11/25
© 2022 ROHM Co., Ltd.
65UG028E Rev.001
2022.7
User's Guide
BD7F105EFJ-EVK-001
Figure 29. Surface Temperature
Vin = 8 V, IOUT1 = 0.3 A, IOUT2 = 0.1 A
IOUT3 = 0.3 A (Ta = 25
℃
)
Figure 30. Surface Temperature Reference
Figure 31. Peak Current Waveform
Vin = 8 V, IOUT1 = 0.3 A, IOUT2 = 0.1 A
IOUT3 = 0.3 A
Table 1. Tj Calculation
Measured data-continued
Component surface temperature
Tj calculation of IC is calculated using the above table.
Loss of IC is divided into 1: Turn on loss, 2: conduction loss, 3: Turn off loss, and 4: ICC.
Calculate the loss according to Table1 from the actual current waveform and power supply spec.
In this case, Tj is estimated to be 39 °C because Tc = 30.3 °C and ΔTj = 7.41 °C.
Tj should be designed to be 150 °C or less.
In this case, when Ta = 125 °C, Tj = 146 °C, and Tj = 150 °C is not reached, so it can be judged that there is no problem in the
whole temperature range.
V
IN
(10V/div)
V
SW
(20V/div)
I
SW
(2A/div)
V
OUT
(20V/div)
39℃
V
IN
(10V/div)
V
SW
(10V/div)
I
OUT
(500mA/div)
①
②
③
