• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 63 subscribers
  • Views 439 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Enabled DC power on/off.

Boots
Prodigy 50 points
Other Parts Discussed in Thread: UCD9240

Hi,

 

I am looking for a way to switch on/off a 3.3V signal (with max current 0.24 A) by using a 3.3V enable signal (or 2.5 V if possible). 

 

Once on, the 3.3V must be stable and not fluctuate any more than 0.1 V, but half that is preferable. 

 

Should I just use a BJT design that can support the current?   

 

Thanks for your help!

  • 0
    TI__Intellectual 1755 points

    Hello,

    When Texas Instruments talks about "Digital Power" in this forum it is describing products that can be configured (change the regulation voltage, change the fault conditions, etc.) over the PMBus.  The PMBus is a serial interface based on the SMBus, which uses the I2C physical layer.  These devices, like the UCD9240 family, are typically used in applications with current requirements > 6 Amps.

     

    For your application where you need a 1/4 Amp of 3.3V.  I would recommend a SWIFT family PWM controller, most of these devices have an enable pin.  One of the advantages of using a PWM controller to provide your 3.3V signal is that a PWM controller ramps the voltage up and down in a controlled manner.  If you just enable the voltage with a BJT or MOSFET the capacitance on the output circuit may draw tens of Amps each time you switch the signal.