L6590A
Figure 28. Standby Function timing diagram
Pout
Peak
Primary
Current
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Load
regulation
Vout
STANDBY
(before filter)
small glitch
STANDBY
(filtered)
2 ms
1 ms
fsw
65 kHz
22 kHz
Brownout Protection
Brownout Protection is basically a not-latched device shutdown functionality. It will typically be used to detect a
mains undervoltage (brownout). This condition may cause overheating of the primary power section due to an
excess of RMS current.
Figure 29. Brownout Function internal schematic and timing diagram
HV Input bus
VON
VOFF
HV Input bus
Vcc
50 µA
BOK
+
6.4 V
-
2.5 V
VinOK
L6590A
VinOK
Vcc
PWM
Vout
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