View tl431cx datasheet:

INTEGRATED CIRCUITS TL431C, TL431AC, TL431I, TL431AI, LM431AC Adjustable precision shunt regulators Product specification 1997 Feb 25 Philips Semiconductors Philips Semiconductors Product specification TL431C, TL431AC, TL431I, Adjustable precision shunt regulators TL431AI, LM431AC DESCRIPTION PIN CONFIGURATIONS The TL431 and TL431A are 3-terminal adjustable shunt regulators with specified thermal stability over applicable automotive and M, D Package commercial temperature ranges. The output voltage may be set to TOP VIEW any value between VREF (approximately 2.5V) and 36V with two CATHODE 1 8 REF external resistors (see Figure 4). These devices have a typical ANODE 2 7 ANODE output impedance of 0.2?. Active output circuitry provides a very ANODE 3 6 ANODE sharp turn-o