SE5509ALG-LF SEAWARD [Seaward Electronics Inc.], SE5509ALG-LF Datasheet - Page 5

• Manufacturer Part Number: SE5509ALG-LF
• Description: 300mA Low Power Low Noise LDO CMOS Voltage Regulator
• Manufacturer: SEAWARD [Seaward Electronics Inc.]

Revision 12/5/2008
Application Hints
Like any low dropout regulator, SE5509 requires
external capacitors to ensure stability.
external capacitors must be carefully selected to
ensure performance.
Input Capacitor
An input capacitor of at least 1μF is required.
Ceramic or Tantalum can be used. The value can
be increase without upper limit.
Output Capacitor
An output capacitor is required for stability. It must
be placed no more than 1 cm away from the V
pin, and connected directly between V
pins. Electrolytical capacitor is recommended. The
minimum value is 1μF but may be increase without
limit. Ceramic can be used. But the value should not
be more than 2.2μF.
Application Diagram
Preliminary and all contents are subject to change without prior notice
© Seaward Electronics Inc., 2006. • www.seawardinc.com.cn • Page 5
LDO CMOS Voltage Regulator
300mA Low Power Low Noise
OUT
and GND
The
OUT
Thermal Considerations
It is important that the thermal limit of the package is
not exceeded. The SE5509 has built-in thermal
protection.
the IC will enter protection, and V
to ground.
application can be calculated as following:
The power dissipation (P
P
The thermal limit of the package is then limited to
P
temperature, TA is the ambient temperature, and
Θ
designed to enter thermal protection at 150°C. For
example, if T
limited to about 0.6W. In other words, if I
300mA, then [V
D
D(MAX)
JA
= I
is around 230°C/W for SE5509. SE5509 is
OUT
= [T
* [V
J
When the thermal limit is exceeded,
IN
The power dissipation for a given
A
– T
– V
IN
is 25°C then the maximum P
– V
OUT
A
]/Θ
OUT
]
JA
] cannot exceed 2V.
D
where T
) is
OUT
J
is the junction
will be pulled
SE5509
OUT(MAX)
D
is
=