Data Sheet
October 1, 2009
Austin SuperLynxTM II 12V SMT Non-isolated Power Modules:
8.3 – 14Vdc Input; 0.75Vdc to 5.5Vdc Output;16A output current
LINEAGE POWER 14
Feature Descriptions (continued)
Voltage Sequencing
Austin SuperLynxTM II 12V series of modules include a
sequencing feature, EZ-SEQUENCETM 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 VIN 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 VIN 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 to ensure a controlled
shutdown of the modules.
When using the EZ-SEQUENCETM 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-
SEQUENCETM 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-SEQUENCETM feature must be
disabled. For additional guidelines on using EZ-
SEQUENCETM feature of Austin SuperLynxTM II 12V,
contact Lineage Power technical representative for
preliminary application note on output voltage
sequencing using Austin Lynx II series.
Remote Sense
The Austin SuperLynxTM II 12V SMT 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 31). 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.
VO
COM
VIN(+)
COM
RLOAD
Rcontact Rdistribution
Rcontact Rdistribution
Rcontact
Rcontact
Rdistribution
Rdistribution
Sense
Figure 31. Remote sense circuit configuration.