Dear Sir/Madam,
Could you please review my attached schematic. I am using a 2 Amp switch mode power supply to generate a 4.48V supply. This is fed to the LM662200DRLR ideal diode switch. The 4.48V supply is also going to the BQ25173. The BQ25173 is used to output 4.2V and charge a supercapacitor. The output from the supercapacitor is also fed to the LM662200DRLR. The load is connected to the output of the LM662200DRLR.
The idea is that the 4.48V supply will be fed to my load under normal circumstances and when main power is disconnected, the output from the supercapacitor is used to power the load.
Note that resistor R339 is not inserted.
Also note that the supercapacitor that I am using is the Vishay MAL219690101E3 Hybrid Storace capacitor (90 Farad, 4.2 Volt)
I have tried building this cicuit in my lab using the evaluation boards for both of these devices. Unfortuanltey the circuit does not seem to work. The supercapacitor does not charge. Could this be because it is a hybrid supercapacitor instead ot a standard supercapacitor ?
