Kenwood TK-890/(B) Service Manual page 36

Flash ROM : AT29C020-90TI (Control Unit IC519)
• Terminal description
Pin Name
A0~A17 Addresses
CE Chip enable
OE Output enable
WE Write enable
I/O0~I/O7 Data inputs/outputs
NC No connect
Power Amplifier : M68769H (Final Unit IC1) TK-890/(B) K type
: M68769SH (Final Unit IC1) TK-890(B) K2 type
: M68769L (Final Unit IC1) TK-890(B) K3 type
• Equivalent circuit
2
1
Final Amplifier : 2SC4989 (Final Unit Q6, Q7) TK-890H(B)
• Absolute maximum ratings
Symbol Parameter
V Collector-base voltage
CBO
V Emitter-base voltage
EBO
V Collector-emitter voltage
CEO
Ic Collector current
Pc Collector dissipation
Tj Junction temperature
Tstg Storage temperature
SEMICONDUCTOR DATA
Function
3
4
Tc= 25°C unless otherwise noted
Conditiona Rating
35V
4V
∞
R = 17V
BE
18A
150W
175°C
–55 to 175°C
TK-890/
• Block diagram
Vcc
GND
OE
OE, CE, AND WE
WE
LOGIC
CE
Y DECODER
Address
input
X DECODER
5
1 : Input
2 : 1st stage power supply
6
3 : Drive stage power supply
4 : Final stage power supply
5 : Output
6 : Fin (Earth)
( B ) /H ( B
Data inputs/outputs
I/O0~I/O7
DATA LATCH
INPUT/OUTPUT
BUFFERS
Y-GATING
OPTIONAL BOOT
BLOCK (8K BYTES)
MAIN MEMORY
(240K BYTES)
OPTIONAL BOOT
BLOCK (8K BYTES)
35
)