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High Side switch for multiple channels, 2A to 4A per channel

PaulR
Prodigy 145 points

Looking for some smart High Side switches with

- current limiting per channel (2A to 4A would be good)

- overheat protection

- good for 16VDC-30VDC operation

- fault per channel reporting

- Bonus: Current measurement per channel (current sense?)

Previously we used an 8channel IC with 1A/channel, but new design needs more power, at least 2A per channel.

Any leads? Where to start?

Paul

I have found some ICs that can do 500mA to 1A per channel, 

  • 0
    TI__Mastermind 24740 points
    Hello,

    Are you looking for 8 channels in a single device and 2A per channel? Please let me know if multiple devices is accepted as solution.

    Regards
  • 0 in reply to Mahmoud Harmouch
    Prodigy 145 points

    Multiple ICs is acceptable. 

    Paul

  • 0 in reply to PaulR
    TI__Mastermind 24740 points
    Here is the devices that can fit this application:
    1- TPS1H100 is a single channel but you need 8 parts
    2- TPS4H160 is a 4 channel device. For lowering the junction temperature, it is good to parallel 2 channels for each load. In this case you need 4 parts.

    Regards, Mahmoud
  • 0 in reply to Mahmoud Harmouch
    Prodigy 145 points
    Hi Mahmoud,
    Thank you for information.

    - TPS4H160B section 9.2.1 says 0.1-1A with current limit at 2.5A (dual channel 0.2-2A, limit 5A)
    - TPS1H100B section 9.2.1 says nominal 2A, with current limit at 5A

    Does that mean I shouldn't run a single channel on TPS4H160B at 2A continuous, or a single channel on TPS1H100B at 3A/4A continuous?
    To reach 4A continuous would I need to use all four channels of an TPS4H160B?
    Are the high current limits only for short periods, and the nominal the continuous rating?
    I'm sorry, but I'm just not clear on this spec.

    Thank you
    Paul
  • 0 in reply to PaulR
    TI__Mastermind 24740 points
    Hi Paul, the paragraph 9.2.1 is an example of typical application. The device can drive DC current up to current limit but at high DC current the junction temperature may reach the thermal shutdown threshold. This depends on the ambient temperature. The junction temperature needs to be kept below 150C. The DC current can be calculated using this formula:
    Junction temperature (Tj) = Ambient temperature (Ta) + Junction to ambient thermal resistance (THETAja) x power dissipation(Pd)
    Tj = Ta + THETAja x Ron x square(load current)
    For example TPS4H160:
    Load current = 1A on each channel
    Ron = 0.25Ohms at 150C junction
    THETAja = 32.7W/C
    Ta = 85C
    Tj = 85 + 4x (32.7 x 0.25 x 1) = 85 + 32.7 = 117.7C
    If each channel load current is 2A:
    Tj = 85 + 4x (32.7 x 0.25 x 4) = 215.8C the device will be in thermal shutdown and can not deliver the power. the solution is to parallel channels for 2A load.

    I hope this answers your question and please let me know for further concern.

    Regards, Mahmoud