Wurth Elektronik MDC901-EVKHB, Technical Manual

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MDC901-EVBHB Rev2021Jan5 MinDCet NV www.mindcet.com
Attention: Please refer to Evaluation Kit Important Notice on page 20 Page 12
Manual Dead time Selection
CAUTION: Dead time must be monitored by an
oscilloscope in manual dead time mode to avoid
HS/LS overlap
Four operating modes are available for MDC901 operation, defined by MHS_sel and MLS_sel state,
described in the truth table in Table 1.
Table 1: Truth table for mode selection
mode
select synch/async
buck/boost sync buck
PWM=VinHS sync boost
PWM=VinLS transparent
VinLS &
VinHS
MHS_sel 0 0 1 1
MLS_sel 0 1 0 1
Figure 6: Synchronous buck mode example with placed jumpers
Figure 6 displays an example of the EVB configured for manual dead time in synchronous buck mode
(determined by the MHS_sel and MLS_sel state, as well as the jumpers on
disILD and DTselect according to Table 1).
TgapOn is the time between the LS falling and HS rising as shown here:
TgapOff is the reverse situation to TgapOn from HS off to LS switching on.
DTselect
+9ns TgapOn2
+18ns TgapOn3
+36ns TgapOn4
ZVSin
+9ns TgapOff2
+18ns TgapOff3
+36ns TgapOff4
VinLS
VinHS
disILD
MHS_sel
MLS_sel
PWM
Placed
jumpers
LS HS
HS LS
TgapOff=2.8ns + …
TgapOn=2.8ns + …