19
425112fd
LTC4251/LTC4251-1/
LTC4251-2
For more information www.linear.com/4251
APPLICATIONS INFORMATION
Figure 10. Undervoltage Timing with an Overvoltage Glitch (All Waveforms are Referenced to V
EE
)
1 3
2
4 5 6 7
8 9
V
UV/0V
DROPS BELOW V
OVLO
AND TIMER RESTARTS INITIAL TIMING CYCLE.
V
UV/0V
CLEARS V
UVHI
. CHECK TIMER < V
TMRL
, GATE < V
GATEL
AND SENSE < V
CB
.
V
UV/0V
OVERSHOOTS V
OVHI
AND TIMER ABORTS INITIAL TIMING CYCLE.
TIMER CLEARS V
TMRL
, CHECK GATE < V
GATEL
AND SENSE < V
CB
.
V
OVHI
V
UVHI
V
OVLO
V
TMRH
V
TMRL
V
ACL
V
CB
5.8礎
230礎
58礎
58礎
5.8礎
5.8礎
INITIAL TIMING CYCLE
START-UP CYCLE
425112 F10
UV/0V
TIMER
GATE
SENSE
10
1
3
2
4
5 6 7
UV/0V
TIMER
GATE
SENSE
V
OVHI
V
TMRH
V
OVLO
V
ACL
V
CB
5.8礎
5.8礎
5.8礎
5.8礎
425112 F11
230礎
58礎
58礎
V
UV/0V
DROPS BELOW V
OVLO
AND GATE RESTARTS.
V
UV/0V
OVERSHOOTS V
OVHI
AND GATE PULLS TO V
EE
. TIMER UNAFFECTED.
Figure 11. Overvoltage Timing (All Waveforms are Referenced to V
EE
)