OPA593: OPA593 Output query

Tejendra varma

Part Number: OPA593
Other Parts Discussed in Thread: OPA992, OPA990

Hi,

I'm using OPA593 as a unity buffer for my motor application. I have seen in the datasheet that there will be a 0.7V diode drop in the output in page no - 24.

My application is +10V to -10V single-ended input that must be amplified.

by using this amplifier as a unity buffer, if I give +10V will the output be 9.3?? and if I give -10 the output will be -10.7 ??

if yes kindly suggest an alternate part number for +/-12V input and with enable disable function.

i have attached the schematic for your reference kindly please go through it and suggest the best possible way to reduce it.

Any wrong with the circuit please suggest modifications.

/resized-image/__size/320x240/__key/communityserver-discussions-components-files/14/OPA593-Schematic.png

Tejendra

9 months ago

0 Clemens Ladisch 9 months ago

Guru 280970 points

Section 7.3.5 of the datasheet does not say anything about the output. It does say about the inputs that there are no diodes.

The OPA593 does not have rail-to-rail inputs (see the V_CM specification in section 6.5), so with ±12 V supplies, it will not handle input voltages above +8.5 V.

Here is a search for 24 V, rail-to-rail opamps with shutdown:
ti.com/amplifier-circuit/op-amps/general-purpose/products.html#78=In&480=1;1&2192=Shutdown&1261max=24;48
Choose whatever speed you need.

0 Raymond Zhang1 9 months ago

TI__Guru 56271 points

Hi Tejendra,

As Clemens suggested, OPA593 does not use back to back diodes at the input. However, OPA593 is not rail to rail input amplifier, see Vcm input for linear operating range. The output voltage swing or headroom depend on the output current. If the motor application draws high current, then you need to take into account the output headroom at the output.

The simulation below may be your example.

OPA593 20V swings 02122024.TSC

If you have other questions, please let us know.

Best,

Raymond

0 Tejendra varma 9 months ago in reply to Clemens Ladisch

Prodigy 50 points

Hi Clemens,

My power supply is +/-12V can I give 10V input for in+ ?? and its a single-ended. This needs to be unity gained. And does the OPA992 work with +/-12V for +/- 10V in+ Please let me know.

If it not works suggest a part which supports my requirement.

0 Clemens Ladisch 9 months ago in reply to Tejendra varma

Guru 280970 points

The V_CM specification in section 6.5 says that the OPA593 needs a headroom of 3.5 V to the positive supply.

The OPA992 has rail-to-rail inputs and outputs.

0 Raymond Zhang1 9 months ago

TI__Guru 56271 points

Hi Tejendra,

OPA990 is the rail to rail op amp, but it is unable to source beyond ±40mA-50mA current range. What are the application's current requirements?

Best,

Raymond

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OPA593: OPA593 Output query