Spartan-3 FPGA Family: DC and Switching Characteristics
DS099 (v3.1) June 27, 2013
Product Specification
61
Table 33: General DC Characteristics of User I/O, Dual-Purpose, and Dedicated Pins
Symbol
Description
Test Conditions
Min
Typ
Max
Units
Leakage current at User I/O,
Dual-Purpose, and Dedicated pins
Driver is Hi-Z, VIN =
0V or VCCO max,
sample-tested
VCCO ≥ 3.0V
–-
±25
μA
VCCO < 3.0V
–-
±10
μA
Current through pull-up resistor at User I/O,
Dual-Purpose, and Dedicated pins
VIN = 0V, VCCO = 3.3V
–0.84
-
–2.35
mA
VIN = 0V, VCCO = 3.0V
–0.69
-
–1.99
mA
VIN = 0V, VCCO = 2.5V
–0.47
-
–1.41
mA
VIN = 0V, VCCO = 1.8V
–0.21
-
–0.69
mA
VIN = 0V, VCCO = 1.5V
–0.13
-
–0.43
mA
VIN = 0V, VCCO = 1.2V
–0.06
-
–0.22
mA
Equivalent resistance of pull-up resistor at
User I/O, Dual-Purpose, and Dedicated
pins, derived from IRPU
VCCO = 3.0V to 3.465V
1.27
-
4.11
k
Ω
VCCO = 2.3V to 2.7V
1.15
-
3.25
k
Ω
VCCO = 1.7V to 1.9V
2.45
-
9.10
k
Ω
VCCO = 1.4V to 1.6V
3.25
-
12.10
k
Ω
VCCO = 1.14 to 1.26V
5.15
-
21.00
k
Ω
Current through pull-down resistor at User
I/O, Dual-Purpose, and Dedicated pins
VIN = VCCO
0.37
-
1.67
mA
Equivalent resistance of pull-down resistor
at User I/O, Dual-Purpose, and Dedicated
pins, driven from IRPD
VIN = VCCO = 3.0V to 3.465V
1.75
-
9.35
k
Ω
VIN = VCCO = 2.3V to 2.7V
1.35
-
7.30
k
Ω
VIN = VCCO = 1.7V to 1.9V
1.00
-
5.15
k
Ω
VIN = VCCO = 1.4V to 1.6V
0.85
-
4.35
k
Ω
VIN = VCCO = 1.14 to 1.26V
0.68
-
3.465
k
Ω
RDCI
Value of external reference resistor to support DCI I/O standards
20
-
100
Ω
IREF
VREF current per pin
VCCO ≥ 3.0V
–-
±25
μA
VCCO < 3.0V
–-
±10
μA
CIN
Input capacitance
3
-
10
pF
Notes:
1.
The numbers in this table are based on the conditions set forth in
Table 32.2.
The IL specification applies to every I/O pin throughout power-on as long as the voltage on that pin stays between the absolute VIN minimum
and maximum values (
Table 28). For hot-swap applications, at the time of card connection, be sure to keep all I/O voltages within this range
before applying VCCO power. Consider applying VCCO power before connecting the signal lines, to avoid turning on the ESD protection
diodes, shown in Module 2:
Figure 7, page 11. When the FPGA is completely unpowered, the I/O pins are high impedance, but there is a
path through the upper and lower ESD protection diodes.
3.
This parameter is based on characterization. The pull-up resistance RPU = VCCO / IRPU. The pull-down resistance RPD =VIN /IRPD.
Spartan-3 family values for both resistances are stronger than they have been for previous FPGA families.
4.
For single-ended signals that are placed on a differential-capable I/O, VIN of –0.2V to –0.3V is supported but can cause increased leakage
between the two pins. See the Parasitic Leakage section in
UG331, Spartan-3 Generation FPGA User Guide.