolated Current Sensing
Practical AMC1202DWVR design guide covering shunt sizing, isolation layout, input filtering, ADC scaling, and sourcing choices.
Jul 4, 2026
1206 100 uF MLCC Design Guide for Compact Bulk Decoupling
Design guidance for applying CL31A107MQHNNNE and related 1206 MLCCs in compact bulk decoupling networks.
Jul 3, 2026
0402 10 nF MLCC Design Guide for High-Speed Decoupling
Practical design guidance for using CL05B103KB5NNNC and related 0402 MLCCs in high-speed decoupling networks.
Jul 3, 2026
Why Buy from FindMyChip
About STMicroelectronics
STMicroelectronics is a global semiconductor leader serving customers across the spectrum of electronics applications. ST's products are found in a wide range of applications including automotive, industrial, personal electronics, and communications.
| Qty. | Unit Price | Ext. Price |
|---|---|---|
| 1+ | $0.0742 | $0.07 |
| 10+ | $0.0730 | $0.73 |
| 25+ | $0.0718 | $1.80 |
| 2000+ | $0.0645 | $129.00 |
| 6000+ | $0.0614 | $368.40 |
| 50000+ | $0.0576 | $2880.00 |
In Stock · 24h Response · Worldwide Shipping
Response within 24 hours · Worldwide shipping
“Response time is incredible — usually under 4 hours. They understand that production lines can't wait.”