DS1388 2 I C RTC/Supervisor with Trickle Charger and 512 Bytes EEPROM General Description Features 2 2 The DS1388 I C real-time clock (RTC), supervisor, and Fast (400kHz) I C Interface EEPROM is a multifunction device that provides a RTC Counts Hundredths of Seconds, Seconds, clock/calendar, programmable watchdog timer, power- Minutes, Hours, Day, Date, Month, and Year with supply monitor with reset, and 512 bytes of EEPROM. Leap Year Compensation Valid Up to 2100 The clock provides hundredths of seconds, seconds, Programmable Watchdog Timer minutes, and hours, and operates in 24-hour or 12-hour format with an AM/PM indicator. The calendar provides Automatic Power-Fail Detect and Switch Circuitry day, date, month, and year information. The date at the Reset Output with Pushbutton Reset Input end of the month is automatically adjusted for months Capability with fewer than 31 days, including corrections for leap 512 x 8 Bits of EEPROM year. A watchdog timer provides a reset for an unre- sponsive microprocessor. It is programmable in 10ms Integrated Trickle-Charge Capability for Backup intervals from 0.01 to 99.99 seconds. A temperature- Supply compensated voltage reference and comparator circuit Three Operating Voltages: 5.0V, 3.3V, and 3.0V monitors the status of V . If a primary power failure is CC detected, the device automatically switches to the Low Timekeeping Voltage Down to 1.3V backup supply and drives the reset output to the active -40C to +85C Temperature Range state. The backup supply maintains time and date UL Recognized operation in the absence of V . When V returns to CC CC nominal levels, the reset is held low for a period to allow Ordering Information the power supply and processor to stabilize. The device also has a pushbutton reset controller, which TOP debounces a reset input signal. The device is PART TEMP RANGE PIN-PACKAGE MARK 2 accessed through an I C serial interface. DS1388Z-5+ -40C to +85C 8 SO (150 mils) DS1388-5 Applications DS1388Z-33+ -40C to +85C 8 SO (150 mils) DS138833 Portable Instruments DS1388Z-3+ -40C to +85C 8 SO (150 mils) DS1388-3 Point-of-Sale Equipment +Denotes a lead(Pb)-free/RoHS-compliant package. Network Interface Cards Wireless Equipment Pin Configuration Typical Operating Circuit V V CRYSTAL VCC CC CC TOP VIEW + X1 1 8 V CC X1 X2 VCC RPU RPU X2 2 7 RST DS1388 SCL V 3 6 SCL BACKUP DS1388 CPU RST SDA GND 4 5 SDA V BACKUP SO GND RPU = t /C R B For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrateds website at www.maximintegrated.com. 19-4984 Rev 4 4/13DS1388 2 I C RTC/Supervisor with Trickle Charger and 512 Bytes EEPROM ABSOLUTE MAXIMUM RATINGS Voltage Range on V or V Pins Operating Temperature Range CC BACKUP Relative to Ground.............................................-0.3V to +6.0V (noncondensing) .............................................-40C to +85C Voltage Range on Inputs Relative Storage Temperature Range .............................-55C to +125C to Ground ...............................................-0.3V to (V + 0.3V) CC Lead Temperature (soldering, 10s) .................................+300C Junction-to-Ambient Thermal Resistance ( ) (Note 1)..170C/W JA Soldering Temperature (reflow) .......................................+260C Junction-to-Case Thermal Resistance ( ) (Note 1) ......40C/W JC Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial. Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. RECOMMENDED DC OPERATING CONDITIONS (T = -40C to +85C, unless otherwise noted.) (Note 2) A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DS1388Z-5 4.5 5 5.5 Supply Voltage V (Note 3) DS1388Z-33 2.97 3.3 3.63 V CC DS1388Z-3 2.7 3 3.3 0.7 x V + CC Logic 1 V (Note 3) V IH V 0.3 CC +0.3 x Logic 0 V (Note 3) -0.3 V IL V CC Pullup Voltage (SCL, SDA), V 5.5 V PU V = 0V CC V Voltage V (Note 3) 1.3 3.0 5.5 V BACKUP BACKUP DS1388Z-5 4.15 4.33 4.50 Power-Fail Voltage V (Note 3) DS1388Z-33 2.70 2.88 2.97 V PF DS1388Z-3 2.45 2.60 2.70 DC ELECTRICAL CHARACTERISTICS (V = V to V , T = -40C to +85C, unless otherwise noted.) (Note 2) CC CC(MIN) CC(MAX) A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS R1 (Notes 4, 5) 250 Trickle-Charger Current-Limiting R2 (Note 6) 2000 Resistors R3 (Note 7) 4000 Input Leakage (SCL) I -1 +1 A LI I/O Leakage (SDA) I -1 +1 A LO I/O Leakage (RST) I (Note 8) -200 +10 A LORST SDA Logic 0 Output I 3 mA OLDOUT (V = 0.15 x V ) OL CC 2 Maxim Integrated