LTC3829 Datasheet, PDF (10/40 Pages) Linear Technology – 3-Phase, Single Output Synchronous Step-Down DC/DC Controller with Diffamp

LTC3829
Pin Functions (UHF/FE)
BOOST1, BOOST2, BOOST3 (Pins 33, 26, 19/Pins 35,
28, 21): Boosted Floating Driver Supplies. The (+) terminal
of the bootstrap capacitors connect to these pins. These
pins swing from a diode voltage drop below INTV_CC up
to V_IN + INTV_CC.
CLKOUT (Pin 34/Pin 36): Clock Output Pin. CLKOUT is
60° out of phase relative to channel 1 in non-shedding
mode. During stage shedding, CLKOUT is 180° out of
phase with channel 1.
MODE (Pin 35/Pin 37): Forced Continuous Mode, Burst
Mode or Shed Mode Selection Pin. Connect this pin to
SGND to force IC in continuous mode of operation. Con-
nect to INTV_CC to enable shed mode operation. Leave the
pin floating to enable Burst Mode operation.
IFAST (Pin 36/Pin 38): Programmable Pin for Nonlinear
Control Trip Threshold. A resistor to ground programs the
tripping threshold for nonlinear control circuit. Connect
this pin to INTV_CC to disable this feature. See Applications
Information section for details.
ITEMP (Pin 37/Pin 1): Input of the Temperature Sensing
Comparator. Connect this pin to external NTC resistors
placed near inductors.
DIFFOUT (Pin 38/Pin 2): Output of Remote Sensing
Differential Amplifier. Connect this pin to V_FB through a
resistive divider.
SGND/PGND (Exposed Pad Pin 39/Exposed Pad Pin 39):
Combined Signal and Power Ground Pad. Connect this pad
closely to the sources of the bottom N-channel MOSFETs,
the (–) terminal of C_VCC and the (–) terminal of C_IN. All
small-signal components and compensation components
should also Kelvin-connect to this pad.
3829f
10