Datasheet LT3383 (Analog Devices) - 9

LT3383
PIN FUNCTIONS FB_L2 (Pin 1):
Feedback Input for LDO2. Set output volt-
GND (Pin 12):
Ground age using a resistor divider connected from LDO2 to this
GND (Pin 13):
Ground pin to ground.
GND (Pin 14):
Ground
VIN_L2 (Pin 2):
Power Input for LDO2. This pin should be bypassed to ground with a 1μF or greater ceramic
PVIN1 (Pin 15):
Power Input for Step-Down Switching capacitor. Voltage on VIN_L2 should not exceed voltage Regulator 1. Tie this pin to VIN supply. This pin should on VIN pin. be bypassed to ground with a 10μF or greater ceramic capacitor.
LDO2 (Pin 3):
Output Voltage of LDO2. Nominal output voltage is set with a resistor feedback divider that servos
PVIN2 (Pin 16):
Power Input for Step-Down Switching to a fixed 725mV reference. This pin must be bypassed to Regulator 2. Tie this pin to the VIN supply. This pin should ground with a 1µF or greater ceramic capacitor. be bypassed to ground with a 10μF or greater ceramic capacitor.
LDO3 (Pin 4):
Output Voltage of LDO3. Nominal output voltage is a fixed 1.8V. This pin must be bypassed to
EN_B1 (Pin 17):
Enable Step-Down Switching Regulator 1. ground with a 1µF or greater ceramic capacitor. Active high input enables step-down switching regulator 1. A weak pull-down pulls EN_B1 low when left floating.
VIN_L3 (Pin 5):
Power Input for LDO3. This pin should be bypassed to ground with a 1µF or greater ceramic
EN_B2 (Pin 18):
Enable Step-Down Switching Regulator 2. capacitor. Voltage on VIN_L3 should not exceed voltage Active high input enables step-down switching regulator 2. on VIN pin. A weak pull-down pulls EN_B2 low when left floating.
LDO1 (Pin 6):
Output Voltage of LDO1. Nominal output
GND (Pin 19):
Ground. voltage is set with a resistor feedback divider that servos
SW2 (Pin 20):
Switch Pin for Step-Down Switching to a fixed 725mV reference. This pin must be bypassed to Regulator 2. Connect one side of step-down switching ground with a 1µF or greater ceramic capacitor. regulator 2 inductor to this pin.
VIN_L1 (Pin 7):
Power Input for LDO1. This pin should
PWR_ON (Pin 21):
Power On. PWR_ON is a master be bypassed to ground with a 1μF or greater ceramic enable and disable input. When low, PWR_ON inhibits capacitor. Voltage on VIN_L1 should not exceed voltage the regulator enable pins. When high, PWR_ON allows on VIN pin. enable pin operation.
FB_L1 (Pin 8):
Feedback Input for LDO1. Set output volt-
FB_B2 (Pin 22):
Feedback Input for Step-Down Switching age using a resistor divider connected from LDO1 to this Regulator 2. Set output voltage using resistor divider con- pin to ground. nected from the output of step-down switching regulator
EN_L1 (Pin 9):
Enable LDO1 Input. Active high enables 2 to this pin to ground. LDO1. A weak pul -down pul s EN_L1 low when left
FB_B1 (Pin 23):
Feedback Input for Step-Down Switching floating. Regulator 1. Set output voltage using resistor divider con-
EN_L3 (Pin 10):
Enable LDO3 Input. Active high enables nected from the output of step-down switching regulator LDO3. A weak pul -down pul s EN_L3 low when left 1 to this pin to ground. floating.
FB_B4 (Pin 24):
Feedback Input for Step-Down Switching
SW1 (Pin 11):
Switch Pin for Step-Down Switching Regulator 4. Set output voltage using resistor divider con- Regulator 1. Connect one side of step-down switching nected from the output of step-down switching regulator regulator 1 inductor to this pin. 4 to this pin to ground. Rev. 0 For more information www.analog.com 9 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