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Monitoring & Controlling multiple power path serially?

Question asked by alejohn on Jun 8, 2018
Latest reply on Jun 11, 2018 by mpeters

We would like to monitor all of our power path to external devices, for power management, diagnostic and fault isolation.

Most power path start from an isolating DCDC and then fan out to 3-5 outputs, we will have 48V,24V,12V DCDC all isolated from each other. We would like to monitor all output from a microcontroller on the other side of the isolation(s) & have the ability to turn ON/OFF the output, ideally via the same IC.

 

Because of the electrical isolation and the number of monitored channels I feel that serially controlled devices will be better suited as they reduce the number of isolation crossing or ADC required on the micro.

 

Looking at the range I have mainly found the following 2 families:

 

Power System Managers (e.g. LTC2974)

+ Support multi-channel though often does not go to 48V

+I2C/PMBus with isolation in mind (splitting SDA into 2)

- Mainly designed to control DC/DC, unwanted features such as trimming, margining

- Usually if output is available designed to turn ON/OFF DCDC rather than control MOSFET

 

Hot Swap Controller

+A few IC will handle up to 48V

+ Will control mosfet, include overcurrent & soft start ability

-  Only has 1 channel 

-  Intended to be self sufficient e.g. turn ON system after Hot Swape, some usually offer some sort of serial control of the mosfet (possibly)

 

 

Question:

1. Is their a range of devices I have missed which would allow me to monitor and control multiple power path?

2. If no such device exist, why does it appear that controlling just the DCDC is preferable (IC made for that) than monitoring the individual consumers?Example Power Monitoring

 

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