Datasheet

DS_DCM12S0A0S12NFA_06092014 E-mail: [e-mail]
http://www.deltaww.com/dcdc
P14
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 47: 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 DCM 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 DCM 12A modules have monotonic start-up and
shutdown behavior for any combination of rated input
voltage, output current and operating temperature range.
Synchronization
The DCM 12A 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.