DRV2605L Datasheet, PDF (58/69 Pages) Texas Instruments – DRV2605L 2 to 5.2 V Haptic Driver for LRA and ERM With Effect Library and Smart-Loop Architecture

DRV2605L
SLOS854C – MAY 2014 – REVISED SEPTEMBER 2014
11 Layout
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11.1 Layout Guidelines
Use the following guidelines for the DRV2605L layout:
• The decoupling capacitor for the power supply (V_DD) should be placed closed to the device pin.
• The filtering capacitor for the regulator (REG) should be placed close to the device REG pin.
• When creating the pad size for the WCSP pins, TI recommends that the PCB layout use nonsolder mask-
defined (NSMD) land. With this method, the solder mask opening is made larger than the desired land area
and the opening size is defined by the copper pad width. Figure 65 shows and Table 34 lists appropriate
diameters for a wafer-chip scale package (WCSP) layout.
Copper
Trace Width
Solder Mask
Thickness
Solder
Pad Width
Solder Mask
Opening
Copper Trace
Thickness
Figure 65. Land Pattern Dimensions
Table 34. Land Pattern Dimensions
SOLDER PAD
DEFINITIONS
COPPER PAD
SOLDER MASK
OPENING
COPPER
THICKNESS
STENCIL
OPENING
STENCIL
THICKNESS
Nonsolder mask
defined (NSMD)
275 µm
(0, –25 µm)
375 µm
(0, –25 µm)
1-oz maximum (32 µm)
275 µm × 275 µm²
(rounded corners)
125-µm thick
1. Circuit traces from NSMD defined PWB lands should be 75-µm to 100-µm wide in the exposed area inside
the solder mask opening. Wider trace widths reduce device stand-off and impact reliability.
2. The recommend solder paste is Type 3 or Type 4.
3. The best reliability results are achieved when the PWB laminate glass transition temperature is above the
operating the range of the intended application.
4. For a PWB using a Ni/Au surface finish, the gold thickness should be less 0.5 µm 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. The best solder stencil performance is achieved using laser-cut stencils with electro polishing. Use of
chemically-etched stencils results in inferior solder paste volume control.
7. Trace routing away from the WCSP device should be balanced in X and Y directions to avoid unintentional
component movement because of solder-wetting forces.
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