• Resolved

# TS5A3157: TS5A3157YZP operating Tamax

Part Number: TS5A3157

Hello,

My customer is using TS5A3157 YZP at current design.

Though TS5A3157YZP operating tamax=85oC, they are using TS5A3157YZP for new design at which Tamax is 95oC.

I think even the datasheet specifies tamax=85oC, TS5A3157YZP can be used at 95oC as far as Tj < Tjmax.

What is Tjmax at TS5A3157YZP?

Or any other alternative device candidate to meet Tamax >=95oC?

Best regards,

K.Hiano

• K.Hiano,

The max junction temperature of the a signal switch can be calculated using the excel calculator in this e2e post.

Using the calculator you can see that the TS5A3157 doesn't heat up much at max power only 89 deg C.

Using the ti.com switch selection tool I can sort on devices that support 95 deg C ambient temperature.

What are you doing in your application that you originally selected the TS5A3157?  Would the SN74LVC1G3157 be an appropriate alternative?

Thank you,

I understood TS5A3157 Tj is 89oC at Ta=85oC at max power by the excel calculator.

And Tj is also calculated 99oC at Ta=95oC at max power.

Then, up to how much Tj can TS5A3157 accept?

I feel Tamax=85oC is too conservative.

Best regards,

K.Hirano

• In reply to Kazuhiko Hirano:

K. Hirano,

You can see in the abs max table that the TS5A3157 device can be stored up to 150 deg C which would been the max junction temperature would and there wouldn't be any issue.

The excel calculator proves this is a low power signal switch which you could never get the junction temperature to 150 deg C without violating the recommended operating conditions.

Thank you,

According to the excel calculator, the Tj = 99oC at Ta=95oC, this is much less than absolute Tjmax=150oC.

So, can you use TS5A3157 at Ta=95oC safely even if the datasheet states recommended Tamax=85oC?

Best regards,

K.Hirano

• In reply to Kazuhiko Hirano:

K. Hirano,

The max ambient temperature operation specified for this device is 85 deg C so we cannot guarantee the performance of the device beyond that rating.

Thank you,