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sinara-hw / Thermostat_EEM

Thermostat with 4 TEC and 8 sensor channels in EEM form factor
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P5V0A load #28

Closed jordens closed 3 years ago

jordens commented 3 years ago

I think the R at the P5V0A LDO input needs to go away. ADCs, DACs and the Vexc branches are about (3 + 1 + 20 mA) * 4 ~ 100 mA max. That would bee too much for that 1/16 W resistor.

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gkasprow commented 3 years ago

With 100mA of current, we will dissipate 700mW in the package. Even with a thermal pad to solid GND, the Rth is about 45K/W This would give us a temperature increase of the die by 31degrees. That's not much but we can use a higher power resistor which would dissipate part of the power. If we use 0.5W 33R resistor, it will dissipate 330mW of power,

obraz

gkasprow commented 3 years ago

we already use 10R 0805 resistors so I will place two in series.