Datasheet

© 2007 Microchip Technology Inc. DS21991C-page 9
MCP1701A
3.0 PIN DESCRIPTIONS
The descriptions of the pins are listed in Table 3-1.
TABLE 3-1: PIN FUNCTION TABLE
3.1 Ground Terminal (GND)
Regulator ground. Tie GND to the negative side of the
output and the negative side of the input capacitor.
Only the LDO bias current (2 µA, typ.) flows out of this
pin, there is no high current. The LDO output regulation
is referenced to this pin. Minimize voltage drops
between this pin and the negative side of the load.
3.2 Regulated Voltage Output (V
OUT
)
Connect V
OUT
to the positive side of the load and the
positive terminal of the output capacitor. The positive
side of the output capacitor should be physically
located as close as possible to the LDO V
OUT
pin. The
current flowing out of this pin is equal to the DC load
current.
3.3 Unregulated Supply Input (V
IN
)
Connect the input supply voltage and the positive side
of the input capacitor to V
IN
. Like all low-dropout linear
regulators, low source impedance is necessary for the
stable operation of the LDO. The amount of
capacitance required to ensure low source impedance
will depend on the proximity of the input source
capacitors or battery type. The input capacitor should
be physically located as close as possible to the V
IN
pin. For most applications, 1 µF of capacitance will
ensure stable operation of the LDO circuit. For
applications that have load currents below 100 mA, the
input capacitance requirement can be lowered. The
type of capacitor used can be ceramic, tantalum or
aluminum electrolytic. The low equivalent series
resistance characteristics of the ceramic will yield
better noise and PSRR performance at high frequency.
The current flow into this pin is equal to the DC load
current, plus the LDO bias current (2 µA, typical).
Pin No.
SOT-23A
Pin No.
SOT-89
Pin No.
TO-92
Name Function
1 1 1 GND Ground Terminal
233V
OUT
Regulated Voltage Output
322V
IN
Unregulated Supply Input