Datasheet

DS_DCL12S0A0S20NFA_06182014 E-mail: [e-mail]
http://www.deltaww.com/dcdc
P13
FEATURE DESCRIPTIONS (CON.)
After the 10msec delay, an analog voltage is applied to the SEQ
pin and the output voltage of the module will track this voltage on
a one-to-one volt bases until the output reaches the set-point
voltage. To initiate simultaneous shutdown of the modules, the
SEQ pin voltage is lowered in a controlled manner. The output
voltage of the modules tracks the voltages below their set-point
voltages on a one-to-one basis. A valid input voltage must be
maintained until the tracking and output voltages reach ground
potential.
When using the EZ-SEQUENCETM feature to control start-up
of the module, pre-bias immunity during startup is disabled. The
pre-bias immunity feature of the module relies on the module
being in the diode-mode during start-up. When using the
EZ-SEQUENCETM feature, modules goes through an internal
set-up time of 10msec, and will be in synchronous rectification
mode when the voltage at the SEQ pin is applied. This will result
in the module sinking current if a pre-bias voltage is present at
the output of the module.
Figure 37: Circuit showing connection of the sequencing signal
to the SEQ pin.
Simultaneous
Simultaneous tracking (Figure 41) 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.
Power Good
The DCL modules provide a Power Good (PGOOD) signal
that is implemented with an open-drain output to indicate that
the output voltage is within the regulation limits of the power
module. The PGOOD signal will be de-asserted to a low state
if any condition such as over temperature, over current or loss
of regulation occurs that would result in the output voltage
going ±10% outside the set point value. The PGOOD terminal
should be connected through a pull up resistor (suggested
value 100KΩ) to a source of 5VDC or lower.
Monotonic Start-up and Shutdown
The DCL 20A modules have monotonic start-up and shutdown
behavior for any combination of rated input voltage, output
current and operating temperature range.
Synchronization
The DCL 20A modules can be synchronized using an external
signal. Details of the SYNC signal are provided in below table.
If the synchronization function is not being used, leave the
SYNC pin floating.