the maximum ICA and VCA are the same as standard (100 mA and 36 V). Unity gain frequency is reduced to 250 kHz to attenuate high frequency ripples so they are not fed back to the controller. The ATL431 has a very different instability area. At low voltages and currents it is absolutely stable with any practical capacitive load, provided the capacitors are of a high-quality, low-impedance type. The minimal recommended value of the series decoupling resistor is 250 Ohm (standard TL431: 1 Ohm). Apart from the TL431 and its descendants, as of 2015, only two shunt regulator ICs found wide use in the industry. Both types have similar functionality and applications, but different internal circuits, different reference levels, maximum currents and voltages: The bipolar LMV431 by Texas Instruments has a VREF of 1.24 V and is capable of regulating voltages up to 30 V at currents from 80 μA to 30 mA; The low-voltage CMOS NCP100 by ON Semiconductor has a VREF of 0.7 V and is capable of regulating voltages up to 6 V at currents from 100 μA to 20 mA. References Bibliography Books and journals Corporate publications Linear integrated circuits Texas Instruments 1977 introductions