Comments on Two way circuit breaking capability for ideal diode controllers
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Two way circuit breaking capability for ideal diode controllers
I would like to save some costs with ideal diode controllers. Basic requirement is for the diode controller to block overcurrents (short circuits) in both directions.
The MAX16141A IC can do it and the datasheet openly discusses it, i.e with two back to back MOSFETs and a sense resistor
Thie LM5069 IC I think can also do the same, just that its datasheet does not mention a second anti-series MOSFET at all. Its cost is half of the first IC, so I would want to use it. Would it be fine, and if so, could I use two different MOSFET types or do they have to be of the same kind ?
edit - New user here, can't comment on other's answers.
So, among the dozen features or so supported by LM5069 there is also "Circuit breaker function for severe overcurrent events".
Could I add in a second mosfet, placed back-to-back with the mosfet in their example diagrams, controlled by the same GATE pin, and get the circuit breaking feature - this time in both ways ? Would other features fail / be impacted if I did that ?
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The two ICs you reference don't do the same thing. The first sentence of the first datasheet says:
The MAX16141/MAX16141A ideal diode controllers provide system protection against a variety of system faults, such as reverse current, reverse voltage, overcurrent, input overvoltage/undervoltage, and overtemperature conditions.
The title of the second datasheet says:
LM5069 Positive High-Voltage Hot Swap and In-Rush Current Controller with Power Limiting
The first IC is meant to protect downstream circuitry from a variety of abuses to the power supply input of the unit. Note that these include reverse voltage. That's why two back to back FETs of opposite polarity are needed.
The second IC isn't meant to deal with power input abuse. It's purpose is to allow hot swapping by inrush current limiting, also known as a "soft start". If you plug a unit with this chip into an existing bus, it's not going to glitch the power supply for a few nanoseconds as some cap charges up.
Note that the second chip is specifically for positive voltages. It's not trying to defend against an incorrectly connected supply. It's trying to play nice with the supply.
The purposes of the two chips are completely different, so it's not surprising that they each require different external parts.
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