ZSLS7031 Datasheet

© 2016 Integrated Device Technology, Inc.

12

January 26, 2016

2.7

Output Over-Voltage Protection

Over-voltage protection of the output (OVP) is achieved by connecting a resistor network from the auxiliary

winding to the FB pin. By sensing the voltage of the auxiliary winding, which is proportional to the output voltage,

the ZSLS7031 detects when there is an open circuit condition on the secondary side and consequently reduces

the switching action to a minimum burst mode. The threshold voltage for the FB pin is typically 1.25V. Care must

be taken that the high ripple current bursts do not lead to an overshoot of the output capacitor’s rated voltage.

This can be accomplished by a Zener diode in parallel, rated slightly lower than the output capacitor’s nominal

voltage or a reasonable discharge resistor. The ZSLS7031 will recover to normal operation when the open-circuit

condition has been corrected.

Figure 2.4

Output Over-Voltage Protection

2.8

Output Over-Current Protection (OCP)

If the output of the circuit is suddenly shorted, the resulting over-current condition is detected on the primary side

specification 1.3.7) has elapsed.

2.9

Under-Voltage Lock Out (UVLO)

under voltage lock out (UVLO) will be triggered. In this event, the device will stop operating until the VCC voltage