FSEZ1016AMY datasheet(12/16 Pages) FAIRCHILD

12 / 16 page

www.fairchildsemi.com

FSEZ1016A • Rev. 1.0.2

Protections

The FSEZ1016A has several self-protective functions,

such

Over-Voltage

Protection

(OVP),

Over-

Temperature

Protection

(OTP),

and

brownout

protection. All the protections are implemented as auto-

restart mode. When the auto-restart protection is

triggered, switching is terminated and the MOSFET

remains off. This causes VDD to fall. When VDD reaches

the VDD turn-off voltage of 5V, the current consumed by

FSEZ1016A reduces to the startup current (maximum

10µA) and the current supplied startup resistor charges

the VDD capacitor. When VDD reaches the turn-on

voltage of 16V, FSEZ1016A resumes normal operation.

In this manner, the auto-restart alternately enables and

disables the switching of the MOSFET until the fault

condition is eliminated (see Figure 29).

Fault

Situation

16V

VDS

Fault

Occurs

Fault Removed

Normal

Operation

Normal

Operation

Power

Operating Current

3.5mA

10µA

Figure 29. Auto-Restart Operation

VDD Over-Voltage Protection (OVP)

VDD over-voltage protection prevents damage from over-

voltage conditions. If the VDD voltage exceeds 28V by

open-feedback condition, OVP is triggered. The OVP

has a debounce time (typical 250µs) to prevent false

triggering by switching noise. It also protects other

switching devices from over voltage.

Over-Temperature Protection (OTP)

A built-in temperature-sensing circuit shuts down PWM

output if the junction temperature exceeds 140°C.

Brownout Protection

FSEZ1016A detects the line voltage using auxiliary

winding voltage since the auxiliary winding voltage

reflects the input voltage when the MOSFET is turned

on. The VS pin is clamped at 1.15V while the MOSFET

is turned on and brownout protection is triggered if the

current out of the VS pin is less than IVS-UVP (typical

180

μA) during the MOSFET conduction.

Pulse-by-Pulse Current Limit

When the sensing voltage across the current sense

resistor exceeds the internal threshold of 1.3V, the

MOSFET is turned off for the remainder of the switching

cycle. In normal operation, the pulse-by-pulse current

limit is not triggered since the peak current is limited by

the control loop.

FSEZ1016AMY Folha de dados(PDF) 12 Page - Fairchild Semiconductor

FSEZ1016AMY Folha de dados(HTML) 12 Page - Fairchild Semiconductor

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Folha de dados Download

Ligação URL