Sharp R-980J Service Manual page 23

LSI(IZA840DR):
The I/O signals of the LSI(IZA840DR) are detailed in the following table.
Pin No. Signal
1 VCC
2 VEE
3 AVSS
4 VREF
5 AN7
6 AN6
7-9 AN5-AN3
10 AN2
11 AN1
12 AN0
13 P55
14 P54
15 P53
16 P52
DESCRIPTION OF LSI
I/O
IN Connected to GND.
IN Anode (segment) of Fluorescent Display light-up voltage: -30V.
Vp voltage of power source circuit input.
IN Power source voltage: -5V.
VC 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
GND.(0V)
IN Used for initial balancing of the bridge circuit (absolute humidity sensor). This input
is an analog input terminal from the AH sensor circuit, and connected to the A/D
coverter built into the LSI.
IN AH sensor input.
This input is an analog input terminal from the AH sensor circuit, and connected
to the A/D converter built into the LSI.
IN Heating constant compensation terminal.
IN Input signal which communicates the door open/close information to LSI.
Door closed; "H" level signal(0V).
Door opened; "L" level signal(-5V).
IN Input signal which communicates the damper open/close information to LSI.
Damper opened; "H" level signal(0V:GND).
Damper closed; "L" level signal(-5V).
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.
OUT Digit selection signal.
The relationship between digit signal and digit are as follows;
Digit signal
P03 ........................... 1st.
P02 .......................... 2nd.
P01 ........................... 3rd.
P00 ........................... 4th.
P37 ........................... 5th.
P36 .......................... 6th.
P35 .......................... 7th.
P55 .......................... 8th.
Normally, one pulse is output in every ß
period, and input to the grid of the
Fluorescent Display.
OUT Oven lamp and turntable motor driving signal. (Square Waveform : 50Hz)
To turn on and off the shut-off
relay(RY1). The square waveform volt-
age is delivered to the relay(RY1) driv-
ing circuit.
OUT Convection motor driving signal.
To turn on and off shut-off relay(RY5). "L"
level during CONVECTION; "H" level oth-
erwise.
OUT Cooling fan motor driving signal.
To turn on and off shut-off relay(RY6). "L"
level during both microwave and convec-
tion cooking; "H" level otherwise.
Description
Digit
§(50Hz)
P03
P02
P01
P00
P37
P36
P35
P55
21
GND
VP
20 msec.
H
L
During cooking
H.
During
OFF
cooking
(Convection)
ON
L
H.
OFF
During
cooking
L
ON
R-980J
H
L
GND
GND