Datasheet

LTC3619B
6
3619bfb
V
FB1
(Pin 1/Pin 1): Regulator 1 Output Feedback. Receives
the feedback voltage from the external resistive divider
across the regulator 1 output. Nominal voltage for this
pin is 0.6V.
RUN1 (Pin 2/Pin 2): Regulator 1 Enable. Forcing this pin
to V
IN
enables regulator 1, while forcing it to GND causes
regulator 1 to shut down.
RLIM (Pin 3/Pin 3): Average Input Current Limit Program
Pin. Place a resistor and capacitor in parallel from this
pin to ground.
PGOOD1 (Pin 4/Pin 4): Open-Drain Logic Output. PGOOD1
is pulled to ground if the voltage on the V
FB1
pin is not
within power good threshold.
SW1 (Pin 5/Pin 5): Regulator 1 Switch Node Connection
to the Inductor. This pin swings from V
IN
to GND.
V
IN
(Pin 6/Pin 6): Main Power Supply. Must be closely
de-coupled to GND.
SW2 (Pin 7/Pin 7): Regulator 2 Switch Node Connection
to the Inductor. This pin swings from V
IN
to GND.
PGOOD2 (Pin 8/Pin 8): Open-Drain Logic Output. PGOOD2
is pulled to ground if the voltage on the V
FB2
pin is not
within power good threshold.
RUN2 (Pin 9/Pin 9): Regulator 2 Enable. Forcing this pin
to V
IN
enables regulator 2, while forcing it to GND causes
regulator 2 to shut down.
V
FB2
(Pin 10/Pin 10): Regulator 2 Output Feedback.
Receives the feedback voltage from the external resistive
divider across the regulator 2 output. Nominal voltage for
this pin is 0.6V.
GND (Pin 11/Pin 11): Ground. Bottom Exposed Pad. Con-
nect to the (–) terminal of C
OUT
, and the (–) terminal of
C
IN
. The Exposed Pad must be soldered to PCB.
pin FuncTions
Typical perForMance characTerisTics
T
A
= 25°C, V
IN
= 5V, unless otherwise noted.
(DD/MSE)
Average Input Current Limit
vs Temperature Load Step (Channel 1) Load Step (Channel 1)
TEMPERATURE (°C)
–50
–8
I
INLIM
ERROR (%)
–4
–2
–6
0
6
4
2
8
75 10050250–25
3619B G19
125
V
IN
= 5V
I
LIM
= 475mA
V
IN
= 5V, V
OUT
= 3.3V
I
LOAD
= 0A TO 400mA
C
L
= 4.7µF
20µs/DIV
3619B G20
I
LOAD
500mA/DIV
I
L
500mA/DIV
V
OUT
200mV/DIV
AC-COUPLED
V
IN
= 5V, V
OUT
= 1.8V
I
LOAD
= 40mA TO 400mA
C
L
= 4.7µF
20µs/DIV
3619B G21
I
LOAD
500mA/DIV
I
L
500mA/DIV
V
OUT
200mV/DIV
AC-COUPLED