Other Parts Discussed in Thread: TPS55288
Please help fix problem with TPS61378-Q1 . I want to get 2A output current
12.5 V , when input is 9...14V
I designed this circuit.
R(comp) = 82K
C(comp) = 0.001uF ****
L = 2.2uH () **** calculated value is ~0.5uH
R(freq) = 18k
R(ilim) = 20k
PIN(mode/sync) = GND
R(pg) = 50k
C(bst) = 0.22uF
C(vcc) = 10 x C(bst) = 2.2uF
C(in/out)= 47uF ; 0.1uF / 47uF ; 0.1uF
C(PIN-10)= 2.2uF
When the input voltage is higher than the output, the TPS61378 gets very
hot, and the temperature protection quickly works, but this question is
probably for later.
I want to understand first with the UP-MODE
output =
12.5 V
input = 9 V
output current = ~0.5A
when C(comp) = 0.001uF
then, at startup, it was not possible to take the output current more than ~
0.5A. the microschema immediately fell into protection mode and did not
start even (if the R(load) was turned on during the start of the TPS61378).
when changed C(comp) = 10uF then it helped and started working.
now when I try to take I(out) more current than ~ 1A, then basically output
voltage increases ~ 0.2V , in a few seconds , and then the protection is
triggered and the output Voltage goes to ~0. OR PIN-10(vcc) on fire , and
goes into a short circuit with the ground(PIN-10<->GND) .
maybe some nominales are not true
also noticed that when the difference between ... decreases then during the
start, the current consumption increases much, and the efficiency drops.
From what it can be, how to understand it?
thanks in advance
