L7986TA STMicroelectronics, L7986TA Datasheet - Page 21

• Manufacturer Part Number: L7986TA
• Description: 3A step-down switching regulator
• Manufacturer: STMicroelectronics

Specifications of L7986TA

• Low Dropout Operation: 100% duty cycle

L7986TA
Equation 23
Figure 9.
In
and the open loop gain (G
Figure 10. Open loop gain: module Bode diagram
The guidelines for positioning the poles and the zeroes and for calculating the component
values can be summarized as follow:
1.
2.
Figure 10
Choose a value for R
Choose a gain (R
the Bode diagram of the PWM and LC filter transfer function (G
Type III compensation network
f
P0
4
/R
=
0
1
1
LOOP
) in order to have the required bandwidth (BW), that means:
,
, usually between 1 kΩ and 5 kΩ.
Doc ID 022098 Rev 1
f
(f) = G
P1
=
----------------------------- -
2π R
PW0
⋅
1
3
· G
⋅
C
LC
3
,
(f) · G
f
P2
TYPEIII
=
------------------------------------------- -
2π R
⋅
(f)) are drawn.
4
1
⋅
------------------- -
C
C
Application informations
4
4
+
⋅
C
C
5
5
PW0
· G
LC
(f))
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