Author Topic: Test uSupply, cann't generate 0V ???  (Read 2200 times)

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Offline xiaoao360Topic starter

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Test uSupply, cann't generate 0V ???
« on: February 01, 2015, 12:41:04 am »
Cann't generate 0V ???
 

Offline mij59

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Re: Test uSupply, cann't generate 0V ???
« Reply #1 on: February 01, 2015, 05:31:31 am »
Take a look at the data sheet of the LT6016, output voltage swing low, no load typical 3 mV.
The LT3080 will source a 10 uA current out of the set pin, so the output voltage of the LT6016 can never be 0 volts.
The resistors R12 and R13 are also causing a voltage drop.

 

Offline xiaoao360Topic starter

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Re: Test uSupply, cann't generate 0V ???
« Reply #2 on: February 01, 2015, 07:32:27 am »
Take a look at the data sheet of the LT6016, output voltage swing low, no load typical 3 mV.
The LT3080 will source a 10 uA current out of the set pin, so the output voltage of the LT6016 can never be 0 volts.
The resistors R12 and R13 are also causing a voltage drop.

In the actual circuit, I use LM358 as a replacement of LT6016. There is 33mv voltage on the set pin and out pin.
and the resistors R12 and R13 are necessary in the original circuit, you can download the cirucit at:
http://www.eevblog.com/projects/usupply/
I don't know whether there is a 0V output in David's original circuit.
I think the resistors R11 and R12(in the Rev.C circuit) are also causing a voltage drop.
 

Offline mij59

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Re: Test uSupply, cann't generate 0V ???
« Reply #3 on: February 01, 2015, 08:24:07 am »
Take a look at the data sheet of the LT6016, output voltage swing low, no load typical 3 mV.
The LT3080 will source a 10 uA current out of the set pin, so the output voltage of the LT6016 can never be 0 volts.
The resistors R12 and R13 are also causing a voltage drop.

In the actual circuit, I use LM358 as a replacement of LT6016. There is 33mv voltage on the set pin and out pin.
and the resistors R12 and R13 are necessary in the original circuit, you can download the cirucit at:
http://www.eevblog.com/projects/usupply/
I don't know whether there is a 0V output in David's original circuit.
I think the resistors R11 and R12(in the Rev.C circuit) are also causing a voltage drop.

To get 0V at the output of the opamp you need a negative voltage rail, the minimum value of the negative voltage rail depends on the properties of the opamp.
 

Offline xiaoao360Topic starter

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Re: Test uSupply, cann't generate 0V ???
« Reply #4 on: February 01, 2015, 08:38:06 am »
I used to think David's circuit can generate 0V output.
 


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