SLVSCV5E March 2015 – December 2024 ATL431 , ATL432
PRODUCTION DATA
When using the ATL43x in a flyback supply (see Figure 8-1), it is often common for designers to place the bias resistor between the Anode of the Opto-Coupler and the output voltage (VO = 24V). However, this makes the ATL43x more susceptible to EOS/ESD damage. Therefore, TI recommends placing the bias resistor between the Cathodes of the Opto-Coupler and the ATL43x, as shown in Figure 8-1. For further explanation, see Designing with the "Advanced" TL431, ATL431 (SLVA685).
When using the ATL43x as a Linear Regulator to supply a load, designers will typically use a bypass capacitor on the output/cathode pin. Be sure that the capacitance is within the stability criteria shown in Figure 5-14 through Figure 5-21.
To not exceed the maximum cathode current, be sure that the supply voltage is current limited. Also, be sure to limit the current being driven into the Ref pin, as not to exceed the absolute maximum rating.
For applications shunting high currents, pay attention to the cathode and anode trace lengths, adjusting the width of the traces to have the proper current density.