Datasheet
1 2
0 484 0 764 0 37
V V
M M . . .
s sm m
´ = ´ =
(90)
1 2
0 37 0 372
V V
. M M .
s sm m
@ =
(91)
2
3
0 0510 0 1543 0 1167= ´ - ´ -then : M . VCOMP . VCOMP .
(92)
2
3
0 1026 0 3596 0 3085= ´ - ´ +then : M . VCOMP . VCOMP .
(93)
2
3
4
0 1026 4 0 3596 4 0 3085 0 512
VCOMP
M . . . .
=
= ´ - ´ + =
(94)
1
1
2p
=
mi
ICOMP
IAVG
g M
C
K f
(95)
0 95 0 484
1100
7 2 9 5
ICOMP
. mS .
C pF
. kHzp
´
= =
´ ´ ´
(96)
1
1
2p
=
mi
IAVG
ICOMP
g M
f
K C
(97)
0 95 0 484
8 7
7 2 1200p
´
= =
´ ´ ´
IAVG
. mS .
f . kHz
pF
(98)
UCC28019A
SLUS828B – DECEMBER 2008 – REVISED APRIL 2009 ..................................................................................................................................................
www.ti.com
Verify that the product of the individual gain factors is approximately equal to the M
1
M
2
factor determined above,
if not, reselect VCOMP and recalculate M
1
M
2
.
The non-linear gain variable, M
3
, can now be calculated:
• if : 0 < VCOMP < 3
• if : 3 ≤ VCOMP < 7
In this example:
The frequency of the current averaging pole, f
IAVG
, is chosen to be at 9.5 kHz. The required capacitor on ICOMP,
C
ICOMP
, for this is determined using the transconductance gain, g
mi
, of the internal current amplifier:
Using a 1200 pF capacitor for C
ICOMP
results in a current averaging pole frequency of 8.7 kHz:
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