Current rating selection

AN4363

4/20

DocID025296 Rev 1

For example, for a 0.4 A rms current, this device has to work with a maximum ambient

temperature lower than approximately 72 °C. In other words, up to 72°C, the ACS108-6SA

can control a maximum rms current of 0.4 A.

Figure 1. Maximum rms current versus ambient temperature for an ACS108-6SA

For the T1635T-8FP, as the device package is a TO220FPAB, and as this device can handle

up to 16 A for a 150 °C junction temperature, a heatsink is used in most of the cases. The

curve is then given versus the operating case temperature as shown in Figure 2.

This figure shows that for instance, for a 12 A rms current, the package case temperature

has to be lower than 107 °C. So the used heatsink has to ensure of evacuating the power

case temperature below 107 °C.

Figure 2. Maximum rms current versus ambient temperature for a T1635T-8FP

I

(A)

T(RMS)

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Single layer Printed

circuit board FR4

Natural convection

TO-92

SOT-223

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current

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TO-92

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