Data Sheet
Austin MegaLynxTM SMT: Non-Isolated DC-DC Power Modules:
2.7 – 4.0Vdc input; 0.8 to 2.0Vdc Output; 30A output current
October 21, 2009
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
Feature Descriptions
Remote On/Off
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 of the
module.
The ATM030 SMT power modules feature a On/Off
pin for remote On/Off operation. If not using the
On/Off pin, connect the pin to ground (the module
will be ON). The On/Off signal (Von/off) is referenced
to ground. Circuit configuration for remote On/Off
operation of the module using the On/Off pin is
shown in Figure 29.
During a Logic High on the On/Off pin (transistor Q1
is OFF), the module remains OFF. The external
resistor RX should be chosen to maintain 2.5V
minimum on the On/Off pin to ensure that the
module is OFF when transistor Qx is in the OFF
state. A suitable values for RX is 3K for 5Vin.
During Logic-Low when QX is turned ON, the
module is turned ON.
Rdistribution Rcontact
Rcontact Rdistribution
VIN(+)
VO
Sense
RLO AD
Rdistribution Rcontact
Rcontact Rdistribution
CO M
CO M
VIN+
Figure 30. Effective Circuit Configuration for
Remote Sense operation.
MODULE
R1
Thermal SD
Over Current Protection
I
ON/OFF
+
1K
PWM Enable
100K
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. The average
ON/OFF
V
ON/OFF
Q1
10K
GND
_
output current during hiccup is 10% IO, max
.
Figure 29. Remote On/Off Implementation
using ON/OFF .
Over Temperature Protection
To provide protection in a fault condition, the unit is
equipped with a thermal shutdown circuit. The unit
will shutdown if the overtemperature threshold of
125oC is exceeded at the thermal reference point
Tref. The thermal shutdown is not intended as a
guarantee that the unit will survive temperatures
beyond its rating. Once the unit goes into thermal
shutdown it will then wait to cool before attempting
to restart.
The On/Off pin can also be used to synchronize the
output voltage start-up and shutdown of multiple
modules in parallel. By connecting On/Off pins of
multiple modules, the output start-up can be
synchronized (please refer to characterization
curves). When On/Off pins are connected together,
all modules will shutdown if any one of the modules
gets disabled due to undervoltage lockout or over
temperature protection.
Input Under Voltage Lockout
Remote Sense
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.
The ATM030 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 30). The voltage between the Sense
pin and Vo pin must not exceed 0.5V.
LINEAGE POWER
11
LINEAGEPOWER [ LINEAGE POWER CORPORATION ]
