Data Sheet
12V Pico TLynxTM 6A: Non-isolated DC-DC Power Modules
4.5 – 14Vdc input; 0.59Vdc to 5.5Vdc output; 6A output current
November 22, 2010
Power Good
MODULE
VIN+
The 12V Pico TLynxTM 6A modules provide a Power
Good (PGOOD) signal that is implemented with an
open-drain output to indicate that the output voltage is
within the regulation limits of the power module. The
PGOOD signal will be de-asserted to a low state if any
condition such as overtemperature, overcurrent or loss
of regulation occurs that would result in the output
voltage going ±10% outside the setpoint value. The
PGOOD terminal should be connected through a
pullup resistor (suggested value 100KΩ) to a source of
5VDC or lower.
499K
+
-
OUT
R1
SEQ
10K
Tunable LoopTM
GND
Figure 47. Circuit showing connection of the
sequencing signal to the SEQ pin.
The 12V Pico TLynxTM 6A modules have a new feature
that optimizes transient response of the module called
Tunable LoopTM
.
After the 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 the
output reaches the set-point voltage. 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.
When using the EZ-SEQUENCETM feature to control
start-up of the module, pre-bias immunity 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 the voltage at the SEQ pin is applied. This
will result in the module sinking current if a 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 the EZ-SEQUENCETM
feature please refer to Application Note AN04-008
“Application Guidelines for Non-Isolated Converters:
Guidelines for Sequencing of Multiple Modules”, or
contact the Lineage Power technical representative for
additional information.
External capacitors are usually added to the output of
the module for two reasons: to reduce output ripple
and noise (see Fig. 41) 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 SENSE and TRIM pins of the
module, as shown in Fig. 48. This R-C allows the user
to externally adjust the voltage loop feedback
compensation of the module.
VOUT
SENSE
RTUNE
C O
MODULE
CTUNE
TRIM
RTrim
GND
Figure. 48. Circuit diagram showing connection of
RTUME and CTUNE to tune the control loop of the
module.
LINEAGE POWER
16
LINEAGEPOWER [ LINEAGE POWER CORPORATION ]
