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| OPA445 Op amp question. |
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| Jwillis:
I got these OPA 445 op amps to mess around with because of the higher voltage rating then the more commonly used 741s. Now they should both operate generally the same way aside from the difference of supply voltage correct? The OPA445 needs a minimum of +/- 10 volts to a maximum of +/- 45 V so they should operate at 25 volts which means +12.5 /-12.5 or am I missing something in the data sheet .I've tried higher voltages but still get no reaction from the chip. Is there a different way I can test these other than setting them up as an oscillator because I can't get them to oscillate at any voltage. http://www.ti.com/lit/ds/sbos156b/sbos156b.pdf |
| Audioguru:
The input and output voltage ranges are 5V more positive than the negative supply to 5V more negative than the positive supply so with your -12.5V and +12.5V supplies, the input and output voltage ranges are -7.5V to +7.5V. |
| Jwillis:
Ok .So what does that mean? The input voltage is to high? |
| Bassman59:
--- Quote from: Jwillis on March 27, 2019, 10:13:13 pm ---Ok .So what does that mean? The input voltage is to high? --- End quote --- It means that with power-supply rails of ± 12.5, the output voltage cannot swing beyond ± 7.5 V. Nor can the inputs, although you don't show any circuit. You say "how can I test this other than setting them up as an oscillator" -- why would you do that? A reasonable circuit might be a simple inverter. |
| Jwillis:
I don't a have a real use for them in any particular circuit right now .Because they're used with unknown condition I wanted to set them in a simple circuit to test them so I put them in an flashing LED circuit like this one below . But get no response.Did I burn them out? |
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