Overview
The TL431CDE4, produced by Texas Instruments, is a precision programmable reference voltage regulator. It is part of the TL431 family, which includes three-terminal adjustable shunt regulators known for their thermal stability across various temperature ranges. These devices are designed to replace Zener diodes in many applications due to their sharp turn-on characteristics and low output impedance.
The TL431CDE4 is specifically packaged in an 8-pin SOIC tube and is characterized by its adjustable output voltage, which can be set between approximately 2.5V and 36V using two external resistors. This device is suitable for a wide range of applications, including on-board regulation, adjustable power supplies, and switching power supplies.
Key Specifications
| Parameter | Minimum | Typical | Maximum | Unit |
|---|---|---|---|---|
| Cathode Voltage (VKA) | - | - | 37 | V |
| Continuous Cathode Current (IKA) | -100 | - | 150 | mA |
| Reference Input Current (II(ref)) | -0.05 | - | 10 | mA |
| Operating Junction Temperature Range (TJ) | - | - | 150 | °C |
| Reference Voltage Tolerance at 25°C | - | - | 0.5% (B grade), 1% (A grade), 2% (Standard grade) | % |
| Adjustable Output Voltage | 2.5 | - | 36 | V |
| Operating Temperature Range | -40 | - | 125 | °C |
| Typical Output Impedance | - | 0.2 | - | Ω |
| Sink-Current Capability | 1 | - | 100 | mA |
Key Features
- Adjustable Output Voltage: The output voltage can be set to any value between approximately 2.5V and 36V using two external resistors.
- Sharp Turn-On Characteristic: Active output circuitry provides a very sharp turn-on characteristic, making these devices excellent replacements for Zener diodes.
- Low Output Impedance: Typical output impedance of 0.2Ω.
- Low Output Noise: Suitable for applications requiring minimal noise.
- Temperature Stability: Specified thermal stability over applicable automotive, commercial, and military temperature ranges.
- Multiple Grades: Available in three grades with initial tolerances of 0.5%, 1%, and 2% at 25°C.
- Wide Operating Temperature Range: Operation from -40°C to 125°C depending on the device variant.
Applications
- On-Board Regulation: Used in various on-board voltage regulation applications.
- Adjustable Power Supplies: Ideal for adjustable power supply designs.
- Switching Power Supplies: Suitable for switching power supply applications due to its sharp turn-on characteristic.
- Voltage Monitoring: Can be used for voltage monitoring and as a comparator with an integrated reference.
- Secondary Side Regulation in Flyback SMPSs: Used in secondary side regulation in flyback switching mode power supplies (SMPSs).
Q & A
- What is the TL431CDE4 used for?
The TL431CDE4 is used as a precision programmable reference voltage regulator, often replacing Zener diodes in applications such as on-board regulation, adjustable power supplies, and switching power supplies.
- What is the adjustable output voltage range of the TL431CDE4?
The output voltage can be set to any value between approximately 2.5V and 36V using two external resistors.
- What are the different grades of the TL431 available?
The TL431 is available in three grades with initial tolerances of 0.5%, 1%, and 2% at 25°C, denoted as B, A, and standard grades respectively.
- What is the typical output impedance of the TL431CDE4?
The typical output impedance is 0.2Ω.
- What is the operating temperature range of the TL431CDE4?
The operating temperature range depends on the variant but can be from -40°C to 125°C.
- Can the TL431CDE4 replace Zener diodes?
Yes, the TL431CDE4 can replace Zener diodes due to its sharp turn-on characteristic and low output impedance.
- What are some common applications of the TL431CDE4?
Common applications include on-board regulation, adjustable power supplies, switching power supplies, and voltage monitoring.
- How does the TL431CDE4 achieve temperature stability?
The TL431CDE4 achieves temperature stability through its specified thermal stability over applicable automotive, commercial, and military temperature ranges.
- What is the sink-current capability of the TL431CDE4?
The sink-current capability ranges from 1mA to 100mA.
- Is the TL431CDE4 suitable for high-noise environments?
No, the TL431CDE4 is not suitable for high-noise environments due to its low output noise characteristic.
