Answers Database

PROMs: Can the VPP/VCC pin be tied through a resistor to +5V?


Record #1420

Product Family:  Hardware

Product Line:  1700

Problem Title:
PROMs: Can the VPP/VCC pin be tied through a resistor to +5V?


Problem Description:
Keywords:  prom, resistor, vpp, vcc

Urgency:  standard

General Description:

Can a customer tie the VPP/VCC pin of a XC1700 PROM through a resistor to +5 Vol
ts?

Customers may want to do this if they are switching between
Xilinx and Atmel PROMs.


Solution 1:

Solution:


Do not use a resistor between VCC and VPP pins on XC1700. This has severe impact
s on speed and data reliability.
Vpp is actually the power supply for the read section.

If a customer is using a resistor between the VCC and
the VPP they should be aware that this will affect the
reliability and speed of the part.

To prevent this problem, tie VPP and VCC directly to +5 Volts.



End of Record #1420