GE Industrial Solutions 2 × 12A Digital Dual Output MicroDLynx - Manual (Page 16)

GE
Datasheet
2 × 12A Digital Dual MicroDlynx TM : Non-Isolated DC-DC Power Modules
4.5Vdc –14.4Vdc input; 0.51Vdc to 5.5Vdc output; 2 × 12AOutput Current
February 14, 2014 ©2014 General Electric Corporation. All rights reserved. Page 16
Figure 43. Circuit Configuration for margining Output
voltage.
Digital Output Voltage Margining
Please see the Digital Feature Descriptions section.
Overcurrent Protection
To provide protection in a fault (output overload) condition,
the unit is equipped with internal current-limiting circuitry on
both outputs 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.
Digital Adjustable Overcurrent Warning
Please see the Digital Feature Descriptions section.
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 135
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.
Digital Temperature Status via PMBus
Please see the Digital Feature Descriptions section.
Digitally Adjustable Output Over and Under Voltage
Protection
Please see the Digital Feature Descriptions section.
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.
Digitally Adjustable Input Undervoltage Lockout
Please see the Digital Feature Descriptions section.
Digitally Adjustable Power Good Thresholds
Please see the Digital Feature Descriptions section.
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
SIG_GND
+
─
Figure 45. External source connections to synchronize
switching frequency of the module.
Measuring Output Current, Output Voltage and
Input Voltage
Please see the Digital Feature Descriptions section.
Tunable Loop TM
The module has a feature that optimizes transient response
of the module called Tunable Loop TM .
External capacitors are usually added to the output of the
module for two reasons: to reduce output ripple and noise
(see Figure 38) and to reduce output voltage deviations from
the steady-state value in the presence of dynamic load
current changes. Adding external capacitance however
affects the voltage control loop of the module, typically
causing the loop to slow down with sluggish response.
Larger values of external capacitance could also cause the
module to become unstable.
The Tunable Loop TM allows the user to externally adjust the
voltage control loop to match the filter network connected
to the output of the module. The Tunable Loop
TM is
implemented by connecting a series R-C between the VS+
and TRIM pins of the module, as shown in Fig. 47. This R-C
allows the user to externally adjust the voltage loop
feedback compensation of the module.
Vo2
MODULE
SIG_GND
Trim2
Q3
Rtrim1
Rmargin-up
Q4
Rmargin-down