Datasheet LTC3810 (Analog Devices) - 10

LTC3810
PIN FUNCTIONS BG (Pin 19):
Bottom Gate Drive. The BG pin drives the
SW (Pin 26):
Switch Node Connection to Inductor and gate of the bottom N-channel synchronous switch MOSFET. Bootstrap Capacitor. Voltage swing at this pin is from a This pin swings from BGRTN to DRVCC. Schottky diode (external) voltage drop below ground to V
BGRTN (Pin 20):
Bottom Gate Return. This pin connects to IN. the source of the pull-down MOSFET in the BG driver and
TG (Pin 27):
Top Gate Drive. The TG pin drives the gate of is normally connected to ground. Connecting a negative the top N-channel synchronous switch MOSFET. The TG supply to this pin allows the synchronous MOSFET ’s gate driver draws power from the BOOST pin and returns to the to be pulled below ground to help prevent false turn-on SW pin, providing true fl oating drive to the top MOSFET. during high dV/dt transitions on the SW node. See the
BOOST (Pin 28):
Top Gate Driver Supply. The BOOST pin Applications Information section for more details. supplies power to the fl oating TG driver. BOOST should
SENSE+, SENSE– (Pin 25, Pin 21):
Current Sense Com- be bypassed to SW with a low ESR (X5R or better) 0.1μF parator Input. The (+) input to the current comparator is capacitor. An additional fast recovery Schottky diode from normally connected to SW unless using a sense resistor. DRVCC to the BOOST pin will create a complete fl oating The (–) input is used to accurately kelvin sense the bottom charge-pumped supply at BOOST. side of the sense resistor or MOSFET. 3810fc 10