User`s guide
SMPS AC/DC Reference Design User’s Guide
DS70320B-page 66 © 2008 Microchip Technology Inc.
The LED flashes the same number of times as the fault ID of the source that caused
the fault. The source of the fault can be decoded using the values in Table 3-6 and
Table 3- 7.
TABLE 3-6: FAULT SOURCE INDICATION ON PRIMARY SIDE
TABLE 3-7: FAULT SOURCE INDICATION ON SECONDARY SIDE
Fault ID Source of Fault
1 PCB overtemperature
2 PFC output overvoltage
3 ZVT overcurrent
4 AC overvoltage
5 AC undervoltage
6 Secondary UART failure
7 System overload
Fault ID Source of Fault
1 12V Buck overvoltage
2 12V Buck undervoltage
3 Multi-phase overcurrent
4 PCB overtemperature
5 Single-phase overcurrent