FEATURE DESCRIPTIONS (CON.)
The output voltage tracking feature (Figure 35 to Figure
37) is achieved according to the different external
connections. If the tracking feature is not used, the
TRACK pin of the module can be left unconnected or tied
to Vin.
Sequential Start-up
Sequential start-up (Figure 35) is implemented by placing
an On/Off control circuit between VoPS1 and the On/Off pin
of PS2.
PS1
PS2
Vin
Vin
For proper voltage tracking, input voltage of the tracking
power module must be applied in advance, and the
remote on/off pin has to be in turn-on status. (Negative
logic: Tied to GND or unconnected. Positive logic: Tied to
Vin or unconnected)
VoPS1
VoPS2
R3
On/Off
R1
Q1
C1
On/Off
R2
PS1
PS2
PS1
PS2
Simultaneous
Simultaneous tracking (Figure 36) is implemented by
using the TRACK pin. The objective is to minimize the
voltage difference between the power supply outputs
during power up and down.
Figure 35: Sequential start-up
The simultaneous tracking can be accomplished by
connecting VoPS1 to the TRACK pin of PS2. Please note
the voltage apply to TRACK pin needs to always higher
than the VoPS2 set point voltage.
PS1
PS1
PS2
PS2
PS1
PS2
Vin
Vin
VoPS1
VoPS2
TRACK
On/Off
Figure 36: Simultaneous
On/Off
PS1
PS1
PS2
+△V
PS2
Figure 37: Ratio-metric
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DELTA [ DELTA ELECTRONICS, INC. ]
