EZZE SL900A, Техническое руководство

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M
ODEL
SL900A V
ERSION
V_1.0
P
REPARED BY
H/W D
ATE
2006.06.30
S
UBJECT
T
ECHNICAL
M
ANUAL
P
AGE
47/51
SL900A T
ECHNICAL
M
ANUAL
- Recommended Operating Range
Item Symbol Min Typ Max Unit
Power Supply Voltage(VBAT) VBAT 3.1 3.6 3.6 V
Power Supply Voltage(VCCD) VCCD 2.5 2.8 3.1 V
Operating Ambient Temperature Topr -20 25 75 C
1. Receiver
The receiver section of MT612 0 includes Quad-band low noise amplifiers(LNAs), RF quadrature
mixers, an on-chip channel filter, Programmable Gain Amplifiers(PGAs), quadrature second mixers,
and a final low-pass filter. The very low-IF MT6129 uses image-rejection mixers and filters to
eliminate interference. With accurate RF quadrature signal generation and mixer matching techniques,
the image rejection of the MT6129 can reach 35dB for all bands. Compared to a direct conversion
receiver(DCR), MT6129’s very low-IF architecture improves the blocking rejection, AM suppression,
as well as the adjacent channel interference performance.
The SL900A was designed for Tri-Band(GSM900, DCS1800, PCS1900)
- Receiver Input Frequency
Mode Min Max Unit
GSM900 925 960 Mhz
DCS 1805 1880 Mhz
PCS 1930 1990 Mhz
2. Transmitter
The MT612 0 transmitter section consists of two on-chip TX VCOs, buffer amplifiers, a down-
converting mixer, a quadrature modulator, an analog phase detector and a digital phase frequency
detector, each with a charge pump output and on chip loop filter. The dividers and loop filters are used
to achieve the desired IF frequency from the down-conversion mixer and quadrature modulator. For a
given transmission channel, the transmitter will select one of the two different TX reference dividing
numbers. These built-in components, along with an internal voltage controlled oscillator and a loop
filter, implement a translation loop modulator. The TX VCO output is fed to the power amplifier. A
control loop, implemented externally, is used to control the PA’s output power level.
- Transceiver Output Frequency
Mode Min Max Unit
GSM850 824 849 Mhz
GSM900 880 915 Mhz
DCS 1710 1785 Mhz
PCS 1850 1910 Mhz