Hi,

I am currently using the configuration shown to obtain a -ve supply in the
region of -2.5V, for an LCD. Is there a more optimal solution?
The clock is driven straight from a buffer, at 4MHz.

                                 1n4148                 100n       3K3
                            -------|<--------------------|
|---------R-------------CLK (3V Drive)
                            |                             |
+3        +3       GND                     _|_
   |           |                                         ^   1n4148
 --- C1   Z 6V8                                |
 ---          |                                          |
   |_____|__________________|__________TO LCD ( ~ -2.5V)

Apologies for the very bad ASCII.

C1=100nF, Z=Zener diode, 6V8, cathode to +3V rail (got a bit squashed up at
that side!),

Anyone help, please? I know it's nasty, but it only needs to control the
contrast.

Regards,

Dan

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