Datasheet

 2007-2012 Microchip Technology Inc. DS22042B-page 13
MCP1603/B/L
3.0 PIN DESCRIPTIONS
The descriptions of the pins are listed in Table 3-1.
3.1 Power Supply Input Voltage Pin
(V
IN
)
Connect the input voltage source to V
IN
. The input
source must be decoupled to GND with a 4.7 µF
capacitor.
3.2 Ground Pin (GND)
Ground pin for the device. The loop area of the ground
traces should be kept as minimal as possible.
3.3 Shutdown Control Input Pin
(SHDN
)
The SHDN pin is a logic-level input used to enable or
disable the device. A logic high (>45% of V
IN
) will
enable the regulator output. A logic low (<15% of V
IN
)
will ensure that the regulator is disabled.
3.4 Feedback / Output Voltage Pin
(V
FB
/V
OUT
)
For adjustable output options, connect the center of the
output voltage divider to the V
FB
/V
OUT
pin. For fixed-
output voltage options, connect the output directly to
the V
FB
/V
OUT
pin.
3.5 Switch Node, Buck Inductor
Connection Pin (L
X
)
Connect the L
X
pin directly to the buck inductor. This
pin carries large signal-level current; all connections
should be made as short as possible.
3.6 Exposed Metal Pad (EP)
For the DFN package, connect the Exposed Pad to
GND, with vias into the GND plane. This connection to
the GND plane will aid in heat removal from the
package.
TABLE 3-1: PIN FUNCTION TABLE
MCP1603/B
TSOT-23
MCP1603L
TSOT-23
MCP1603
2x3 DFN
Symbol Description
147V
IN
Power Supply Input Voltage Pin
2 2 8 GND Ground Pin
3 1 3 SHDN
Shutdown Control Input Pin
454V
FB
/V
OUT
Feedback / Output Voltage Pin
531L
X
Switch Node, Buck Inductor Connection Pin
— — 2, 5, 6 NC No Connect
— — Exposed
Pad
EP For the DFN package, the center exposed pad is a thermal
path to remove heat from the device. Electrically, this pad is
at ground potential and should be connected to GND.