PM6681ATR datasheet(41/47 Pages) STMICROELECTRONICS

부품명	PM6681ATR

상세설명	Dual synchronous step-down controller with adjustable LDO

PDF	47 Pages

Scroll/Zoom	100%

제조업체	STMICROELECTRONICS [STMicroelectronics]

홈페이지	http://www.st.com

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41 / 47 page

PM6681A

Design guidelines

41/47

(Let's assume Tmax = 75 °C in RDS(on) calculation)

9.8.5

Input capacitor

Maximum input capacitor RMS current is about 1.1 A. Then ICinRMS > 1.1 A

We can put two 10

µF ceramic capacitors with I

rms = 1.5 A.

9.8.6

Synchronous rectifier

OUT1: Schottky diode STPS1L40M

OUT2: Schottky diode STPS1L40M

9.8.7

Integrator loop

(Refer to Figure 40)

OUT1: The ripple is smaller than 40mV, then the virtual ESR network is required.

CINT = 1 nF; Cfilt = 47 pF; RINT = 1 kΩ

C = 5.6 nF; R = 36 k

Ω; R1 = 3 kΩ

OUT2: The ripple is smaller than 40mV, then the virtual ESR network is required.

CINT = 1 nF; Cfilt = 110 pF; RINT = 1 kΩ

C = 5.6 nF; R = 22 k

Ω; R1 = 3.3 kΩ

9.8.8

Output feedback divider

(Refer to Figure 32)

OUT1: R1 = 10 k

Ω; R2 = 6.8 kΩ

OUT2: R1 = 11 k

Ω; R2 = 1.8 kΩ

Ω

≈

Ω

⋅

≡

680

100

RCSENSE

PM6681ATR 데이터시트(PDF) 41 Page - STMicroelectronics