IZ1223M
1
B
ASIC
F
UNCTION
8-D
IGITS
LCD
C
ALCULATOR
W
ITH
T
OUCH
T
ONE AND
P
UNCTUATION
F
UNCTION
The IZ1223M is a single chip CMOS LSI with 8-digit arithmetic operation, single memory,
extraction-of-square-root, percentage calculation and auto power off and punctuation and touch
tone function, designed for FEM LCD operation with a 3.0V power supply.
FUNCTIONS
Four standard functions (+, -,
,
)
Auto constant calculations (constant: multiplicand,
divisor,
addend and subtrahend)
Square and reciprocal calculations
Mark-up and mark-down calculations
Extraction of square root
Percentage calculations
Chain multiplication and division
Power calculations
Rough estimate calculations
Touch tone function
Punctuation comma display
Clear key: ON/C, ON/CE, CE
FEATURES
Single chip CMOS construction
Floating decimal point
LCD direct drive
Overflow indication: "E"
Accumulating memory: M+, M-, RM,
CM, RM/CM
Bare chip available
Mirror type
ABSOLUTE MAXIMUM RATINGS (T
a
= 25
o
C)
Characteristic Symbol
Value
Unit
Note
V
GG
- 0.3 ~ + 3.5
V
Terminal Voltage
V
IN
- 0.3 ~ V
GG
+
0.3 V
1
Supply Voltage
V
GG
2.5 ~ 3.5
V
Operating Temperature
T
OPR
0 ~ + 50
o
C
Storage Temperature
T
stg
- 55 ~ + 125
o
C
Note: 1. Maximum voltage on any pin with respect to the GND
ELECTRICAL CHARACTERISTICS (T
a
= 25
o
C, V
GG
= 3.0V, unless otherwise specified)
Characteristic Symbo
l
Test Condition
Min
Typ
Max Uni
t
V
IH1
V
GG
-
0.4
Input Voltage 1 (K2 ~ K6, TI,
S2)
V
IL1
0.4
V
V
IH2
V
GG
-
0.4
Input Voltage 2 (S1)
V
IL2
0.2
V
I
IH1
V
IN
= V
GG
1
Input Current 1 (K2 ~ K6, TI)
I
IL1
V
IN
= 0V
5.5
10
A
I
IH2
V
IN
= V
GG
1
Input Current 2 (S2)
I
IL2
V
IN
= 0V
1
A
I
IH3
V
IN
= V
GG
1
Input Current 3 (S1)
I
IL3
V
IN
= 0V
S2=GN
D
5 10
15
A
Input Current 4 (S1)
I
IH4
V
IN
= V
GG
S2 =
20
30
40
A
IZ1223M
2
Characteristic Symbo
l
Test Condition
Min
Typ
Max Uni
t
I
IL4
V
IN
= 0V
V
GG
1
Output Voltage 1 (P1, P2,
A2~A5)
V
OH1
without
load V
GG
-
0.15
V
OL1
I
OUT
= 15
A
0.15
V
Output Voltage 2 (H1 ~ H3,
V
OA
without load
2.80
2.95
a1 ~ a9, b1 ~ b8, c1
~ c8)
V
OB
without
load 1.30
1.50
1.70
V
OC
without
load
0
0.20
V
Display Frequency
F
d
V
GG
= 3V while
display is on,
50 75
Hz
Touch Tone (PO)
I
OL
V
GG
= 3V, V
OL
=
0.5V, TI =3V
3
Output Drive Current
I
OH
V
GG
= 3V, V
OL
=
0.5V, TI =3V
-3
mA
I
OFF
(1)
Display off, V
GG
=
3V
0.1
Dissipation
I
dis
(2)
V
GG
= 3V while
display is on,
20
30
A
NOTE: 1) Measured by the next test circuit after power supply automatically turns off.
2) Measured by the next test circuit while "0" is being displayed after auto clear operation and while
key is not being depressed.
OUTPUT WAVEFORM 1; Hi (i = 1, 2, 3)
OUTPUT WAVEFORM 2; ai, bi, ci, (i = 1, 2, ... , 8)
FUNCTIONAL DESCRIPTION
Decimal point system
Complete floating decimal point system.
Integral number : 8 digits leading zero suppression. Zero shift.
Symbols : - : negative number display
E : error display
M : memory display
, : punctuation comma
: touch tone indicator
IZ1223M
3
Error detections
System errors occur when:
1) The integral part of any memory calculation result exceeds 8 digits.
2) The division by zero.
3) The extraction of square root of a negative number.
Rough estimate calculation error
When the integral part of the result of any standard functions, percentage, square, reciprocal,
or power calculations exceed 8 digits.
Error indication
System error
"0" is indicated in the 1-digit position and "E" in the sign-digit position.
Rough estimate calculation error
The high-order 8-digit calculation result is indicated together with "E".
The decimal point is indicated in the position corresponding to a calculation result of time 10
-8
,
and no zero shift is performed
Error release
System error
A system error can be release by the ON/C or ON/CE key.
Rough estimate calculation error
A rough estimate calculation error can be released by the ON/C, ON/CE, CE key.
A calculation result is not cleared by ON/CE, CE key but is retained.
Number entry
Numerical can be entered up to 8 digits. Numerical entries equal to 9 digits or more are ignored.
Memory protection
In any error detection, the memory content is retained.
Memory indication
If the memory content is not zero, "M" is indicated in the sign-digit position.
Doubler key depression
The order of the priority when two keys are being depressed simultaneously, is as follows:
IZ1223M
4
OFF
ON/C
5
ON/CE
6
4
RM/CM
.
9
-
8
7
CM
2
3
1
0
x
M +
=
+/-
CE
+
M -
%
RM
.
.
When the OFF and ON/C key are depressed simultaneously, the OFF key is given priority.
Key bounce protection
Front edge
Down to 1 word and up to about 3 words.
Trailing edge
9 words
1 word is 3.3ms when display frequency is fd = 100Hz.
DISPLAY FONTS
Numericals font
Sigh font
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b7
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b3
b2
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a5
a4
a3
a2
a1
AUTO POWER OFF
Power automatically turns off after 9 - 11 minutes pass from the last key pressure. (S
1
= Low, S
2
=
High)
ON/C KEY
All operations except memory content are cleared by ON/C key.
TOUCH TONE (
) KEY
When power is ON, the touch tone function is enable and the beep sound is generated output
during 125ms and
sing is displayed on LCD.
Selection of touch tone function is toggled by touch tone key.
Output wave form.
MARK-UP AND MARK-DOWN CALCULATION
Mark-up and mark-down calculation are performed as follows.
ENTRY DISPLAY
A
B
%
A
x
B
%
+OR-
=
A
A
B
A AB/100
A
A
B
AB/100
AB/100
A+AB/100 OR A --AB/100
- V
OC
- V
OA
ft = 2KHz
125 ms
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