AP3301

Document number: DS38018 Rev. 4 - 2

12 of 16

www.diodes.com

June 2016

© Diodes Incorporated

AP3301

Figure 3

SOVP Protection Function

For some applications, the system requires the output over voltage protection function. The DEM pin compares the divided voltage from the VCC

duration, AP3301 will trigger SOVP function and the system will enter the latch

protection mode. Since the value of VCC winding’s waveform

reflects the output voltage precisely, the Secondary Output Voltage Protection (SOVP) can be achieved by this function.

Other System Protection and Pin Fault Protection

The AP3301 provides versatile system and pin fault protections. The OCP comparator realizes the cycle-by-cycle current limiting (OCP). In

universal input line voltage, the IC realizes the constant over load protection (OLP). VCC over voltage protection can be applied as the primary

OVP or opto-coupler broken protection. The AP3301 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.

Internal OTP Protection Function

The AP3301 integrates an internal temperature sensor. It has a trigger window of entering OTP mode at +150°C and exiting at +125°C. The

internal OTP protection mode is auto-recovery mode.

DEM

3

Line Voltage

Detector

Auxiliary

4

OCP

VREF1

BNO

VREF_H

VREF_L

21

1

1

:

HV

Gate

SENSE

Inside AP3301