12
LTC4221
4221fa
OPERATIO
V
CCn
TIMER
FAULT
FILTER
ON1
V
ON(OFF)
+ 擵
ON(OFFHYST)
V
ON(RESET)
+ 擵
ON(RESETHYST)
V
ON(OFF)
V
GATE(OV)
V
ON(OFF)
+ 擵
ON(OFFHYST)
ON2
GATE1
GATE2
SENSE1
SENSE2
V
OUT1
V
OUT2
PWRGD1
PWRGD2
UVLO
OFF
INITIAL TIMING
RESET
100糀
100糀
V
CCn(UVL)
1
V
CCn
CLEARS V
CCn(UVL)
ELECTRONIC CIRCUIT BREAKER ARMED, CHECK FILTER < V
FILTER(TH)
,
FAULT > V
FAULT(TH)
+ 擵
FAULT(HYST)
ON1 > V
ON(RESET)
+ 擵
ON(RESETHYST)
CHANNEL 1 SLOW COMPARATOR ARMED
ON2 > V
ON(OFF)
, + 擵
ON(OFFHYST)
,
CHECK GATE < V
GATE(OV)
,
TIMER < 0.4V
ON1 > V
ON(OFF)
+ 擵
ON(OFFHYST)
,
CHECK GATE < V
GATE(OV)
,
TIMER < 0.4V
2
CHANNEL 2 SLOW COMPARATOR ARMED
3
4
5 6 7 8 910
11 12 13 14
15
1.9糀
V
TMR(H)
V
TMR(L)
20糀
20糀
1.8糀
V
FILTER(TH)
105糀
V
ON1(RESET)
V
GATE(OV)
9.5糀
9.5糀
25mV
9mV
9mV
V
SENSE(FC)
V
SENSE(SC)
FB1 > V
FB(UV)
+ 擵
FB(HYST)
FB1 < V
FB(UV)
FB2 < V
FB(UV)
FB2 > V
FB(UV)
+ 擵
FB(HYST)
CHANNEL 1
START-UP
CHANNEL 2
START-UP
NORMAL
FAULT
RESET
4221 F01
Figure 1. LTC4221 Operation