8.1 Power Dissipation

The LMH6572 is optimized for maximum speed and performance in the small form factor of the standard SSOP package. To achieve its high level of performance, the LMH6572 consumes 23 mA of quiescent current, which cannot be neglected when considering the total package power dissipation limit. To ensure maximum output drive and highest performance, thermal shutdown is not provided. Therefore, it is of utmost importance to make sure that the T_JMAX is never exceeded due to the overall power dissipation.

Follow these steps to determine the Maximum power dissipation for the LMH6572:

1. Calculate the quiescent (no-load) power:
Equation 1. P_AMP = I_CC* (V_S)
where
• V_S = V⁺ - V⁻
2. Calculate the RMS power dissipated in the output stage:
Equation 2. P_D (rms) = rms [(V_S - V_OUT) * I_OUT]
where
• V_OUT and I_OUT are the voltage across and the current through the external load
• V_S is the total supply voltage
3. Calculate the total RMS power:
Equation 3. P_T = P_AMP + P_D

The maximum power that the LMH6572 package can dissipate at a given temperature can be derived with the following equation: