LR8421 datasheet(6/7 Pages) LRC

부품명	LR8421

상세설명	5A, 500KHz Synchronous Boost Converter with Output Disconnect

PDF	7 Pages

Scroll/Zoom	100%

제조업체	LRC [Leshan Radio Company]

홈페이지	http://www.lrc.cn/

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6 / 7 page

APPLICATION

INFORMATION

PROGRAMMING THE OUTPUT VOLTAGE

The LR8421 internal 1.2V referenc e voltage is compared to the voltage at the FB pin to generate an error

signal at the output of the error amplifier. The output voltage is set by an external resistive voltage divider

from the VOUT to FB. The current drawn by the resistor network should be limited to maintain the overall

converter efficiency. The maximum value of the resistor network is limited by the feedback input bias

current and the potential for noise being coupled into the feedback pin. A resistor network less than 100k

is recommended.

Typically, a minimum current of 50 A flowing through the feedback divider gives good accuracy and noise

covering. A standard low side resistor of 24k

is typically selected. The resistors are then calculated as:

R2=VFB/50 A=24k , R1= R2X (VOUT VFB)/VFB

VFB=1.2V

The use of 1% accuracy metal film resistor is recommended for the better output voltage accuracy.

LESHAN RADIO COMPANY, LTD.

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LR8421 데이터시트(PDF) 6 Page - Leshan Radio Company