All Forums  MCUmall Forums  True USB Willem Programmer (GQ-2X,3X,4X & GQ-4x4)  GQ-4X 27C256 and 27256 VPP Voltage Value Settings

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Screensize: 640 x 480 800 x 600 1024 x 768 1280 x 1024 UserName: Password: Format Mode: Basic  Help  Prompt  Format: Font Andale Mono Arial Arial Black Book Antiqua Century Gothic Comic Sans MS Courier New Georgia Impact Lucida Console Script MT Bold Stencil Tahoma Times New Roman Trebuchet MS Verdana   Size 1 2 3 4 5 6   Color Black Red Yellow Pink Green Orange Purple Blue Beige Brown Teal Navy Maroon LimeGreen Message: * HTML is OFF * Forum Code is ON Smilies [quote][i]Originally posted by Krankshaft[/i] [br]I have a question regarding the VPP voltage the GQ-4X applies to 27C256 CMOS EPROMS during programming. While checking the details in the GQ-4X software I found that the programmer only applies 12 volts to VPP. While in an ST datasheet it says to apply 12.7 volts. I then looked at the exact same size EPROM of the NMOS variety a 27256 and found the programmer applies 12.7 volts which falls into the tolerance specified on that parts datasheet (12.5V +- 0.3V). Is there any particular reason less voltage is applied to VPP on the CMOS EPROMS compared to the NMOS or is that extra 3/4 of a volt just not that critical? I've programmed both of these parts the code verified and they operate fine but I'm just curious. [/quote]    Insert an Image File Check here to include your profile signature.