The OPA1632 does not have thermal shutdown protection. Make sure that the maximum junction temperature is not exceeded. Excessive junction temperature can degrade performance or cause permanent damage. For best performance and reliability, make sure that the junction temperature does not exceed the absolute maximum ratings for the junction temperature.

The thermal characteristics of the device are dictated by the package and the circuit board. Maximum power dissipation for a given package can be calculated using the following formula:

where:

• P_DMax is the maximum power dissipation in the amplifier (W)
• T_Max is the absolute maximum junction temperature (°C)
• T_A is the ambient temperature (°C)
• θ_JA = θ_JC + θ_CA
• θ_JC is the thermal coefficient from the silicon junctions to the case (°C/W)
• θ_CA is the thermal coefficient from the case to ambient air (°C/W)

For systems where heat dissipation is more critical, the OPA1632 is offered in an HVSSOP-8 (DGN) PowerPAD integrated circuit package. The thermal coefficient for the PowerPAD integrated circuit package is substantially improved over the traditional SO package. Maximum power dissipation levels are depicted in Figure 8-6 for the two packages. The data for the DGN package assume a board layout that follows the layout guidelines listed in Section 8.4.1.1.

Figure 8-6 Maximum Power Dissipation vs Ambient Temperature