LT3383 PIN FUNCTIONS FB_B3 (Pin 25): Feedback Input for Step-Down Switching EN_B3 (Pin 34): Enable Step-Down Switching Regulator 3. Regulator 3. Set output voltage using resistor divider con- Active high input enables step-down switching regulator 3. nected from the output of step-down switching regulator A weak pull-down pulls EN_B3 low when left floating. 3 to this pin to ground. PVIN3 (Pin 35): Power Input for Step-Down Switching GND (Pin 26): Ground. Regulator 3. Tie this pin to VIN supply. This pin should V be bypassed to ground with a 10μF or greater ceramic IN (Pin 27): Supply Voltage Input. This pin should be bypassed to ground with a 1μF or greater ceramic capaci- capacitor. tor. All switching regulator PVIN supplies should be tied PVIN4 (Pin 36): Power Input for Step-Down Switching to VIN. Regulator 4. Tie this pin to VIN supply. This pin should GND (Pin 28): Ground. be bypassed to ground with a 10μF or greater ceramic capacitor. GND (Pin 29): Ground. EN_B4 (Pin 37): Enable Step-Down Switching Regulator 4. EN_L2 (Pin 30): Enable LDO2 Input. Active high enables Active high enables step-down switching regulator 4. A LDO2. A weak pul -down pul s EN_L2 low when left week pull-down pulls EN_B4 low when left floating. floating. GND (Pin 38): Ground. SW3 (Pin 31): Switch Pin for Step-Down Switching Regulator 3. Connect one side of step-down switching PGOOD (Pin 39): Power Good Output. Open-drain output regulator 3 inductor to this pin. pulls low when any enabled regulator falls below power good threshold. Pulls low when all regulators are disabled. GND (Pin 32): Ground. SW4 (Pin 40): Switch Pin for Step-Down Switching GND (Pin 33): Ground. Regulator 4. Connect one side of step-down switching regulator 4 inductor to this pin. GND (Exposed Pad Pin 41): Ground. The exposed pad must be connected to a continuous ground plane of the printed circuit board by multiple interconnect vias directly under the LT3383 to maximize electrical and thermal conduction. Rev. 0 10 For more information www.analog.com Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Introduction Step-Down Switching Regulators Power On Sequencing Fault Detection and Reporting Applications Information Thermal Considerations and Board Layout Typical Applications Package Description Typical Application Related Parts
