SBAS738A June 2018 – October 2018 ISO224
PRODUCTION DATA.
In a typical application, the high-side power supply (VDD1) for the ISO224 is generated from the low-side supply (VDD2) of the device by an isolated DC/DC converter circuit. A low-cost solution is based on the push-pull driver SN6501 and a transformer that supports the desired isolation voltage ratings. TI recommends using a low-ESR decoupling capacitor of 0.1 µF and an additional capacitor of a minimum 1 µF for both supplies of the ISO224. Figure 51 shows the recommended placement of these decoupling capacitors as close as possible to the ISO224 power-supply pins to minimize supply current loops and electromagnetic emissions.
To decouple the output of the integrated LDO, use a 0.22-µF capacitor placed as close to the VCAP pin of the ISO224 as possible.
The ISO224 does not require any specific power up sequencing. Consider the analog settling time tAS as specified in the Switching Characteristics table after ramp up of the VDD1 high-side supply.