(1) The maximum safety temperature, T
S, has the same value as the maximum junction temperature, T
J, specified for the device. The I
S and P
S parameters represent the safety current and safety power, respectively. Do not exceed the maximum limits of I
S and P
S. These limits vary with the ambient temperature, T
A.
The junction-to-air thermal resistance, R
θJA, in the
Thermal Information table is that of a device installed on a high-K test board for leaded surface-mount packages. Use these equations to calculate the value for each parameter:
T
J = T
A + R
θJA × P, where P is the power dissipated in the device.
T
J(max) = T
S = T
A + R
θJA × P
S, where T
J(max) is the maximum junction temperature.
P
S = I
S × LDOIN
max + I
S × DVDD
max, where LDOIN
max is the maximum LDO input voltage and DVDD
max is the maximum controller-side supply voltage.