Hi, team
Please tell me about the variation of TCLK.
LM3881 can adjust TCLK by external capacitor CADJ. I think TCLK is affected by VHTH, VLTH, ITADJ_SRC, ITADJ_SINK as well as CADJ. ITADJ_SRC and ITADJ_SINK are equivalent including variations, so if we consider them collectively as ITADJ.
Calculating TCLK from the above parameters gives:
TCLK = 2*CADJ*(VHTH-VLTH)/ITADJ
if CADJ = 10nF,
TCLK(typ) = 2*10n*(1.22-0.5)/12u = 1.2 msec
This is similar to the value given in the datasheet. Similarly, calculating the maximum and minimum values is as follows.
TCLK(max) = 2*10n*(1.4-0.3)/4u = 0.3 msec (-75%)
TCLK(min) = 2*10n*(1.0-0.7)/20u = 5.5 msec (+358%)
This TCLK variation is very high. Is my understanding correct ?
Regards,
Hayakawa
