Datasheet

Pin settings VIPER17
4/32 DocID14419 Rev 9
3 Pin settings
Figure 3. Connection diagram (top view)
Note: The copper area for heat dissipation has to be designed under the DRAIN pins.
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Table 3. Pin description
Pin N.
Name Function
DIP-7 SO16
1 1...2 GND This pin represents the device ground and the source of the power section.
-4N.A.
Not available for user. It can be connected to GND (pins 1-2) or left not
connected.
25VDD
Supply voltage of the control section. This pin also provides the charging current
of the external capacitor during start-up time.
3 6 CONT
Control pin. The following functions can be selected:
1. current limit set point adjustment. The internal set default value of the cycle-
by-cycle current limit can be reduced by connecting to ground an external
resistor.
2. output voltage monitoring. A voltage exceeding V
OVP
threshold (see Table 8)
shuts the IC down reducing the device consumption. This function is strobed and
digitally filtered for high noise immunity.
47FB
Control input for duty cycle control. Internal current generator provides bias
current for loop regulation. A voltage below the threshold V
FBbm
activates the
burst-mode operation. A level close to the threshold V
FBlin
means that we are
approaching the cycle-by-cycle over-current set point.
510BR
Brownout protection input with hysteresis. A voltage below the threshold V
BRth
shuts down (not latch) the device and lowers the power consumption. Device
operation restarts as the voltage exceeds the threshold V
BRth
+ V
BRhyst
.
It can be connected to ground when not used.
7,8 13...16 DRAIN
High voltage drain pin. The built-in high voltage switched start-up bias current is
drawn from this pin too. Pins connected to the metal frame to facilitate heat
dissipation.