Datasheet

MCP1755/1755S
DS25160A-page 16  2012 Microchip Technology Inc.
3.5 Unregulated Input Voltage (V
IN
)
Connect V
IN
to the input unregulated source voltage.
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. For most
applications, 1 µF of capacitance will ensure stable
operation of the LDO circuit. The input capacitor should
have a capacitance value equal to or larger than the
output capacitor for performance applications. The
input capacitor will supply the load current during
transients and improve performance. For applications
that have load currents below 10 mA, the input
capacitance requirement can be lowered. The type of
capacitor used may be ceramic, tantalum or aluminum
electrolytic. The low ESR characteristics of the ceramic
will yield better noise and PSRR performance at high
frequency.
3.6 Exposed Pad (EP)
Some of the packages have an exposed metal pad on
the bottom of the package. The exposed metal pad
gives the device better thermal characteristics by
providing a good thermal path to either the PCB or
heatsink to remove heat from the device. The exposed
pad of the package is internally connected to GND.