Searching operational amplifer meeting -24V input/output

Katsuya Sato

Other Parts Discussed in Thread: LM4562

Hi, experts,

I am looking for an operational amplifier that meets the following conditions of use.

Input -24V to -18V DC and 100mVpp AC to each input terminal.
Output signal is piled up with the DC and AC.
AC frequency: 500Hz~20MHz
Output current: 10mA or higher
Slew rate: 150V/us or higher

Could you tell me the product meets above specifications?

thanks,

Katsuya

over 1 year ago

0 Clemens Ladisch over 1 year ago

Guru 284810 points

What are the power supply rails? ±24 V, or −24 V and 0 V?

What are the desired output voltages?

0 Katsuya Sato over 1 year ago in reply to Clemens Ladisch

Prodigy 85 points

Thank you for replying.

If the signal input is -24V, the output is considered to be -24V ±100mVpp, and the power supply to the op amp is considered to be 0V and about -28V.

Sorry, the slew rate is 15V/us or higher, not 150V/us due to wrong calculation.

0 Ron Michallick over 1 year ago in reply to Katsuya Sato

TI__Guru**** 152966 points

Katsuya-san,

Are you saying that VOUT = VIN , gain of 1?

LM4562 is a low cost option.

0 Katsuya Sato over 1 year ago in reply to Ron Michallick

Prodigy 85 points

I misunderstood the usage.
The op-amp is used as a voltage follower, with DC (-18V~-24V) and AC (100mVpp, 500Hz~20MHz) superimposed as input signal.

I think that the LM4562 cannot input/output at -24V because the power supply is -5V, is this correct?

0 Clemens Ladisch over 1 year ago in reply to Katsuya Sato

Guru 284810 points

The LM4562 will work with the 0 V / −28 V supplies. Where does the −5 V number come from?

0 Katsuya Sato over 1 year ago in reply to Clemens Ladisch

Prodigy 85 points

A datasheet of LM4562 says that "Power Supply Voltage Range: ±2.5V to ±17V", but is it OK to apply -28V?

Could you provide a schematic?

-5V was by my mistake.

+1 Clemens Ladisch over 1 year ago in reply to Katsuya Sato

Guru 284810 points

Only the difference between the two supply rails matters. ±17 V = 34 V, so 28 V is OK.

+1 Ron Michallick over 1 year ago in reply to Katsuya Sato

TI__Guru**** 152966 points

Katsuya-san,

If the input is capable of providing high current (>10mA) then add series resistance between VIN and IN+ (to protect op amp and your Vin source). Especially if VIN may be present before Vs- is powered.

Vs+ can be 0V and Vs- can be -28V

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Searching operational amplifer meeting -24V input/output