SC424MLTRT【PDF 27/29 页】IC REG DL BUCK/LINEAR 28MLPQ

收藏本站

您好，
买卖IC网欢迎您。
请登录
免费注册

买卖IC网

Sheet目录46

23页 24页 25页 26页 [27页]28页 29页

SC414/SC424

Applications Information (continued)

All other decoupling capacitors must be located

as close as possible to the IC.

PGND Plane

PGND requires its own copper plane with no

other signal traces routed on it.

Copper planes, multiple vias, and wide traces are

needed to connect PGND to input capacitors,

output capacitors, and the PGND pins on the IC.

The PGND copper area between the input

capacitors, output capacitors, and PGND pins

must be as small as and as compact as possible

to reduce the area of the PCB that is exposed to

noise due to current fl ow on this node.

Connect PGND to AGND with a short trace or

0?SPAN class="pst SC424MLTRT_2473221_5"> resistor. This connection should be as close

to the IC as possible.

AGND Island

AGND should have its own island of copper with

no other signal traces routed on this layer that

connects the AGND pins and pad of the IC to the

analog control components.

All of the components for the analog control cir-

cuitry should be located so that the connections

to AGND are done by wide copper traces or vias

down to AGND.

Connect PGND to AGND with a short trace or 0?

resistor. This connection should be as close to

the IC as possible.

FB, VOUT, and Other Analog Control Signals

The connection from the V

OUT

power to the

analog control circuitry must be routed from the

output capacitors and located on a quiet layer.

The traces between VOUT and the analog control

circuitry (VOUT, and FB pins) must be short and

routed away from noise sources, such as BST, LX,

VIN, and PGND between the input capacitors,

output capacitors, and the IC.

ILIM and TON nodes must be as short as possible

to ensure the best accuracy in current limit and

on time.

ILIM

should be close to the IC and connected to

LXS with a Kelvin trace to pin 24 on the IC. This

will be a suffi cient connection and will prevent

the need to connect the resistor further into the

LX plane.

The feedback components for the switcher need

to be as close to the FB pin of the IC as possible

to reduce the possibility of noise corrupting

these analog signals.

BST, ILIM and LX

LX and BST are very noisy nodes and must be

carefully routed to minimized the PCB area that

is exposed to these signals.

The connections for the boost capacitor

between the IC and LX must be short and directly

connected to the LXBST (pin 12).

The connections for the current limit resistor

between the ILIM pin and LX must be as short as

possible and directly connected to pin 24 (LXS).

The LX node between the IC and the inductor

should be wide enough to handle the inductor

current and short enough to eliminate the pos-

sibility of LX noise corrupting other signals.

Multiple vias should be used to provide a good

connection to LX between the IC and the

inductor.

Capacitors and Current Loops

The current loops between the input capacitors,

the IC, the inductor, and the output capacitors

must be as close as possible to each other to

reduce IR drop across the copper.

All bypass and output capacitors must be con-

nected as close as possible to the respective pin

on the IC.

发布紧急采购，3分钟左右您将得到回复。

采购需求

(若只采购一条型号，填写一行即可)

*型号	*数量	厂商	批号	封装

添加更多采购

采购需求

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

我的联系方式