Overview
The TL431CPKG3 is a precision programmable reference voltage regulator produced by Texas Instruments. It is part of the TL431 series, which includes three-terminal adjustable shunt regulators known for their thermal stability across various temperature ranges. The TL431CPKG3 is particularly useful in applications requiring adjustable output voltages and high precision voltage referencing.
The device operates with a reference voltage tolerance of 0.5% (B grade), 1% (A grade), and 2% (Standard grade) at 25°C. It can be adjusted to output voltages ranging from the reference voltage (approximately 2.5V) to 36V using two external resistors. This flexibility makes it an excellent choice for on-board 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 (Q Grade) | °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 | TO-243AA (for TL431CPKG3) | - |
| Body Size | Varies by package (e.g., 2.90 mm × 1.30 mm for SOT-23-3) | mm |
Key Features
- Precision Reference Voltage: The TL431CPKG3 offers high precision with reference voltage tolerances of 0.5%, 1%, and 2% at 25°C.
- Adjustable Output Voltage: The output voltage can be set to any value between the reference voltage (approximately 2.5V) and 36V using two external resistors.
- Low Output Noise: The device features low output noise, making it suitable for applications requiring stable voltage references.
- Low Output Impedance: A typical output impedance of 0.2 Ω ensures minimal voltage drop and high stability.
- Wide Operating Temperature Range: The device operates from –40°C to 125°C, making it suitable for a variety of environmental conditions.
- High Sink-Current Capability: The TL431CPKG3 can sink currents from 1 mA to 100 mA.
Applications
- Rack Server Power: Used in power supply designs for rack servers due to its high precision and adjustable output voltage.
- Industrial AC/DC Power Supplies: Suitable for industrial power supplies requiring stable and adjustable voltage references.
- AC Inverter & VF Drives: Applied in inverter and variable frequency drive systems for precise voltage control.
- Servo Drive Control Modules: Used in servo drive control modules to ensure stable and precise voltage references.
- Notebook PC Power Adapters: Utilized in power adapter designs for notebook PCs to provide adjustable and stable output voltages.
Q & A
- What is the reference voltage tolerance of the TL431CPKG3 at 25°C?
The reference voltage tolerance is 0.5% (B Grade), 1% (A Grade), and 2% (Standard Grade) at 25°C.
- What is the adjustable output voltage range of the TL431CPKG3?
The output voltage can be adjusted from the reference voltage (approximately 2.5V) to 36V using two external resistors.
- What is the typical output impedance of the TL431CPKG3?
The typical output impedance is 0.2 Ω.
- What is the operating temperature range of the TL431CPKG3?
The device operates from –40°C to 125°C.
- What is the sink-current capability of the TL431CPKG3?
The device can sink currents from 1 mA to 100 mA.
- What are some common applications of the TL431CPKG3?
Common applications include rack server power, industrial AC/DC power supplies, AC inverter & VF drives, servo drive control modules, and notebook PC power adapters.
- What package types are available for the TL431 series?
The TL431 series is available in various packages including SOT-23-3, SOT-23-5, SOIC, PDIP, and SOP.
- How does the TL431CPKG3 compare to Zener diodes?
The TL431CPKG3 offers better stability, lower temperature drift, and a sharper turn-on characteristic compared to Zener diodes, making it an excellent replacement in many applications.
- What is the significance of the different temperature grades (C, I, Q) for the TL431 series?
The different temperature grades (C, I, Q) indicate the operating temperature range: C (0°C to 70°C), I (–40°C to 85°C), and Q (–40°C to 125°C).
- How can the output voltage of the TL431CPKG3 be adjusted?
The output voltage can be adjusted by using two external resistors connected to the reference and cathode pins.
