1 Features
• Reference Voltage Tolerance at 25°C
– 0.5% (B Grade)
– 1% (A Grade)
• Minimum Typical Output Voltage: 2.495 V
• Adjustable Output Voltage: Vref to 36 V
• Operation From −40°C to +125°C (Q Temp)
• Maximum Temperature Drift
– 10 mV (C Temp)
– 17 mV (I Temp)
– 27 mV (Q Temp)
• 0.3-Ω Typical Output Impedance
• Sink-Current Capability
– Imin = 1 mA (max)
– IKA = 15 mA (max)
• Reference Input Current IREF: 0.4 μA (max)
• Deviation of Reference Input Current over
Temperature, II(dev): 0.3 μA (max)

2 Applications
• Adjustable Voltage and Current Referencing
• Secondary Side Regulation in Flyback SMPS
• Zener Diode Replacement
• Voltage Monitoring
• Precision Constant Current Sink/Source
• Comparator with Integrated Reference

3 Description
The TL431LI device is a three-terminal adjustable
shunt regulator, with specified thermal stability over
applicable automotive, commercial, and military
temperature ranges. The output voltage can be set to
any value between Vref (approximately 2.495 V) and
36 V, with two external resistors. These devices have
a typical output impedance of 0.3 Ω. Active output
circuitry provides a very sharp turn-on characteristic,
making these devices excellent replacements for
Zener diodes in many applications, such as onboard
regulation, adjustable power supplies, and switching
power supplies. This device is a pin-to-pin alternative
to the industry standard TL431, with optimized Iref and
IIdev performance. The lower Iref and IIdev values
enable designers to achieve higher system accuracy
and lower leakage current. The TL432LI device has
exactly the same functionality and electrical
specifications as the TL431LI device, but has a
different pinout for the DBZ package.
The TL431LI device is offered in two grades, with
initial tolerances (at 25°C) of 0.5% and 1%, for the B
and A grade, respectively. In addition, low output drift
versus temperature ensures good stability over the
entire temperature range.
The TL43xLIxQ devices are characterized for
operation from –40°C to 125°C.