LT3048 Series PIN FUNCTIONS LT3048LT3048-XXSW (Pin 1): Boost Regulator Switch Node. This is the SW (Pin 1): Boost Regulator Switch Node. This is the collector of the internal power transistor and the anode collector of the internal power transistor and the anode of the internal Schottky diode. of the internal Schottky diode. VIN (Pin 2): Input Supply. Provides operating current to VIN (Pin 2): Input Supply. Provides operating current to the boost regulator. Bypass to ground. the boost regulator. Bypass to ground. GND (Pin 3): Ground. This pin must be soldered to PCB GND (Pin 3): Ground. This pin must be soldered to PCB ground. The exposed pad must also be soldered to PCB ground. The exposed pad must also be soldered to PCB ground. ground. BYP (Pin 4): Bypass. Add an optional capacitor from BYP (Pin 4): Bypass. Add an optional capacitor from LDOOUT to BYP to reduce noise at LDOOUT; otherwise LDOOUT to BYP to reduce noise at LDOOUT; otherwise leave BYP unconnected. A capacitor also soft-starts the leave BYP unconnected. A capacitor also soft-starts the linear regulator. linear regulator. FB (Pin 5): The LT3048 regulates the FB pin to 1.235V. LDOOUT (Pin 5): LDO Linear Regulator Output. This pin Connect the feedback resistor divider tap to this pin. is regulated to a fixed voltage. Bypass to ground with a LDOOUT (Pin 6): LDO Linear Regulator Output. This pin minimum of 1μF. is programmed by the feedback resistor divider. Bypass LDOIN (Pin 6): LDO Linear Regulator Input. Normally to ground with a minimum of 1μF. connected to BSTOUT. Bypass to ground. EN (Pin 7): Enable. Logic input to enable the boost and EN (Pin 7): Enable. Logic input to enable the boost and linear regulator. linear regulator. BSTOUT (Pin 8): Boost Regulator Output. This pin is con- BSTOUT (Pin 8): Boost Regulator Output. This pin is con- nected to the internal Schottky diode and is regulated to nected to the internal Schottky diode and is regulated to 1.1V above LDOOUT. Bypass to ground. 1.1V above LDOOUT. Bypass to ground. GND (Exposed Pad Pin 9): The internal boost power switch GND (Exposed Pad Pin 9): The internal boost power switch is connected to the exposed pad. Tie to ground. is connected to the exposed pad. Tie to ground. Rev B 8 For more information www.analog.com Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions LT3048 LT3048-xx LT3048 Block Diagrams Operation Applications Information Package Description Revision History Related Parts