Overview
The TL431BQPKG3 is a precision programmable reference voltage regulator produced by Texas Instruments. It is part of the TL431 family, which includes three-terminal adjustable shunt regulators known for their thermal stability across various temperature ranges. The TL431BQPKG3 is particularly suited for applications requiring adjustable output voltages and high stability over a wide temperature range.
This device is characterized by its ability to set the output voltage between approximately 2.5V (Vref) and 36V using two external resistors. It features a sharp turn-on characteristic, making it an excellent replacement for Zener diodes in many applications such as onboard regulation, adjustable power supplies, and switching power supplies.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Reference Voltage Tolerance at 25°C | 0.5% (B Grade), 1% (A Grade), 2% (Standard Grade) | % |
| Adjustable Output Voltage | Vref to 36V | V |
| Operating Temperature Range | −40°C to 125°C | °C |
| Typical Temperature Drift | 6 mV (C Temp), 14 mV (I Temp, Q Temp) | mV |
| Output Impedance | 0.2 Ω (Typical) | Ω |
| Sink-Current Capability | 1 mA to 100 mA | mA |
| Package Type | SOT-89 (PK) |
Key Features
- Adjustable Output Voltage: The output voltage can be set to any value between Vref (approximately 2.5V) and 36V using two external resistors.
- Thermal Stability: Operates over a wide temperature range from −40°C to 125°C with low output drift versus temperature.
- 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.
- High Stability: Available in three grades with initial tolerances of 0.5%, 1%, and 2% at 25°C.
Applications
- Adjustable Voltage and Current Referencing: Used in applications requiring precise voltage and current referencing.
- Secondary Side Regulation in Flyback SMPSs: Suitable for secondary side regulation in flyback switching mode power supplies.
- Zener Replacement: Often used as a replacement for Zener diodes due to its sharp turn-on characteristic and adjustable output voltage.
- Voltage Monitoring: Used in voltage monitoring circuits to ensure stable voltage levels.
- Comparator with Integrated Reference: Can be used in comparator circuits with an integrated reference voltage.
Q & A
- What is the TL431BQPKG3 used for?
The TL431BQPKG3 is used as a precision programmable reference voltage regulator in various applications such as onboard regulation, adjustable power supplies, and switching power supplies.
- What is the adjustable output voltage range of the TL431BQPKG3?
The output voltage can be set to any value between approximately 2.5V (Vref) and 36V using two external resistors.
- What are the operating temperature ranges for the TL431BQPKG3?
The device operates from −40°C to 125°C.
- What is the typical output impedance of the TL431BQPKG3?
The typical output impedance is 0.2 Ω.
- What are the sink-current capabilities of the TL431BQPKG3?
The device can sink currents from 1 mA to 100 mA.
- Can the TL431BQPKG3 replace Zener diodes?
Yes, it is often used as a replacement for Zener diodes due to its sharp turn-on characteristic and adjustable output voltage.
- What are the different grades of the TL431BQPKG3 based on reference voltage tolerance?
The device is available in three grades with initial tolerances of 0.5% (B Grade), 1% (A Grade), and 2% (Standard Grade) at 25°C.
- What is the typical temperature drift of the TL431BQPKG3?
The typical temperature drift is 6 mV for C Temp and 14 mV for I Temp and Q Temp.
- What package type is the TL431BQPKG3 available in?
The TL431BQPKG3 is available in the SOT-89 (PK) package type.
- What are some common applications of the TL431BQPKG3?
Common applications include adjustable voltage and current referencing, secondary side regulation in flyback SMPSs, Zener replacement, voltage monitoring, and comparator circuits with integrated references.
