Sharp R-2277 Service Manual page 21

LSI(IZA648DR)
The I/O signal of the LSI(IZA648DR) is detailed in the following table.
Pin No. Signal
1 VCC
2 VEE
3 AVSS
4 VREF
5-6 AN7-AN6
7 AN5
8 AN4
9 AN3
10 AN2
11 AN1
12 P60
13 P55 OUT
14-16 P54-P52 OUT
17 P51
18 P50
19 P47 OUT
20 P46 OUT
21 P45 OUT
22 P44 OUT
23 P43 OUT
24 P42
25 INT1
DESCRIPTION OF LSI
I/O
IN Connected to GND.
IN Anode (segment) of Fluorescent Display light-up voltage: -35V.
Vp voltage of power source circuit input.
IN Reference voltage input terminal.
A reference voltage applied to the A/D converter in the LSI. Connected to DC. (-5V)
IN Reference voltage input terminal.
A reference voltage applied to the A/D converter in the LSI. Connected to GND.
IN Terminal to switch the specification.
IN Temperature measurement input: INTAKE THERMISTOR.
By inputting DC voltage corresponding to the temperature detected by the thermis-
tor, this input is converted into temperature by the A/D converter built into the LSI.
IN A/D input for troubleshooting Magnetron 1.
IN A/D input for troubleshooting Magnetron 2.
IN Temperature measurement input: EXHAUST THERMISTOR.
By inputting DC voltage corresponding to the temperature detected by the thermis-
tor, this input is converted into temperature by the A/D converter built into the LSI.
IN Temperature measurement input: MAGNETRON THERMISTOR.
By inputting DC voltage corresponding to the temperature detected by the thermis-
tor, this input is converted into temperature by the A/D converter built into the LSI.
IN Input signal which communicates the door open/close information to LSI.
Door closed; "H" level signal (0V).
Door opened; "L" level signal (-5.0V).
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.
IN Signal coming from switch unit.
When either one of switches SW2 and SW4 on the switch unit is pressed, a
corresponding signal out of P44 and P43 will be input into P51.
IN Signal similar to P51.
When either one of switches SW1,SW3 and SW5 on the switch unit is pressed, a
corresponding signal out of P43,P44 and P45 will be input into P50.
Signal to sound buzzer.
This signal is to control the 2.5kHz con-
tinuous signal.
A: Switch touch sound.
B: Completion sound.
Terminal not used.
Switch strobe signal.
Signal is applied to the switch unit. A pulse signal is input to P50 terminal while
switch SW5 is pressed.
Switch strobe signal.
Signal is applied to the switch unit. A pulse signal is input to P50 or P51 terminal
while switch SW3 or SW4 is pressed.
Switch strobe signal.
Signal is applied to the switch unit. A pulse signal is input to P50 or P51 terminal
while switch SW1 or SW2 is pressed.
IN Signal coming from encoder.
When the encoder is turned, the contacts of encoder make pulse signals. And pulse
signals are input into P42.
IN Signal coming from encoder.
Signal similar to R42. Pulse signals are input into INT1.
Description
19
0.12 sec
A
1.2 sec 1.2 sec
B
R-2277
R-2287
GND
-5V