GE Industrial Solutions 20A Analog MicroDLynx - Manual (Page 15)

GE
Data Sheet
20A Analog MicroDLynx TM : Non-Isolated DC-DC Power Modules
3Vdc –14.4Vdc input; 0.45Vdc to 5.5Vdc output; 20A Output Current
April 24, 2013 ©2012 General Electric Company. All rights reserved. Page 15
multiple modules together, multiple modules can track their
output voltages to the voltage applied on the SEQ pin.
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.
Overcurrent Protection
To provide protection in a fault (output overload) condition,
the unit is equipped with internal current-limiting circuitry
and can endure current limiting continuously. At the point of
current-limit inception, the unit enters hiccup mode. The unit
operates normally once the output current is brought back
into its specified range.
Overtemperature Protection
To provide protection in a fault condition, the unit is equipped
with a thermal shutdown circuit. The unit will shut down if the
overtemperature threshold of 120
o C(typ) is exceeded at the
thermal reference point T
ref
.Once the unit goes into thermal
shutdown it will then wait to cool before attempting to
restart.
Input Undervoltage Lockout
At input voltages below the input undervoltage lockout limit,
the module operation is disabled. The module will begin to
operate at an input voltage above the undervoltage lockout
turn-on threshold.
Synchronization
The module switching frequency can be synchronized to a
signal with an external frequency within a specified range.
Synchronization can be done by using the external signal
applied to the SYNC pin of the module as shown in Fig. 45,
with the converter being synchronized by the rising edge of
the external signal. The Electrical Specifications table
specifies the requirements of the external SYNC signal. If the
SYNC pin is not used, the module should free run at the
default switching frequency. If synchronization is not being
used, connect the SYNC pin to GND.
MODULE
SYNC
GND
+
─
Figure 45. External source connections to synchronize
switching frequency of the module.
Dual Layout
Identical dimensions and pin layout of Analog and Digital
MicroDLynx modules permit migration from one to the other
without needing to change the layout. In both cases the trim
resistor is connected between trim and signal ground. The
output of the analog module cannot be trimmed down to
0.45V
Power Good
The module provides 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 overtemperature, overcurrent or
loss of regulation occurs that would result in the output
voltage going ±10% outside the setpoint value. The PGOOD
terminal can be connected through a pullup resistor
(suggested value 100K
 ) to a source of 5VDC or lower.