I've try to evaluate TDA8939TH/N1C (N4D5W9 HSE04391X), and slightly disappointed about Ii(bias)which claimed in the TDA8939_1.pdf <10uA , but in my case the input bias 20 times bigger! I used symmetrical supply +/-25V, and it seems each of the comparators inputs have pull-down resistors around 120KOhm (connected to the Vssa, and my Ohm-meter shows 123Kohm too). Anyone has noticed too? Well, it would be great, if someone will make measurement of the impedance between #1 and #2 pins etc, and report here. Thank you!
BTW, Philips answered today: "There have not been any changes to the device.. "
But i still see 123KOhm!! Probably the comparator isn't so bad, and noisy just because feeding from noisy negative rail?😕 Maybe try to put the same res to Vdda too, and adjust loop gain to improve PSRR even..🙄
BTW, Philips answered today: "There have not been any changes to the device.. "
But i still see 123KOhm!! Probably the comparator isn't so bad, and noisy just because feeding from noisy negative rail?😕 Maybe try to put the same res to Vdda too, and adjust loop gain to improve PSRR even..🙄