Texas Instruments TPS73601DRBEVM-518 Evaluation Module TPS73601DRBEVM-518 TPS73601DRBEVM-518 데이터 시트
제품 코드
TPS73601DRBEVM-518
Board Layout, Schematic, and Parts List
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All temperatures are in degrees Celsius.
The measured thermal resistance from junction to ambient for the TPS73x01EVM has a typical value of
40°C/W. The recommended maximum operating junction temperature specified in the product data sheet
for the TPS73x01 family is +125°C. With these two pieces of information, the maximum power dissipation
can be found by using Equation (1).
40°C/W. The recommended maximum operating junction temperature specified in the product data sheet
for the TPS73x01 family is +125°C. With these two pieces of information, the maximum power dissipation
can be found by using Equation (1).
What is the maximum input voltage that can be applied to a TPS73701DRB with a 1.8-V output voltage if the
ambient temperature is +85°C and the full 1 A of load current is required?
ambient temperature is +85°C and the full 1 A of load current is required?
Given:
T
J
= +125°C, T
A
= +85°C,
θ
JA
= 40°C/W
Using
, we substitute in the given values above and find that the maximum power dissipation for the
part is P
D
= 1 W.
125°C = 85°C + P
D
(40°W/C)
This result means that the total power dissipation of the TPS73701DRB must be less than 1 W. Now the input
voltage can be calculated.
voltage can be calculated.
P
D
= (V
IN
– V
OUT
) × I
OUT
= (V
IN
– 1.8 V) × 1 A = 1 W
So the maximum input voltage would need to be 2.8 V or less in order to maintain a safe junction temperature.
Similar analysis can be performed to determine the maximum input voltage at room temperature (+25°C)
or +85°C to provide full output current while maintaining the junction temperature at or below +125°C. The
answer depends on the desired output voltage, as
or +85°C to provide full output current while maintaining the junction temperature at or below +125°C. The
answer depends on the desired output voltage, as
shows.
Table 3. Maximum Input Voltage
TPS73701DRB
TPS73601DRB
TPS73201DRB
Output
Ambient Temperature
Ambient Temperature
Ambient Temperature
Voltage
V
OUT
+25°C
+85°C
+25°C
(1)
+85°C
+25°C
(1)
+85°C
(1)
1.8 V
4.3 V
2.8 V
5.5 V
4.3 V
5.5 V
5.5 V
2.5 V
5.0 V
3.5 V
5.5 V
5.0 V
5.5 V
5.5 V
2.8 V
5.3 V
3.8 V
5.5 V
5.3 V
5.5 V
5.5 V
3.0 V
5.5 V
4.0 V
5.5 V
5.5 V
5.5 V
5.5 V
3.3 V
5.5 V
(1)
4.3 V
5.5 V
5.5 V
(1)
5.5 V
5.5 V
(1)
Limited by recommended operating maximum temperature, not thermal resistance.
5
Board Layout, Schematic, and Parts List
This section provides the TPS73x01DRBEVM-518 board layout and illustrations. It also provides the
TPS73x01DRBEVM-518 schematic and bill of materials.
TPS73x01DRBEVM-518 schematic and bill of materials.
5.1
PCB Layout
through
show the layout for the TPS73x01DRBEVM-518 PCB.
NOTE:
Board layouts are not to scale. These figures are intended to show how the board is laid
out; they are not intended to be used for manufacturing TPS73x01DRBEVM-518 PCBs.
4
TPS73x01DRBEVM-518
SBVU014 – August 2009
Copyright © 2009, Texas Instruments Incorporated