The TL431LI-Q1 / TL432LI-Q1 are pin-to-pin alternatives to TL431-Q1 / TL432-Q1. TL43xLI-Q1 offers better stability, lower temperature drift (VI(dev)), and lower reference current (Iref) for improved system accuracy. The TL431-Q1 is a three-pin adjustable shunt regulator with specified thermal stability over applicable automotive temperature ranges. The output voltage can be set to any value from VREF (approximately 2.5 V) to 36 V, with two external resistors (see Figure 28). This device has a typical output impedance of 0.2 Ω. Active output circuitry provides a sharp turnon characteristic, making this device an excellent replacement for Zener diodes in many applications, such as onboard regulation, adjustable power supplies, and switching power supplies. The TL432-Q1 has exactly the same functionality and electrical specifications as the TL431-Q1 device, but has a different pinout for the DBZ package.