LT3992EFE View Datasheet(PDF) - Linear Technology
Part Name
Description
MFG CO.
'LT3992EFE' PDF : 36 Pages View PDF
LT3992
Applications Information
If the synchronization signal powers up in an undetermined
state (VOL, VOH, Hi-Z), connect the synchronization clock
to the LT3992 as shown in Figure 9. The circuit as shown
will isolate the synchronization signal when the output
voltage is below 90% of the regulated output. The LT3992
will start up with a switching frequency determined by the
resistor from the RT/SYNC pin to ground.
If the synchronization signal powers up in a low impedance
state (VOL), connect a resistor between the RT/SYNC pin
and the synchronizing clock. The equivalent resistance
seen from the RT/SYNC pin to ground will set the start-
up frequency.
If the synchronization signal powers up in a high imped-
ance state (Hi-Z), connect a resistor from the RT/SYNC
pin to ground. The equivalent resistance seen from the
RT/SYNC pin to ground will set the start-up frequency.
SW1
SW2
CLKOUT
tDCLKOSW1
RT/SYNC
tP
tP/2
tP
tP/2
tP
tDCLKOSW2
tP/2
tP
tDRTSYNC
3992 F10
Figure 10. Timing Diagram RT/SYNC = 1MHz, Duty Cycle = 50%
VOUT1
LT3992
PG1 RT/SYNC
VCC
SYNCHRONIZATION
CIRCUITRY
CLK
3992 F09
Figure 9. Synchronous Signal Powered from Regulator’s Output
tP
SW1
tP
SW2
CLKOUT
tPON
tP
tDCLKOSW1
RT/SYNC
tDRTSYNCH
tDCLKOSW2
tPON
tP
tDRTSYNCH
3992 F11
Figure 11. Timing Diagram RT/SYNC = 1MHz, Duty Cycle > 50%
For more information www.linear.com/LT3992
3992fa
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