User's Manual
Table Of Contents
- Introduction
- General Characteristics
- Feature Details
- Feature Descriptions
- Applications
- Mechanical Design Overview
- Mechanical Dimensions
- Climatic and Mechanical Environment Testing Compliance
- Introduction
- 50-Pin Connector Interfaces
- Flashing LED
- SIM Interface
- RF Interface
- DTE/DCE Interface Rates
- Serial Test/Demo Board Components
- Serial Test/Demo Board Block Diagram
- General Guidelines for the Use of the ModemModule
- Reference Documents
- Related Manuals
- Additional Information
- Safety Precautions
- Regulatory Standards Compliance
- Where to Find SMD Connectors
- GSM Antenna
- SIM Card Holder
- LIST OF TABLES
Chapter 3 – Electrical Characteristics
Wireless ModemModule MTMMC-G-F1 and MTMMC-G-F2 Developer’s Guide 27
Speaker 2 Outputs
Speaker outputs SPK2 are push-pull amplifiers and can be loaded down to 50 Ohms and up to 1nF. These
outputs are differential and the output power can be adjusted by step of 2dB. The output can be directly
connected to a speaker. When using a single-ended connection, be sure to have a very good ground plane, a
very good filtering as well as shielding in order to avoid any disturbance on the audio path.
SPK2P
+
C1
Differential Connection
SPK2P
SPK2N
Single-Ended Connection
Figure 3-10: Speaker 2 Output
C1 = from 100nF to 47µF as per the speaker characteristics and the output power.
Using a single-ended connection also includes losing half of the output power compared to a differential
connection.
Table 3-21: Speaker 2 Output Pin Description
Signal Pin Number I/O I/O Type* Description
SPK2P 10 O Analog Speaker 2 positive output
SPK2N 8 O Analog Speaker 2 negative output
* See “Table 3-2: Operating Conditions” in section on the 50-pin Connector Description.