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yelenavik
USA
31 Posts |
 Posted - 03/31/2010 : 17:47:05
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| Hello,ZLM.I have now problem Vcc in PLCC-32 .I checked 4.16v,so all chip like 25mxlv040 a29o40 other too(3v only)ID-check ok,read ok,erase ok,blank ok,but can't write(stay in O%).I think too much VCC for 3V chips.I dont have schematic could try fix or need send to you.H/W test passed.So please help.(for 24xx eeprom show 3.4V -ok).Thank's. |
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| Reply #1
ZLM
2945 Posts |
Posted - 04/05/2010 : 23:08:33
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| How do you measured the vcc? Which chip you selected and which pins you measured? |
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| Reply #2
yelenavik
USA
31 Posts |
Posted - 04/06/2010 : 05:29:27
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| SST39VF040 adapter ADP-005 PIN 16-32 multimeter fluke,pin out from ZIF,pin connection checked good.4.3v in standby,drop to 4.16 in program time |
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| Reply #3
ZLM
2945 Posts |
Posted - 04/06/2010 : 09:33:23
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I think the voltage comes from the signal pull-up resistors.
If you remove the chip and place a resistor(about 500-ohm to 1K) between pin 16 and 32 chip position on ZIF. When the VCC is ON, it should be about 3.3-3.6V.
In your case, I think is something else stops writing. What software version you are using? Dose the software freeze during the writing?
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| Reply #4
yelenavik
USA
31 Posts |
Posted - 04/07/2010 : 12:50:42
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| ZLM,Yes with resistor when read 3.38v,without resistor erase 4,3v write 4.16 for MX29LV040(3V only) unprotected checked read ok,erase ok blank ok write ok ,verify ok.probably problem in adapter ADP-005sometime loose ID.I think gold pin better .ZLM may be need decrease VCC for 3V chips for sample via diode or zener 3v between 16 and 32 pin on the ADP-005,because many flash 3v chips.What do You think.Thank's. |
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| Reply #5
ZLM
2945 Posts |
Posted - 04/07/2010 : 19:41:11
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| That is a good idea. Will do some changes on adapter. |
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GQ-4 problem VCC
