LTC3620 PIN FUNCTIONSSW (Pin 1): Switch Node Connection to Inductor. This pin NC (Pin 5): No Connect. connects to the internal power MOSFET Switches. VFB (Pin 6): Regulator Feedback Pin. This pin receives GND (Pin 2): Ground Connection for Internal Circuitry and the feedback voltage from the resistive divider across the Power Path Return. Tie directly to local ground plane. output. For the LTC3620-1, this pin must be connected directly to V FMIN/MODE (Pin 3): Frequency Clamp Select Input. Driv- OUT . VOUT is internally divided from VOUT to the reference voltage of 0.6V as seen in the Block Diagram. ing this pin with a 20kHz to 300kHz external clock sets the minimum switching frequency. Pulling this pin low sets RUN (Pin 7): Regulator Enable Pin. Apply a voltage greater the minimum switching frequency to the internally set than 0.8V to enable the regulator. Do not fl oat this pin. 50kHz. Pulling this pin high defeats the minimum switching V frequency and allows the part to switch at arbitrarily low IN (Pin 8): Input Supply Pin. Must be locally bypassed. frequencies dependent on the load current. GND (Exposed Pad Pin 9): Ground. Must be soldered to PCB. LOBATB (Pin 4): Low-Battery Status Output. This open- drain output pulls low when VIN falls below 3V. 3620fa 7 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 APPLICATIONS RELATED PARTS