Kenwood TS-990S Service Manual

TS-990S
36
CIRCUIT DESCRIPTION
Fig. 41 Control circuit
IC31
Extension port 01
IC36
Extension port 02
IC32
Extension port 03
IC37
Extension port 04
IC33
Extension port 05
IC38
Extension port 06
IC34
Extension port 08
IC39
Extension port 09
IC42
Extension port 07
IC43
Extension port 10
IC30
Multiplexer3
IC35
Multiplexer2
IC46
Main MCU
Frequency: 88.4736MHz
IC44
Reset IC
11.0592MHz
IC40
5V→3V
Converter
IC41
3V→5V
Converter
TTO/TSO
TT/TS
TTI/TSI
IC45
OR GATE
VBINT
UVBINT
Type Version judgement
IBK
32.768kHz
IC49
RTC
32KOUT
I2C
IC47
EEPROM
IC48
Buffer
5B
33B 33B
33B
1SS388F
5D
33B
33B
33B
33B
33B
33B 33B
RT32S
IBK
CN3
PH2P
From X43-322
CN2
PH4P
From X43-322
33SD
5A
CN1
PH4P
From X43-322
14SD
14SD
33B 33B
IC381
Scope DSP
Frequency: 331.776MHz
(Max.333MHz)
Core：1.2V
I/O：3.3V
24.576MHz
SDTI1
MCLK
SCLK
LRCK(96kHz)
1.2V
33SD
SDTI0
1.2V
DC-DC
IC380
Scope
MCU
Frequency:
18.432MHz
18.432MHz.
IC390
Parallel frash
(8Mbit)
IC389
Latch IC
IC388
Latch IC
33SD
UART
SPI
IC382
ADC
96kHz
IC384
OP_AMP
Differential
conversion
IC387
Filter
IC385
OP_AMP
Ref. for OP-AMP
33SD
5A
5A 5A
5A
IC386
ADC
96kHz
CN453
33SD 5A
CN450
CN451
Lch
Lch+
Lch-
Rch
33SD
33SD
33SD
33B
IC2
3.3V Reg.
33B
To X53-453
X50-323 FFC CN(CN47) X50-323 FFC CN(CN43) X57-827 FFC CN(CN37) X55-313 FFC CN(CN32)
X54-385 FFC CN(CN65)
X43-322 FFC CN(CN70)
X46-339 FFC CN(CN71)
X53-453 FFC CN(CN72) X42-343 FFC CN(CN73)
33B 33B
33B
33B
33B
33B
OP_AMP
Type Version judgement
9-4. Scope DSP and Its Periphery
The scope DSP (IC381) is powered by two supply volt-
ages, i.e., 3.3 V (I/O) and 1.2 V (Core). The scope DSP is
operated at a clock frequency of 331.776MHz obtained by
dividing 24.576MHz in the scope DSP and multiplying the
divided frequency by 27.
The fl ash memory (IC390) for program storage, latch ICs
(IC388 and IC389) for address decoding, and ADCs (IC382
and IC386) are connected as peripheral devices for the
scope DSP. The scope DSP and the scope MCU are in the
SPI communication mutually (at a communication speed of
approximately 1.15MHz). Drawing data for a single screen
is transferred at a cycle of 150 ms to the application MCU
(X46-339). Such drawing data is transferred under the SPI
communication at a speed of approximately 2MHz.
9-5. Scope IF Signal
A 24kHz IF signal received from the scope unit (X42-
343 A/10) passes through the quaternary LPFs (IC384 and
IC387), and is converted to a differential signal at a single
end. This signal is applied to the ADC (IC382) and converted
to drawing data in the scope DSP (IC381) (Band scope).
Fig. 42 Scope IF signal
IC382
ADC
96kHz
IC384
OP_AMP
Differential conversion
IC387
OP_AMP
Filter
CN453
Lch+
Lch-
Total fc≒40kHz
From X42-343
IF signal
24kHz
9-6. MSCPI signal
The audio signal of the main receiver is received from the
DSP unit (X53-453) and input into the ADC (IC386 L chan-
nel). The signal is converted to drawing data in the scope
DSP (IC381) (Audio scope).
9-7. SSCPI signal
The audio signal of the sub receiver is received from the
DSP unit (X53-453) and input into the ADC (IC386 R chan-
nel). The signal is converted to drawing data in the scope
DSP (IC381) (Audio scope).

Kenwood TS-990S Specifications

General

Receiver Type	Triple Conversion Superheterodyne
Antenna Tuner	Built-in automatic antenna tuner
DSP	Yes
IF DSP	Yes
Modes	SSB, CW, AM, FM
Display	7-inch TFT color LCD
Weight	25 kg (55.1 lbs)
Antenna Connectors	SO-239
Power Supply	13.8V DC