Hello people of Earth,
I come to you from a distant and remote satelite called Kenphuscien.
I've been trying to understand the LM13700 OTA (operational transconductance amplifier) (datasheet) in order to make a voltage controlled amplifier (VCA) I get the basics of operation; current applied to the amp bias input controls conductance however I don't quite understand the first VCA circuit in the datasheet (figure 2) or why there is diode bias on the inputs?
Why don't they use the ordinary arrangement for a differential amplifier or even an inverting amplifier?
By the By I'll be running my circuits on a single supply (+12V) ordinarily I'd apply half Vs to the non-inverting input of an op amp to make a single supply, non-inverting amplifier ... but the arrangement suggested in the LM13700 datasheet is strange and confusing
I'm reading and re-reading the datasheet and it slowly making more sense (but why don't they just use an ordinary non-confusing op amp arrangement!?!?!? )
My point is; another person's explanation would help me understand more, another wording or a different take on the description of the VCA would shed more light.
I come to you from a distant and remote satelite called Kenphuscien.
I've been trying to understand the LM13700 OTA (operational transconductance amplifier) (datasheet) in order to make a voltage controlled amplifier (VCA) I get the basics of operation; current applied to the amp bias input controls conductance however I don't quite understand the first VCA circuit in the datasheet (figure 2) or why there is diode bias on the inputs?
Why don't they use the ordinary arrangement for a differential amplifier or even an inverting amplifier?
By the By I'll be running my circuits on a single supply (+12V) ordinarily I'd apply half Vs to the non-inverting input of an op amp to make a single supply, non-inverting amplifier ... but the arrangement suggested in the LM13700 datasheet is strange and confusing
I'm reading and re-reading the datasheet and it slowly making more sense (but why don't they just use an ordinary non-confusing op amp arrangement!?!?!? )
My point is; another person's explanation would help me understand more, another wording or a different take on the description of the VCA would shed more light.