NXP Semiconductors KIT34932SEKEVB, User Manual, Page: 18 / 39

Getting to Know the Hardware
KT34FS6407-34FS6408UG User’s Guide Rev. 1.0 8/2015
18 Freescale Semiconductor, Inc.
4.8.1 Compensation Network
A voltage regulator needs feedback from the V
CORE
voltage to be able to adjust (control) output voltage. For this reason, two bridges are
implemented in the external MC34FS6407 or MC34FS6408 circuitry. Static feedback (steady-state) voltage is defined by a simple resistor
bridge (given by RA3/RB3 and RA4). Dynamic behavior of the regulator is controlled by another bridge that is an RC divider (defined by
RBx, CBx, R1, C1, R2, C2).
Figure 4 shows the compensation network. Steady-state voltage can be either 1.2 V or 3.3 V. To tune the
dynamic performance, the board is equipped with two different bridges (possible combinations of the jumpers J1 and J9 are shown in
Table 7 ). The combinations shown in Table 7 are chosen to provide optimal performance for the given output voltage. The real dynamic
performance can differ for different applications and can be tuned by changing the compensation network and by adding output capacitors
(J2).
Figure 4. Compensation Network and V
CORE
Setup Schematic
Table 7. Compensation Network and V
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Settings
V
CORE
(V)
Jumper Settings
Static Behavior Dynamic Behavior
J5 J1 J9
1.23 3-4 3-4 3-4
3.3 1-2 1-2 1-2
V
CORE
V
CORE
_sense