GE Data Sheet
6A Analog SlimLynxTM Encapsulated: Non-Isolated DC-DC Power Modules
3Vdc –14.4Vdc input; 0.6Vdc to 5.5Vdc output; 6A Output Current
June 24, 2014 ©2014 General Electric Corporation. All rights reserved. Page 15
sequencing voltage must be set higher than the set-point
voltage of the module. The output voltage follows the
sequencing voltage on a one-to-one basis. By connecting
multiple modules together, multiple modules can track their
output voltages to the voltage applied on the SEQ pin.
The module’s output can track the SEQ pin signal with slopes
of up to 0.5V/msec during power-up or power-down.
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 150oC(typ) is
exceeded at the thermal reference point Tref .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.
Tunable LoopTM
The module has a feature that optimizes transient response
of the module called Tunable LoopTM.
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 LoopTM allows the user to externally adjust the
voltage control loop to match the filter network connected
to the output of the module. The Tunable LoopTM is
implemented by connecting a series R-C between the VS+
and TRIM pins of the module, as shown in Fig. 46. This R-C
allows the user to externally adjust the voltage loop
feedback compensation of the module.
Figure. 46. Circuit diagram showing connection of RTUME
and CTUNE to tune the control loop of the module.
Recommended values of RTUNE and CTUNE for different output
capacitor combinations are given in Table 2. Table 2 shows
the recommended values of RTUNE and CTUNE for different
values of ceramic output capacitors up to 1000uF that
might be needed for an application to meet output ripple
and noise requirements. Selecting RTUNE and CTUNE according
to Table 2 will ensure stable operation of the module.
In applications with tight output voltage limits in the
presence of dynamic current loading, additional output
capacitance will be required. Table 3 lists recommended
values of RTUNE and CTUNE in order to meet 2% output
voltage deviation limits for some common output voltages
in the presence of a 3A to 6A step change (50% of full load),
with an input voltage of 12V.
Please contact your GE Critical Power technical
representative to obtain more details of this feature as well
as for guidelines on how to select the right value of external
R-C to tune the module for best transient performance and
stable operation for other output capacitance values.
VS+
MODULE
SIG_GND
TRIM
VOUT
RTune
CTune
RTrim
CO
GND