Hi,
I have simulated the below circuit in LTspice and found that the BJT (Q203) is having less power dissipation (~1mW) then the Q202 BJT.
However, the designer selected a 200mW package for the Q203 and 100mW for the Q202.
Can anyone help me understand what am I missing here? As per my understanding even if I select the 100mW BJT part then also the circuit will be okay as per the LTspice simulations.
In scenario 1, When Motor is ON, Q203 (ON), Q202 (OFF)
In scenario 2, When Motor is OFF Q203 (OFF), Q202 (ON)
Q202 MPN: RN1102
Q203 MPN: RN1402
View attachment 182789
LTspice file are attached for the reference.
Thank you.