正确的布局和元件选择是控制EMI的关键

正确的布局和元件选择是控制EMI的关键MOSFET

EMI
LDO IC 300mV

LDO 1V 100mV

/ EMI/EMC

LDO LDO

/

3

/ / MAX1653 DC-DC 1 N1 N1 N2 2 N1 CIN IL-IINPUT CIN ESR COUT 10kHz

DC-DC 100kHz CIN

COUT CIN N1 N1 ESL 20MHz LX COUT 50MHz

CIN

I(INPUT) 660mA 0

INPUT 5V V+ VL

330mA I(CIN) 0 -660mA

BST MAX1653 DH LX SS N2 DL PGND REF GND CSH CSL D N1 L OUTPUT 3.3V

I(L) 1.0A 0 I(COUT) 0 5V V(LX) 0

1. N2

N1

2.

1

4

Q

LC

SEPIC SEPIC 5

3

SEPIC

INPUT

4
VL VCC

OUTPUT

EXT REF CS+ MAX668 PGND FREQ GND FB

4.

INPUT

INPUT

VL

VCC

OUTPUT EXT

VL

VCC

OUTPUT

EXT REF CS+ MAX668 PGND FREQ

REF

CS+ MAX668 PGND

FREQ GND FB

GND

FB

3.

5.

SEPIC

5

CP1

C P2A CP2B 7 CML1 CML2 SEPIC LDO IC LDO LDO PSRR
INPUT LX

6

300mV

POUT OUT TRACK

MAX1706 REF

FB

LDO

OUTPUT

7 MOSFET MOSFET

FBLDO PGND GND

TO-220 MOSFET

MOSFET
6.