DATASHEET ISL12020M FN6667 Rev 6.00 Low Power RTC with Battery Backed SRAM, Integrated 5ppm Temperature January 9, 2015 Compensation and Auto Daylight Saving The ISL12020M device is a low power Real Time Clock (RTC) Features with an embedded temperature sensor and crystal. Device Embedded 32.768kHz quartz crystal in the package functions include oscillator compensation, clock/calendar, power fail and low battery monitors, brownout indicator, 20 Ld DFN package (for SOIC version, refer to the one-time, periodic or polled alarms, intelligent battery backup ISL12022M) switching, Battery Reseal function and 128 bytes of Calendar battery-backed user SRAM. The device is offered in a On-chip oscillator temperature compensation 20 Ld DFN module that contains the RTC and an embedded 32.768kHz quartz crystal. The calibrated oscillator provides 10-bit digital temperature sensor output less than 5ppm drift across the 0C to +85C temperature 15 selectable frequency outputs range. Interrupt for alarm or 15 selectable frequency outputs The RTC tracks time with separate registers for hours, minutes Automatic backup to battery or supercapacitor and seconds. The calendar registers track date, month, year and day of the week and are accurate through 2099, with V and battery status monitors DD automatic leap year correction. Battery Reseal function to extend battery shelf life Daylight Savings time adjustment is done automatically, using Power status brownout monitor parameters entered by the user. Power fail and battery Time stamp for battery switchover monitors offer user-selectable trip levels. The time stamp function records the time and date of switchover from V to 128 Bytes battery-backed user SRAM DD V power and also from V to V power. 2 BAT BAT DD I C-Bus RoHS compliant Related Literature AN1549, Addressing Power Issues in Real Time Clock Applications Applications Utility meters AN1389, Using Intersils High Accuracy Real Time Clock POS equipment Module Printers and copiers Digital cameras 1 X2 X1 20 2 X2 X1 19 3 X2 X1 18 4 X2 X1 17 3.3V 5 X2 X1 16 C 1 SCHOTTKY DIODE 6 NC NC 15 R R R 2 3 1 0.1F BAT54 7 VBAT VDD 14 10k 10k 10k BATTERY C 2 8 GND IRQ/FOUT 13 VDD 0.1F 3.0V 9 NC SCL 12 SCL MCU 10 NC SDA 11 INTERFACE SDA ISL12020M GND IRQ/FOUT FIGURE 1. TYPICAL APPLICATION CIRCUIT FN6667 Rev 6.00 Page 1 of 34 January 9, 2015ISL12020M Table of Contents Block Diagram 4 Pin Descriptions . 5 Absolute Maximum Ratings . 6 Thermal Information . 6 DC Operating Characteristics - RTC 6 Power-Down Timing 7 2 I C Interface Specifications . 7 SDA vs SCL Timing . 9 Symbol Table 9 Typical Performance Curves 9 General Description 11 Functional Description 11 Power Control Operation 11 Normal Mode (V ) to Battery-Backup Mode (V ) 11 DD BAT Battery-Backup Mode (V ) to Normal Mode (V ) 11 BAT DD Power Failure Detection 12 Brownout Detection 12 Battery Level Monitor 12 Real Time Clock Operation . 12 Single Event and Interrupt 12 Frequency Output Mode 13 General Purpose User SRAM 13 2 I C Serial Interface 13 Oscillator Compensation 13 Register Descriptions . 13 Real Time Clock Registers . 15 Addresses 00h to 06h 15 Control and Status Registers (CSR) . 15 Addresses 07h to 0Fh . 15 Status Register (SR) . 15 Interrupt Control Register (INT) 17 Initial AT and DT setting Register (ITRO) . 18 ALPHA Register (ALPHA) . 20 BETA Register (BETA) 20 Final Analog Trimming Register (FATR) . 22 Final Digital Trimming Register (FDTR) 22 ALARM Registers (10h to 15h) 22 Time Stamp VDD to Battery Registers (TSV2B) . 23 Time Stamp Battery to VDD Registers (TSB2V) . 23 DST Control Registers (DSTCR) 23 TEMP Registers (TEMP) . 24 NPPM Registers (NPPM) 25 XT0 Registers (XT0) 25 ALPHA Hot Register (ALPHAH) . 26 User Registers (Accessed by Using Slave Address 1010111x) . 26 Addresses 00h to 7Fh . 26 2 I C Serial Interface . 26 Protocol Conventions 26 Device Addressing 27 Write Operation 27 Read Operation 27 Application Section . 28 Power Supply Considerations 28 FN6667 Rev 6.00 Page 2 of 34 January 9, 2015