T6M74A

The T6M74A is a kind of CMOS single-chip microcomputer for 16-digit 1-memory calculator. The device is the complete single-chip CMOS LSI for calculator with single power supply operation. Wide operating voltage range and low-power consumption make it suitable for 1.5 V solar battery operated. In addition, the device can be selectable with a pin-programmable to function of power timer and memory hold.

There are some features of T6M74A as follows: (1)display: 16 digits of data, 1 digit of sign, error symbol, memory load symbol; (2)algebraic mode; (3)automatic percentage operation with add-on, discount; (4)automatic delta percentage, mark-up and markdown operations; (5)square root; (6)constant calculation; (7)chain calculation; (8)change sign; (9)floating point or momentary mode (selectable with a switch); (10)adding point mode (selectable with a switch); (11)rounding switches (rounding up, down and off); (12)leading zero suppression; (13)trailing zero suppression; (14)punctuation on display, commas for thousands; (15)memory contents indicator, turned on with non-zero in the memory; (16)result overflow, indicating during calculation (most functions keys are locked as it happened); (17)memory overflow indicating to flashing of memory load mark; (18)key roll over function; (19)floating minus; (20)registration overflow, indicating that too many digits are entered (the most significant digit are protected).

The following is about the maximum ratings about T6M74A: (1)supply voltage, VDD1: -0.3 to 2.0  V; (2)input voltage, VIN: -0.3 to VDD1+0.3 V; (3)operating temperature, Topr: 0 to 40; (4)storage temperature, Tstg: -55 to 125. Then is about the eletrical characteristics (VDD1=1.5±0.5 V, VDD2=3.0±0.4 V, VSS=0 V, Ta=25): (1)"1" input voltage, VIH(1): VDD1-0.4 V min and VDD1 V max at K2-K9 RESET; (2)"1" input voltage, VIH(2): VDD2-0.4 V min and VDD2 V max at K10-K13 RESET; (3)"0" input voltage, VIL: 0 V min and 0.4 V max at K2-K13 RESET; (4)"1" output voltage, VOH(1): VDD2-0.4 V min and VDD2 V max at SGEMENT COM1-3; (5)"0" output voltage, VOL(1): 0 V min and 0.2 V max at SGEMENT COM1-3.