TK-7160
15
Control Circuit
The CPU carries out the following tasks:
1) Controls the WIDE, NARROW, TX/RX outputs.
2) Controls the AQUA IC (IC241).
3) Controls the PLL (IC401).
4) Controls the D/A converter (IC201) and adjusts the vol-
ume, modulation and transmission power.

Fig. 10 Control circuit

Fig. 11 Memory circuit

Fig. 13 Key matrix circuit

IC201
D/A
converter
IC401
PLL
IC101
CPU
LD
DT
CK
PLLE

■ Memory Circuit

The transceiver has an 64k-bit EEPROM (IC81). The
EEPROM contains adjustment data. The CPU (IC101) con-
trols the EEPROM through three serial data lines.
EEPCK
IC101
CPU
IC81
EEPROM
EEPDT
EEPWP

■ Display Circuit

The CPU (IC101) controls the display LCD and LEDs.
When power is on, the CPU will use the MBL line to control
the LCD illumination and key backlight LEDs.
The dimmer function is controlled by the switch Q1. The
LCD controller (IC1) controls the functions of the LCD
through the DO, CE, CL, DI lines from the CPU.

■ Key Matrix Circuit

The TK-7160 front panel has function keys. Each of them
is connected to a cross point of a matrix of the KMI1 to KMO3
ports of the IC1 LCD driver. The KMO1 to KMO3 ports are
always high, while the KMI1 to KMI3 ports are always low.
The microprocessor monitors the status of the KMI1 to
KMO3 ports. If the state of one of the ports changes, the
microprocessor assumes that the key at the matrix point cor-
responding to that port has been pressed.
IC101
CPU
Q3
SW D1~D6
Key backlit
Q2
SW
Q1
SW
D7~D18
LCD
illumination
Q4
SW
IC1
LCD
driver
CE
CL
DI
DO BRI
BL

Fig. 12 Display circuit

IC1
LCD
driver
KMI1
KMI2
KMI3
KMO3
KMO2
KMO1
VOL
UP
VOL
DN
CH
UP
CH
DN
S
A
<B
C>

■ Encode

The QT and DQT signals are output from QT/DQT of the
CPU (IC101) and summed with the external pin DI line by the
AQUA IC (IC241) and the resulting signal goes to the D/A con-
verter (IC201). The DTMF signal is output from DTMF of the
CPU and goes to the D/A converter (IC201). The signal is
summed with a MIC signal by the AQUA IC (IC241), and the
resulting signal goes to the D/A converter (IC201).
The D/A converter (IC201) adjusts the MO level and the
balance between the MO and QT/DQT levels. Part of a QT/
DQT signal is summed with MO and the resulting signal goes
to the VCOMOD pin of the VCO. This signal is applied to a
varicap diode in the VCO for direct FM modulation.
X401
TCXO
IC201
D/A VCO
IC241
AQUA
IC
IC241
AQUA
IC
IC201
D/A
IC401
PLL
TCXO
MOD
VCO
MOD
HT
DI
QT/DQT
DTMF
IC101
CPU

Fig. 14 Encode

CIRCUIT DESCRIPTION