Design Guide
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V 1.0
2018-06-06
XDPL8218 design guide
For high power factor flyback converter with constant voltage output
Debugging guide
19
Debugging guide
This section presents guidelines for system debugging if the board has any problems with powering up or
shutting down during testing.
19.1
Pin signal debugging
Scenario I: V
CC
voltage stays above V
CC
turn-off threshold (6 V typ.) and the UART pin signal toggles every 0.4 sec
for a duration of t
auto,restart
before every restart. See an example in
This scenario means a protection with auto-restart reaction has been triggered. It is recommended to activate
the XDPL8218 debug mode for firmware status code read-out in this case, to know exactly which protection has
been triggered. For more details on the XDPL8218 debug mode, please refer
Section 19.2
Note:
As shown in
, the actual auto-restart time of a protection with auto-restart time is typically
longer than the configured t
auto,restart
value, due to an additional time of t
VCCON,recharge
needed for V
CC
recharging to V
CC
turn-on threshold (20.5 V typ.) before every restart.
Figure 26
Scenario I waveform example (protection with auto-restart reaction)
Scenario II: V
CC
stays above V
CC
turn-off threshold (6 V typ.) and the UART pin always stays low. See an example
in
This scenario means a protection with latch-mode reaction has been triggered. It is recommended to activate
the XDPL8218 debug mode for firmware status code read-out in this case, to know exactly which protection has
been triggered. For more details on the XDPL8218 debug mode, please refer to
Section 19.2
As there are only a few system protections in which the reaction can be configured to latch-mode, an
alternative debugging option could be to identify which system protection with latch-mode reaction, after its
reaction is configured to auto-restart, would cause the triggered protection waveform change from scenario II
to scenario I.
