Copyright

© ANPEC Electronics Corp.

Rev. A.3 - Aug., 2011

www.anpec.com.tw

9

APL3213/A

Over-Temperature Protection

nal thermal sense circuit turns off the power FET and

allows the device to cool down. When the device’s junc-

circuit will enable the device, resulting in a pulsed output

during continuous thermal protection. Thermal protec-

tion is designed to protect the IC in the event of over-

temperature conditions. For normal operation, the junc-

tion temperature cannot exceed T

Function Description

Power-Up

The APL3213/A have a built-in power-on-reset circuit to

keep the output shutting off until internal circuitry is oper-

ating properly. The POR circuit has hysteresis and a

deglitch feature so that it will typically ignore undershoot

transients on the input. When input voltage exceeds the

POR threshold and after 8ms blanking time, the output

voltage starts a soft-start to reduce the inrush current.

Input Over-Voltage Protection (OVP)

The input voltage is monitored by the internal OVP circuit.

When the input voltage rises above the input OVP

threshold, the internal FET will be turned off within 1

µs to

protect connected system on OUT pin. When the input

voltage returns below the input OVP threshold minus the

hysteresis, the FET is turned on again after 8ms recovery

time. The input OVP circuit has a 200mV hysteresis and

a recovery time of T

against transient conditions.

Figure 2. OVP Timing Chart

V

ACIN

V

OUT

V

OVP

V

POR