NR8576 series Real-time Clock Modules OVERVIEW The NR8576 series devices are serial-interface type real-time clock modules with built-in crystal oscillator elements. They feature timer counter circuits that keep track of time from the current second to the current year, automatic leap-year adjustment, and a supply voltage detect function. Also, a 32.768kHz/1Hz select output function is incorporated for independent hardware control. FEATURES ■ ■ ■ ■ ■ ■ ■ ■ PINOUT Crystal oscillator element built-in for adjustmentfree use Timer counters for second, minute, hour, day, day of the week, month, and year 2.5 to 5.5V operating voltage range 1.7 ± 0.3V supply voltage detection threshold 1.0µA at 3.0V (typ) current consumption Automatic leap-year calendar adjustment 32.768kHz and 1Hz output selectable Package: 14-pin SOP (Top view) VSS 1 14 FOUT NC 2 13 NC CE 3 12 NC FSEL 4 11 DATA WR 5 10 CLK FOE 6 9 VDD NC 7 8 NC SERIES CONFIGURATION 5 ± 23 ppm (Unit: mm) 10.1 ± 0.2 0 to 10° 1.27 0.6 ± 0.2 14-pin SOP NR8576AB PACKAGE DIMENSIONS 7.4 ± 0.2 5 ± 12 ppm 0.10 ± 0.05 NR8576AA Frequency deviation 5.0 Package 3.2 ± 0.1 Device 0.15 0.35 ± 0.1 SEIKO NPC CORPORATOIN—1 NR8576 series BLOCK DIAGRAM VDD VSS 32.768kHz OSC Divider Timer Counter FOUT Output Controller FSEL FOE Shift Register Voltage Detect DATA CLK I/O Controller WR Control Circuit CE PIN DESCRIPTION Number Name I/O Description 1 VSS – Ground Connect a ≥ 0.1µF capacitor between VDD and VSS. 2 NC – No connection. Leave open for normal use. 3 CE I Chip enable. HIGH: Enable LOW: DATA goes high impedance; input on WR, CLK, and DATA stops; and the TM bit is cleared. 4 FSEL I FOUT output frequency select. HIGH: 1Hz LOW: 32.768kHz 5 WR I DATA input/output control switch. HIGH: Data input mode (RTC write) LOW: Data output mode (RTC read) 6 FOE I FOUT output enable control. HIGH: The frequency selected by FSEL is output on FOUT. LOW: FOUT goes high impedance. 7 NC – No connection. Leave open for normal use. 8 NC – No connection. Leave open for normal use. 9 VDD – Supply voltage. Connect a ≥ 0.1µF capacitor between VDD and VSS. 10 CLK I System clock input. Data is input (RTC write mode) and output (RTC read mode) on the rising edge of CLK. 11 DATA I/O 12 NC – No connection. Leave open for normal use. 13 NC – No connection. Leave open for normal use. 14 FOUT O Frequency output (output controlled by FOE and frequency selected by FSEL). In 1Hz output mode, the 1Hz signal is synchronized to the internal 1 second signal. FOUT output is not affected by the CE signal. Data read and write input/output SEIKO NPC CORPORATOIN—2 NR8576 series SPECIFICATIONS Absolute Maximum Ratings VSS = 0V unless otherwise noted. Parameter Symbol Condition Rating Unit Supply voltage range VDD Ta = 25°C −0.3 to 7.0 V Input voltage range VIN Ta = 25°C VSS − 0.3 to VDD + 0.3 V Output voltage range VOUT Ta = 25°C VSS − 0.3 to VDD + 0.3 V Storage temperature range TSTG −55 to 125 °C Rating Unit Recommended Operating Conditions VSS = 0V unless otherwise noted. Parameter Symbol Condition Supply voltage range VDD 2.5 to 5.5 V Clock supply voltage range VCLK 1.4 to 5.5 V Operating temperature range TOPR −40 to 85 °C Rating Unit NR8576AA 5 ± 12 ppm NR8576AB 5 ± 23 ppm +10/−120 ppm Oscillator Characteristics VSS = 0V unless otherwise noted. Parameter Symbol Condition ∆f/fO Ta = 25°C, VDD = 5.0V Frequency temperature characteristic TOP Ta = −10 to 70°C, VDD = 5.0V, 25°C std Frequency voltage characteristic f/V Ta = 25°C, VDD = 2.0 to 5.5V ±2 max ppm/V Oscillator start time tSTA Ta = 25°C, VDD = 2.5V 3 max sec fA Ta = 25°C, VDD = 5.0V, first year ±5 max ppm/year Frequency deviation Aging SEIKO NPC CORPORATOIN—3 NR8576 series DC Electrical Characteristics VSS = 0V, VDD = 5.0V ± 10%, Ta = −40 to 85°C unless otherwise noted. Rating Parameter Symbol Condition Unit min typ max – 1.5 3.0 µA – 1.0 2.0 µA – 0.5 1.0 µA – 4.0 10.0 µA – 2.5 6.5 µA – 1.5 4.0 µA IDD1 VDD = 5.0V IDD2 VDD = 3.0V IDD3 VDD = 2.0V IDD4 VDD = 5.0V IDD5 VDD = 3.0V IDD6 VDD = 2.0V HIGH-level input voltage VIH CE, FSEL, WR, FOE, CLK, DATA 0.8VDD – – V LOW-level input voltage VIL CE, FSEL, WR, FOE, CLK, DATA – – 0.2VDD V Input OFF leakage current IOFF CE, FSEL, WR, FOE, CLK; VIN = VDD or VSS – – 0.5 µA VOH1 VDD = 5.0V 4.5 – – V VOH2 VDD = 3.0V 2.0 – – V VOL1 VDD = 5.0V – – 0.5 V VOL2 VDD = 3.0V – – 0.8 V N/CL FOUT IOZH VOUT = 5.5V; DATA, FOUT −1.0 – 1.0 µA IOZL VOUT = 0V; DATA, FOUT −1.0 – 1.0 µA 1.4 1.7 2.0 V Current consumption HIGH-level output voltage LOW-level output voltage Output load fanout Output leakage current Supply voltage detect threshold voltage VDT CE = VSS, FOE = VSS, FSEL = VDD, FOUT: floating CE = VSS, FOE = VDD, FSEL = VSS, FOUT: 32kHz output IOH = −1.0mA; DATA, FOUT IOL = 1.0mA; DATA, FOUT 2 LSTTL/30pF max SEIKO NPC CORPORATOIN—4 NR8576 series AC Characteristics Ta = −40 to 85°C, CL = 50pF unless otherwise noted. Rating Parameter Symbol VDD = 5V ± 10% VDD = 3V ± 10% min max min max Unit CLK clock period tCLK 0.75 7800 1.5 7800 µs CLK LOW-level pulsewidth tCLKL 0.375 3900 0.75 3900 µs CLK HIGH-level pulsewidth tCLKH 0.375 3900 0.75 3900 µs CE setup time tCES 0.375 3900 0.75 3900 µs CE hold time tCEH 0.375 – 0.75 – µs CE enable time tCE – 0.9 – 0.9 sec Write data setup time tSD 0.1 – 0.2 – µs Write data hold time tHD 0.1 – 0.1 – µs WR setup time tWRS 100 – 100 – ns WR hold time tWRH 100 – 100 – ns DATA output delay time tDATD – 0.2 – 0.4 µs DATA output floating time tDZ – 0.1 – 0.2 µs Clock rise time tr1 – 50 – 100 ns Clock fall time tf1 – 50 – 100 ns FOUT rise time (CL = 30pF) tr2 – 100 – 200 ns FOUT fall time (CL = 30pF) tf2 – 100 – 200 ns tHZ – 100 – 200 ns tLZ – 100 – 200 ns tZH – 100 – 200 ns tZL – 100 – 200 ns FOUT duty cycle (CL = 30pF) Duty 40 60 40 60 % Wait time tRCV 0.95 – 1.9 – µs Disable time (CL = 30pF) Enable time (CL = 30pF) SEIKO NPC CORPORATOIN—5 NR8576 series Timing Diagrams Data read tCE WR tWRH tWRS CE tCES tCEH tCLK tRCV CLK tCLKH tCLKL tf1 tr1 tDZ DATA tDATD Data write tCE WR tWRS tWRH CE tCES tCEH tCLK tRCV CLK tCLKH tCLKL tSD tHD tf1 tr1 DATA SEIKO NPC CORPORATOIN—6 NR8576 series FOUT tH tf2 90% FOUT 50% 10% tr2 t Duty = tH t 100 (%) Disable/Enable tZH FOE tHZ 50% 50% 90% FOUT 10% tZL FOE tLZ 50% 50% 90% FOUT 10% Note that FOE and FSEL do not have chatter elimination circuits. Consequently, switching either FOE or FSEL during 32kHz mode operation may generate chatter noise on the FOUT output. Also, note that the 1Hz and 32kHz oscillators are not synchronized to each other, so switching intervals shortens the duty cycle. Accordingly, a wait time (≥ chattering time + output frequency period) should be incorporated when switching intervals. SEIKO NPC CORPORATOIN—7 NR8576 series FUNCTIONAL DESCRIPTION Timer data configuration ■ ■ ■ ■ Counter data in BCD code format Automatic long/short month and leap-year adjustment 24-hour time display LSB first write and read data MSB LSB Second ( 0 to 59 ) FDT S40 S20 S10 S8 S4 S2 S1 Minute ( 0 to 59 ) ∗ mi40 mi20 mi10 mi8 mi4 mi2 mi1 Hour ( 0 to 23 ) ∗ ∗ h20 h10 h8 h4 h2 h1 ∗ w4 w2 w1 Week ( 1 to 7 ) ∗ ∗ d20 d10 d8 d4 d2 d1 Month ( 1 to 12 ) TM ∗ ∗ mo10 mo8 mo4 mo2 mo1 Year ( 0 to 99 ) y80 y40 y20 y10 y8 y4 y2 y1 Day ( 1 to 31 ) 1. * bit: Optional write bits. 2. FDT bit: Supply voltage detect bit • The FDT bit is set to 1 when the voltage between VDD and VSS falls below 1.7 ± 0.3V. • The FDT bit is reset to 0 for data reads longer than 48 bits. Note that the FDT bit is not reset to 0 for data reads of 47 bits or less. • The read/write data bits should be should be set to 0. After the supply voltage is applied, the FDT bit should be set to 0. VDD VDET 0.5 second 0.5 second Detected Pulse CE (READ MODE) FDT 3. TM bit: Factory test bit. Should be set to 0 for normal use. SEIKO NPC CORPORATOIN—8 NR8576 series Data Read 1 2 3 52 53 54 54+n CLK CE WR DATA S1 S2 S4 S8 S10 S20 S40 FDT y8 y10 y20 y40 y80 OUTPUT MODE second year NON CHANGE OUTPUT DATA Data is output when WR is LOW and CE is HIGH. Time and calendar data is loaded into shift registers on the first rising edge of the clock CLK, and the seconds’ digit LSB is output on DATA. The data is then loaded and shifted in the sequence second, minute, hour, week, day, and month on the rising edge of CLK, and output on DATA. The output data is valid after 52 rising edges of the clock; data input after 52 cycles does not alter the first 52 bits of valid data. Within the 52 cycles of valid data, data already input can be output if there is a falling edge of CE after the corresponding number of cycles. For example, the data comprising the second-to-week is output is CE goes LOW after 28 clock cycles. For continuous data reads, a wait time (tRCV) is required before the next data cycle if CE has gone LOW. Note that if an update operation (a 1s carry) occurs during a data read, an error of −1s in the read data is generated. The data read time should be completed after tCE ≤ 0.9s. SEIKO NPC CORPORATOIN—9 NR8576 series Data Write 1 2 3 S1 S2 S4 52 53 54 54+n CLK CE WR DATA INPUT MODE S8 S10 S20 S40 FDT second y8 y10 y20 y40 y80 year Data is input when WR is HIGH and CE is HIGH. The seconds’ digit signal to the timer counter stops on the first falling edge of CLK and the counter remains stopped until the next rising edge of CE. The 1Hz to 128Hz frequency divider step counters are reset during the interval between the first and second rising edges of CLK. The data is then input on DATA into the shift register, starting with seconds’ digit LSB synchronized with the rising edge of CLK. After the final data is input into the shift register following 52 cycles, the shift register contents are transferred to the timer counters. Note that a data write must contain 52 bits of input data. If CE goes LOW before 52 bits are input, the input data is invalid. If the input data exceeds 52 bits, data from the 53rd bit is ignored (the first 52 bits remain valid). The data write time should be completed after tCE ≤ 0.9s. If a data read occurs immediately after a data write, a wait time (tRCV) is required if CE has gone LOW. Note that writing null data will cause incorrect operation. All bits must be valid data bits. SEIKO NPC CORPORATOIN—10 NR8576 series Please pay your attention to the following points at time of using the products shown in this document. The products shown in this document (hereinafter “Products”) are not intended to be used for the apparatus that exerts harmful influence on human lives due to the defects, failure or malfunction of the Products. Customers are requested to obtain prior written agreement for such use from SEIKO NPC CORPORATION (hereinafter “NPC”). Customers shall be solely responsible for, and indemnify and hold NPC free and harmless from, any and all claims, damages, losses, expenses or lawsuits, due to such use without such agreement. NPC reserves the right to change the specifications of the Products in order to improve the characteristic or reliability thereof. NPC makes no claim or warranty that the contents described in this document dose not infringe any intellectual property right or other similar right owned by third parties. Therefore, NPC shall not be responsible for such problems, even if the use is in accordance with the descriptions provided in this document. Any descriptions including applications, circuits, and the parameters of the Products in this document are for reference to use the Products, and shall not be guaranteed free from defect, inapplicability to the design for the mass-production products without further testing or modification. Customers are requested not to export or re-export, directly or indirectly, the Products to any country or any entity not in compliance with or in violation of the national export administration laws, treaties, orders and regulations. Customers are requested appropriately take steps to obtain required permissions or approvals from appropriate government agencies. SEIKO NPC CORPORATION 1-9-9, Hatchobori, Chuo-ku, Tokyo 104-0032, Japan Telephone: +81-3-5541-6501 Facsimile: +81-3-5541-6510 http://www.npc.co.jp/ Email: [email protected] NC9603EE 2008.05 SEIKO NPC CORPORATOIN—11