CM3003-25SA CALMIRCO [California Micro Devices Corp], CM3003-25SA Datasheet - Page 10

• Manufacturer Part Number: CM3003-25SA
• Description: 1.5 Amp Dual Mode Low Dropout CMOS Regulator
• Manufacturer: CALMIRCO [California Micro Devices Corp]

Performance Information (cont’d)
CM3003 Typical Thermal Characteristics
The overall junction to ambient thermal resistance
(
rily of two paths in series. The first path is the junction
to the case (
and the second path is case to ambient (
resistance which is dependent on board layout. The
final operating junction temperature for any set of con-
ditions can be estimated by the following thermal equa-
tion:
The CM3003 uses a thermally enhanced package
where all the GND pins (5 through 8) are integral to the
leadframe. When this package is mounted on a double
sided printed circuit board with two square inches of
copper allocated for "heat spreading", the resulting
is about 50°C/W.
Based on a typical operating power dissipation of 1.0W
(3.0V-2.5Vx 2.0A) with an ambient of 70°C, the result-
ing junction temperature will be:
Thermal characteristics were measured using a double
sided board with two square inches of copper area
connected to the GND pin for "heat spreading".
Measurements showing performance up to junction
temperature of 125°C were performed under light load
conditions (5mA). This allows the ambient temperature
to be representative of the internal junction tempera-
ture.
Note: The use of multi-layer board construction with
separate ground and power planes will further enhance
the overall thermal performance. In the event of no
copper area being dedicated for heat spreading, a
multi-layer board construction, using only the minimum
size pad layout, will provide the CM3003 with an overall
θ
dissipated for the maximum junction temperature.
© 2004 California Micro Devices Corp. All rights reserved.
10
θ
JA
JA
) for device power dissipation (PD) consists prima-
of 70°C/W which allows up to 800mW to be safely
T
JUNC
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430 N. McCarthy Blvd., Milpitas, CA 95035-5112
JUNC
θ
= T
= T
= T
JC
= 70°C + 1.0W X (50°C/W)
= 70°C + 50°C = 120°C
AMB
AMB
) which is defined by the package style,
AMB
+ P
+ P
+ P
D
D
D
(
(
θ
(
θ
θ
JA
JC
JA
)
) + P
)
D
(
θ
CA
)
θ
CA
) thermal
L Tel: [phone] L Fax: [phone] L www.calmicro.com
θ
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CM3003
01/15/04