LTC1735
U
U
U
PI FU CTIO S
VOSENSE: Receives the feedback voltage from an external
INTVCC: Output of the Internal 5.2V Regulator and EXTVCC
Switch. The driver and control circuits are powered from
thisvoltage.Decoupletopowergroundwitha1µFceramic
capacitor placed directly adjacent to the IC together with a
minimum of 4.7µF tantalum or other low ESR capacitor.
resistive divider across the output.
SENSE– : The (–) Input to the Current Comparator.
SENSE+: The (+) Input to the Current Comparator. Built-in
offsets between SENSE– and SENSE+ pins in conjunction
with RSENSE set the current trip threshold.
VIN: Main Supply Pin. Must be closely decoupled to power
ground.
PGOOD (LTC1735F Only): Open-Drain Logic Output.
SW: Switch Node Connection to Inductor and Bootstrap
Capacitor. Voltage swing at this pin is from a Schottky
diode (external) voltage drop below ground to VIN.
PGOOD is pulled to ground when the voltage on the
V
OSENSE pin is not within ±7.5% of its set point.
EXTVCC:InputtotheInternalSwitchConnectedtoINTVCC.
This switch closes and supplies VCC power whenever
EXTVCC is higher than 4.7V. See EXTVCC connection in the
Applications Information section. Do not exceed 7V on
this pin and ensure EXTVCC ≤ VIN.
BOOST: Supply to Topside Floating Driver. The bootstrap
capacitor is returned to this pin. Voltage swing at this pin
is from a diode drop below INTVCC to (VIN + INTVCC).
TG: High Current Gate Drive for Top N-Channel MOSFET.
This is the output of a floating driver with a voltage swing
equal to INTVCC superimposed on the switch node voltage
SW.
PGND: Driver Power Ground. Connects to the source of
bottom N-channel MOSFET, the anode of the Schottky
diode, and the (–) terminal of CIN.
BG: High Current Gate Drive for Bottom
N-Channel MOSFET. Voltage swing at this pin is from
ground to INTVCC.
1735fc
8
Linear [ Linear ]
