Shenzhen Coban Electronics Co. Ltd. CB900 Manuale Utente
4.13. 2-Wire Serial Interface
This is a half-duplex serial port using 2-line for data transmission consisting of SDA data signal
and SDL clock signal. It can transfer at speeds up to 400Kbits/s (fast-mode).
Note: Supports 1.8V I2C compliant devices.
Pin Description and Electrical Characteristics
This feature is not enabled in the standard module firmware as it requires a certain level of
firmware customization depending on its intended application. Please contact COBAN for more
information.
4.14. RF interface
CB900 RF interface has a characteristic impedance of 50. The matching networks for an
external antenna connection are not included in the module and should be placed on the
application board.
4.14.1.
RF Performance
4.14.2.
Recommendations
The antenna must fulfill the following requirements below:
57
58
62
63
64
KROW4
KROW3
KCOL4
KROW0
KROW2
High level output voltage, VOH
2.6
2.8
2.85
V
Low level output voltage, VOL
-
-
0.45
V
Pin
Signal Name
Parameters
Min
Type
Max Unit
65
66
SCL28
SDA28
High level input voltage (SDA and SCL), VIH
-
-
2.8
V
Low level input voltage(SDA and SCL), VIL
0
-
-
V
Frequency Bands
RF Sensitivity (dBm) (Nominal)
GSM 850/EGSM 900
-106dBm
DCS1800/ PCS1900
-104dBm
Frequency Bands
EGSM 900
DCS 1800
GSM 850
PCS 1900