I'm using the TPS61041 to generate 26 V - 3.5 mA (load - current source). The sawtooth ripple at the output (Vout) reaches 1,6 Vpp with 1.4 kHz (approx.).
However, the projected fs(load) was 51.86 kHz with (15 mV + 0,257*ESR) of ripple, what is wrong? Where does this 1.4 kHz come from?
My current source is ensuring a 3.5 mA consumption.
Vin: 3,3 V (LDO regulator).
L: 47 uH (toroidal - homemade, but OK) --> Iloadmax_calc = 0,257 A ( 0,25 + 3,3/47u* 100n)
D: MBR0520L ~ 300 mV
Cin: 10uF ceramic
Cout: 4.7uF + 0.1uF both ceramic. ( Problem?)
Feedback R1: 2M
Fd. R2:. 100 k ohm
Feedback cap (Cff): 10pF, but the calc. indicates 30 pF. ( Problem?)
Delta_output calc = 15 mV + Ip*ESR ----> 15 mV + 0,257*ESR, (would be my ESR too high?)
I really appreciate any help you can provide.
