Greetings All,
I'm currently working on learning about sine generation techniques and 3 level PWM for driving an Hbridge. I came across this "Precision TriWave Generator Circuit" from National Semiconductor and a differential pair circuit to convert the triangle wave to a sine wave with fairly high accuracy. My issue is that I was told I need to temperature compensate the signal controlling the base of the BJT differential pair if I want to have good accuracy but I'm not sure how to do this.
TI has an example log shaper circuit with clamping diodes as temperature compensation but I cant tell how this compensates for temp in any way. I think the diodes are for standard reference and the double diodes are there for a 1.4V reference of some kind instead of 0.7V with one, but again, don't know how they compensate for temp.
Any help, or literature, in understanding what is actually going on in the diode section of TI circuit or how to modify a circuit for temperature compensation is what I'm really after.
Thanks in advance
I'm currently working on learning about sine generation techniques and 3 level PWM for driving an Hbridge. I came across this "Precision TriWave Generator Circuit" from National Semiconductor and a differential pair circuit to convert the triangle wave to a sine wave with fairly high accuracy. My issue is that I was told I need to temperature compensate the signal controlling the base of the BJT differential pair if I want to have good accuracy but I'm not sure how to do this.
TI has an example log shaper circuit with clamping diodes as temperature compensation but I cant tell how this compensates for temp in any way. I think the diodes are for standard reference and the double diodes are there for a 1.4V reference of some kind instead of 0.7V with one, but again, don't know how they compensate for temp.
Any help, or literature, in understanding what is actually going on in the diode section of TI circuit or how to modify a circuit for temperature compensation is what I'm really after.
Thanks in advance
Attachments

80.2 KB Views: 5