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. SEQ pin not provided in -73Z
codes.
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 GE technical
representative for preliminary application note on output
voltage sequencing using Austin Lynx II series.
Remote Sense
The Austin SuperLynxTM II 12V 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 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.