User's Manual

Page 10 of 31
2.2 Application note of U6100 interfaces
U6100 provides rich interfaces for secondary development by the 60PIN board to board connector, such as Micro
SD/T-Flash card interface (Compatible for MMC card), USIM card interface, USB interface, audio interface, UART
interface, PCM（Pulse Code Modulation) interface, SPI（Serial Peripheral interface) interface, power supply interface
and so on. The detail information will be described in the following sections.
2.2.1 RF antenna interface
The ground impedance of RF antenna is 50Ω. There are two different modes for connection.
A. Connector mode: Recommended, a connector is on the rear side of PCB board
B. Solder pad mode: Antenna pad and ground pad are on the front side of PCB board
It’s required to use RF cable of which the insertion loss should comply with:
• GSM850/900<1dB
• DCS1800/PCS1900<1.5dB
• UMTS2100/ UMTS1900/ UMTS850<1.5dB
And the gain of antenna should comply with the Table 2-3:
Table 2-3 Antenna gain requirements
Item Parameter
Gain (dBi)
GSM DCS UMTS
0.5 1 1
Type
Omnidirectional antenna
2.2.2 Power supply and ground
There are two power supply input for U6100 module listed as follows:
1. DC +3.4V～+4.2V, for U6100 working voltage;
2. DC +5V, for USB working voltage;
The description of U6100 Power supply and GND pins is shown in Table 2-4 below.
The device does not operate at temperatures below -20°