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Please recommend an IC

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air2008

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hi,
I need an IC which can perform the following function.
(1) Just ONE voltage input, Vin.
(2) Just ONE voltage output, Vout.
(3) If Vin is less than a threshold (say, 1.8V), Vout is zero.
(4) If Vin is larger than this threshold, Vout = Vin.
I have considered to use a voltage comparater, but the voltage comparater needs a reference voltage, in addition to a voltage input Vin.
Anybody can recommend an IC to me?


air2008
 

try on semiconductor NCP346
 

You will need at least two IC: one will be working as comparator with adjutable threshold, and as reference voltage you can use the supply voltage, say, +5Vdc.
This IC can be a typical comparator, such as LM311, or any opamp woking as comparator.
The second IC should connect 0V if signal is smaller than threshold ,and allow the input voltage if the value is abov threshold. This can be realized with CD4066 (cmos quad switch), where two switches will ave connected their outputs, and one input will be connected to 0V, and the other input from the second switch is connected to Vin.
Regards,
IanP
 

hi,
I have considered to use a SINGLE MAX4544(Single Pole/Double Throw Switch) to realize these functions.
IN(digital control input ) ----1 6---- NO(normally open)
V+(supply voltage input) ----2 5---- COM(common)
GND(ground ) ---3 4---- NC(normally closed)

PIN 1,2,6 are connected together to Vin. PIN 4 is connected to GND. When Vin is above the threshold, the Vout, which is connected to PIN 5, is the same as Vin (excepted a little voltage drop).
However, when Vin is smaller than the threshold, Vout is also the same as Vin, for the supply voltage (connected to Vin) is out of the proper range of supply voltage.
 

I have a few questions first.

What is the input voltage range?
What is the output current?
How close does Vout need to follow Vin?
 

air2008 said:
hi,
I need an IC which can perform the following function.
(1) Just ONE voltage input, Vin.
(2) Just ONE voltage output, Vout.
(3) If Vin is less than a threshold (say, 1.8V), Vout is zero.
(4) If Vin is larger than this threshold, Vout = Vin.
I have considered to use a voltage comparater, but the voltage comparater needs a reference voltage, in addition to a voltage input Vin.
Anybody can recommend an IC to me?


air2008
Click to expand...

I think you need something like CPU supervisor AD690 or MAX690 that is standard chip for this application.
**broken link removed**
 

Ithink a battery supervisor chip would do what you're looking for try maximic.com
 

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