Dear hiren
Hi
DC or AC ? from what source ? how much is your input voltage ? how much current do you need ? if you mention these parameters i can help you as well .
Best Wishes
Goldsmith
Although the original post is unclear as to the input voltage, "generate" implies that the author wants to generate a negative voltage from a positive voltage supply, not simply regulate an existing negative voltage.
Can you elaborate a little more on how the LM337 will generate a negative voltage from a positive supply? The datasheet does not show that application.
Dear John
Hi
I think you are right . if the author wants to convert a positive voltage to a negative voltage , , can use a simple buck boost converter . but if the author doesn't need high currents , he will be able to use a simple multiplier with diode and capacitor ! isn't it ?
Best Regards
Goldsmith
There are numerous chips for generating negative bias, such as the ICL7660/7660A that is a switched capacitor device.
If he is using this with a microcontroller, e.g., for GLCD bias, then one pin can be used to drive a simple charge pump. A typical circuit is shown in the New Haven Display application note, "Voltage Generating Circuits for LCD Contrast Control." Unfortunately, I do not have a direct link handy to supply for that document. As its title would suggest, that document also shows several other approaches.
Humm , your suggested circuit seems pretty good ! but if he needs high value of currents it can't be good . for example 10 amperes ! the main problem is that he didn't mention the exact specifications .
Respectfully
Goldsmith