SM8577B

SM8577B NIPPON PRECISION CIRCUITS INC. Real-time Clock IC OVERVIEW The SM8577B is a CMOS serial-interface type realtime clock IC that operates at 32.768 kHz. It employs a 3-line serial interface to transfer time and date data. It incorporates a supply-voltage detect function to determine data validity/invalidity. It features an output interrupt with 32 kHz or 1 Hz output frequency. It is available in 8-pin SOPs. PINOUT CE DATA CLK FOUT 1 8 VDD XTN XT VSS 8577B FEATURES s s s s s 4 5 s s s s s 2.5 to 5.5 V operating voltage range 1.0 µA at 3.0 V (typ) current consumption 3-line serial interface 1.7 ± 0.3 V supply voltage detection threshold Timer counters for second, minute, hour, day, day of the week, month, and year Automatic leap-year calendar adjustment 32.768 kHz and 1 Hz output interrupt selectable Crystal oscillator circuit built-in (CD built-in) 24-hour time mode 8-pin SOP PACKAGE DIMENSIONS Unit: mm 8-pin SOP 0.15− 0.05 + 0.10 4.4 0.2 6.2 0.3 5.2 0.3 0 to 10∞ ORDERING INFOMATION Device SM8577BS Package 8pin SOP 0.4 0.1 NIPPON PRECISION CIRCUITS—1 0.05 0.05 1.5 0.1 1.27 4.4 0.2 SM8577B BLOCK DIAGRAM VDD VSS XT XTN OSC Divider Timer Counter FOUT Output Controller Voltage Detect Shift Register DATA CLK CE I/O Controller Controll Circuit PIN DESCRIPTION Number 1 2 3 Name CE DATA CLK I/O I I/O I Description Chip enable. With pull-down resistor built-in. HIGH: Enable LOW: DATA goes high impedance; input on CLK and DATA stops; and the TM ...