General Controller Block 5-5
1.4 GNSS/Bluetooth/WiFi
1.4.1 GNSS
The GNSS section is a receiver which operates on 3 frequencies, 1.560GHz (Beidou), 1.575
GHz(GPS) & 1.602 GHz(GLONASS). It consists of Front end and Back end. The front end is made up
of Diplexer, first SAW filter, LNA, second SAW filter and input match. The back end is made up of
mixer, PLL for generation of LO, backend, baseband & microcontroller. The entire back end is inside
the GNSS IC (UBlox). The function of Dual band diplexer is to isolated BT/WIFI and GNSS band and
attenuates transmit & receive signals of main transceiver. The first SAW filter will filters spurious
signals with frequencies close to GNSS frequency and the GNSS signals will be amplified by LNA for
better sensitivity. The second SAW filter will provide additional filtering of spurious signals. The last
stage is the input match for UBlox which is to provide impedance matching between 2nd SAW and
UBlox IC.
1.4.2 Bluetooth/WiFi
The Bluetooth and WiFi section uses Marvell Avastar 88W8777 chipset to provide Bluetooth and WiFi
functionality. The Marvell Avastar 88W8777 chipset is a single-chip Bluetooth/WiFi solution that
provides both simultaneous and independent operation of IEEE 802.11b/g/n (2.4 GHz band
operation) WiFi payload data rates and BT 4.0 with BT Smart Ready (BT Low Energy). The BT and
WiFi section consists of front end and back end. The front end is made up of dual band diplexer, RF
switch and input match. The function of dual band diplexer is to isolated Bluetooth/WiFi and GNSS
band and attenuates transmit & receive signals of main transceiver. The RF switch provides selection
of Bluetooth or WiFi RF path and operation. The input match provide impedance matching for the
Bluetooth and WiFi output pin of the chipset. The back end is made up of Marvell Avastar 88W8777
(with integrated power amplifier) and microcontroller. The generic host interfaces utilizes a shared
SDIO for connecting Bluetooth & WiFi to the microcontroller and utilizes PCM interface for BT audio.
Figure 5-5. GPS/Bluetooth/WiFi
Diplexer
Pre
Saw
Filter
EXT
LNA
Post
Saw
Filter
GNSS RF
RTC_CLK
Matching
Network
GNSS RF UBLOX
LNA_IN
UBX-M8030
DIG_EXT_LNA_EN_UB
I2C
DIG_EN_UB
GNSS_EN
GNSS_I2C_DATA\SCL
FREON
I/O V_BCKP CORE
CPCAP POWER & POWER CTL
1.8V
Marvell 88W8777
SDIO
SSI2
SDIO BUS
SSI BUS
TCXO_CL K
26MHz
XTAL_IN
XTAL_OUT
VIOVIO_SDAVDD18 LVLDO_ IN
1.8V
PDNRF_CNTL0_N
RF_CNTL1_P
Matching
Network
Matching
Network
RF Switch
VCTL1 VCTL2
OUT1
OUT2
RFC
BFR_ANT
RF_TR
BT
WIFI
AVDD33 SLP_CLK_IN
32.768kHz
DIG_PDN_IC
3.3V LDO
OUT
IN
EN
3.6V
5V
SQI
Flash
DIG_SQI
3.3V
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