1-22 (No.RA032)2.4.8 Signaling Circuit2.4.8.1 Encode (QT/DQT/DTMF/2-tone/MSK)Each signaling data signal of QT, DQT, DTMF, 2-tone and MSK is generated by IC706, superposed on a modulation signal and outputto TX VCO and PLL IC.2.4.8.2 Decode (QT/DQT/DTMF/2-tone/MSK)The audio signal is removed from the FM detection signal sent to the IC706 and the resulting signal is decoded by IC706.2.4.9 Bluetooth/GPS CircuitThe main component of the Bluetooth/GPS circuit is Bluetooth / GPS IC (IC5) on MODULE unit.The clocks of Bluetooth/GPS IC require 19.2MHz for core and 32.768kHz slow clock (X1 and X2) for UART.Bluetooth/GPS IC communicates to the OMAP processor (IC706) on the HCI UART. Interface of UART & Digital audio (PCM) betweenthe OMAP processor (IC706) and the Bluetooth/GPS IC (IC5), have level conversion at the level shift IC (IC6 and IC7) on MODULEunit.The Bluetooth/GPS IC is powered by 1.8V and 3.3V which are supplied from 2 discrete external regulators (IC2 and IC3) on MOD-ULE unit.Fig.5 Bluetooth/GPS circuit2.4.9.1 Bluetooth CircuitThe Bluetooth / GPS IC (IC5) support Bluetooth 3.0 up to HCI level.TX/RX frequency is 2400-2483.5MHz (79ch Hopping, 2402-2480MHz, 1MHz step). Transmitting power is +2dBm at Bluetooth anten-na input.Using the printed antenna with Bluetooth, and connected to the Bluetooth / GPS IC (IC5) through the saw filter (L11).Frequency configuration for Bluetooth is following:There are two LO modes: 2X and Offset LO (OSLO). 2X where LO is 2*RF_FREQ (e.g. when transmitting at 2441MHz it is at4882MHz). OSLO where LO is at (2/3)*RF_FREQ (e.g. when transmitting at 2441MHz it is at 1627.333MHz).In RX the 2X is always used.In GFSK TX if power is >10dBm then OSLO is usedIn EDR2 TX if power is >-12dBm then OSLO is usedIn EDR3 TX if power is >-12dBm then OSLO is usedOtherwise 2X is used for TX as well.2.4.9.2 GPS CircuitThe GPS RF signal is received with the active antenna, and connected to the Bluetooth / GPS IC (IC5) through the terminal (CN5)and saw filter (L9).The output is passed to pin L2 of the GPS IC. The input match for pin L2 comprises of C38, C36 and L7.The control and data lines for the GPS IC are GPS_PA_EN, BTFM_nSHUTDOWN, GPS_TX and GPS_RX.GPS_TX and GPS_RX are shared with Bluetooth data line.Frequency configuration for GPS is following: Lo is GPS: 1571.324MHzFig.6 GPS circuitIC706 IC6 IC5UART UART UARTIC7PCM PCM PCMX1 X2CN5BT/GPS ICTCXO19.2MHz32.768kHzClockBPF BluetoothantennaLevelshift ICLevelshift IC BPF GPSantennaconnectorModule (BT/GPS) unitMain unitMPU/DSPBPFGPSantennaTCXO19.2MHzMPU/DSP1.8V3.3VGPS_LNA_IN(L2)TCXO_CLK_LV(F1)BT_HCI_UART_TX(A4)BT_HCI_UART_RX(B5)RTC_CLK(H9) OSCILLATOR32.768kHzBTFM_nSHUTDOWN(A6)GPS_PA_EN(G3)VBAT1(A2)LEVELSHIFTTCXO_LDO_IN(H1)VDDSGPS TXGPS_RXBTantennaBT_RFBT/GPS ICAntennaconnectorBPFGPS ANT ALMGPS ANT PWRGPSdetect3.3V33GPS33BT18BTIC706
