Signaling Circuit; Bluetooth/Gps Circuit; Encode; Decode - Kenwood NX-3220 K Service Manual

5VC
SBC
ANTSW
TXC
SBC
F2
(0.5A)
F650
(0.315A)

2.3.8 Signaling Circuit

2.3.8.1 Encode (QT/DQT/DTMF/2-tone/MSK)
Each signaling data signal of QT, DQT, DTMF, 2-tone and MSK is generated by IC401, superposed on a modulation signal and output
to VCO and PLL.
2.3.8.2 Decode (QT/DQT/DTMF/2-tone/MSK)
The audio signal and signaling data (QT, DQT, DTMF, 2-tone and MSK) are separated by IC401. Next IC401 decode the signaling
data.

2.3.9 Bluetooth/GPS Circuit

The main component of the Bluetooth/GPS circuit is Bluetooth /GPS IC (IC351).
The clocks of Bluetooth/GPS IC require 19.2MHz for core and 32.768kHz slow clock (X351) for UART. 19.2MHz clock (X401) is shared
with MPU/DSP (IC401), and is supplied through the Clock buffer amplifier (Q401).
Bluetooth/GPS IC communicates to the MPU/DSP (IC401) on the HCI UART. Interface of UART & Digital audio (PCM) between the
MPU/DSP (IC401) and the Bluetooth/GPS IC (IC351), have level conversion at the level conversion IC (IC352, IC353).
The Bluetooth/GPS IC is powered by 1.8V and 3.2V which are supplied from 2 discrete external regulators (IC8 and IC7). The input
of these regulators is sourced from a switching regulator (IC3) which regulates the battery voltage to 3.8V.
GPS antenna
Matching
HPF
BT antenna
1-20 (No.RA053<Rev.001>)
IC17
50A
IC651
50J
IC6
50C
IC15
50T
Q4
SB2
Q7
53AF
Q650
AF SW
Fig.6 Power supply circuit
LNA Supply
Pre-SAW LNA
Post-SAW
LNA Module
TCXO
19.2MHz
LC filter
Fig.7 Bluetooth/GPS circuit
IC201
SW
VDD_TCXO(G1)
VBAT1(A2)
TCXO_LDO_IN(H1)
GPS_EXT_LNA_EN(H6)
GPS IC(IC850)
GPS_LNA_IN(L2)
BT_HCI_UART_TX(A4)
Post-SAW
BT_HCI_UART_RX(B5)
BTFM_nSHUTDOWN(A6)
GPS PA EN(G3)
Clock
TCXO_CLK_LV(F1)
Buffer
RTC_CLK(H9)
BT_RF
KEY Back Light, 3Color LED,
8bit/16ch ADC
2Pin Jack Option
VCO
ANTSW
TX circuit
8bit ADC
Int AF Amp
Audio Amp(2Pin Jack Option)
3.2V
VDDS 1.8V
GPS_TX
Level
GPS_RX
Conversion
MPU/DSP
OSCILLATOR
32.768kHz