LX7720 Daughter Board Configuration Options
June 2020
LX7720 Daughter Board rev 2.1
15
© 2020 Microsemi Corporation
Figure 17. Reset Schematic
4.11 Safe Mode (LX7720 SM_EN pin 17)
The LX7720's active-high Safe Mode input enables protection countermeasures when faults are detected.
Table 12. Safe Mode Link Settings
Safe Mode
J39 Link
Disable Safe Mode by setting LX7720 SM_EN pin 17 = low
Link 2 to 1
LX7720 SM_EN pin 17 is controlled by an external signal on FMC connector J10 pin H17 or 40 pin header
J20 pin 27.
A pull-up resistor ensures that Safe Mode is enabled by default if the external signal is open
Link 2 to 3
Enable Safe Mode by setting LX7720 SM_EN pin 17 = high
Open
Figure 18. Safe Mode Schematic
4.12 Bi-Level Comparator Inputs BL1 to BL6
The LX7720's 6 bi-level comparator inputs BLI1 to BLI6 are routed to connector J15 pins 3 to 8 respectively. The common
comparator threshold LX7720 BLI_TH pin 119 is set to VCC/2 by R4 & R5.
The LX7720's 6 bi-level comparator outputs BLO1 to BLO6 are routed to the FMC connector (Table 16 on page 19) and
to the 40-way header J20 (Table 17 on page 19).
Figure 19. Bi-Level Comparator Inputs BL1 to BL6 Schematic
