LTC3600 LINER [Linear Technology], LTC3600 Datasheet - Page 8

• Manufacturer Part Number: LTC3600
• Description: 15V, 1.5A Synchronous Rail-to-Rail Single Resistor
• Manufacturer: LINER [Linear Technology]

PIN FUNCTIONS
LTC3600
ISET (Pin 1): Accurate 50μA Current Source. Positive input
to the error amplifier. Connect an external resistor from this
pin to signal GND to program the V
an external capacitor from ISET to ground will soft start
the output voltage and reduce current inrush when turning
on. V
with an external supply from 0 to V
external supply would be sinking the provided 50μA. Do
not drive V
ITH (Pin 2): Error Amplifier Output and Switching
Regulator Compensation Point. The internal current
comparator’s trip threshold is linearly proportional to
this voltage, whose normal range is from 0.3V to 2.4V.
For external compensation, tie a resistor (R
with a capacitor (C
high frequency filtering capacitor can also be placed
from ITH to signal GND. Tying ITH to INTV
internal compensation.
RT (Pin 3): Switching Frequency Programming Pin. Con-
nect an external resistor (between 100k to 10k) from RT
to SGND to program the frequency from 400kHz to 4MHz.
Tying the RT pin to INTV
Do not float the RT pin.
PGFB (Pin 4): Power Good Feedback. Place a resistor
divider on V
more than 0.645V, or less than 0.555V, PGOOD will be
pulled down. Tie PGFB to INTV
function. Tying PGFB to a voltage greater than 0.64V and
less than 4V will force continuous synchronous operation
regardless of the MODE/SYNC state.
RUN (Pin 5): Run Control Input. Enables chip operation by
tying RUN above 1.5V. Tying it below 1V shuts down the
8
OUT
can also be programmed by driving ISET directly
ISET
OUT
above V
to detect power good level. If PGFB is
ITH
) to signal GND. A separate 10pF
IN
or below GND. Do not float ISET.
CC
programs 1MHz operation.
CC
OUT
to disable the PGOOD
IN
voltage. Connecting
, in which case the
ITH
CC
) in series
activates
switching regulator. Tying it below 0.4V shuts off the entire
chip. When tying RUN to more than 12V, place a resistor
(100k to 500k) between RUN and the voltage source.
MODE/SYNC (Pin 6): Operation Mode Select. Tie this pin
to INTV
all output loads. Tying it to GND enables discontinuous
mode operation at light loads. Applying an external clock
signal to this pin will synchronize switching frequency
to the external clock. During external clock synchroniza-
tion, R
frequency is within 30% of the external clock frequency.
SW (Pin 7): Switch Node Connection to External Inductor.
Voltage swing of SW is from a diode voltage drop below
ground to V
V
capacitor close to the V
BOOST (Pin 9): Boosted Floating Driver Supply for Inter-
nal Top Power MOSFET. The (+) terminal of the bootstrap
capacitor connects here. This pin swings from a diode
voltage drop below INTV
INTV
power drivers and control circuits are powered from this
voltage. Decouple this pin to GND with a minimum of 1μF
low ESR ceramic capacitor.
V
voltage regulator. Also the negative input of the error
amplifier which is driven to be the same voltage as ISET.
PGOOD (Pin 12): Output Power Good with Open-Drain
Logic. PGOOD is pulled to ground when the PGFB pin is
more than 0.645V or less than 0.555V. PGOOD open-drain
logic will be disabled if PGFB is tied to INTV
GND (Exposed Pad Pin 13): Ground. Return path of internal
power MOSFETs. Connect the exposed pad to the negative
terminal of the input capacitor and output capacitor.
IN
OUT
(Pin 8): Input voltage. Must decouple to GND with a
CC
(Pin 11): Output Voltage Pin. Output of the LTC3600
T
(Pin 10): Internal 5V Regulator Output. The internal
CC
value should be set up such that the free running
to force continuous synchronous operation at
IN
.
IN
CC
pin.
up to V
IN
+ INTV
CC
CC
.
.
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