VIPer01
Pin setting
1
Pin setting
Figure 2: Connection diagram
Table 1: Pin description
Function
SSOP10 Name
Ground and MOSFET source. Connection of source of the internal MOSFET
and the return of the bias current of the device. All groundings of bias
components must be tied to a trace going to this pin and kept separate from the
pulsed current return.
1
GND
Controller supply. An external storage capacitor has to be connected across
this pin and GND. The pin, internally connected to the high voltage current
source, provides the VCC capacitor charging current at startup and during
steady-state operation, if the self-supply mode is selected. A small bypass
capacitor (0.1 μF typ.) in parallel, placed as close as possible to the IC, is also
recommended, for noise filtering purpose.
2
VCC
Disable. If its voltage exceeds the internal threshold VDIS_th (1.2 V typ.) for more
than tDEB time (1 ms, typ.), the PWM is disabled in auto-restart mode. An input
overvoltage protection can be built by connecting a voltage divider between DIS
pin and the rectified mains. In case of non-isolated topologies, with the same
principle an output overvoltage protection can be implemented. If the disable
function is not required, DIS pin must be soldered to GND, which excludes the
function.
3
DIS
FB
Direct feedback. It is the inverting input of the internal transconductance E/A,
which is internally referenced to 1.2 V with respect to GND. In case of non-
isolated converter, the output voltage information is directly fed into the pin
through a voltage divider. In case of primary regulation, the FB voltage divider is
connected to the VCC. The E/A is disabled soldering FB to GND.
4
5
Compensation. It is the output of the internal E/A. A compensation network is
placed between this pin and GND to achieve stability and good dynamic
COMP performance of the control loop. In case of secondary feedback, the internal E/A
must be disabled and the COMP directly driven by the optocoupler to control the
DRAIN peak current setpoint.
MOSFET drain. The internal high voltage current source sinks current from this
pin to charge the VCC capacitor at startup and during steady-state operation.
These pins are mechanically connected to the internal metal PAD of the
MOSFET in order to facilitate heat dissipation. On the PCB, copper area must
6 to 10
DRAIN
be placed under these pins in order to decrease the total junction-to-ambient
thermal resistance thus facilitating the power dissipation.
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