Overview
The TL431CP is a three-terminal adjustable shunt regulator produced by Texas Instruments. Introduced in 1978, this device is part of the TL431 series, known for its high precision and versatility. The TL431CP is designed to provide a stable reference voltage that can be adjusted between approximately 2.5V and 36V using two external resistors. This component is widely used in various applications requiring precise voltage regulation, such as on-board regulation, adjustable power supplies, and switching power supplies.
Key Specifications
| Characteristic | Symbol | Unit | Min | Typ | Max |
|---|---|---|---|---|---|
| Reference Input Voltage | Vref | V | 2.44 | 2.495 | 2.55 |
| Cathode to Anode Voltage | VKA | V | - | - | 37 |
| Cathode Current Range | IK | mA | -100 | - | 150 |
| Reference Input Current Range | Iref | mA | -0.05 | - | 10 |
| Operating Junction Temperature | TJ | °C | - | - | 150 |
| Operating Ambient Temperature Range | TA | °C | -40 | - | 125 |
| Typical Output Impedance | Zout | Ω | - | 0.2 | - |
| Typical Temperature Drift | - | mV/°C | - | 6 (C temp), 14 (I temp, Q temp) | - |
Key Features
- Adjustable Output Voltage: The output voltage can be set to any value between approximately 2.5V and 36V using two external resistors.
- High Precision: Available in three grades with initial tolerances of 0.5%, 1%, and 2% at 25°C for B, A, and standard grades, respectively.
- Low Output Noise: Features low output noise, making it suitable for noise-sensitive applications.
- Sharp Turn-On Characteristic: Active output circuitry provides a very sharp turn-on characteristic, making it an excellent replacement for Zener diodes.
- Wide Operating Temperature Range: Operates from -40°C to 125°C, depending on the device grade (C, I, Q).
- High Stability: Low output drift versus temperature ensures good stability over the entire temperature range.
Applications
- On-Board Regulation: Used for local voltage regulation on circuit boards.
- Adjustable Power Supplies: Ideal for applications requiring adjustable output voltages.
- Switching Power Supplies: Suitable for use in switching power supply designs.
- Replacement for Zener Diodes: Often used as a more stable and precise alternative to Zener diodes.
- Automotive, Commercial, and Military Applications: Due to its specified thermal stability, it is used in various temperature ranges applicable to these sectors.
Q & A
- What is the TL431CP used for?
The TL431CP is a three-terminal adjustable shunt regulator used for precise voltage regulation in various applications, including on-board regulation, adjustable power supplies, and switching power supplies.
- How is the output voltage of the TL431CP adjusted?
The output voltage can be adjusted between approximately 2.5V and 36V using two external resistors.
- What are the different grades of the TL431CP?
The TL431CP is available in three grades with initial tolerances of 0.5%, 1%, and 2% at 25°C for B, A, and standard grades, respectively.
- What is the operating temperature range of the TL431CP?
The device operates from -40°C to 125°C, depending on the device grade (C, I, Q).
- What is the typical output impedance of the TL431CP?
The typical output impedance is 0.2Ω.
- Can the TL431CP replace Zener diodes?
Yes, the TL431CP is often used as a more stable and precise alternative to Zener diodes due to its sharp turn-on characteristic and low output noise.
- What is the maximum cathode to anode voltage for the TL431CP?
The maximum cathode to anode voltage (VKA) is 37V.
- What is the typical temperature drift of the TL431CP?
The typical temperature drift is 6mV (C temp) and 14mV (I temp, Q temp).
- Is the TL431CP suitable for automotive applications?
Yes, the TL431CP is suitable for automotive applications due to its specified thermal stability over applicable automotive temperature ranges.
- What is the maximum operating junction temperature of the TL431CP?
The maximum operating junction temperature (TJ) is 150°C.
