Datasheet

 2010 Microchip Technology Inc. DS22051D-page 15
MCP1801
5.0 FUNCTIONAL DESCRIPTION
The MCP1801 CMOS low dropout linear regulator is
intended for applications that need the low current
consumption while maintaining output voltage
regulation. The operating continuous load range of the
MCP1801 is from 0 mA to 150 mA. The input operating
voltage range is from 2.0V to 10.0V, making it capable
of operating from three or more alkaline cells or single
and multiple Li-Ion cell batteries.
5.1 Input
The input of the MCP1801 is connected to the source
of the P-Channel PMOS pass transistor. As with all
LDO circuits, a relatively low source impedance (10)
is needed to prevent the input impedance from causing
the LDO to become unstable. The size and type of the
capacitor needed depends heavily on the input source
type (battery, power supply) and the output current
range of the application. For most applications a 0.1 µF
ceramic capacitor will be sufficient to ensure circuit
stability. Larger values can be used to improve circuit
AC performance.
5.2 Output
The maximum rated continuous output current for the
MCP1801 is 150 mA.
A minimum output capacitance of 1.0 µF is required for
small signal stability in applications that have up to
150 mA output current capability. The capacitor type
can be ceramic, tantalum, or aluminum electrolytic.