LCMXO2280C-5TN144C LATTICE SEMICONDUCTOR, LCMXO2280C-5TN144C Datasheet - Page 199

• Manufacturer Part Number: LCMXO2280C-5TN144C
• Description: MACHXO PLD FLASH, SCRAM 1.8V, SMD
• Manufacturer: LATTICE SEMICONDUCTOR
• Series: MachXOr

Specifications of LCMXO2280C-5TN144C

• Cpld Type: FLASH
• No. Of Macrocells: 1140
• No. Of I/o's: 113
• Propagation Delay: 3.6ns
• Global Clock Setup Time: 1.1ns
• Frequency: 600MHz
• Supply Voltage Range: 1.71V To 3.465V
• Operating: RoHS Compliant

Power Estimation and Management
Lattice Semiconductor
for MachXO Devices
Figure 11-15. Importing Trace Report File in the Existing Project in the Power Calculator
Activity Factor and Toggle Rate
Activity Factor% (or AF%) is defined as the percentage of frequency (or time) that a signal is active or toggling of
the output. Most of the resources associated with a clock domain are running or toggling at some percentage of the
frequency at which the clock is running. Users are required to provide this value as a percentage under the AF%
column in the Power Calculator tool.
Another term used for I/Os is the I/O Toggle Rate or the I/O Toggle Frequency. The AF% is applicable to the PFU,
routing and memory read write ports, etc. The activity of I/Os is determined by the signals provided by the user (in
the case of inputs) or as an output of the design (in the case of outputs). So, the rates at which I/Os toggle defines
their activity. The Toggle Rate (or TR) in MHz of the output is defined as:
Toggle Rate (MHz) = 1/2 * f
* AF%
MAX
Users are required to provide the TR (MHz) value for the I/O instead of providing the frequency and AF% in case of
other resources. The AF can be calculated for each routing resource, output or PFU, however it involves long calcu-
lations. The general recommendation of a design occupying roughly 30% to 70% of the device is that the AF%
used can be between 15% to 25%. This is an average value that can be seen most of the design. The accurate
value of an AF depends upon clock frequency, stimulus to the design and the final output.
Ambient and Junction Temperature and Airflow
A common method of characterizing a packaged device’s thermal performance is with Thermal Resistance, . For
a semiconductor device, thermal resistance indicates the steady state temperature rise of the die junction above a
given reference for each watt of power (heat) dissipated at the die surface. Its units are °C/W.
11-16