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Axelite Confidential Materials, do not copy or distribute without written consent.

Rev.2.0 Nov.16, 2011

AX6604/5

Thermal Considerations

The AX6604/5 series can deliver a current of up to 200mA/channel over the full

operating junction temperature range. However, the maximum output current must be

debated at higher ambient temperature to ensure the junction temperature does not exceed

125°C. With all possible conditions, the junction temperature must be within the range

specified under operating conditions. Power dissipation can be calculated based on the

output current and the voltage drop across regulator.

PD = (VIN - VOUT) IOUT + VIN IGND

The final operating junction temperature for any set of conditions can be estimated by

the following thermal equation:

PD (MAX) = (TJ (MAX) - TA) / θJA

Where TJ (MAX) is the maximum junction temperature of the die (125°C) and TA is the

maximum ambient temperature. The junction to ambient thermal resistance (θJA) SOT-23-6L

package at recommended minimum footprint is 250°C/W. Visit our website in which

“Recommended Footprints for Soldering Surface Mount Package” for detail.