VESTEL 17MB12, Service Manual

Page: 33 / 64

Pin4:GND
Ground.
Pin5:FB
Feedback Input. FB senses the output voltage to regulate that voltage. Drive FB with a
resistive voltage divider from the output voltage. The feedback threshold is 1.222V.
Pin6:COMP
Compensation Node. COMP is used to compensate the regulation control loop. Connect
a series RC network from COMP to GND to compensate the regulation control loop. In
some cases, an additional capacitor from COMP to GND is required.
Pin7:EN
Enable Input. EN is a digital input that turns the regulator on or off. Drive EN high to turn
on the regulator, drive EN low to turn it off. An Under Voltage Lockout (UVLO) function
can be implemented by the addition of a resistor divider from VIN to GND. For complete
low current shutdown its needs to be less than 0.7V. For automatic startup, leave EN
unconnected.
Pin8:SS
Soft-Start Control Input. SS controls the soft-start period. Connect a capacitor from SS
to GND to set the soft-start period. A 0.1
μ F capacitor sets the soft-start period to 10ms.
To disable the soft-start feature, leave SS unconnected.
15.4 FDC642P
15.4.1 General Description
This p-channel 2.5V specified MOSFET is produced using Fairchild’s advanced
PowerTrench process that has been especially tailored to minimize on state resistance
and yet maintain low gate charge for superior switching performance.
15.4.2 Features
15.4.3 Absolute Maximum Ratings