NPIZ datasheet(16/24 Pages) ENPIRION

16 / 24 page

06489

April 16, 2012

Rev: C

EN6360QI

Enpirion Confidential

www.enpirion.com, Page 16

the current flowing through a sense P-FET. When

the sensed current exceeds the current limit, both

power FETs are turned off for the rest of the

switching cycle. If the over-current condition is

removed, the over-current protection circuit will re-

enable PWM operation. If the over-current condition

persists, the circuit will continue to protect the load.

The OCP trip point is nominally set as specified in

the Electrical Characteristics table. In the event the

OCP circuit trips consistently in normal operation,

the device enters a hiccup mode. The device is

disabled for 27µs and restarted with a normal soft-

start. This cycle can continue indefinitely as long as

the over current condition persists.

Thermal Overload Protection

Temperature sensing circuits in the controller will

disable operation when the junction temperature

exceeds approximately 150ºC. Once the junction

temperature drops by approx 20ºC, the converter

will re-start with a normal soft-start.

Input Under-Voltage Lock-Out

When the input voltage is below a required voltage

level (VUVHI) for normal operation, the converter

switching is inhibited. The lock-out threshold has

hysteresis to prevent chatter. Thus when the device

is operating normally, the input voltage has to fall

below the lower threshold (VUVLO) for the device to

stop switching.

NPIZ Datasheet(PDF) 16 Page - Enpirion, Inc.