Preliminary CBC34523 EnerChip™ RTC I2C Real-Time Clock/Calendar with Integrated Backup Power Features • Integrated rechargeable solid state battery with power-fail detect and automatic switchover, providing greater than 24 hours of backup • Smallest commercially available RTC with integrated backup power in compact 5mm x 6mm 1.4mm QFN package • Temperature compensated charge control • Integrated EnerChip™ recharged at VDD > 2.5V • SMT - lead-free reflow tolerant • Real time clock provides year, month, day, weekday, hours, minutes, and seconds based on a 32.768 kHz quartz crystal • Resolution: seconds to years • Watchdog functionality • Freely programmable timer and alarm with interrupt capability • 2-line I2C-bus with separate, but combinable data input and output • Selectable integrated oscillator load capacitors for CL = 7 pF or CL = 12.5 pF • Internal power-on reset (POR) • Open-drain interrupt or clock output pins • Programmable offset register for frequency adjustment • Eco-friendly, RoHS compliant - tested Applications • Wireless sensors and RFID tags and other powered, low duty cycle applications. • Power bridging to provide uninterrupted RTC function during exchange of main batteries. • Consumer appliances that have real-time clocks; provides switchover power from main supply to backup battery. • Business and industrial systems such as: network routers, point-of-sale terminals, singleboard computers, test equipment, multi-function printers, industrial controllers, and utility meters. • Time keeping application • Battery powered devices • Metering • High duration timers • Daily alarms • Low standby power applications 5mm x 6mm x 1.4mm 16-QFN Package General Description The EnerChip RTC CBC34523-Q5C combines a RealTime Clock (RTC) and calendar optimized for low power applications with an integrated rechargeable solid state backup power source and all power management functions. The EnerChip RTC ensures a seamless transition from main power to backup power in the event of power loss. The integrated power management circuit provides thousands of charge-discharge cycles from the integrated the EnerChip and manages battery charging, discharge cutoff, power switchover, and temperature compensation to maximize the service life of the device. The CBC34523 provides greater than 24 hours of backup time in the event main power is interrupted. Typical blackout times are less than 4 hours. The EnerChip has extremely low self-discharge, recharges quickly, is non-flammable, and RoHScompliant. The EnerChip is charged automatically anytime VDD is above 2.5V. Data is transferred serially via an I2C-bus with a maximum data rate of 1000 Kbits/s. Alarm and timer functions provide the option to generate a wake-up signal on an interrupt pin. An offset register allows fine tuning of the clock. Figure 1: CBC34523 Pin-out Diagram ©2012 Cymbet Corporation • Tel: +1-763-633-1780 • www.cymbet.com DS-72-32 Rev V.05 Page 1 of 9 Preliminary CBC34523 EnerChip™ RTC 16 OSCI 1 OSCO CLKOUT OSCILLATOR 32.768 kHz C OSC0 DIVIDER & OFFSET FUNCTION C OSC1 0Eh Offset_register 0Fh Timer_CLKOUT_ctrl 8 CLOCKOUT INT1/CLKOUT TIMER FUNCTION 6 VCHG 7 VEC 14 RESET 15 ENERCHIP AND CHARGER EN 10h Tmr_A_freq_ctrl 11h Tmr_A_reg 12h Tmr_B_freq_ctrl 13h Tmr_B_reg INTERRUPT CONTROL 5 VBAT 13 VDD 3 VSS 2 NC 11 NC 9 SDA 10 SCL BATTERY BACKUP SWITCH-OVER CIRCUITRY POWERON RESET I2CBUS INTERFACE 00h Control_1 01h Control_2 02h Control_3 03h Seconds 04h Minutes 05h Hours TIME 06h Days 07h Weekdays 08h Months 09h Years ALARM FUNCTION 0Ah Minute_alarm 0Bh Hour_alarm 0Ch Day_alarm 0Dh Weekday_alarm INT2 4 Figure 2: CBC34523 EnerChip RTC Block Diagram with Registers Figure 3: Internal Schematic of CBC34523 EnerChip RTC ©2012 Cymbet Corporation • Tel: +1-763-633-1780 • www.cymbet.com DS-72-32 Rev V.05 Page 2 of 9 12 Preliminary CBC34523 EnerChip™ RTC CBC34523 Input/Output Descriptions Pin Number Label Description 1 OSCO Oscillator output; high-impedance node; minimize wire length between quartz and package 2 NC Not connected; do not connect and do not use it as feed through 3 VSS Ground 4 INT2/ Interrupt 2 output (open-drain; active LOW) 5 VBAT Backup battery supply input 6 VCHG 4.1V (typical) charging source - connect to VBAT only, or VBAT and optional EnerChip(s) 7 VEC Positive terminal of integrated thin film battery - connect to VCHG and nothing else 8 CLKOUT Clock output (open-drain) 9 SDA Serial data input/output 10 SCL Serial clock input 11 NC Not connected; do not connect and do not use it as feed through 12 INT1/ CLKOUT/ Interrupt 1 / clock output (open-drain) 13 VDD Supply voltage 14 RESET/ Output signal indicating RTC is operating in backup power mode 15 EN Charge pump enable; activates VCHG 4.1V (typ.) charging source OSCI Oscillator input; high-impedance node; minimize wire length between quartz and package 16 Package Dimensions 5mm x 6mm x 1.4mm Pad Pitch 0.8mm Pad Dimensions 0.4mm x 0.3mm Figure 4: CBC34523 EnerChip RTC Package Pin-Out (top view, looking through package) EnerChip Properties Energy capacity (typical): Recharge time to 80%: Charge/discharge cycles: Operating temperature: Storage temperature: Minimum VDD to charge EnerChip: 5µAh 10 minutes >5000 to 10% depth-of-discharge -20°C to +70°C -40°C to +125°C 2.5V ©2012 Cymbet Corporation • Tel: +1-763-633-1780 • www.cymbet.com DS-72-32 Rev V.05 Page 3 of 9 Preliminary CBC34523 EnerChip™ RTC Absolute Maximum Ratings PARAMETER CONDITION MIN TYPICAL MAX UNITS VDD with respect to GND 25°C GND - 0.3 - 6.0 V ENABLE Input Voltage 25°C GND - 0.3 - VDD+0.3 V VBAT 25°C 3.0 - 4.15 V 25°C 3.0 - 4.15 V RESET Output Voltage 25°C GND - 0.3 - VOUT+0.3 V CP, Flying Capacitor Voltage 25°C GND - 0.3 - 6.0 V CN 25°C GND - 0.3 - VDD+0.3 V (1) VCHG (1) (1) No external connections to these pins are allowed, except parallel EnerChips. Integrated EnerChip Thin Film Battery Operating Characteristics PARAMETER CONDITION MIN TYPICAL MAX UNITS Non-recoverable - 2.5 - % per year Recoverable - 1.5 - % per year Operating Temperature - -20 25 Storage Temperature - -40 - 10% depth-of-discharge 5000 - - cycles 50% depth-of discharge 1000 - - cycles 10% depth-of-discharge 2500 - - cycles 50% depth-of-discharge 500 - - cycles Charge cycle 2 - 11 22 Charge cycle 1000 - 45 70 150nA discharge; 25°C 5 - - Self-Discharge (5 yr. average) Recharge Cycles (to 80% of rated capacity) 25°C 40°C Recharge Time (to 80% of rated capacity; 4.1V charge; 25°C) Capacity (1) First month recoverable self-discharge is 5% average. (2) Storage temperature is for uncharged EnerChip CC device. (1) +70 +125 °C (2) °C minutes µAh Note: All specifications contained within this document are subject to change without notice. ©2012 Cymbet Corporation • Tel: +1-763-633-1780 • www.cymbet.com DS-72-32 Rev V.05 Page 4 of 9 Preliminary CBC34523 EnerChip™ RTC Functional Description of Integrated PCF8523 Real-Time Clock The PCF8523 contains: •20 8-bit registers with an auto-incrementing address register •An on-chip 32.768 kHz oscillator with two integrated load capacitors •A frequency divider, which provides the source clock for the Real-Time Clock (RTC) •A programmable clock output •A 1 Mbit/s I2C-bus interface •An offset register, which allows fine-tuning of the clock All 20 registers are designed as addressable 8-bit registers although not all bits are implemented. •The first three registers (memory address 00h, 01h, and 02h) are used as control and status registers •The addresses 03h through 09h are used as counters for the clock function (seconds up to years) •Addresses 0Ah through 0Dh define the alarm condition •Address 0Eh defines the offset calibration •Address 0Fh defines the clock-out mode and the addresses 10h and 12h the timer mode •Addresses 11h and 13h are used for the timers Standby Mode When the device is first powered up from the battery (VBAT) but without a main supply (VDD), the PCF8523 automatically enters the standby mode. In standby mode, the PCF8523 does not draw any power from the backup battery until the device is powered up from the main power supply VDD. Thereafter, the device switches over to battery backup mode whenever the main power supply VDD is lost. It is also possible to enter into standby mode when the chip is already supplied by the main power supply VDD and a backup battery is connected. To enter the standby mode, the power management control bits PM[2:0] have to be set logic 111. Then the main power supply VDD must be removed. As a result of it, the PCF8523 enters the standby mode and does not draw any current from the backup battery before it is powered up again from main supply VDD. The interface is disabled in battery backup operation: •Interface inputs are not recognized, preventing extraneous data being written to the device •Interface outputs are high-impedance ©2012 Cymbet Corporation • Tel: +1-763-633-1780 • www.cymbet.com DS-72-32 Rev V.05 Page 5 of 9 Preliminary CBC34523 EnerChip™ RTC PCF8523 Register Overview The 20 registers of the PCF8523 are auto-incrementing after each read or write data byte up to register 13h. After register 13h, the auto-incrementing will wrap around to address 00h. Bit positions labeled as ‘-’ are not implemented and will return a ‘0’ when read. Bit ‘T’ must always be written with logic ‘0’. Address Register name Bit 7 6 5 4 3 2 1 0 CIE Control registers 00h Control_1 CAP_SEL T STOP SR 12_24 SIE AIE 01h Control_2 WTAF CTBF SF AF WTAIE CTAIE CTBIE 02h Control_3 PM[2:0] - BSF BLF BSIE CTAF BLIE Time and date registers 03h Seconds OS SECONDS (0 to 59) 04h Minutes - MINUTES (0 to 59) 05h Hours - - AMPM HOURS (1 to 12 in 12 hour mode) HOURS (0 to 23 in 24 hour mode) 06h Days - - DAYS (1 to 31) 07h Weekdays - - - - 08h Months - - - MONTHS (1 to 12) 09h Years YEARS (0 to 99) - WEEKDAYS (0 to 6) Alarm registers 0Ah Minute_alarm AE_M MINUTE_ALARM (0 to 59) 0Bh Hour_alarm AE_H - AMPM - HOUR_ALARM (0 to 23 in 24 hour mode) HOUR_ALARM (1 to 12 in 12 hour mode) 0Ch Day_alarm AE_D - DAY_ALARM (1 to 31) 0Dh Weekday_alarm AE_W - - - - WEEKDAY_ALARM (0 to 6) Offset register 0Eh Offset MODE OFFSET[6:0] CLOCKOUT and timer registers 0Fh Tmr_CLKOUT_ ctrl TAM TBM COF[2:0] 10h Tmr_A_freq_ctrl - - - 11h Tmr_A_reg TIMER_A_VALUE[7:0] 12h Tmr_B_freq_ctrl - 13h Tmr_B_reg TIMER_B_VALUE[7:0] TBW[2:0] TAC[1:0] - - TAQ[2:0] - TBQ[2:0] ©2012 Cymbet Corporation • Tel: +1-763-633-1780 • www.cymbet.com DS-72-32 Rev V.05 TBC Page 6 of 9 Preliminary CBC34523 EnerChip™ RTC POWER SUPPLY CURRENT CHARACTERISTICS Ta = -20ºC to +70ºC CHARACTERISTIC SYMBOL CONDITION ENABLE=GND Quiescent Current IQ ENABLE=VDD EnerChip Cutoff Current (IQBATON adds to RTC current when in backup mode) MIN MAX UNITS VDD=3.3V - 3.5 µA VDD=5.5V - 6.0 µA VDD=3.3V - 35 µA VDD=5.5V - 38 µA IQBATOFF VBAT < VBATCO, VOUT=0 - 0.5 nA IQBATON VBAT > VBATCO, ENABLE=VDD, IOUT=0 - 42 nA INTERFACE LOGIC SIGNAL CHARACTERISTICS VDD = 2.5V to 5.5V, Ta = -20ºC to +70ºC CHARACTERISTIC SYMBOL CONDITION MIN High Level Input Voltage VIH - Low Level Input Voltage VIL - High Level Output Voltage VOH VDD>VTH (see Figures 4 and 5) IL=10µA Low Level Output Voltage VOL Logic Input Leakage Current IIN (1) MAX UNITS VDD - 0.5 - Volts - 0.5 Volts VDD 0.04V (1) - Volts IL = -100µA - 0.3 Volts 0<VIN<VDD -1.0 +1.0 nA RESET tracks VDD; RESET = VDD - (IOUT x ROUT). RESET SIGNAL AC/DC CHARACTERISTICS VDD = 2.5V to 5.5V, Ta = -20ºC to +70ºC CHARACTERISTIC SYMBOL CONDITION MIN MAX UNITS VDD Rising to RESET Rising tRESETH VDD rising from 2.8V TO 3.1V in <10µs 60 200 ms VDD Falling to RESET Falling tRESETL VDD falling from 3.1V to 2.8V in <100ns 0.5 2 µs TRIP Voltage VDD Rising VRESET VMODE=GND 2.85 3.15 V VMODE=VDD 60 100 VMODE=GND 45 75 VMODE = VDD/2 30 50 RESET Hysteresis Voltage (3) (VDD to RESET) VHYST mV (2) User-selectable trip voltage can be set by placing a resistor divider from the VMODE pin to GND. Refer to Figure 8. (3) The hysteresis is a function of trip level in Mode 2. Refer to Figure 9. ©2012 Cymbet Corporation • Tel: +1-763-633-1780 • www.cymbet.com DS-72-32 Rev V.05 Page 7 of 9 Preliminary CBC34523 EnerChip™ RTC CHARGE PUMP CHARACTERISTICS VDD = 2.5V to 5.5V, Ta = -20ºC to +70ºC CHARACTERISTIC SYMBOL ENABLE=VDD to Charge Pump Active tCPON ENABLE Falling to Charge Pump Inactive tCPOFF CONDITION ENABLE to 3rd charge pump pulse, VDD=3.3V - MIN MAX UNITS 60 80 µs 0 1 µs - 120 KHz (1) 150 300 Ω Charge Pump Frequency fCP Charge Pump Resistance RCP Delta VBAT, for IBAT charging current of 1µA to 100µA CFLY=0.1µF, CBAT=1.0µF VCHG Output Voltage VCP CFLY=0.1µF, CBAT=1.0µF, IOUT=1µA, Temp=+25ºC 4.075 4.125 V VCHG Temp. Coefficient TCCP IOUT=1µA, Temp=+25ºC -2.0 -2.4 mV/ºC Charge Pump Current Drive ICP IBAT=1mA CFLY=0.1µF, CBAT=1.0µF 1.0 - mA ENABLE=VDD 2.5 - V Charge Pump on Voltage (1) VENABLE fCP = 1/tCPPER ADDITIONAL CHARACTERISTICS Ta = -20ºC to +70ºC CHARACTERISTIC VBAT Cutoff Threshold SYMBOL VBATCO Cutoff Temp. Coefficient TCCO VBAT Cutoff Delay Time tCOOFF CONDITION LIMITS IOUT=1µA VBAT from 40mV above to 20mV below VBATCO IOUT=1µA UNITS MIN MAX 2.75 3.25 V +1 +2 mV/ºC 40 - ms Note: All specifications contained within this document are subject to change without notice Important Reference Documents For complete specifications of the integrated PCF8523 Real-Time Clock, see here: http://www.nxp.com/documents/data_sheet/PCF8523.pdf For complete specifications of the Cymbet 5µAh EnerChip and integrated power management circuit, see here: http://www.cymbet.com/pdfs/DS-72-21.pdf ©2012 Cymbet Corporation • Tel: +1-763-633-1780 • www.cymbet.com DS-72-32 Rev V.05 Page 8 of 9 Preliminary CBC34523 EnerChip™ RTC Ordering Information EnerChip CC Part Number Description Notes CBC34523-Q5C EnerChip RTC in 5mm x 6mm x 1.4mm 16-QFN Land Grid Array Shipped in Tube CBC34523-Q5C-TR1 CBC34523-Q5C-TR5 EnerChip RTC in 5mm x 6mm x 1.4mm 16-QFN Land Grid Array Tape-and-Reel - 1000 pcs (TR1) or 5000 pcs (TR5) per reel U.S. Patent No. 8,144,508. Additional U.S. and Foreign Patents Pending Disclaimer of Warranties; As Is The information provided in this data sheet is provided “As Is” and Cymbet Corporation disclaims all representations or warranties of any kind, express or implied, relating to this data sheet and the Cymbet EnerChip product described herein, including without limitation, the implied warranties of merchantability, fitness for a particular purpose, non-infringement, title, or any warranties arising out of course of dealing, course of performance, or usage of trade. Cymbet EnerChip products are not authorized for use in life critical applications. Users shall confirm suitability of the Cymbet EnerChip product in any products or applications in which the Cymbet EnerChip product is adopted for use and are solely responsible for all legal, regulatory, and safety-related requirements concerning their products and applications and any use of the Cymbet EnerChip product described herein in any such product or applications. Cymbet, the Cymbet Logo, and EnerChip are Cymbet Corporation Trademarks ©2012 Cymbet Corporation • Tel: +1-763-633-1780 • www.cymbet.com DS-72-32 Rev V.05 Page 9 of 9