AP3302

Document number:DS38882 Rev. 4 - 2

13 of 17

www.diodes.com

March 2017

© Diodes Incorporated

AP3302

0V

Gate

Figure 6

Internal OTP Protection Function

The AP3302 integrates an internal temperature sensor. It has a trigger window of +150°C enter and +125°C exit. The internal OTP protection

mode is auto-recovery mode.

The AP3302 provides versatile protection to ensure the reliability of the power system. FOCP protection is an ultra fast short-current protection

which is helpful to avoid catastrophic damage of the system when the secondary rectifier is short. The primary peak current will be monitored by

the FOCP protection will be active to shut down the switching pulse. SSCP might be triggered at ultra low line voltage condition or other failure

condition that short the SENSE pin to ground. The SSCP module senses the voltage across the primary sense resistor with a delay of 3

s after

protection will be triggered and the drive signal will be disabled. All these protections described above will restart the system when the VCC

voltage falls below UVLO.

The AP3302 also has pin fault connection protection including floating and short connection. The floating pin protection includes the SENSE, FB,

etc. The short pin protection includes the DEM pin short protection. When these pins are floated or DEM pin is shorted to ground, PWM switching

will be disabled, thus protecting the power system.