MIC2580A
Micrel, Inc.
Timing Diagrams
/ON
+5V
/ON
+5V
5VOUT
0V
+3.3V
5VOUT
0V
+3.3V
Short Circuit
3VOUT
0V
+12V
3VOUT
0V
+12V
12VOUT
0V
0V
12VOUT
0V
0V
M12VOUT
–12V
M12VOUT
–12V
/PWRGD
/FAULT
t
RESET
/POR
/PWRGD
t
START
/FAULT
/POR
Figure 1. Controller Timing: Normal Cycle
Figure 2. Controller Timing: Enable Into Short
Circuit Breaker
Reset
/ON
+5V
Fault
5VOUT
0V
+3.3V
3VOUT
0V
+12V
12VOUT
0V
0V
M12VOUT
–12V
V
IN
}
1V
t
/good
+5V
V
PGTH
t
good
/PWRGD
/FAULT
/EPWRGD
0V
Figure 3. Controller Timing: Short on 5V
Figure 4. Early Power Good Response Time
MIC2580A
6
February 2005