Sharp R-820BK Service Manual

25
R-820BK
R-820BW
DESCRIPTION OF LSI
LSI(IZA888DR)
The I/O signal of the LSI(IZA888DR) are detailed in the following table.
Pin No. Signal I/O Description
A
B
C
H: GND
L
0.1 sec
2.0 sec
1.0 sec
1.0 sec
16.7 msec.
H : GND
L (-5V)
1 C1 IN Terminal not used.
2 VL1 IN Power source voltage input terminal.
Standard voltage for LCD.
3-5 AN7-AN5 IN Heating constant compensation terminal.
6 AN4 IN Terminal not used.
7 AN3 IN Temperature measurement input: OVEN 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.
8 AN2 IN Input signal which communicates the door open/close information to LSI.
Door closed; "H" level signal.
Door opened; "L" level signal.
9-10 AN1-AN0 IN Terminal not used.
11 P57 OUT Timing signal output terminal for temperature measurement(OVEN THERMIS-
TOR).
"H" level (GND) : Thermistor OPEN timing.
"L" level (-5V) : Temperature measuring timing. (Convection cooking)
12 P56 OUT Signal to sound buzzer.
A: key touch sound.
B: Completion sound.
C: When the temperature of the oven cav-
ity reaches the preset temperature in
the preheating mode, or when the
preheating hold time (30 minutes) is
elapsed.
13 P55 OUT Timing signal output terminal for temperature measurement(OVEN THERMIS-
TOR).
"H" level (GND) : Thermistor OPEN timing.
"L" level (-5V) : Temperature measuring timing. (Convection cooking)
14-18 P54-P50 IN/OUT Terminal not used.
19 P47 IN Signal coming from touch key.
When any one of G12 line keys on key matrix is touched, a corresponding signal from
P40, P41, P72, P73, P74, P75, P76 and P77 will be input into P47. When no key is
touched, the signal is held at "L" level.
20 P46 IN Signal similar to P47.
When any one of G11 line keys on key matrix is touched, a corresponding signal will
be input into P46.
21 P45 IN Signal similar to P47.
When any one of G10 line keys on key matrix is touched, a corresponding signal will
be input into P45.
22 P44 IN Signal similar to P47.
When any one of G9 line keys on key matrix is touched, a corresponding signal will
be input into P44.
23 INT1 IN Terminal not used.
24 INT0 IN Signal to synchronized LSI with commercial power source frequency(60Hz).
This is basic timing for time processing of LSI.
25 P41 OUT Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P44 - P47 terminal while
one of G8 line key on matrix is touched.

Sharp R-820BK Specifications

General

Brand	Sharp
Model	R-820BK
Category	Microwave Oven
Language	English