lists the bill materials (BOM).
Table 10-1. BOM
ITEM
DESCRIPTION
PART NUMBER
PACKAGE
REF.
QTY MFR
1
TI WL1835 Wi-Fi / Bluetooth module
WL1835MODGI
13.4 x 13.3 x 2.0 mm
U1
1
TI
2
XOSC 3225 / 32.768 kHz / 1.8 V /
±50 ppm
7XZ3200005
3.2 x 2.5 x 1.0 mm
OSC1
1
TXC
3
Antenna / chip / 2.4 and 5 GHz / peak gain
> 5 dBi
ANT016008LCD2442MA1
1.6 mm x 0.8 mm
ANT1, ANT2
2
TDK
6
Mini RF header receptacle
U.FL-R-SMT-1 (10)
3.0 x 2.6 x 1.25 mm
J5, J6
2
Hirose
7
Inductor 0402 / 1.1 nH / ±0.05 nH SMD
LQP15MN1N1W02
0402
L1
1
Murata
8
Inductor 0402 / 1.5 nH / ±0.05 nH SMD
LQP15MN1N5W02
0402
L2
1
Murata
9
Capacitor 0402 / 1.2 pF / 50 V / C0G /
±0.1 pF
GJM1555C1H1R2BB01
0402
C11
1
Murata
10
Capacitor 0402 / 2.2 pF / 50 V / C0G /
±0.1 pF
GJM1555C1H1R2BB01
0402
C9
1
Murata
11
Capacitor 0402 / 4 pF / 50 V / C0G /
±0.1 pF
GJM1555C1H4R0BB01
0402
C14
1
Murata
12
Capacitor 0402 / 8 pF / 50 V / C0G /
±0.1 pF
GJM1555C1H8R0BB01
0402
C13
1
Walsin
13
Capacitor 0402 / 10 pF / 50 V / NPO / ±5% 0402N100J500LT
0402
C5, C6
2
Walsin
14
Capacitor 0402 / 0.1 µF / 10 V / X7R /
±10%
0402B104K100CT
0402
C3, C4
1
Walsin
15
Capacitor 0402 / 1 µF / 6.3 V / X5R /
±10% / HF
GRM155R60J105KE19D
0402
C1
1
Murata
16
Capacitor 0603 / 10 µF / 6.3 V / X5R /
±20%
C1608X5R0J106M
0603
C2
1
TDK
10.1.2 Design Recommendations
This section describes the layout recommendations for the WL1835 module, RF trace, and antenna.
summarizes the layout recommendations.
Table 10-2. Layout Recommendations Summary
ITEM
DESCRIPTION
Thermal
1
The proximity of ground vias must be close to the pad.
2
Signal traces must not be run underneath the module on the layer where the module is mounted.
3
Have a complete ground pour in layer 2 for thermal dissipation.
4
Have a solid ground plane and ground vias under the module for stable system and thermal dissipation.
5
Increase the ground pour in the first layer and have all of the traces from the first layer on the inner layers, if possible.
6
Signal traces can be run on a third layer under the solid ground layer, which is below the module mounting layer.
RF Trace and Antenna Routing
7
The RF trace antenna feed must be as short as possible beyond the ground reference. At this point, the trace starts to radiate.
8
The RF trace bends must be gradual with an approximate maximum bend of 45° with trace mitered. RF traces must not have sharp
corners.
9
RF traces must have via stitching on the ground plane beside the RF trace on both sides.
10
RF traces must have constant impedance (microstrip transmission line).
11
For best results, the RF trace ground layer must be the ground layer immediately below the RF trace. The ground layer must be
solid.
12
There must be no traces or ground under the antenna section.
13
RF traces must be as short as possible. The antenna, RF traces, and modules must be on the edge of the PCB product. The
proximity of the antenna to the enclosure and the enclosure material must also be considered.
WL1801MOD, WL1805MOD, WL1831MOD, WL1835MOD
SWRS152N – JUNE 2013 – REVISED APRIL 2021
Copyright © 2021 Texas Instruments Incorporated
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