EUP7968
Application Information
External Capacitors
Like any low-dropout regulator, the EUP7968 requires
external capacitors for regulator stability. The EUP7968
is specifically designed for portable applications
requiring minimum board space and smallest components.
These capacitors must be correctly selected for good
performance.
Input Capacitor
A minimum input capacitance of 1µF is required between
the EUP7968 input pin and ground (the amount of the
capacitance may be increased without limit).This
capacitor must be located a distance of not more than
1cm from the input pin and returned to a clean analog
ground.
Any good quality ceramic, tantalum, or film capacitor
may be used at the input. If a tantalum capacitor is used
at the input, it must be guaranteed by the manufacturer to
have a surge current rating sufficient for the application.
Output Capacitance
The EUP7968 is specifically designed to employ ceramic
output capacitors as low as 2.2µF. Ceramic capacitors
below 10µF offer significant cost and space savings,
along with high frequency noise filtering. Higher values
and other types and of capacitor may be used, but their
equivalent series resistance (ESR) should be maintained
below 0.5Ω. Ceramic capacitor of the value required by
the EUP7968 are available in the following dielectric
types: Z5U, Y5V, X5R, and X7R. The Z5U and Y5V
types exhibit a 50% or more drop in capacitance value as
their temperature increase from 25°C, an important
consideration. The X5R generally maintain their
capacitance value within ± 20%. The X7R type are
desirable for their tighter tolerance of 10% over
temperature.
DS7968 Ver1.3
Sep. 2007
7
EUTECH [ EUTECH MICROELECTRONICS INC ]
