LHC4913 SERIES

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APPLICATION DIAGRAM FOR REMOTE SENSINS OPERATION FOR ADJUSTABLE VERSION

FUNCTIONAL DESCRIPTION

ADJUSTABLE VERSION

The ADJUST pin shall be set at 1.225V with the

ADJ-GROUND resistor value must not be greater

than 2.5 K

Ω.For a given V

OVERTEMPERATURE PROTECTION OPTION

The

LHC4913

is

protected

by

a

junction-

temperature detection circuit, turning the device

“OFF” when the temperature attains 175°C. The

recovery of the ON mode occurs with a hysteresys

of 40 °C.

OVERCURRENT PROTECTION

The device is equipped with a circuit having the

purpose of limiting the maximum load current, in

order to protect the output stage against possible

overcurrent-related damages. Its threshold can be

modified externally by means of a resistor put

For this characteristic, when the load current gets

close to the above threshold, the regulation is

inhibited. Thus, an excellent operation is granted

only up to 66% of preset maximum current.

SHORT CIRCUIT MONITORING / SIGNALLING

In the event of an overcurrent at the output, a

voltage level of 0.4V is present at the OCM pin. In

REMOTE SENSING FOR ADJ VERSION

SENSE are not linked to each other in order to get

a regulation with a load located far away from the

chip. Under ordinary applications, the SENSE

the best performances it is recommended to be

compliant with the configuration shown in the

figure at top page.

What can degrade the regulation performances of

this configuration is the variable voltage drop

between the chip ground and the load termination

Lv.

This is brought mostly by the current Ib coming

from the output power base and going to ground

through the driver stage. The degradation amount

APPLICATION INFORMATION

value according to above mentioned and thermal

dissipation limits.

An input filtering capacitor of 100nF is always

mandatory.

Device stability is granted in any circumstance

witha1

µF output capacitor.

The device operation is guaranteed with any

Vin-Vout

dropout

under

the

above

thermal

constraints.

Although

two

embedded

protections

first

mentioned

(the

overtemperature

and

the

overcurrent) ensure the L4913 integrity against

any fault load condition, it is recommended to

comply with the specified absolute maximum

ratings also in applications involving fast switching

of output currents.

To achieve this, a polyester capacitor of at least

470nF, put close to the regulator between input

and ground, improves the L4913 reliability by