LT8551 datasheet(27/32 Pages) AD

27 / 32 page

LT8551

Rev 0

For more information www.analog.com

APPLICATIONS INFORMATION

• The decoupling capacitors for REG, VCC, VIN and the

current sense, etc. should be placed close to their

pins, use PGND for the REG decoupling capacitor

and SGND for VIN and VCC decoupling capacitors.

To minimize the connection impedance, it’s desired

to connect the decoupling capacitors directly to the

pins without using any via.

• Of all the small signal traces, current sensing traces

are most sensitive to noise. The current sensing

traces should be routed differentially with minimum

spacing to minimize the chance of picking-up noise,

as shown in Figure 20. In addition, the filter resistors

and capacitors for current sensing traces should be

placed as close to the ISPx/ISNx pins as possible. If

the DCR sensing is used with an R/C network, the

DCR sensing resistor R1 should be close to the induc-

tor, while R2 and C should be close to the IC. Place

the vias that connect the ISPx/ISNx lines directly at

the terminals of the current sensing resistors or the

inductors as shown in Figure 20.

• When routing the interface signals between a mas-

ter LT8551, primary controller, and/or slave LT8551,

keep the small-signal lines far from the noisy lines

and shield these lines with a ground plane. A recom-

mended line arrangement is shown in Figure 21.

Figure 20. Current Sensing PCB Design

Figure 21. Recommended Signal Lines Arrangement for PCB

8551 F20

VIN

a) Resistor Sensing

b) Inductor DCR Sensing

ISNx

ISPx

LT8551

DIRECT TRACE CONNECTION

DO NOT USE VIA

THIS VIA SHOULD NOT

TOUCH ANY OTHER

INTERNAL VOUT

COPPER PLANE

DIFFERENTIAL TRACE

VIN

ISNx

ISPx

LT8551

DIRECT TRACE CONNECTION

DO NOT USE VIA

THIS VIA SHOULD NOT

TOUCH ANY OTHER

INTERNAL VOUT

COPPER PLANE

DIFFERENTIAL TRACE

ALL LINES ARE SHIELDED

BY THE GROUND PLANE

ROUTE IN DIFFERENTIAL PAIR

ALL LINES ARE SHIELDED

BY THE GROUND PLANE

GROUND PLANE

BST

SYNC

SENSE+

SENSE–

INTVCC

RUN/ENABLE

PRIMARY

CONTROLLER

TGSR

TGSH

TGSL

BGSH

CLK1

ISP

ISN

REGSNS

ENOUT

MASTER

LT8551

TGBUF

BGBUF

CLK2

CLK1

MODE

IAMPP

IAMPN

REGSNS

ENOUT

MASTER

LT8551

TGSH

BGSH

CLK2

SYNC

MODE

IAMPP

IAMPN

REGSNS

ENOUT

SLAVE

LT8551

8551 F21

LT8551 Datasheet(PDF) 27 Page - Analog Devices

LT8551 Datasheet(HTML) 27 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

Datasheet Download

Link URL