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# TPS1HA08-Q1: Searching TI solution that can drive 10A current continuously in -40℃~85℃. Is there a higher specification high-side switch recommended?

Part Number: TPS1HA08-Q1

Hi Team

1.According to the TPS1HA08B-Q1 specification, the ambient temperature of its continuous driving current capability of 10A is only 70℃. If calculated synchronously according to the specification parameters, Imax=8.8A @ 85℃

2.The internal resistance and thermal resistance of the TPS1HA08B-Q1 specification are slightly larger. Please help to confirm whether there is a conservative margin for the internal resistance and thermal resistance data in the existing specification? If the TPS1HA08B-Q1 is selected to drive 10A at 85°C, is it feasible and the risk is controllable?

TPS1HA08B-Q1: Rja=32.8℃/W, Ron=20 mΩ@Tj=150℃

3.Customer demand is -40℃~85℃ can drive 10A current continuously. Is there a higher specification high-side switch recommended?

• Hello Kygo,

1.

Yes, I_max is 10A at an ambient of 70°C for the TPS1HA08-Q1 and this is what we have specified the device at. We can find the thermal junction temperature at these conditions using this equation TJ = TA + ((ILOAD^2*RON) *RƟJA)

TJ = 70°C + ((10A^2*0.02Ω) *32.8°C/W) = 135.6°C

If you wanted to keep this thermal junction temperature and increase the ambient temperature to 85°C, then 135.6°C = 85°C + ((I_max^2*0.02Ω) *32.8°C/W) = 8.78A

2.

If the end goal is having ambient temperatures ranging from -40°C to 85°C while having a continuous load current of 10A, Thermal junction temperatures would range from 25.6°C to 150.6°C

TJ = -40°C + ((10A^2*0.02Ω) *32.8°C/W) = 25.6°C

TJ = 85°C + ((10A^2*0.02Ω) *32.8°C/W) = 150.6°C

The maximum thermal junction temperature for the TPS1HA08-Q1 is 150°C, so the 85°C at 10A is marginally exceeding that maximum thermal junction temperature. Exposure to absolute-maximum-rated conditions above 150°C may affect the device reliability and could cause permanent damage. Currently we don’t have a device that has a smaller RON than 8mΩ. For further questions about devices/parameters, please contact the team directly.

Regards,

Quentin