TPS82740A, TPS82740B

SLVSCE3A – JUNE 2014 – REVISED JUNE 2014

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12 Power Supply Recommendations

The TPS82740 device is a complete and optimized power supply module working within the given

specification range without additional components. Please use the information given in the Application

Information section to connect the input and output circuitry appropriately.

13 Layout

13.1 Layout Guidelines

In making the pad size for the uSiP LGA balls, it is recommended that the layout use a non-solder-mask defined

(NSMD) land. With this method, the solder mask opening is made larger than the desired land area, and the

layout. Figure 46 shows a suggestion for the PCB layout.

13.2 Layout Example

Figure 45. Recommended Land Pattern Image and Dimensions

SOLDER PAD

COPPER

COPPER PAD

STENCIL THICKNESS

OPENING

THICKNESS

OPENING

Non-solder-mask

0.30mm

0.360mm

1oz max (0.032mm)

0.34mm diameter

0.1mm thick

defined (NSMD)

(1)

Circuit traces from non-solder-mask defined PWB lands should be 75

μm to 100μm wide in the exposed area inside the solder mask

opening. Wider trace widths reduce device stand off and affect reliability.

(2)

Best reliability results are achieved when the PWB laminate glass transition temperature is above the operating the range of the

intended application.

(3)

Recommend solder paste is Type 3 or Type 4.

(4)

For a PWB using a Ni/Au surface finish, the gold thickness should be less than 0.5mm to avoid a reduction in thermal fatigue

performance.

(5)

Solder mask thickness should be less than 20

μm on top of the copper circuit pattern.

(6)

For best solder stencil performance use laser cut stencils with electro polishing. Chemically etched stencils give inferior solder paste

volume control.

20

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