LM5035 datasheet(25/28 Pages) NSC

Numer części	LM5035

Szczegółowy opis	PWM Controller with Integrated Half-Bridge and SyncFET Drivers

PDF	28 Pages

Scroll/Zoom	100%

Producent	NSC [National Semiconductor (TI)]

Strona internetowa	http://www.national.com

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25 / 28 page

Application Circuit Example

The following schematic shows an example of a 100W half-

bridge power converter controlled by the LM5035. The op-

erating input voltage range (V

PWR) is 36V to 75V, and the

output voltage is 3.3V. The output current capability is 30

Amps. Current sense transformer T2 provides information to

the CS pin for current limit protection. The error amplifier and

reference, U3 and U5 respectively, provide voltage feedback

via opto-coupler U4. Synchronous rectifiers Q4, Q5, Q6 and

Q7 minimize rectification losses in the secondary. An auxil-

iary winding on transformer T1 provides power to the

LM5035 VCC pin when the output is in regulation. The input

voltage UVLO thresholds are )34V for increasing V

PWR,

and )32V for decreasing V

PWR. The circuit can be shut

down by driving the ON/OFF input (J2) below 1.25V with an

open-collector or open-drain circuit. An external synchroniz-

ing frequency can be applied through a 100pF capacitor to

the RT input (U1 pin 5). The regulator output is current

limited at )34A.

LM5035 Arkusz danych(PDF) 25 Page - National Semiconductor (TI)