in Figure 2-1 can further simplified by using a TL431 device by taking advantage of the internal error amplifier of the TL431 as this eliminates the need for an additional op amp. The TL431 CATHODE to REF feedback loop allows the insertion of a transistor to allow the regulation of VXto be V REF across R .SThis level of integration with the TL431 works for all 431 like products because they share the same architecture as shown in Figure 2-2. CATHODE REF + _ V ref ANODE Figure 2-2. TL431 Functional Block Diagram 2 Precision Current Sources and
