Answers Database
2000L,3000L,3100L,4000L,4000XL: How do these 3.3V parts differ from their 5V counterparts?
Record #1907
Product Family: Hardware
Product Line: 4000L
Product Part: 4000L
Problem Title:
2000L,3000L,3100L,4000L,4000XL: How do these 3.3V parts differ from their 5V counterparts?
Problem Description:
XC4000XL, XC5200L
More and more Xilinx families are becomimg available in 3.3 V
versions, but not all Xilinx 3.3-V families are created equal.
Here are the details:
XC2000L is the same die as XC2000, but the "L"-version is
bonded differently, to make the chip wake up with CMOS
thresholds ( 50% of Vcc, vs TTL thresholds in XC2000 ).
The low-voltage detector is around 2.5 V for all XC2000
devices.
XC3000L is the same die as XC3000A, and
XC3100L is the same die as XC3100A,
but the "L" versions are specially bonded to make two
changes:
The device wakes up with CMOS input thresholds
(50% of Vcc, vs TTL thresholds in XC3000A ), and the
low-voltage detector kicks in at 2.5V (vs. 3.2V in the
XC3000A ).
XC4000L is the same die as XC4000E, but the "L"-version is
bonded differently, so that it wakes up with CMOS input
thresholds. Both XC4000E and XC4000L have the low-voltage
detector @ 2.5 V.
XC4000XL is a new design, circuit details are different from
XC4000EX. Internal geometries are optimized for the 0.35
micron process and 3.3-V operation. The I/O structure is
completely redesigned to achieve 5-V tolerance.
XC5200L is the same die as XC5200, but the "L" versions are
specially bonded to make three changes:
The low-voltage detector kicks in at 2.2V (vs. 3.2V in the
XC5200 ), and the device wakes up with CMOS input
thresholds =50% of Vcc Inputs are 5-V tolerant if one of
the Vcc pin (called Vtt ) is connected to the 5-V Vcc.
This is a simpler structure than the one in XC4000XL.
Note that XC3100L and XC5200L use a continuously running
internal oscillator to generate an elevated voltage for driving
the pass-transistor gates , This is called "pumped gates" and
gives better speed, but results in significantly elevated idle
( quiescent ) current consumption, bad for battery-operated
systems. XC3100 devices have always used this technique, while
the original XC5200 devices did not, but the coming releases
will.
Solution 1:
End of Record #1907 - Last Modified: 09/05/97 18:22 |
