TS-590S
19
Display Circuit
The Display unit (X54-370) consists of the panel MCU
(IC103) and the peripheral circuits, LCD display, and LED in-
cluding LCD back light. Communication with the main MCU
(X53-446 IC306) is carried out in PTXD, PRXD, PCTS, PRTS.
(Transmission speed: 115200bps)
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Circuits around the panel MCU
The 33C power supply (3.3V) sent from the transceiver is
used as the power supply for the digital portion. The panel
MCU clock is 11.0592MHz (X101). The reset signal is con-
trolled from the main MCU. Also, the panel MCU accepts
the key matrix, various encoders, and volume.
Fig. 16 Display circuit
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LCD driver
The LCD driver used is LC75897PW (IC101). In accor-
dance with the IC’s specifi cation, the 5V power supply for
the LCD needs to be input after VDD (3.3V), a power supply
switch circuit (Q102) for turning 5V ON after 3.3V occurs.
In order to reliably control the power ON sequence, such
control is executed by the panel MCU. (Frame frequency:
97.66Hz, duty: 1/3, bias: 1/3)
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LED
LCD back light uses 54 LEDs for 1 color, and amber or
green can be chosen by the menu. There are 5 steps of the
back light luminance: 4 steps with the dimmer and OFF. Be-
cause the drive transistors (Q101, Q103, Q104, Q105) can-
not be directly controlled with the panel MCU because of
the quantity of LEDs, logic ICs (IC102, IC104) are used as a
buffer. LCD back light’s default value is amber. LED at times
of transmit/receive is controlled by the panel MCU.
LCD
COM1~COM3
S1~S119
KIN0~KIN7
KO0~KO7
DATA/CLK/CE
11.0592MHz
5C_L (5V)
MU/MD/PCTS/PRXD/PRTS/
PTXD/BKC/PRESET/PWS
8A (8V)
IC101
LCD driver
Key matrix
Q102
Power supply
control
Q101/Q103
Drive circuir
for Amber
LCD backlight
(Amber)
IC105
Voltage converter
LCD backlight
(Green)
DIMM
LCDB_Y
LCDB_YG
IC102
Buffer
Main Encoder
IC103
Panel MCU
IC106
Voltage converter
Q104/Q105
Drive circuir
for Green
IC104
Buffer
RIT Encoder
CN107
to Control unit
X53-446 (A/3)
Multi Encoder
Lo/Hi Encoder
Notch VR/SQL VR
AF VR/RF VR
CIRCUIT DESCRIPTION
Содержание TS-590S
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