DSB75 Development Support Board Rev. B1 Hardware Description
Confidential / Released
DSB75_hd_v12
Page 84 of 96
2008-08-26
Parameters
Condition
Min.
Typical
Max.
Unit
Ignition via VBUS line
@USB-Interface
V
I
min = 4V
signal
~~~
|________|
~~~~~~~~~~~~~~~
|
≥
1s |
≥
0.5s |
Rise time
≤
1ms
Low high transition of this signal switches the module on.
RF attenuation
Adapter between RF
connector X505 (type
Hirose U.FL-R-SMT)
and RF connector X506
(type SMA)
0.1 0.2 dB 0.1
Antenna
Frequency range
GSM 850
1)
GSM 900
GSM 1800
GSM 1900
824
880
1710
1850
894
960
1880
1990
MHz
MHz
MHz
MHz
Antenna VSWR
2:1
Antenna gain
0
dBd
Dimensions of
DSB75 PCB
Depth
Width
Height with feet
177
160
43
mm
mm
mm
Weight
240
g
1)
Although the provided antenna is rated for a frequency range from 890MHz to
1990MHz (2170MHz), its coverage also includes the 850MHz frequency band,
sufficient ground plane and mounting provided.
8.1 Cable
Requirements
The DSB75 has been tested and approved for use with a maximum cable length of 3m for
following interfaces:
- USB interface (shielded)
- Serial interfaces COM1 to COM3 (RS232)
- Power supply
- Charger
- Analog audio interface
- Antenna interface
- ADC inputs
- DAC output
It is recommended to keep the digital lines for I²C-, SPI- and DAI- interfaces as short as
possible.
