Datasheet

Datasheet

10/17

TSZ02201-0T2T0AN00050-1-2

© 2013 ROHM Co., Ltd. All rights reserved.

08.Feb.2013 Rev.001

www.rohm.com

TSZ22111・15・001

BD00C0AWFPS-M

Refer to the heat mitigation characteristics illustrated in Figure 19 and Figure 20 when using the IC in an environment of

≥25°C. The characteristics of the IC are greatly influenced by the operating temperature, and it is necessary to operate

under the maximum junction temperature Timax.

Even if the ambient temperature Ta is at 25°C it is possible that the junction temperature Tj reaches high temperatures.

Therefore, the IC should be operated within the power dissipation range.

Figure 19 and Figure 20 show the acceptable power dissipation characteristic curves of TO252S-5 package. Even when the

ambient temperature Ta is a normal temperature (25℃), the chip (junction) temperature Tj may be quite high so please

operate the IC at temperatures less than the acceptable loss Pd.

The following method is used to calculate the power consumption Pc (W).

Acceptable loss Pd

≥Pc

The load current Io is obtained by operating the IC within the power dissipation range.

Thus, the maximum load current Iomax for the applied voltage Vcc can be calculated during the thermal design process.

Calculation Example) with TO252S-5,Ta=85℃,Vcc=10V, Vo=5V

At Ta=85℃ with Figure 20③ condition, the calculation shows that ca about 500mA of output current is possible at 5V

potential difference across input and output.

The thermal calculation shown above should be taken into consideration during the thermal design in order to keep the whole

operating temperature range within the power dissipation range.

(Please refer to Figure.12 for Ib.)

(Please refer to Figure.8 for Ishort.)

Figure 20③:

θja=26.0℃/W → -38.4mW/℃

25℃=4.80W

→ 85℃=2.496W

(Ib: 0.5mA)

2.496－10×Ib

5

: Input voltage

: Output voltage

: Load current

Ib

: Circuit current

Ishort : Short current