Datasheet

DS_DNL10SIP16_07182012
11
FEATURE DESCRIPTIONS (CON.)
Sequential Start-up
Sequential start-up (Figure 27) is implemented by placing
an On/Off control circuit between Vo
PS1
and the On/Off pin
of PS2.
Simultaneous
Simultaneous tracking (Figure 28) 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.
The simultaneous tracking can be accomplished by
connecting Vo
PS1
to the TRACK pin of PS2. Please note
the voltage apply to TRACK pin needs to always higher
than the Vo
PS2
set point voltage.
Ratio-Metric
Ratio–metric (Figure 29) is implemented by placing the
voltage divider on the TRACK pin that comprises R1 and
R2, to create a proportional voltage with Vo
PS1
to the
Track pin of PS2.
For Ratio-Metric applications that need the outputs of
PS1 and PS2 reach the regulation set point at the same
time
The following equation can be used to calculate the value
of R1 and R2.
The suggested value of R2 is 10kΩ.
,2
2
, 1 1 2
o PS
o PS
V
R
V R R


R1
R2
TRACK
Vo
PS1
PS2
Vo
PS2
PS1
Vin
Vin
On/Off
On/Off
The high for positive logic
The low for negative logic
R1
R2
Vo
PS1
PS1
Vin
On/Off
On/Off
PS2
Vo
PS2
Vin
C1
Q1
R3
TRACK
Vo
PS1
PS2
Vo
PS2
PS1
Vin
Vin
On/Off
On/Off