SC623A View Datasheet(PDF) - Semtech Corporation

Part Name

Description

MFG CO.

SC623A

LED Light Management Unit Charge Pump, 4 LEDs, 400mA Flash LED, and I2C Interface

Semtech Corporation 

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SC623A

Applications Information (continued)

PCB Layout Considerations

The layout diagram in Figure 1 illustrates a proper

two-layer PCB layout for the SC623A and supporting

components. Following fundamental layout rules is

critical for achieving the performance specified in the

Electrical Characteristics table. The following guidelines

are recommended when developing a PCB layout:

• Place all bypass and decoupling capacitors —

C1, C2, CIN, and COUT, as close to the device as

possible.

• All charge pump current passes through VIN,

VOUT, and the bucket capacitor connection

pins. Ensure that all connections to these pins

make use of wide traces so that the resistive

drop on each connection is minimized.

• The thermal pad should be connected to the

ground plane using multiple vias to ensure

proper thermal connection for optimal heat

transfer.

GND

GND

• Make all ground connections to a solid

ground plane as shown in the example layout

(Figure 3).

• If a ground layer is not feasible, the following

groupings should be connected:

ƒ PGND — CIN, COUT

ƒ AGND — Ground Pad

• If no ground plane is available, PGND and AGND

should be routed back to the negative battery

terminal as separate signals using thick traces.

Joining the two ground returns at the terminal

prevents large pulsed return currents from

mixing with the low-noise return currents.

CIN

C1

C2

COUT

C2-

NC

PGND

NC

FL

SC623A

NC

BL1

EN

BL2

SDA

Figure 2 — Layer 1

Figure 1 — Recommended PCB Layout

Figure 3 — Layer 2

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