IZ1278U 10/12-DIGIT SELECTABLE DESK TOP CALCULATOR The IZ1278 is a single chip CMOS LSI with 10-digit or 12-digit arithmetic operation, 2memory, extraction-of-square-root, percentage, MU calculation and auto power off function, designed for FEM LCD operation with a 1.5V power supply. FUNCTIONS FEATURES • 10/12 digits selectable display by diode option • Four standard functions (+, -, ×, ÷ ) • Memory, GT (grand total) memory calculations • Auto-percentage calculations (add on, discount) • Constant calculations • Square root calculations • Chain calculations • MU calculations • Power calculations • Rough estimate calculations • Change sign • Single chip CMOS construction • Floating point or memory mode (sw selectable) • Fixed point (0,2,3,4) and adding point mode • Rounding switches (rounding up, down and off) • Leading and trailing zero suppression • Punctuation comma display for thousands • LCD direct drive • Over flow indication: “E” • On-chip key board debouncing and encoding • Wide supply voltage range (1.2V ~ 2.0V) • Very low power consumption (7µw TYP) • PKG type: 64 QFP and bare chip available • Symbols: GT, M, -, E, K, +, -, ×, ÷ ABSOLUTE MAXIMUM RATINGS ( Ta = 25oC ) Characteristic Terminal Voltage Operating Temperature Storage Temperature Symbol Value Unit VDD VIN Ta Tstg - 0.3 ~ + 2.0 - 0.3 ~ VDD + 0.3 0 ~ + 40 - 55 ~ + 125 V V o C o C ELECTRICAL CHARACTERISTICS (Ta = 25oC, VDD = 1.5V, VSS = 0V unless otherwise specified) Characteristic Symbol High Input Voltage(K3~K10) VIH (K11~K12) Low Input (KI) Voltage (K3~K12) Test Condition Max Unit VDD - 0.4 VDD V VIH VCC - 0.4 VCC VIL VSS 0.4 V High Output Voltage(K1~K8) VOH VDD - 0.2 VDD V Low Output Voltage(K1~K8) VOL VSS 0.2 V Key Pull Down (KI) Rpd1 KΩ Resistor (K1 ~ K10) Rpd2 Key Pull Up (KI) Rpu1 Resistor (K1 ~ K10) Rpu2 (K11 ~ K12) Rpu3 Vout = 0.3V Vout = 1.2V Vout = 2.7V Min Typ 0.5 1 1.5 10 17 28 145 170 195 0.6 1.2 1.9 250 400 550 KΩ High Output Voltage (LCD, COM) VOH VCC -0.2 VCC V “M” Output Voltage (LCD, COM) VOM VDD -0.2 VDD V Low Output Voltage (LCD, VOL VSS 0.2 V 1 IZ1278U Characteristic Symbol Test Condition Min Typ Max Unit Fdis Stand-by 5.4 9.0 12.6 KHz Fopr Operating 28.8 48 67.2 Frame Frequency Ff Stand-by 56.3 93.8 131 Hz Operating Voltage VDD 1.2 1.5 2.0 V COM) OSC Frequency Supply Current IOFF Display is off IDIS Display is on 4.4 6.5 IOP Operating 7.0 15 FUNCTIONAL DESCRIPTION Decimal point system 1 µA Zero is displayed at first-digit and “E” sign is indicated at symbol. Integral number : 10/12 digits leading zero suppression. Zero shift. • Rough estimate calculation error The high-order 12 digits (10 digits) of any calculation result is indicated together with “E” sign, and the decimal point is displayed at the position corresponding to 10-12 (10-10) of the calculation result also no zero shift is performed. Symbols Error release Floating point for momentary mode by TAB Selection. M : memory display E : error display - : negative number display GT : negative number • System error Released by AC, C, CE key. Error detections (Parenthesis is in case of 10 digits) • Rough estimate calculation error AC, C key can release a rough estimate calculation error and can clear calculation result at once, also CE key can just only release error flag ‘E’ at first time and can clear calculation result at second time. • System errors occur when: Number entry display +, -, ×, ÷ : for rules operator K : constant 1) The division by zero. 2) The integral part of any memory calculation result exceeds 12(10) digits. 3) The integral part of GT memory contents exceeds 12 (10) digits. • Rough estimate calculation error The integral part of any calculationfour standard functions, percentage, square or power calculations result exceeds 12 digits (10 digits). Error indication • System error Numericals can be entered up to 12 digits (10 digits). Numericals more then 13 digits (11 digits) are ignored. Memory protection Under any error detection, the memory data before error detection are protected. Memory indication If the memory data is not zero, “M” is indicated at symbol position. AUTO POWER OFF 2 IZ1278U Power turns off after about 5 minutes pass from the last key pressure. DP I = 0, 2, 3, 4 mode SELECTION MODE SWITCH FUNCTION The calculation results follow to fixed decimal point system and I+1 decimal place is counted by TAB ‘CUT’, TAB ‘UP’, TAB ‘5/4’. Fix ‘CUT’ mode 10-digits/12-digits mode depends on K11 pin, please refer to application circuit. Fixed/floating decimal point mode and ADD2 mode are selection by rounding switch. The rounding switch should be so composed that either one ‘ 4, 3, 2, 0, ADD2 ‘ is selected. Fix ‘F’ mode When TAB ‘F’ is selected, both entered numbers and calculation results follow to floating decimal point system. The number of i +1 decimal position is counted as cutting away. Fix ‘UP’ mode The number of i decimal position is counted as added to ‘1’. Fix ‘5/4’ mode When ‘+’ and ‘-’ operations are performed after a number except decimal point is entered. The calculation is executed as 1/100 value of number being entered. 3 IZ1278U KEY DESCRIPTION 0 ~ 9 00 . + Numerals input key Decimal point key Clear key ON/AC AC CE - x : Four standard function key % Percent key GT Grand total memory key M- Memory add and memory subtract key M+ MRC MR MC Recall and clear memory Recall memory, clear memory Extraction of square root key = +/- Enter key Sign change key Shift Right key MU Mark-up and mark-down key OFF Power off key ON/AC: Power ON/All clear (system rest) C: All except memory contents CE: Entry clear such as only the entered data is cleared * Recall the data in GT GT flag is released by AC or C key * When = key is pressed, the result of calculator is added to GT memory automatically 4