PIO DRIVER REPORT AT 160 MHz
Nishank R Shinde
The Driver macro is tested at 160MHz for set of process corners and temperatures combinations.
The enable pin is added to the schematic and the layout to have more control on the input data.
Corresponding DRC and LVS checking has also been done. The simulations results done at critical
points (worst cases) and resulting plots are shown below. Also, the driver block is tested for both ON
and OFF states for enable.
Schematics
Enable
Fig. PIO Driver testbench schematic
Simulation Cases

Simulations showing variation of output current with process corners
Process corner
Temperature
TT
FF
SF
FS
SS
25 C
25 C
25 C
25 C
25 C
Current
levels
010
010
010
010
010
Voltage
Enable
1.2 V
1.2 V
1.2 V
1.2 V
1.2 V
1
1
1
1
1
LVDS_P
Current
-1.03 mA
-1.09 mA
-1.07 mA
-997.1 uA
-985.2 uA
LVDS_N
Current
1.03 mA
1.09 mA
1.07 mA
997.1 uA
985.2 uA
Output check
Yes
Yes
Yes
Yes
Yes
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
Process
corner
TT
TT
TT
TT
TT
TT
TT
TT
TT

Process
corner
TT
TT
TT
TT
Simulations showing variation of output current strength with input current
combinations
Temperature Current Voltage
levels
0C
000
1.2 V
0C
001
1.2 V
0C
010
1.2 V
0C
011
1.2 V
0C
100
1.2 V
0C
101
1.2 V
0C
110
1.2 V
0C
111
1.2 V
0C
111
1.2 V
Enable
1
1
1
1
1
1
1
1
0
LVDS_P
Current
-34.9 uA
-520.46 uA
-1.03 mA
-1.53 mA
-2.03 mA
-2.51 mA
-2.99 mA
-3.45 mA
-34.9 nA
LVDS_N
Current
34.9 uA
520.46 uA
1.03 mA
1.53 mA
2.03 mA
2.51 mA
2.99 mA
3.45 mA
34.9 nA
Output check
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Simulations showing variation of output current with temperature
Temperature Current
levels
-25 C
010
0C
010
25 C
010
50 C
010
Voltage
1.2 V
1.2 V
1.2 V
1.2 V
Enable
1
1
1
1
LVDS_P
Current
-1.022 mA
-1.031 mA
-1.039 mA
-1.047 mA
LVDS_N
Current
1.022 mA
1.031 mA
1.039 mA
1.047 mA
Output check
Yes
Yes
Yes
Yes
Plots
Note: The left side in the plot(s) represent differential voltage (LVDS_P – LVDS_N) and right
side of the plot(s) represents the din, current through LVDS_P and current through LVDS_N
terminals.

Process corner: FF, Temperature: -25 C, Current levels: 111, Enable: ON
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
Process corner: FF, Temperature: -25 C, Current levels: 111, Enable: OFF

Process corner: FS, Temperature: 25 C, Current levels: 010, Enable: ON

Process corner: SS, Temperature: 50 C, Current levels: 000, Enable: ON
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
Process corner: TT, Temperature: 0 C, Current levels: 000, Enable: ON

Process corner: TT, Temperature: 0 C, Current levels: 001, Enable: ON

Process corner: TT, Temperature: 0 C, Current levels: 100, Enable: ON
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
Process corner: TT, Temperature: 25 C, Current levels: 010, Enable: ON

Process corner: FF, Temperature: 25 C, Current levels: 010, Enable: ON
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
Process corner: FS, Temperature: 25 C, Current levels: 010, Enable: ON

Process corner: SS, Temperature: 25 C, Current levels: 010, Enable: ON
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Conclusion
The above simulations were successfully performed on the extracted model of the PIO
driver at 160 MHz. The simulations were conducted on most important test cases (including
worst case scenarios). The effect of enable can be clearly seen from the simulation cases –
when the enable is ON and current level combination is 000, there is no significant current
flowing the LVDS_P and LVDS_N terminals. When enable is OFF, the current level 111 at
process corner TT at 0 C results in negligible current (few nA) drawn at the LVDS_P and
LVDS_N terminals.
Effects of entities in the simulations can be summarized as follows.
1. At a particular temperature and input current level, output current increases from
process corner SS to process corner FF by 25 uA.
2. Output voltage swing depends on termination resistance.
3. At a particular process corner and input current levels, output current increases as
temperature increases from 1.022 mA at -25 C to 1.047 mA at 50 C.
4. At a particular process corner and temperature, output current increases with
corresponding increase in input current levels. The output current value increases
from 34.9 uA at input current level of 000 to 3.45 mA at input current level of 111.
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