SM8577B Nippon_Precision_Circuits America, SM8577B Datasheet
SM8577B
Related parts for SM8577B
SM8577B Summary of contents
Page 1
... NIPPON PRECISION CIRCUITS INC. OVERVIEW The SM8577B is a CMOS serial-interface type real- time 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 output frequency available in 8-pin SOPs. ...
Page 2
... Ground Crystal oscillator element connection pin 7 XTN O Crystal oscillator element connection pin. Oscillator capacitor C Supply voltage. 8 VDD – Connect a 0.1 µF capacitor between VDD and VSS. SM8577B VDD VSS OSC Divider Voltage Detect I/O Description Timer Counter Shift Register Controll Circuit is built-in. ...
Page 3
... Oscillator Characteristics pF, Seiko Epson C-002SH crystal ( noted P arameter Oscillator start time Oscillator start voltage Oscillator stop voltage Frequency voltage characteristic Frequency accuracy Output capacitance SM8577B Condition OUT T stg sld t ...
Page 4
... Input OFF leakage current I V HIGH-level output voltage V V LOW-level output voltage V I OZH Output leakage current I OZL Supply voltage detect threshold V voltage SM8577B = unless otherwise noted Condition CE, CLK, DATA IH V CE, CLK, DATA IL CE ...
Page 5
... Write data setup time Write data hold time DATA output delay time DATA output floating time Clock rise time Clock fall time FOUT rise time FOUT fall time FOUT duty cycle Wait time SM8577B = 50 pF unless otherwise noted Condition t CLK t CLKL t ...
Page 6
... Measurement Circuit VDD VSS DATA Output Floating Timing CE DATE CE DATA SM8577B SW2 10k DATA 10k SW1 CE P.G 50% 50% Output 50pF t DHZ 90% t DLZ 10% NIPPON PRECISION CIRCUITS—6 ...
Page 7
... FOUT Note that the 1 Hz and 32 kHz oscillators are not synchronized to each other, so switching between 1 Hz and 32 kHz output temporarily shortens the duty cycle. Accordingly, a wait time ( output frequency period) should be incorporated when switching during normal operation. SM8577B CLKL ...
Page 8
... The read/write data bits should initially be set to 0. After the supply voltage is first applied, the FDT bit should also be set to 0. SM8577B • when the decade digit is even and the year digit The time display is 24-hour mode. All data is written and read with the LSB fi ...
Page 9
... Within the 60 cycles of valid data output, partial data output can be obtained by taking CE LOW after the Data Write CLK DATA Dont Care Control Bits Data Input Mode SM8577B y20 Second Data Output Mode corresponding number of cycles. For example, if only the ‘ ...
Page 10
... Customers shall not export, directly or indirectly, any products without first obtaining required licenses and approvals from appropriate government agencies. NIPPON PRECISION CIRCUITS INC. SM8577B During a data write cycle, timer counter operation stops on the first falling edge of CLK, and the 128 Hz frequency divider step counters are reset ...