Integration Manual
Table Of Contents
- Preface
- Contents
- 1 System description
- 1.1 Overview
- 1.2 Architecture
- 1.3 Pin-out
- 1.4 Operating modes
- 1.5 Power management
- 1.6 System functions
- 1.7 RF connection
- 1.8 (U)SIM interface
- 1.9 Serial communication
- 1.10 DDC (I2C) interface
- 1.11 Audio Interface
- 1.12 General Purpose Input/Output (GPIO)
- 1.13 Reserved pins (RSVD)
- 1.14 Schematic for LISA-U series module integration
- 1.15 Approvals
- 2 Design-In
- 2.1 Design-in checklist
- 2.2 Design Guidelines for Layout
- 2.2.1 Layout guidelines per pin function
- 2.2.2 Footprint and paste mask
- 2.2.3 Placement
- 2.3 Thermal aspects
- 2.4 Antenna guidelines
- 2.5 ESD precautions
- 3 Features description
- 4 Handling and soldering
- 5 Product Testing
- Appendix
- A Migration to LISA-U2 series wireless modules
- B Glossary
- Related documents
- Revision history
- Contact
LISA-U series - System Integration Manual
3G.G2-HW-10002-A3 Preliminary System description
Page 77 of 160
Figure 42 shows an example of an application circuit connecting a headset (with a 2.2 k electret microphone
and a 32 receiver) to the LISA-U120 and LISA-U130 modules, with an external low noise LDO voltage
regulator to provide a proper supply for the microphone.
Mount an 82 nH series inductor (e.g. Murata LQG15HS82NJ02) on each microphone line, and a 27 pF
bypass capacitor (e.g. Murata GRM1555C1H270J) on all audio lines to minimize RF coupling and TDMA
noise.
The physical width of the audio outputs lines on the application board must be wide enough to
minimize series resistance.
LISA-U120/U130
C2 C3 C4
J1
2
5
3
4
6
1
L2
54
SPK_N
53
SPK_P
39
MIC_N
40
MIC_P
D1
AUDIO HEADSET
CONNECTOR
D2
INOUT
GND
Low Noise
LDO Regulator
VMAIN
U1
R4
R1
C6
R3R2
C5
2V5
Sense lines connected to GND in one star point
L1
C1
C7
Figure 42: Headset mode application circuit
Reference
Description
Part Number – Manufacturer
C1, C2, C3, C4
27 pF Capacitor Ceramic COG 0402 5% 25 V
GRM1555C1H270JA01 – Murata
C5, C6, C7
10 µF Capacitor Ceramic X5R 0603 20% 6.3 V
GRM188R60J106ME47 – Murata
D1, D2
Low Capacitance ESD Protection
USB0002RP or USB0002DP – AVX
L1, L2
82 nH Multilayer inductor 0402
(self resonance frequency ~1 GHz)
LQG15HS82NJ02 – Murata
J1
Audio Headset 2.5 mm Jack Connector
SJ1-42535TS-SMT – CUI, Inc.
R1, R2, R3, R4
2.2 kΩ Resistor 0402 5% 0.1 W
RC0402JR-072K2L – Yageo Phycomp
U1
Low Noise LDO Linear Regulator 2.5 V 300 mA
LT1962EMS8-2.5#PBF- Linear Technology
Table 35: Example of components for headset jack connection
1.11.1.4 Handset mode
The handset profile is configured when the uplink audio path is set to “Handset microphone” and the downlink
audio path is set to “Normal earpiece” (refer to u-blox AT commands manual [3]: AT+USPM command:
<main_uplink>, <main_downlink> parameters):
Handset microphone must be connected to the module differential input MIC_P / MIC_N
Handset receiver must be connected to the module differential output SPK_P / SPK_N