Other Parts Discussed in Thread: SN74AVC4T245
Hi Team,
Customer is asking for the following SN74XXX logic power consumption data.
Would you please help for Θja, Θjc, Pd and Pc information under VCC 5V(SN74LVC1G00DCKR
) and VCC 3.3V case?
BR,
SHH
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Hi Team,
Customer is asking for the following SN74XXX logic power consumption data.
Would you please help for Θja, Θjc, Pd and Pc information under VCC 5V(SN74LVC1G00DCKR
) and VCC 3.3V case?
BR,
SHH
Hello SHH,
Here are the thermals:
SN74AUCH244RGY:
SN74AVC4T245PWR:
SN74AVC4T774PWR:
SN74LVC1G00DCKR:
Now the thermals are a bit trickier to provide. In your question you have provided me with a method to calculate power consumption. However power consumption is heavily dependent on the frequency of operation.
There is static power consumption which is Ps = Vcc*Icc. Then there is dynamic power consumption which is a combination of the transient power (Pt), capacitative load power (Plc) and resistive load power (Plr). Your equation is only the combination of Ps + Plr. However the transient power Pt is much greater than the other two dynamic power consumption.
You can calculate the
Pc = Cpd*(Vcc)^2*f + Icc*Vcc
Cpd = measure of the dynamic power a device requires (listed in the datasheet for each of those devices)
f = frequency of operation
Vcc and Icc can also be found in the datasheet
The Pd can be calculated based on the temperature data I have provided to you using the equation:
Pmax(W) = (TJ(max)(°C) - TA(max)(°C)) / θJA(°C/W)
Pmax := maximum power consumption before thermal failure
TJ(max) := maximum junction temperature (150°C for standard logic devices, unless otherwise stated in the datasheet)
TA(max) := maximum ambient temperature of operation (system's maximum ambient operating temperature, rather than the device's maximum ambient operating temperature)
θJA := junction-to-ambient thermal resistance
Thanks!
-Karan