MCM12S10Q Delta Electronics, Inc., MCM12S10Q Datasheet - Page 13

• Manufacturer Part Number: MCM12S10Q
• Description: Integrated, Non-isolated, Point Of Load, Dc/dc Power Modules
• Manufacturer: Delta Electronics, Inc.

DESIGN CONSIDERATIONS
The power module should be connected to a low
ac-impedance input source. Highly inductive source
impedances can affect the stability of the module. An
input capacitance must be placed close to the modules
input pins to filter ripple current and ensure module
stability in the presence of inductive traces that supply
the input voltage to the module.
FEATURES DESCRIPTIONS
Remote On/Off
The MCM12S10Q A series power modules have a
Comp/EN pin for remote On/Off control.
When the Comp/EN pin is pulled below the falling
threshold voltage (0.4V nominal), the MCM12S10Q A
will be off. The external pull down device (open collector
or open drain) will initially need to sink 5mA (max.) of pin
output current. Once the MCM12S10Q A is disabled,
only a 20uA current source will continue to draw current.
If the On/Off function is not used, leave the pin open and
the module will be on.
Figure 43: Remote On/Off implementation
Soft-Start
The soft-start ramps the reference on the non-inverting
terminal of the error amplifier internally from 0V to 0.6V
in a nominal 6.8ms. The output voltage will thus follow
the ramp, from zero to the final value. In the same
6.8ms, the soft-start is completed and the output should
be in regulation at the voltage setpoint. This method
provides a rapid and controlled output voltage rise; there
is no large inrush current charging the output capacitors.
The entire start-up sequence from power-on reset
typically takes up to 17ms; up to 10.2ms for the delay
and OCP sample and 6.8ms for the soft-start ramp.
DS_MCM12S10Q_07022008
Vbias Connection
Please connect Vbias pin to VIN pin and add a 1 uF cap
between Vbias pin and PGND pin.
Over current and Short-Circuit Protection
When an OCP or SCP fault is detected, the
MCM12S10Q A over current and short circuit protection
circuit will shut down the high side MOSFET and turn
the low side MOSFET on, then circulating in hiccup
mode. The module will remain in the hiccup mode until
the EN pin is pulled below 0.4V (typ) or if the voltage at
the VIN pin has fallen below the power-on reset
threshold.
There is an OCP pin used to set the over current
protection (OCP) and short-circuit protection (SCP) set
point. MCM12S10Q A initial OCP set point is 20A (typ)
when this pin is left open. Connect a 40.2KΩ resistor
between the OCP pin and the PGND pin will lower the
OCP set point to 16A (typ). If you would like to adjust the
over-current set point to other values, please contact us.
Input Capacitor
Please u
the voltage overshoot, small ceramic capacitors for high
frequency de-coupling and bulk capacitors to supply the
current needed each time module turns on.
The important parameters for the bulk input capacitor
are the voltage rating and the RMS current rating. For
reliable operation, select the bulk capacitor with voltage
and current ratings above the maximum input voltage
and highest RMS current required by the circuit.
These capacitors must be capable of handling the
surge-current at power-up. The
the soft-start function that controls and limits the current
surge.
se a mix of input bypass capacitors to control
MCM12S10Q A
provides
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