TPS27SA08 or ITS428L2 High Side Switch

[jmcgover]

Hi All, I am looking at using either of the two high side switches for my electronics design. The TPS27SA08 from TI or the ITS428L2 from Infinion. Has anybody used either of these or have any preference to one over the other. My use case is to use a SPST mechanical switch to bring in 3.3V to the enable pin and switch in 12V with a 7A load requirement to my system. The system consists of microcontrollers, heater panels, motors and optical electronics. Both ICs recommend resistor to power ground on the ground pin for reverse polarity connection. The TPS27SA08 has 6 Vout pins whereas the ITS428L2 has only 1 Vout Pin while both have a pad for the Vbb input connection. Both have diagnostics that I will not be using except to have a header for debug if required. Ron for TPS27SA08 is 9mOhms compared to 60mOhms for the ITS428L2. The datasheet for the ITS part has no layout recommendations. Any inputs appreciated.

 

[FvM]

No good idea to choose a device that can barely carry the expected load current. ITS428L2 nominal current is specified with minimal 5.8 A. Rdson and losses are simply too high for 7A. Inifineon has PROFET +2 series that is better suited for the intended current range.

 

[KlausST]

Hi,

currently one of the biggest problem is availability. Please check first.

I agree with FvM.

From both I´d prefer the TI one. Lower R_DS_ON, and especially lower EN_threshold.
(The ITS is rated with 3.2Vmax. And a 3.3V supply isn´t always 3.3V, it has a lot of tolerance. )

Klaus

 

[jmcgover]

Hello FvM and Klaus. Thank you for the replies. The enable signal for my system will be a resistor divider from 12v to give 3.3V at the enable pin so I can bump this up to 3.6V I see the max spec on the ITS part for a logic high is 3.2V. Will consider availability too. When my system powers up, initially it will be just the RPi CM4 and touchscreen, then other peripherals after that. So current will be initially 1.5A up to 4A and then up to a max of 7A for small periods when the motor is running specific tasks. The ITS428L2 has a nominal load current of min=5.8A and nominal of 7A with no upper limit. Surely this part can tolerate low loads below 5.8A too? MY power supply adapter is rated to 7A and my power budget shows 7A is sufficient. It will only go above 6A for very brief moments. I prefer the layout of the TI part myself and lower Ron. I will look at the PROFET +2 parts there so thank you for that.
-James

 

[FvM]

You should look at average current. If 7 A is only drawn for small periods, ITS428 can be a good solution.