Datasheet

LTC4253B
28
4253bf
applicaTions inForMaTion
Figure 12. Reset Functions (All Waveforms Are Referenced to V
EE
)
(12a) Reset Forcing Start-Up without Initial TIMER Cycle
(12b) Reset of the LTC4253B’s Latched Fault
(12c) Reset as an ON/OFF Switch
RESET PULSE
WIDTH MUST FULLY
DISCHARGE TIMER
1 2 34 5 6 7 8 9
LATCHED TIMER RESET BY
RESET PULLING HIGH
RESET < V
IL
, CHECK UVLO, UV, OV CONDITION, GATE < V
GATEL
,
SENSE < V
CB
, SS < 20 • V
OS
AND TIMER < V
TMRL
TIMER
GATE
SENSE
RESET
SS
DRAIN
PWRGD1
UV/OV
V
TMRH
V
IH
V
IL
V
ACL
V
CB
V
TMRL
V
GATEL
V
LKO
V
UVHI
20 • (V
ACL
+ V
OS
)
20 • (V
CB
+ V
OS
)
20 • V
OS
5µA
5µA
50µA
50µA
5µA
50µA
V
DRNCL
V
DRNL
V
IN
– V
GATEH
200µA + 8 • I
DRN
RESET PULSE
WIDTH MUST FULLY
DISCHARGE GATE AND SS
1 2 34 5 6 7 8 9
4253b F12
RESET < V
IL
, CHECK UVLO, UV, OV CONDITION, V
SENSE
< V
CB
TIMER
GATE
SENSE
RESET
SS
DRAIN
PWRGD1
UV/OV
V
IH
V
IL
V
ACL
V
CB
V
TMRL
V
GATEL
V
LKO
V
UVHI
20 • (V
ACL
+ V
OS
)
20 • (V
CB
+ V
OS
)
20 • V
OS
5µA
50µA
50µA
5µA
50µA
V
DRNCL
V
DRNL
V
IN
– V
GATEH
200µA + 8 • I
DRN
1 23 4 5 6 7 8
RESET < V
IL
, CHECK UVLO, UV, OV CONDITION, GATE < V
GATEL
,
SENSE < V
CB
, SS < 20 • V
OS
AND TIMER < V
TMRL
TIMER
GATE
SENSE
RESET
SS
DRAIN
PWRGD1
V
IN
V
IN
V
IN
UV/OV
V
IL
V
ACL
V
CB
V
TMRL
V
GATEL
V
LKO
20 • (V
ACL
+ V
OS
)
20 • (V
CB
+ V
OS
)
20 • V
OS
5µA
50µA
50µA
5µA
50µA
V
DRNCL
V
DRNL
V
IN
– V
GATEH
200µA + 8 • I
DRN
V
UVHI