Datasheet
COMP
VSENSE
VREF
4.95V
C
P
C
Z
R
Z
+
g
M
VSENSE
VREF
I
EA
UCC28063
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SLUSAO7 –SEPTEMBER 2011
Improved Error Amplifier
The voltage-error amplifier is a transconductance amplifier. Voltage-loop compensation is connected from the
error amplifier output, COMP, to analog ground, AGND. The recommended Type-II compensation network is
shown in Figure 27. For loop-stability purposes, the compensation network values are calculated based on
small-signal perturbations of the output voltage using the nominal transconductance (gain) of 55 μS.
Figure 27. Transconductance Error Amplifier with Typical Compensation Network
To improve the transient response to large perturbations, the error amplifier gain increases by a factor of ~5X
when the error amp input deviates more than ±5% from the nominal regulation voltage, VSENSEreg. This
increase allows faster charging and discharging of the compensation components following sudden load-current
increases or decreases (also refer to Figure 5 in the Typical Characteristics).
Figure 28. Basic Voltage-Error Amplifier Transconductance Curve
NOTE
Basic voltage-error amplifier transconductance curve showing small-signal and
large-signal gain sections, with maximum current limitations.
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