Post Go back to editing

LTSPICE: When using a single power supply, the AD8041 input bias current is too high.

Category: Software
Product Number: SOFTWARE
Software Version: V24.0.12

Hi all,

When using dual power supply, the input bias current is approximately 1.2uA, which is within the normal range.

When powered by a single 5V supply, the input bias current exceeds 16uA, which is beyond the maximum value specified in the datasheet.

Where is the problem?

thanks

AD8041.asc

Parents
  • If you look at the AD8041 model in ADI.lib, you'll find connections of components at the AD8041 inputs (See FrontEnd.asc).  All four capacitors tied to the inputs are spec'ed with parallel resistances.  When +V and -V are at 5 volts, the bias currents come from I1 and I2 and meet typical spec, but when -V=0 the inputs get additional currents flowing out through the parallel resistances connected to +V making the bias currents approx. -16.8uA.

    FrontEnd.asc

Reply
  • If you look at the AD8041 model in ADI.lib, you'll find connections of components at the AD8041 inputs (See FrontEnd.asc).  All four capacitors tied to the inputs are spec'ed with parallel resistances.  When +V and -V are at 5 volts, the bias currents come from I1 and I2 and meet typical spec, but when -V=0 the inputs get additional currents flowing out through the parallel resistances connected to +V making the bias currents approx. -16.8uA.

    FrontEnd.asc

Children