Buffer Opamp for sinus generator

[dark]

I have a sine wave generator which is providing 5Vrms at 30mA . It has a THD of -55dB , the problem is its getting hot. I thought I should use a buffer Opamp to ease it . What characheristic opamp is required for keep maintaining THD and at temperature of 85C ambient ? .


Thanks
-Adi

 

[audioguru]

5V RMS at 30mA RMS is an output power of only 0.15W which is very low.
The heating from the circuit might be 0.2W which is also low.

Why is the ambient temperature a whopping 85 degrees C which is hotter than hell?

Most inexpensive and half-decent opamps have a distortion of only -90dB or less at low frequencies but only a few can drive a load as low as 600 ohms. They would dissipate the same amount of heat as your oscillator opamp.

What frequency?

 

[Analog]

I cleared my sinuses at 85C

Why not use a class AB booster after the op amp, but in the op amp's feedback loop?

 

[audioguru]

The opamp gets hot because the ambient temperature is hot.
What is the load on the generator?

 

[dark]

5V RMS at 30mA RMS is an output power of only 0.15W which is very low.
The heating from the circuit might be 0.2W which is also low.

Why is the ambient temperature a whopping 85 degrees C which is hotter than hell?

Most inexpensive and half-decent opamps have a distortion of only -90dB or less at low frequencies but only a few can drive a load as low as 600 ohms. They would dissipate the same amount of heat as your oscillator opamp.

What frequency?

The frequency is 3KHz , its getting hot as its for an automotive purpose . The load is roughly 2KOhm .

 

[audioguru]

5V into 2k is only 12.5mW so that does not increase the heat of the generator.
Adding a buffer won't make any difference.
Maybe the generator uses a high current class-A output?

 

[dark]

5V into 2k is only 12.5mW so that does not increase the heat of the generator.
Adding a buffer won't make any difference.
Maybe the generator uses a high current class-A output?

That is the load resistance which is mandatory and after that it is capable of driving a load of roughly 70mW inductive load . Please help me know why cant a buffer opamp share its load current ?



Thanks

 

[jitesh_heartbeat]

I have a sine wave generator which is providing 5Vrms at 30mA . It has a THD of -55dB , the problem is its getting hot. I thought I should use a buffer Opamp to ease it . What characheristic opamp is required for keep maintaining THD and at temperature of 85C ambient ? .


Thanks
jitesh

 

[ericgibbs]

I have a sine wave generator which is providing 5Vrms at 30mA . It has a THD of -55dB , the problem is its getting hot. I thought I should use a buffer Opamp to ease it . What characheristic opamp is required for keep maintaining THD and at temperature of 85C ambient ? .


Thanks
jitesh

Why have you copied/pasted and reposted the ORIGINAL post for this thread.????