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SED1565 problem


New member
I have a TM12864A2FFG displayer , with the SED1565 controler ,the problem that i can't obtain the -9.5V when i applied the power supply circuits :
-> Booster circuit control bit :ON
-> Voltage regulator circuit (V regulator circuit) control bit ON >Voltage follower circuit (V/F circuit) control bit ON
but when i applied the Booster circuit control alone i have the -9 V

the Circuit is : 3X charge pump, 4.7uF between CAP2+ and CAP2-, CAP1+ and CAP1-, and Vout connected to CAP3- and through a 4.7uF capacitor to VSS.
for more information of the circuit see this site :http://www.tianma.com/admin/specification/425TM12864A2FFG.pdf

my circuit is when the voltage regulator internal resistor is not used
thanks for help
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I am not sure I understand your problem.
Are you setting the reference voltage (electronic volume) using the 0x81 command followed by a value 0 to 0x3F? I have found this works best when done both before turning on the charge pump control bits, and again after the charge pump is on. What is your V5 value? about -4.5v will give good contrast (in my experience).
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