سلام به همه
برام سوال پیش اومد که تفاوت اسم های مختلفی که برای تغذیه توی مدار میزارن چیه؟
VDD vs VCC
VSS vs VEE
که به جواب زیر رسیدم و جالب بود گفتم اینجا هم بزارمشون:
مخفف:
از آدرس زیر جواب رو گرفتم:
http://www.edaboard.com/thread74446.html
و برای vpp:
Programming Pulse voltage. Back when the 2708 EPROM was king, the programming was done with 25V pulses applied to the Vpp pin. The timing requirements on this voltage were rather stringent (and the algorithm complicated), so the next parts, starting with 2716, used a FIXED 25V voltage and the programming pulse was just a TTL signal applied to the PGM pin.
However, the name of the Vpp pin lives on, even though it is now used to only supply a DC voltage. You will find it even on FLASH devices. Applying 12V to this pin (again, DC, not pulses) speeds up the programming of the FLASH (but it is not necessary).
In some microcontrollers, such as FLASH-based PICs, the Vpp is required only to put the part into programming mode, not to actually program the internal FLASH memory. For that there is an internal charge pump. But the name Vpp is still used.
برام سوال پیش اومد که تفاوت اسم های مختلفی که برای تغذیه توی مدار میزارن چیه؟
VDD vs VCC
VSS vs VEE
که به جواب زیر رسیدم و جالب بود گفتم اینجا هم بزارمشون:
مخفف:
Vdd= 'Voltage Drain Drain'
Vss='Voltage Source Source'
Vss='Voltage Source Source'
از آدرس زیر جواب رو گرفتم:
http://www.edaboard.com/thread74446.html
It goes back in history, Vcc applies to transistors, Volts collector common, Vdd applies to fets, Volts drain ?. Vee, Volts emitter ?. It's been lost with the passage of time!
و برای vpp:
Programming Pulse voltage. Back when the 2708 EPROM was king, the programming was done with 25V pulses applied to the Vpp pin. The timing requirements on this voltage were rather stringent (and the algorithm complicated), so the next parts, starting with 2716, used a FIXED 25V voltage and the programming pulse was just a TTL signal applied to the PGM pin.
However, the name of the Vpp pin lives on, even though it is now used to only supply a DC voltage. You will find it even on FLASH devices. Applying 12V to this pin (again, DC, not pulses) speeds up the programming of the FLASH (but it is not necessary).
In some microcontrollers, such as FLASH-based PICs, the Vpp is required only to put the part into programming mode, not to actually program the internal FLASH memory. For that there is an internal charge pump. But the name Vpp is still used.
دیدگاه