NSI45020_14 Datasheet, PDF (7/8 Pages) ON Semiconductor – Constant Current Regulator & LED Driver

NSI45020T1G
Thermal Considerations
As power in the CCR increases, it might become
necessary to provide some thermal relief. The maximum
power dissipation supported by the device is dependent
upon board design and layout. Mounting pad configuration
on the PCB, the board material, and the ambient temperature
affect the rate of junction temperature rise for the part. When
the device has good thermal conductivity through the PCB,
the junction temperature will be relatively low with high
power applications. The maximum dissipation the device
can handle is given by:
P_D(MAX)
+
T_J(MAX) *
R_qJA
T_A
Referring to the thermal table on page 2 the appropriate
R_qJA for the circuit board can be selected.
AC Applications
The CCR is a DC device; however, it can be used with full
wave rectified AC as shown in application notes
AND8433/D and AND8492/D and design notes
DN05013/D and DN06065/D. Figure 14 shows the basic
circuit configuration.
Figure 14. Basic AC Application
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