How to connect TPS22966 ground (switching between 2 inputs)

Chee Kang Lim

Intellectual 265 points

Other Parts Discussed in Thread: TPS22966, TPS22930A, TPS22912C, TPS22910A, TPS27081A

_{Hi TIers,}

From functional block diagram, output connects to ground when switched off. (Datasheet page 6)

Problem is that in my circuit, I’m switching between two power inputs.

The connection to ground will short my other output.

Using diodes will cause a voltage drop. Anyway we can resolve this?

Best Regards,

Serial Microelectronics Pte Ltd. (Texas Instruments authorized distributor)

over 12 years ago

0 Vincenzo Pizzolante over 12 years ago

TI__Mastermind 25316 points

I dind't get your riddle, sorry...

TPS22966 is a dual (independent) channels, so...

If I misunderstood something, could you pls provide a scheme or a block diagram?

0 Chee Kang Lim over 12 years ago in reply to Vincenzo Pizzolante

Intellectual 265 points

The design is to switch between two power inputs

The connection to ground will short my other output.

Using diodes will cause a voltage drop. Do you have any advice on how to resolve this?

0 DavidT over 12 years ago in reply to Chee Kang Lim

TI__Prodigy 580 points

Chee Kang,

For this 2:1 power-mux application you will need load switches that do not have quick output discharge resistance (QOD).

Depending on your Max Current requirements, the TPS22912C, TPS22910A, or TPS22930A might work for your application.

These are all 2A load switch devices with integrated reverse current protection and under-voltage lockout.

David

0 Vincenzo Pizzolante over 12 years ago in reply to DavidT

TI__Mastermind 25316 points

Exactly!

Tks David

0 Chee Kang Lim over 12 years ago in reply to Vincenzo Pizzolante

Intellectual 265 points

Guys,

Thanks for the info.

However, 2A is not enough, need at least 3A.

If i would connect two of load switch to the same output, how would it affected if shutdown for long time due to reverse current protection?

Besides, can TPS27081A used in this application, since TPS22930A still in prelim stage?

Best Regards,

0 DavidT over 12 years ago in reply to Chee Kang Lim

TI__Prodigy 580 points

CK,

For this 2-chip power-mux application you will need reverse current protection as well as a load switch device architecture that does not have the discharge resistance.

Currently, we do not have a 3A load switch with these features.

David

Power management

Power management forum

How to connect TPS22966 ground (switching between 2 inputs)