Datasheet

 2004-2013 Microchip Technology Inc. DS21921C-page 9
MCP1612
3.0 MCP1612 PIN DESCRIPTIONS
The descriptions of the pins are listed in Table 3-1.
TABLE 3-1: PIN FUNCTION TABLE
3.1 Input Voltage Pin (V
IN
)
Connect the input voltage source to V
IN
. For normal
operation, the voltage on V
IN
should be between +2.7V
and +5.5V. A 10 µF bypass capacitor should be
connected between V
IN
and P
GND
.
3.2 Analog Input Voltage Pin (V
CC
)
V
CC
provides bias for internal analog functions. This
voltage is derived by filtering the V
IN
supply.
3.3 Shutdown Input Pin (SHDN)
Connect SHDN to a logic-level input in order to turn the
regulator on or off. A logic-high (>45% of V
IN
) will
enable the regulator. A logic-low (<15% of V
IN
) will
force the regulator into Shutdown mode. When in
shutdown, both the P-channel and N-channel switches
are turned off.
3.4 Compensation Pin (COMP)
COMP is the internal transconductance amplifier
output pin. External compensation is connected to
COMP for control-loop stabilization.
3.5 Feedback Pin (FB)
Connect the output voltage of the buck converter
through an external resistor divider to FB to regulate
the output voltage. The nominal voltage compared to
this input for pulse termination is 0.8V.
3.6 Analog Ground Pin (A
GND
)
Tie all small-signal ground returns to A
GND
. Noise on
A
GND
can effect the sensitive internal analog
measurements.
3.7 Power Ground Pin (P
GND
)
Connect all large-signal ground returns to P
GND
. These
large-signal traces should have a small loop area and
length to prevent coupling of switching noise to
sensitive traces.
3.8 Buck Inductor Output Pin (L
X
)
Connect L
X
directly to the buck inductor. This pin
carries large signal-level currents; all connections
should be made as short as possible.
Pin No. Name Function
1V
IN
Input Voltage Pin
2V
CC
Analog Input Voltage Pin
3 SHDN
Shutdown Control Input Pin
4 COMP Transconductance Amplifier Output Pin
5 FB Feedback Input Pin
6A
GND
Analog Ground Pin
7P
GND
Power Ground Pin
8L
X
Buck Inductor Output Pin