Datasheet LTC3890-1 (Analog Devices) - 9

LTC3890-1
PIN FUNCTIONS BG1, BG2 (Pin 23, Pin 18):
High Current Gate Drives
PGOOD1 (Pin 27):
Open-Drain Logic Output. PGOOD1 is for Bottom (Synchronous) N-Channel MOSFETs. Voltage pulled to ground when the voltage on the VFB1 pin is not swing at these pins is from ground to INTVCC. within ±10% of its set point.
BOOST1, BOOST2 (Pin 24, Pin 17):
Bootstrapped Supplies
TRACK/SS1, TRACK/SS2 (Pin 28, Pin 14):
External Track- to the Topside Floating Drivers. Capacitors are connected ing and Soft-Start Input. The LTC3890-1 regulates the between the BOOST and SW pins and Schottky diodes are VFB1,2 voltage to the smaller of 0.8V or the voltage on the tied between the BOOST and INTVCC pins. Voltage swing TRACK/SS1,2 pin. An internal 1µA pull-up current source at the BOOST pins is from INTVCC to (VIN + INTVCC). is connected to this pin. A capacitor to ground at this
SW1, SW2 (Pin 25, Pin 16):
Switch Node Connections pin sets the ramp time to final regulated output voltage. to Inductors. Alternatively, a resistor divider on another voltage supply connected to this pin allows the LTC3890-1 output to track
TG1, TG2 (Pin 26, Pin 15):
High Current Gate Drives for the other supply during start-up. Top N-Channel MOSFETs. These are the outputs of float- ing drivers with a voltage swing equal to INTVCC – 0.5V superimposed on the switch node voltage SW. 38901fb 9 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts