Sharp R-2397 Service Manual page 20

R-2397
LSI(IZA646DR)
The I/O signal of the LSI(IZA646DR) is detailed in the following table.
Pin No. Signal
1 VREF
2 IN7
3 IN6
4 IN5
5 IN4
6 IN3
7 IN2
8 IN1
9 IN0
10 P47 OUT
11 P46 OUT
12 P45 IN/OUT Memory (EEPROM) data input/output.
13-14 P44-P43 OUT
15 P42 OUT
16 P41 OUT
17 P40 OUT
18-22 P37-P33 OUT
23 P32 OUT
24 P31
25 P30 OUT
26 CNVSS
DESCRIPTION OF LSI
I/O
IN Reference voltage input terminal.
A reference voltage applied to the A/D converter in the LSI. Connected to GND.(0V)
IN Temperature measurement input: MAGNETRON THERMISTOR.
By inputting DC voltage corresponding to the temperature detected by the thermistor, this
input is converted into temperature by the A/D converter built into the LSI.
IN Temperature measurement input: EXHAUST THERMISTOR.
By inputting DC voltage corresponding to the temperature detected by the thermistor, this
input is converted into temperature by the A/D converter built into the LSI.
IN A/D input for troubleshooting Magnetron 1.
IN Terminal to change functions according to the model.
Signal in accordance with the model in operation is applied to set up its function.
IN A/D input for troubleshooting Magnetron 2.
IN Connected to GND.(0V)
IN Terminal not used.
IN Temperature measurement input: INTAKE THERMISTOR.
By inputting DC voltage corresponding to the temperature detected by the thermistor, this
input is converted into temperature by the A/D converter built into the LSI.
Terminal not used.
Memory (EEPROM) clock output.
Magnetron high-voltage circuit driving signal.
To turn on and off the cook relay. In 100% power level operation, "L" level during cooking;
"H" level otherwise. In other power level operation (90,80,70,60,50,40,30,20,10 or 0%),
"H" and "L" level is repeated according to power level.
Power level ON
100% 48sec.
90% 44sec.
80% 40sec.
70% 36sec. 12sec.
60% 32sec. 16sec.
50% 26sec. 22sec.
Power supply output at thermistor detecting circuit.
(Output -5V in cooking only, but apply high impedance to others to prevent thermistor from
electrolytic corrosion ocurrence.)
Terminal not used.
Oven lamp, Blower motor and Stirrer motor driving signal. (Square Waveform :
50Hz)
To turn on and off the shut-off relay (RY1). The
Square waveform voltage is delivered to the
RY1 relay driving
relays(RY3,RY4,COOK RELAY) control circuit.
Terminal not used.
Signal to sound buzzer.
This signal is to control the 2.5kHz continuous
signal.
A: key touch sound.
B: Guydance sound.
C: Completion sound.
IN Signal synchronized with commercial power source frequency.
This is basic timing for all time processing of LSI.
Terminal not used.
IN Connected to Vc.(-5V)
Description
OFF Power level ON OFF
0sec. 40% 22sec. 26sec.
4sec. 30% 16sec. 32sec.
8sec. 20% 12sec. 36sec.
10% 8sec. 40sec.
0% 0sec. 48sec.
circuit and
A
1.2 sec
B
18
OFF
ON
48 sec.
During cooking
20 msec
0.12 sec
GND
-5V
1.2 sec
C
T
200 sec.
200 sec.
20 msec
GND
-5V
H
L
2.4 sec
H : GND
L (-5V)