Kenwood TS-990S Service Manual

TS-990S
31
CIRCUIT DESCRIPTION
7-2. 14S, 5 V, and 33S Power Supplies
1. The 14S, 5 V, and 33S power supplies that are input from
the DC-DC PCB are supplied to each PCB through the
following paths.
1) 14S system: 14S input is supplied to the AT PCB, ANT
SW PCB and TX-RX PCB.
2) 5 V system: 5 V input is supplied to the FINAL PCB,
ANT SW PCB and TX-RX PCB.
3) 33S system: 33S input is supplied to the FINAL PCB, AT
PCB, ANT SW PCB and TX-RX PCB.
2. The LINK PCB serves to connect a variety of control sig-
nals input from the CONTROL PCB through the DC-DC
PCB to the FINAL PCB, AT PCB, ANT SW PCB and TX-
RX PCB.
7-3. 1.8V and 1.2V Power Supplies
The DC-DC (APPLI) PCB uses the DC/DC converter to
generate 1.8 V and 1.2 V from 14 V that is input from the
DC-DC PCB and supply the voltages to the DIGITAL PCB.
Fig. 33 14S, 5 V, and 33S power supplies
Fig. 34 1.8V and 1.2V power supplies
1.8V
1.2V
DC-DC(APP) PCB
1.8V DCDC
1.2V DCDC
14V
8. DSP (TXMRX and SRX) Unit
8-1. Outline
The DSP unit (X53-453) consists of two DSPs (IC202
and IC300), a DSP-SubMCU (IC101), two Latch ICs (IC200
and IC201), a Buffer (IC302), two Flash memories (IC203
and IC301), three A/D converters (ADCs) (IC389, IC392
and IC398), eight D/A converters (DACs) (IC385, IC386,
IC387, IC388, IC390, IC391, IC397 and IC658), an optical I/
O (A650 and A651) and two electronic volume ICs (IC664
and IC665), two AF power amplifi ers (IC51 and IC52), and a
headphone amplifi er (IC50).
The DSP-SubMCU uses the UART to perform external
communications with the main MCU (X53-452 IC46) while
the SPI performs communications between the DSP-SubM-
CU and the DSP.
Fig. 35 DSP circuit
IC202
TXMRX-DSP
IC394
DAC(TIF/MAGCV)
IC398
ADC(MRIF/MIC)
IC385
DAC(BEEP/MSCPI)
IC390
DAC(SP1/SP2)
IC391
DAC(MANO/SANO)
IC386
DAC(MUANO/SUANO)
IC387
DAC(MRECI/SRECI)
IC388
DAC(SAGCV/SSCPI)
IC392
ADC(SRIF/ANI,UANI)
IC389
ADC(MRECO/SRECO)
IC300
SRX-DSP
IC101
DSP-sub MCU
IC301
Flash memory
(32M 8bit)
A651
Optical in
A650
Opticai out
IC302
Buffer
CN101
To ControlL unit
(X53-452)
IC203
Flash memory
(8M 8bit)
IC201
Latch
IC200
Latch
IC399
NAND
IC380
Flipflop
IC381
Buffer
IC382
Buffer
IC383
Buffer
18.432MHz
24.576MHz
24.576MHz
IC665
E-VOL
IC664
E-VOL
IC673
OPAMP
IC51
AF AMP
IC52
AF AMP
IC50
HP AMP
PHONES OUT
SP OUT
Ext.SP1
Ext.SP2
IC658
DAC
Link PCB
14S
5V
33S
5V
14S
33S
33S
14S
5V
33S
5V
33S
To Final PCB
To AT PCB
To ANT SW PCB
To TX-RX PCB
-12V
-12V

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