Description Of Lsi - Sharp R-1880LS Service Manual

R-1880LS/LST
LSI(IZA719DR)
The I/O signals of the LSI(IZA719DR) are detailed in the following table.
Pin No. Signal
1 VCC
 VEE
3 AVSS
4 VREF
5 AN7
6 AN6
7-9 AN5-AN3
10 AN
11 AN1
1 AN0
13 P55
14 P54
15 P53
16 P5
17 P51

DESCRIPTION OF LSI

I/O
IN Connected to GND.
Anode (segment) of Fluorescent Display illumination voltage: -31V.
IN
Vp voltage of power source circuit input.
Power source voltage:-5V.
IN
VC voltage of power source circuit input.
Reference voltage input terminal.
IN
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 converter built
into the LSI.
AH sensor input.
IN
This input is an analog input terminal from the AH sensor circuit, and connected to the A/D
converter built into the LSI.
Heating constant compensation terminal.
IN
Input signal which communicates the door open/close information to LSI.
IN
Door closed; "L" level signal(0V).
Door opened; "H" level signal(-5V).
Signal coming from touch key.
IN
When any one of G8 line keys on key matrix is touched, a corresponding signal will from P00
- P06 will be input into AN1. When no key is touched, the signal is held at "L" level.
Temperature measurement input: OVEN THERMISTOR.
IN
By inputting DC voltage corresponding to the temperature detected by the thermistor, this input
is converted into temoerature by the A/D converter built into the LSI.
Segment data signals.
OUT
The relation between signals and indicators are as follows:
Signal Segment
P13 . .......................P16
P1 . .......................P15
P11 . .......................P14
P10 . .......................P13
P07 . .......................P1
P06 . .......................P11
P05 . .......................P10
P04 . .........................P9
(ß : INTO signal)
Refer to the touch control panel circuit about the relation between signals and indicators.
Normally, one pulse is output in every synchronized signal (ß) period, and input to the anode
of the fluorescent display.
Oven lamp driving signal. (Square Waveform : 60Hz)
OUT
To turn on and off the shut-off relay(RY1). The square
waveform voltage is delivered to the relay(RY1) driving
circuit.
Turntable motor driving signal.
OUT
To turn on and off relay(RY4). "L" level: During Turntable
ON. "H" level: During Turntable OFF or during the oven
is off condition.
Cooling fan motor driving signal.
OUT
To turn on and off shut-off relay(RY5). "L" level during
both microwave and convection cooking; "H" level oth-
erwise.
Damper motor driving signal.
OUT
To turn on and off shut-off relay(RY6).
Description
Signal Segment
P03 . .........................P8
P0 . .........................P7
P01 . .........................P6
P00 . .........................P5
(60Hz)
P37 . .........................P4
P36 . .........................P3
P35 . .........................P
P55 . .........................P1
34
GND
VP
16.7 msec.
During cooking
H : GND
OFF
L
ON
H.
OFF
During
cooking
L
ON
H : GND
OFF
ON L
H
L
GND