LTC3816_15 Datasheet, PDF (13/44 Pages) Linear Technology – Single-Phase Wide VIN Range DC/DC Controller for Intel IMVP-6/IMVP-6.5 CPUs

LTC3816
Pin Functions (eTSSOP/QFN)
SW (Pin 32/Pin 29): Switching Node. Connect SW to the
source of the upper power MOSFET and to the negative
terminal of the BOOST pin decoupling capacitor.
PWRGD (Pin 33/Pin 30): Open-Drain Power Good Out-
put/Power Bad Latchoff Input. PWRGD is an open-drain
output pin and can be connected to other open-drain
outputs to implement wire-ORing. PWRGD is externally
pulled high 10ms after the output regulates. After start-up,
if a fault condition causes PWRGD to go low, or PWRGD
is externally pulled low, the regulator output voltage is
actively ramped to 0V and PWRGD remains latched low
until either the power is cycled or VR_ON toggles. PWRGD
has a 750µs de-glitch delay and is masked for 100µs after
the VID code changes. In deeper sleep mode, the PWRGD
comparators are disabled and not allowed to de-assert
the PWRGD pin.
CLKEN# (Pin 34/Pin 31): Open-Drain Clock Enable Indica-
tor. 75µs after V_CC(CORE) reaches the V_BOOT voltage, CLKEN#
pulls low to enable the processor phase-locked loop.
VRTT# (Pin 35/Pin 32): Open-Drain Output for Voltage
Regulator Thermal Throttling. The VRTT# pin pulls low if
the RPTC voltage exceeds 0.47V or if the control IC junc-
tion temperature exceeds 150°C.
LFF (Pin 36/Pin 33): Line Feedforward. This pin has a
1µA pull-up current source to INTV_CC. Floating this pin
or connecting it to INTV_CC enables the line feedforward
compensation. Connect this pin to GND to disable the line
feedforward compensation.
I_SENP (Pin 37/Pin 34): Current Sense Positive Input. Con-
nect this pin to the positive terminal of the current sense
resistor or to the output of the inductor DCR lowpass
filter.
I_MAX (Pin 38/Pin 35): Current Comparator Threshold Set-
ting. The I_MAX pin has an internal 10µA pull-up current
source, allowing the current limit comparator threshold to
be programmed by a single external resistor. The control-
ler allows a momentary 45µs overcurrent event to occur
within a period of 630µs. See Current Sense and Current
Limit in Applications Information.
GND (Exposed Pad Pin 39/Exposed Pad Pin 39): Ground.
The soft-start and slew rate control capacitors as well as
the frequency setting and thermal shutdown resistors
should return to this exposed pad ground pin. This GND
pin should also be connected to the negative terminals of
the local voltage regulator output capacitors through vias
to the PCB ground plane.
3816f
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