cltong
Joined: 03 Jan 2003
Posts: 7
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 26 Jun 2003 14:51 something about low power lcd |
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In the lcd system,use 1.5v (vdd) battery,to show lcd i need to generate -1.5v(vee) source.
The lcd is 2 bias,3 com 7segment, the com need 1.5v 0v -1.5v total three voltage,I supply 1.5v through a pmos,the substrate connet 1.5v;send -1.5v by a nmos,the nmos substrate connet -1.5v;but i sent 0v to com,these is some question:
I use a nmos transfrom 0v to com, if i connect the subsract to lowermost, the vee stop at -0.7v to -1.0v,can't lower,but if i connect the substract to gnd, the problem is solve,why?
thanks!
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