Make-before-break dual mosfet controller logic IC?

[AloyseTech]

Hi,

I'm looking for a make-before-break (MBB) complementary output IC to drive 2 mosfets using one 3V GPIO. Do you guys know any reference?

[T3sl4co1l]

And the MOSFETs are wired how, and to what voltages?  Push-pull, common ground?  Half bridge?  Isolated?

Any TTL-compatible, two-channel independent gate driver will do, if it's PP or HB.

Tim

[AloyseTech]

I have 2 voltage regulators in parallel and I would like to switch between them given certain condition. I have only one GPIO available. I plan to control the enable line of both regulators and eventually isolate their input/output. The part of the circuit I'm still working on is the cheapest/most integrated make before break driver from one single GPIO. My GPIO is 0/3V, and the regulators input voltage is around 4V.

[T3sl4co1l]

Can the regulators not simply be wired in parallel?  The best controller is none at all!

Some types contain internal diodes that allow power to back-flow from the output to the input (for example, 78xx series, most CMOS LDOs, all(?) buck or boost switchers), but some provide full isolation (where the input can go to zero, or even be driven negative, without drawing current from anywhere, or causing damage).  May want to shop around for one of those?

Otherwise, there are 5V-compatible power switches (e.g. for USB, and for local power management like this), and hot-swap controllers and such, that would fit the bill; they usually have logic-level inputs.

If you want to do it yourself, you need either a back-to-back pair of MOSFETs (a single transistor has a body diode that will allow reverse current flow), or a single MOSFET with substrate connection like this,
https://www.digikey.com/product-detail/en/microchip-technology/LND01K1-G/LND01K1-GCT-ND/4918738
and a level shifter to guarantee the gate voltage goes up high enough to turn it on/off.  Which may entail a charge pump for gate drive supply, and a gate driver, level shifter (logic gate), or a few more transistors.  Preferably, with some current sensing and control logic, to turn off the switches in case of fault current (whether through the load, or from one source into the other).

At which point, the hot-swap controller starts looking really nice, despite the added cost...

Tim

[SiliconWizard]

Can the regulators not simply be wired in parallel?  The best controller is none at all!

Yeah. And also, many LDOs have enable input pins. So you don't need any external switch, if you want to switch them.