SE5117
Application Hints
Like any Low dropout regulator, SE5117 requires
external capacitors to ensure stability. The external
capacitors must be carefully selected to ensure the
performances.
Thermal Consideration
It is important that the thermal limit of the package
should not be exceeded. The SE5117 has built-in
thermal protection. When the thermal limit is
exceeded, the IC will enter protection, and the V
OUT
will be reset to zero. The power dissipation for a
given application can be calculated as follows:
Input Capacitor:
An Input Capacitor of at least 10uF is required.
Ceramic or Tantalum can be used. The value can
be increased without upper limit.
The Power Dissipation (P
D
) is
P
D
= I
OUT
* [V
IN
–V
OUT
]
Output Capacitor:
An Output Capacitor is required for look stability. It
must be located no more than 1cm away from the
V
OUT
pin, and connected directly between V
OUT
and
GND pins. The minimum value is 10uF but once
again its value can be increased without limit.
The thermal limit of the package is then limited to
P
D(MAX)
= [T
J
–T
A
]/θ
JA
where T
J
is the junction
temperature, T
A
is ambient temperature, and
θ
JA
is
around 135°
C/W for SE5117. SE5117 is designed
to enter thermal protection at 150° For example, if
C.
T
A
is 25° then the max P
D
is limited to about 1W. In
C
other words, if I
OUT(MAX)
= 1A, then [V
IN
–V
OUT
] can
not exceed 1V.
4
BEIJING ESTEK ELECTRONICS CO.,LTD
ESTEK [ Estek Electronics Co. Ltd ]
