SBOS382H may 2008 – june 2023 OPA2673
PRODUCTION DATA
As a result of the high-output power capability of the OPA2673, heat-sinks or forced airflow can be required under extreme operating conditions. The maximum desired junction temperature sets the maximum allowed internal power dissipation, and is described in the following paragraph. Do not exceed the maximum junction temperature of 150°C.
Operating junction temperature (TJ) is given by:
The total internal power dissipation (PD) is the sum of quiescent power (PDQ) and additional power dissipation in the output stage (PDL) to deliver load power. Quiescent power is the specified no-load supply current times the total supply voltage across the part. The PDL depends on the required output signal and load; for a grounded resistive load, however, PDL is at a maximum when the output is fixed at a voltage equal to 1/2 of either supply voltage (for equal bipolar supplies). Under this condition,
where RL includes feedback network loading.
Equation 14 is the power dissipated at the output stage of OPA2673 that determines the internal power dissipation.
As a worst-case example, compute the maximum TJ using an OPA2673 VQFN-16 in the circuit of Figure 8-1 operating at the maximum specified ambient temperature of 85°C with both outputs driving a grounded 20‑Ω load to 2.5 V.
The output V-I plot in Output Current and Voltage includes a boundary for 2-W maximum internal power dissipation under these conditions.