LTC3826-1 Datasheet, PDF (8/32 Pages) Linear Technology – 30μA IQ, Dual, 2-Phase Synchronous Step-Down Controller

LTC3826-1
PIN FUNCTIONS
RUN1, RUN2 (Pins 8, 9): Digital Run Control Inputs for
Each Controller. Forcing either of these pins below 0.7V
shuts down that controller. Forcing both of these pins
below 0.7V shuts down the entire LTC3826-1, reducing
quiescent current to approximately 4μA.
INTV_CC (Pin 19): Output of the Internal Linear Low Dropout
Regulator. The driver and control circuits are powered
from this voltage source. Must be decoupled to power
ground with a minimum of 4.7μF tantalum or other low
ESR capacitor.
EXTV_CC (Pin 20): External Power Input to an Internal LDO
Connected to INTV_CC. This LDO supplies INTV_CC power,
bypassing the internal LDO powered from V_IN whenever
EXTV_CC is higher than 4.7V. See EXTV_CC Connection in
the Applications Information section. Do not exceed 10V
on this pin.
PGND (Pin 21): Driver Power Ground. Connects to the sources
of bottom (synchronous) N-channel MOSFETs, anodes of
the Schottky rectifiers and the (–) terminal(s) of C_IN.
V_IN (Pin 22): Main Supply Pin. A bypass capacitor should
be tied between this pin and the signal ground pin.
BG1, BG2 (Pins 23, 18): High Current Gate Drives for Bot-
tom (Synchronous) N-Channel MOSFETs. Voltage swing
at these pins is from ground to INTV_CC.
BOOST1, BOOST2 (Pins 24, 17): Bootstrapped Supplies
to the Topside Floating Drivers. Capacitors are connected
between the BOOST and SW pins and Schottky diodes are
tied between the BOOST and INTV_CC pins. Voltage swing
at the BOOST pins is from INTV_CC to (V_IN + INTV_CC).
SW1, SW2 (Pins 25, 16): Switch Node Connections to
Inductors. Voltage swing at these pins is from a Schottky
diode (external) voltage drop below ground to V_IN.
TG1, TG2 (Pins 26, 15): High Current Gate Drives for
Top N-Channel MOSFETs. These are the outputs of float-
ing drivers with a voltage swing equal to INTV_CC – 0.5V
superimposed on the switch node voltage SW.
PGOOD1 (Pin 27): Open-Drain Logic Output. PGOOD1 is
pulled to ground when the voltage on the V_FB1 pin is not
within ±10% of its set point.
TRACK/SS1, TRACK/SS2 (Pins 28, 14): External Track-
ing and Soft-Start Input. The LTC3826-1 regulates the
V_FB1,2 voltage to the smaller of 0.8V or the voltage on the
TRACK/SS1,2 pin. A internal 1μA pull-up current source
is connected to this pin. A capacitor to ground at this
pin sets the ramp time to final regulated output voltage.
Alternatively, a resistor divider on another voltage supply
connected to this pin allows the LTC3826-1 output to track
the other supply during startup.
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