Specifications

PART 2 – Cellular SocketModems Chapter 4 – SocketModem EDGE

Multi-Tech Systems, Inc. Universal Socket Hardware Guide for Developers (S000342P) 84

Application Notes

RF Performances

RF performances are compliant with the ETSI recommendation 05.05 and 11.10.

The main parameters are:

Receiver Features

• EGSM Sensitivity : < -108 dBm

• GSM 1800/GSM 1900 Sensitivity : < -107 dBm

• Selectivity @ 200 kHz : > +9 dBc

• Selectivity @ 400 kHz : > +41 dBc

• Dynamic range : 62 dB

• Intermodulation : > -43 dBm

• Co-channel rejection : + 9 dBc

Transmitter Features

• Maximum output power (EGSM) : 24 dBm +/- 2 dB

• Maximum output power (DCS/PCS) : 30 dBm +/- 2 dB

• Minimum output power (EGSM): 5 dBm +/- 5 dB

• Minimum output power (DCS/PCS): 0 dBm +/- 5 dB

• H2 level : < -30 dBm

• H3 level : < -30 dBm

• Noise in 925 - 935 MHz : < -67 dBm

• Noise in 935 - 960 MHz : < -79 dBm

• Noise in 1805 - 1880 MHz : < -71 dBm

• Phase error at peak power : < 5 ° RMS

• Frequency error : +/- 0.1 ppm max

RF Connection and Antenna

The RF connector on the SocketModem is an MMCX standard type. See Chapter 1 for Antenna System details.

Audio Interface – Electrical Characteristics

Speaker Output

Differential speaker output capable of driving 8 ohm load. 1.0945 Vpp (differential) typical.

Microphone Input

Balanced microphone input: full scale input 1.1 Vpp.

Microphone Inputs

The MIC inputs are differential ones. They already include the convenient biasing for an electret microphone (0,5 mA

and 2 Volts). This electret microphone can be directly connected on these inputs. The impedance of the microphone

has to be around 2K. These inputs are the standard ones for a handset design.

The gain of the MIC inputs is internally adjusted. The gain can be tuned from 30dB to 51dB. The connection to the

microphone is direct.

MIC2N

MIC2P

C1 = 22pF to 100 pF

33 pF recommended