LTC3541-3 PIN FUNCTIONS VIN (Pin 1): Main Supply Pin. This pin must be closely SW (Pin 10): Switch Node Pin. This pin connects the decoupled to GND with a 10µF or greater capacitor. internal main and synchronous power MOSFET switches ENBUCK (Pin 2): Buck Enable Pin. This pin enables the to the external inductor for the buck regulator. buck regulator when driven to a logic high. Exposed Pad (Pin 11): Ground Pin. This pin must be V soldered to the PCB to provide both electrical contact to OUT (Pin 3): Buck Regulator Output Pin. This pin receives the buck regulator’s output voltage. ground and good thermal contact to the PCB. NC (Pin 4): Not Connected. This pin must not be connected Note: Table 1 details the truth table for the control pins or capacitively loaded. of the LTC3541-3. LVOUT (Pin 5): VLDO/Linear Regulator Output Pin. This Table 1. LTC3541-3 Control Truth Table pin provides the regulated output voltage from the VLDO PIN NAME or linear regulator. ENBUCK ENVLDO MODE OPERATIONAL DESCRIPTIONLVIN (Pin 6): VLDO/Linear Regulator Input Supply Pin. 0 0 X LTC3541-3 Powered Down This pin provides the input supply voltage for the VLDO 0 1 X Buck Powered Down, VLDO Powered power FET. Down, Linear Regulator Enabled 1 0 0 Buck Enabled, VLDO Powered Down, GND (Pin 7): Analog Ground Pin. Linear Regulator Powered Down, Burst Mode Operation MODE (Pin 8): Buck Mode Selection Pin. This pin enables 1 0 1 Buck Enabled, VLDO Powered Down, buck Pulse-Skip operation when driven to a logic high Linear Regulator Powered Down, and enables buck Burst Mode operation when driven to Pulse-Skip Mode a logic low. 1 1 0 Buck Enabled, VLDO Enabled, Linear Regulator Powered Down, Burst Mode ENVLDO (Pin 9): VLDO/Linear Regulator Enable Pin. Operation When driven to a logic high, this pin enables the linear 1 1 1 Buck Enabled, VLDO Enabled, Linear Regulator Powered Down, Pulse-Skip regulator when the ENBUCK pin is driven to a logic low, Mode and enables the VLDO regulator when the ENBUCK pin is driven to a logic high. 35413fd 8 For more information www.linear.com/LTC3541-3 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Package Description Revision History Related Parts