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.