During the charging process, to prevent overheating in the device, the juntion temperature of the die, T_J, is monitored. When T_J reaches T_(SHUTDOWN) the device stops charging, disables the PMID output, disables the SYS output, and disables the LS/LDO output. During the time that T_(SHUTDOWN) is exceeded, the safety timer is reset and the watchdog timer continues to operate if in host mode. The charge cycle resumes when T_J falls below T_(SHUTDOWN) by T_(HYS).

To avoid reaching thremal shutdown, ensure that the system power dissipation is under the limits of the device. The power dissipated by the device can be calculated using Equation 5.

Where

• P_(BLOCK) = (V_IN – V_(PMID)) x I_IN
• P_(SYS) = I_SYS² x R_{DS(ON_HS)}
• P_(LS/LDO) = (V_(INLS) – V_(LS/LDO)) x I_(LS/LDO)
• P_(BAT) = (V_(PMID) – V_(BAT)) x I_(BAT)