4.6 Loop Frequency Response
Measuring the frequency response of the feedback loop requires a unique test setup as well as physical
changes to the EVM. The 0-Ω resistor jumper R9, just above the output inductor, L1, must be lifted to break the
loop. Both test points TP20 (BODE) and TP15 (VOUT) are used for connections to the Bode100 instruments.
Figure 4-7. EVM Modification to Measure Frequency Response
The test setup which includes several connections to Picotest Bode100 test instruments is shown in
Measurement results are shown in
. The CHF, high frequency pole, component of
the compensation circuit is optional. Omitting it results in slightly increased phase margin. However, the benefit
of including it is that the gain curve is set in a downward trajectory as frequency increases, making a monotonic
gain curve more likely to be achieved.
TPS7H4002EVM-CVAL Testing
SLVUBI1 – MAY 2021
TPS7H4002EVM-CVAL Evaluation Module
11
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