Datasheet

2
1 2
FB
FB
FB FB
R
G
R R
=
+
(101)
13
0 013
1 13
FB
k
G .
M k
W
= =
W + W
(102)
3
1
2
1 2
1
2
PWM _ PS
SENSE OUT OUT
FQ IN ( typ )
f
K R V C
K M M V
p
=
(103)
3
2
1
1 581
7 0 067 391 270
2
15 385 0 484 0 764 115
m
p
m
m
= =
´ W´ ´
´ ´ ´
PWM _ PS
f . Hz
. V F
V
. s . . V
s
(104)
3
1 2
1
1
2
OUT
PWM _ PS
PWM _ PS
M V
M M s
G ( f )
s( f )
f
m
p
´
=
+
(105)
VL FB PWM _ PS
G ( f ) G G ( f )=
(106)
( )
20
VLdB VL
G ( f ) log G ( f )=
(107)
1*10
4
qG
VL
(f)
f - Hz
-60
20
G
VLdB
(f)
OPEN LOOP VOLTAGE TRANSFER
FUNCTION
-40
-20
0
10 100 1*10
3
-100
-80
-60
-40
-20
0
10.10.01
Gain
Phase
UCC28019A
SLUS828B – DECEMBER 2008 – REVISED APRIL 2009 .................................................................................................................................................. www.ti.com
The open loop of the voltage transfer function, G
VL
(f) contains the product of the voltage feedback gain, G
FB
, and
the gain from the pulse width modulator to the power stage, G
PWM_PS
, which includes the pulse width modulator
to power stage pole, f
PWM_PS
. The plotted result is shown in Figure 31 .
Figure 31. Bode Plot of the Open Loop Voltage Transfer Function
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