Datasheet LTC3642 (Analog Devices) - 6

LTC3642
PIN FUNCTIONS SW (Pin 1):
Switch Node Connection to Inductor. This
VOUT/VFB (Pin 6):
Output Voltage Feedback. For the fixed pin connects to the drains of the internal power MOSFET output versions, connect this pin to the output supply. For switches. the adjustable version, an external resistive divider should
V
be used to divide the output voltage down for comparison
IN (Pin 2):
Main Supply Pin. A ceramic bypass capacitor should be tied between this pin and GND (Pin 8). to the 0.8V reference.
I HYST (Pin 7):
Run Hysteresis Open-Drain Logic Output.
SET (Pin 3):
Peak Current Set Input. A resistor from this pin to ground sets the peak current trip threshold. Leave This pin is pulled to ground when RUN (Pin 5) is below floating for the maximum peak current (115mA). Short 1.2V. This pin can be used to adjust the RUN pin hysteresis. this pin to ground for the minimum peak current (25mA). See Applications Information. A 1µA current is sourced out of this pin.
GND (Pin 8, Exposed Pad Pin 9):
Ground. The exposed
SS (Pin 4)
: Soft-Start Control Input. A capacitor to ground pad must be soldered to the printed circuit board ground at this pin sets the ramp time to full current output dur- plane for optimal electrical and thermal performance. ing start-up. A 5µA current is sourced out of this pin. If left floating, the ramp time defaults to an internal 0.75ms soft-start.
RUN (Pin 5):
Run Control Input. A voltage on this pin above 1.2V enables normal operation. Forcing this pin below 0.7V shuts down the LTC3642, reducing quiescent current to approximately 3µA. 3642fc 6 Document Outline FEATURES DESCRIPTION APPLICATIONS TYPICAL APPLICATION ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION ORDER INFORMATION ELECTRICAL CHARACTERISTICS TYPICAL PERFORMANCE CHARACTERISTICS PIN FUNCTIONS BLOCK DIAGRAM OPERATION APPLICATIONS INFORMATION TYPICAL APPLICATIONS PACKAGE DESCRIPTION REVISION HISTORY TYPICAL APPLICATION RELATED PARTS