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SM74611: Use in sensitive audio and radio equipment

Part Number: SM74611

Hello Team,

Good day my Customer use the SM74611 ICs as drop-in replacements for Schottky diodes in there simple battery backup circuit for an AV cart DC power distribution. Currently the system has a AC/DC power supply in parallel with a rechargeable battery (not charged by this circuit).Typically it's an 11-16V DC system distributed to multiple self contained pieces of audio and wireless equipment and pulling 4-15 A total.

Looking at the data sheets they are concerned that the equipment might not like the cyclical momentary voltage drop as the charge pump charges the capacitor inside the SM74611, routing the current through the internal diode. They would like to here what we can advice to them if this kind of fluctuation typically present any problems for DC powered gear that accepts a range of voltages? (usually 9-18 for most of my stuff) particularly sensitive radio equipment? 

Regards,

-Renan

  • Hi Renan,

    Our Ideal diodes and Ideal diode controllers like SM74611 and LM74610 do not have a ground reference. They only have Anode and Cathode pins. This kind of application requires design architecture where the charge pump cap needs some time to charge itself before it can turn ON the FET (internal or external) again. 

    When the charge pump is OFF< the body diode will conduct and hence the forward voltage drop will be around 0.7V for that small duration. Generally we don't see any issues in IC's like DC-DC  if the input voltage drops 0.7V below nominal for small duration. But it completely depends on customer circuit and system behavior.

    In case customer doesn't want this kind of ON and OFF behavior of the FET. we would recommend you to have a look at LM5050 , LM74700 for DC applications.