GE Industrial Solutions Austin Lynx II SIP - Manual (Page 14)

Data Sheet
October 2, 2009 Austin Lynx TM II SIP Non-isolated Power Modules:
2.4 – 5.5Vdc input; 0.75Vdc to 3.63Vdc Output; 10A output current
LINEAGE POWER 14
Voltage Sequencing
The Austin Lynx TM II series of modules include a
sequencing feature, EZ-SEQUENCE TM that enables
users to implement various types of output voltage
sequencing in their applications. This is accomplished
via an additional sequencing pin. When not using the
sequencing feature, either tie the SEQ pin to V
IN
or
leave it unconnected.
When an analog voltage is applied to the SEQ pin, the
output voltage tracks this voltage until the output
reaches the set-point voltage. The SEQ voltage must
be set higher than the set-point voltage of the module.
The output voltage follows the voltage on the SEQ pin
on a one-to-one volt basis. By connecting multiple
modules together, customers can get multiple modules
to track their output voltages to the voltage applied on
the SEQ pin.
For proper voltage sequencing, first, input voltage is
applied to the module. The On/Off pin of the module is
left unconnected (or tied to GND for negative logic
modules or tied to V
IN
for positive logic modules) so that
the module is ON by default. After applying input
voltage to the module, a minimum of 10msec delay is
required before applying voltage on the SEQ pin.
During this time, potential of 50mV (± 10 mV) is
maintained on the SEQ pin. After 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 output reaches the set-point
voltage. To initiate simultaneous shutdown of the
modules, the SEQ pin voltage is lowered in a controlled
manner. 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-SEQUENCE
TM feature to control
start-up of the module, pre-bias immunity feature during
start-up 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-
SEQUENCE
TM feature, modules goes through an
internal set-up time of 10msec, and will be in
synchronous rectification mode when voltage at the
SEQ pin is applied. This will result in sinking current in
the module if pre-bias voltage is present at the output of
the module. When pre-bias immunity during start-up is
required, the EZ-SEQUENCE
TM feature must be
disabled. For additional guidelines on using EZ-
SEQUENCE
TM feature of Austin Lynx TM II, contact the
Lineage Power technical representative for preliminary
application note on output voltage sequencing using
Austin Lynx II series.
Remote Sense
The Austin Lynx TM II SIP power modules have a
Remote Sense feature to minimize the effects of
distribution losses by regulating the voltage at the
Remote Sense pin (See Figure 33). The voltage
between the Sense pin and Vo pin must not exceed
0.5V.
The amount of power delivered by the module is defined
as the output voltage multiplied by the output current
(Vo x Io). When using Remote Sense, the output
voltage of the module can increase, which if the same
output is maintained, increases the power output by the
module. Make sure that the maximum output power of
the module remains at or below the maximum rated
power. When the Remote Sense feature is not being
used, connect the Remote Sense pin to output pin of
the module.
V O
C O M
V IN (+ )
C O M
R LO A D
R c ontact R distribution
R c ontact R distribution R contac t
R contac t R distribution
R distribution
S ense
Figure 33. Remote sense circuit configuration.