Datasheet

A0
A1
P1
Z1
P2
Aol
BW
Vref
V
O
R1
R3
C1
C2
R2
C
O
R
O
gm
ea
COMP
VSENSE
Type2A Type2B Type1
C2
R3
C1
TPS54160 , TPS54160A
www.ti.com SLVSB56C –MAY 2012–REVISED FEBRUARY 2014
Feature Description (continued)
8.3.22 Small Signal Model for Frequency Compensation
The TPS54160A uses a transconductance amplifier for the error amplifier and readily supports three of the
commonly-used frequency compensation circuits. Compensation circuits Type 2A, Type 2B, and Type 1 are
shown in Figure 50. Type 2 circuits most likely implemented in high bandwidth power-supply designs using low
ESR output capacitors. The Type 1 circuit is used with power-supply designs with high-ESR aluminum
electrolytic or tantalum capacitors.. Equation 18 and Equation 19 show how to relate the frequency response of
the amplifier to the small signal model in Figure 50. The open-loop gain and bandwidth are modeled using the R
O
and C
O
shown in Figure 50. See the application section for a design example using a Type 2A network with a
low ESR output capacitor.
Equation 18 through Equation 27 are provided as a reference for those who prefer to compensate using the
preferred methods. Those who prefer to use prescribed method use the method outlined in the application
section or use switched information.
Figure 50. Types of Frequency Compensation
Figure 51. Frequency Response of the Type 2A and Type 2B Frequency Compensation
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