ltc3447edd-trpbf Linear Technology Corporation, ltc3447edd-trpbf Datasheet - Page 6

• Manufacturer Part Number: ltc3447edd-trpbf
• Description: I2c Controllable Buck Regulator In 3mm ? 3mm Dfn
• Manufacturer: Linear Technology Corporation

PI FU CTIO S
LTC3447
V
resistor divider provides the divided down feedback refer-
ence for comparison.
GND (Pin 2): Ground for all Circuits Excluding the Internal
Synchronous Power NFET.
FB (Pin 3): Feedback Sensing Pin for the Optional External
Feedback Resistors. Must be tied to V
external feedback resistors.
PGOOD (Pin 4): Fault Report. Open drain driver sinks cur-
rent when V
DAC changes can be enabled via the I
V
to GND with a 2.2µF or greater capacitor.
BLOCK DIAGRA
PGOOD
6
OUT
IN
V
RUN
SDA
SCL
CCD
U
(Pin 5): Main Supply Pin. Must be closely decoupled
(Pin 1): Output Voltage Sensing Pin. An internal
LTC3447
U
POWER
GOOD
BURST
OUT
I
2
C
BLANK
is 10% out of tolerance. Blanking during
6-BIT DAC
REF
UV REF
OV REF
U
LOAD
DAC
W
V
DAC
S
MUX
2
C.
Figure 2. LTC3447 High Level Block Diagram
IN
if there are no
+
–
V
IN
SLEW
SOFT-START
C
IN
SW (Pin 6): Switch Node Connector to Inductor. This pin
connects the drains of the internal main and synchronous
power MOSFET switches.
RUN (Pin 7): Run Control Input. Forcing pin above 1.5V
enables the part. Forcing the pin below 0.3V shuts down
the device. In shutdown, all functions are disabled draw-
ing <1µA of supply current. Do not leave the RUN pin
fl oating.
SCL (Pin 8): I
V
SDA (Pin 10): I
Exposed Pad (Pin 11): Ground. Must be connected to
PCB ground for electrical contact and optimized thermal
performance.
CCD
V
(Pin 9): I
REF
REGULATOR
BURST
BUCK
2
2
C Clock Input.
2
C Power Rail.
C Data Input.
SW
V
FB
MUX
R
DAC
1.3R
3447 BD
SW
FB
R1
R2
V
OUT
C
3447f
OUT