LT3710
U
U
U
PI FU CTIO S
BOOST (Pin 1): Topside (Boosted) Driver Supply. This pin
is used to bootstrap and supply the topside power switch
gate drive circuitry. In normal operation VBOOST is powered
from the internally generated 8V GBIAS, VBOOST = VSW
8.2V when TGATE is on.
BGS (Pin 9): Bottom Gate Switching Control. CA2 moni-
tors the inductor current and prohibits BGATE from turn-
ingonwhentheinductorcurrentislow(below8mVacross
the current sense resistor RS1) to allow discontinous
mode operation. Grounding this pin disables comparator
CA2.
+
TGATE (Pin 2): Topside (Boosted) N-Channel MOSFET
Driver.WhenTGATEison,thevoltageisequaltoVSW +6V.
VAOUT (Pin 10): Voltage Amplifier Output.
SW (Pin 3): Switch Node Connection to Inductor.
CL+ (Pin 11): Current Limit Amplifier Positive Input. The
threshold is set at 70mV.
CSET (Pin 4): Oscillator Timing Pin. The capacitor on this
pin sets the PWM switching frequency.
CL– (Pin 12): Current Limit Amplifier Negative Input.
When used, CL– is connected to the output capacitor side
of the current + sense resistor and CL+ is connected to the
inductor side of the current sense resistor.
SYNC (Pin 5): Synchronization Input. This pin should be
connected to the secondary side output of the power
transformer with a series resistor. A filtering capacitor of
10pF is recommended.
VCC (Pin13): SupplyoftheIC. Forproperbypassing, alow
ESR capacitor is required.
ILCOMP (Pin 6): Current Limit Amplifier Compensation
Node. At current limit, CA1 pulls down on this pin to
regulate the output current.
PGND (Pin 14): Ground of the Bottom Side N-Channel
MOSFET Driver.
SS (Pin 7): Soft-Start. A capacitor on this pin sets the
output ramp up rate. The typical time for SS to reach the
programmed level is (C • 0.8V)/10µA.
BGATE (Pin 15): Bottom Side N-Channel MOSFET Driver.
GBIAS (Pin 16): 8V Regulator Output for Boostrapping
VBOOST . A bypass capacitor of at least 2µF is needed.
VFB (Pin 8): Voltage Amplifier Inverting Input. A resistor
divider to this pin sets the output voltage. Nominal voltage
at this pin is 0.8V.
Exposed Pad (Pin 17): Connect to PGND (Pin 14).
3710f
5
Linear [ Linear ]
