Obsolete Product(s) - Obsolete Product(s)
VIPer100/SP - VIPer100A/ASP
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Table 5. Ordering Numbers
Pins Functional Description
Drain Pin (Integrated Power MOSFET Drain):
Integrated Power MOSFET drain pin. It provides internal bias current during start-up via an integrated
high voltage current source which is switched off during normal operation. The device is able to handle
an unclamped current during its normal operation, assuring self protection against voltage surges, PCB
stray inductance, and allowing a snubberless operation for low output power.
Suorce Pin:
Power MOSFET source pin. Primary side circuit common ground connection.
V
DD
Pin (Power Supply):
This pin provides two functions :
■ It corresponds to the low voltage supply of the control part of the circuit. If V
DD
goes below 8V, the start-
up current source is activated and the output power MOSFET is switched off until the V
DD
voltage
reaches 11V. During this phase, the internal current consumption is reduced, the V
DD
pin is sourcing
a current of about 2mA and the COMP pin is shorted to ground. After that, the current source is shut
down, and the device tries to start up by switching again.
■ This pin is also connected to the error amplifier, in order to allow primary as well as secondary
regulation configurations. In case of primary regulation, an internal 13V trimmed reference voltage is
used to maintain V
DD
at 13V. For secondary regulation, a voltage between 8.5V and 12.5V will be put
on V
DD
pin by transformer design, in order to stuck the output of the transconductance amplifier to the
high state. The COMP pin behaves as a constant current source, and can easily be connected to the
output of an optocoupler. Note that any overvoltage due to regulation loop failure is still detected by the
error amplifier through the V
DD
voltage, which cannot overpass 13V. The output voltage will be
somewhat higher than the nominal one, but still under control.
Compensation Pin
This pin provides two functions :
■ It is the output of the error transconductance amplifier, and allows for the connection of a compensation
network to provide the desired transfer function of the regulation loop. Its bandwidth can be easily
adjusted to the needed value with usual components value. As stated above, secondary regulation
configurations are also implemented through the COMP pin.
■ When the COMP voltage is going below 0.5V, the shut-down of the circuit occurs, with a zero duty cycle
for the power MOSFET. This feature can be used to switch off the converter, and is automatically
activated by the regulation loop (no matter what the configuration is) to provide a burst mode operation
in case of negligible output power or open load condition.
OSC Pin (Oscillator Frequency):
An R
t
-C
t
network must be connected on that to define the switching frequency. Note that despite the
connection of R
t
to V
DD
, no significant frequency change occurs for V
DD
varying from 8V to 15V. It
provides also a synchronisation capability, when connected to an external frequency source.
PENTAWATT HV PENTAWATT HV (022Y)
VIPer100
VIPer100A
VIPer100 (022Y)
VIPer100A (022Y)