LFXP20C-3FN256C Lattice, LFXP20C-3FN256C Datasheet - Page 349

• Manufacturer Part Number: LFXP20C-3FN256C
• Description: FPGA - Field Programmable Gate Array 19.7K LUTS 188 I/O
• Manufacturer: Lattice

Specifications of LFXP20C-3FN256C

• Number Of Programmable I/os: 188
• Data Ram Size: 405504
• Supply Voltage (max): 3.465 V
• Maximum Operating Temperature: + 90 C
• Minimum Operating Temperature: 0 C
• Mounting Style: SMD/SMT
• Supply Voltage (min): 1.71 V
• Package / Case: FPBGA-256
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Lattice Semiconductor
The above information was specified under the following environmental conditions:
The goal of this exercise is to compute the following device I/O constraints:
The only parameter which can be obtained from the above is the device junction temperature:
The required constraints can be computed as follows:
1. Input setup specification
2. Input hold specification
3. Output maximum propagation delay requirement
4. Output minimum propagation delay requirement
5. Output loading
The preference file to use for this example is shown in Figure 17-3. For more preference language syntax and
examples, refer to the Constraints & Preferences section of the ispLEVER on-line help system.
• Board trace AC loading (Cbac): 60 pf.
• Board trace parasitic capacitance (Cb): 5 pf.
• Port controller input capacitance (Cp) :9 pf.
• FPGA device input capacitance (Co): 9 pf.
• Maximum ambient temperature (Ta): 70 (C.
• Estimated Power Consumption (Q): 2 W.
• 680 PBGAM Package Thermal resistance (j) at 0 feet per minute (fpm) airflow: 13.4 °C/W.
1. Input setup specification.
2. Input hold specification.
3. Maximum output propagation delay.
4. Minimum output propagation delay.
5. Output loading.
6. Temperature.
Tj = j * Q - Ta
= 13.4 * 2 + 70
= 96.8 °C
= P - PDMAXp - PDMAXb - Tskew
= 30 - 18 - 2 - 1
= 9 ns
= PDMINp + PDMINb - Tskew
= 3 + 1 - 1
= 3 ns
= P - TSp - PDMAXb - Tskew
= 30 - 5 - 6 - 1
= 18 ns
= Thp - PDMINb + Tskew
= 3 - 1 + 1
= 3 ns
= Cbac + Cb + Cp
= 60 + 5 + 9
= 74 pf
17-5
Lattice Semiconductor FPGA
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