Application Hints
Like any Low dropout regulator, SE5167 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 SE5167 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:
The Power Dissipation (P
D
) is
P
D
= I
OUT
* [V
IN
– V
OUT
]
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 250°C/W for SE5167. SE5167 is designed
to enter thermal protection at 150°C. For example, if
T
A
is 25°C then the max P
D
is limited to about 0.5W.
In other words, if I
OUT(MAX)
= 300mA, then [V
IN
–
V
OUT
] can not exceed 1.67V.
Input Capacitor:
An Input Capacitor of at least 2.2uF is required. The
inexpensive Electrolytic capacitor is preferred. The
value can be increased without upper limit.
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 inexpensive Electrolytic capacitor is
recommended. The minimum value is 2.2uF but
once again its value can be increased without limit.
Revision
12/5/2008
Preliminary and all contents are subject to change without prior notice.
© Seaward Electronics, Inc., 2006. • www.seawardinc.com.cn • Page 6
SEAWARD [ Seaward Electronics Inc. ]
