TL431QPK

The TL431 and TL432 devices are three-terminal adjustable shunt regulators that meet the specified thermal stability over the applicable automotive and commercial temperature ranges. The output voltage can be set to any value between Vref (approximately 2.5V) and 36V through two external resistors. These devices have a typical output impedance of 0.2Ω. The active output circuit provides a very sharp turn-on characteristic, making these devices an excellent replacement for Zener diodes in many applications, including on-board regulation, adjustable power supplies, and switching power supplies. The TL432 device has exactly the same functions and electrical characteristics as the TL431 device, but with different pinouts in the DBV, DBZ, and PK packages. Both the TL431 and TL432 devices are available in three grades: B, A, and standard, with initial tolerances at 25°C of 0.5%, 1%, and 2% respectively. In addition, the low output temperature drift ensures excellent stability over the entire temperature range. The TL43xxC devices operate over a temperature range of 0°C to 70°C, the TL43xxI devices operate from -40°C to 85°C, and the TL43xxQ devices operate from -40°C to 125°C.

Applications

• Adjustable voltage and current reference
• Secondary-side regulation in flyback SMPS
• Zener diode replacement
• Voltage monitoring
• Comparator with integrated reference

Key features

• Reference voltage tolerance at 25°C: 0.5% (Grade B), 1% (Grade A), 2% (Standard Grade)
• Adjustable output voltage: Vref to 36V
• Operating range: -40°C to 125°C
• Typical temperature drift (TL43xB): 6mV (C temperature grade), 14mV (I temperature grade, Q temperature grade)
• Low output noise
• Typical output impedance: 0.2Ω
• Sink current capability: 1mA to 100mA