Datasheet

20050 SW 112
th
Ave. Tualatin, Oregon 97062 phone [phone] fax [phone]
rev.
page
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rev.
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DESCRIPTION: point of load converter
5 of 12
08/2007
PART NUMBER: VPOL5A-12-SIP
5. Main Features and Functions
5.1 Operating Temperature Range
CUI INC’s VPOL5A-12-SIP series converters highly efficient converter
design has resulted in its ability to operate over a wide ambient
temperature environment ( -40°C to 85°C). Due consideration must be
given to the de-rating curves when ascertaining maximum power that
can be drawn from the converter. The maximum power drawn is
influenced by a number of factors, such as:
Input voltage range.
Output load current.
Air velocity (forced or natural convection).
Mounting orientation of converter PCB with respect to the Airflow.
Motherboard PCB design, especially ground and power planes.
These can be effective heat sinks for the converter.
5.2 Over-Temperature Protection (OTP)
The VPOL5A-12-SIP Series converters are equipped with non-latching
over-temperature protection. A te mperature sensor monitors the
temperature of the hot spot (typically, top switch). If the temperature
exceeds a threshold of 120°C (t ypical) the converter will shut down,
disabling the output. When the temperature has decreased the
converter
will automatically restart.
The over-temperature condition can be induced by a variety of reasons
such as external overload condition or a system fan failure.
5.3 Output Voltage Adjustment
Section 7.8 describes in detail as to how to trim the output voltage with
respect to its set point. The output voltage on all models is trimmable in
the range 0.75 – 5.0Vdc.
5.4 Safe Operating Area (SOA)
Figure 2 provides a graphical representation of the Safe Operating Area
(SOA) of the converter. This representation assumes ambient
operating conditions such as airflow are met as per thermal guidelines
provided in Sections 7.2 and 7.3.
Vo
IoIo,CLIo,max
Vo,nom
Safe Operating Area
CURRENT (A)
VOLTAGE (V)
Figure 2. Maximum Output Current Safe Operating Area
5.5 Over Current Protection
All different voltage models have a full continuous short-circuit
protection. The unit will auto recover once the short circuit is removed.
To provide protection in a fault condition, the unit is equipped with
internal over-current protection. The unit operates normally once the
fault condition is removed. The power module will supply up to 150% of
rated current. In the event of an over current converter will go into a
hiccup mode protection.
5.6 Remote ON/OFF
The remote ON/OFF input feature of the converter allows external
circuitry to turn the converter ON or OFF. Active-high remote ON/OFF
is available as standard. The VPOL5A-12-SIP series converters are
turned on if the remote ON/OFF pin is high, or left open or floating.
Setting the pin low will turn the converter ‘
Off’. The signal le
vel of the
remote on/off input is defined with respect to ground. If not using the
remote on/off pin, leave the pin open (module will be on). The part
number suffix “N” is Negative remote ON/OFF version. The unit is
guaranteed OFF over the full temperature range if this voltage level
exceeds 2.8Vdc. The converters are turned on If the on/off pin input is
low or left open. The recommended VPOL5A-12-SIP remote on/off
drive circuit as shown as figure 3, 4.
For more information, please visit the product page.