EM3027

R EM MICROELECTRONIC - MARIN SA EM3027 Real Time Clock with I2C or SPI, Crystal Temperature Compensation, Battery Switchover and Trickle Charger Description The EM3027 is an Ultra Low Power CMOS real-time clock IC with two serial interface modes: I2C or SPI. The interface mode is selected by the chip version (see §12). The basic clock is obtained from the 32.768 kHz crystal oscillator. A thermal compensation of the frequency is based on the temperature measurement and calculation of the correction value. The temperature can be measured internally or be input by an external application to the register. The chip provides clock and calendar information in BCD format with alarm possibility. The actual contents are latched at the beginning of a read transmission and afterwards data are read without clock counter data corruption. An integrated 16-bit timer can run in Zero-Stop or AutoReload mode. An interrupt request signal can be provided through INT/IRQ pin generated from alarm, timer, voltage detector and Self-Recovery system. An integrated trickle charger allows recharging backup supply VBack from the main supply voltage VCC through internal resistor(s). The internal device supply will switchover to VCC when VCC is higher than VBack and vice versa. The device operates over a wide 1.4 to 5.5V supply range and requires only 900 nA at 5V. It can detect internally two supply voltage levels. Applications Utility meters Battery operated and portable equipment Consumer electronics White/brown goods Pay phones Cash registers Personal computers Programmable controller systems Data loggers Features Fully operational from 2.1 to 5.5V Supply current typically 600 nA at 1.4V Thermal compensated crystal frequency Oscillator stability 0.5 ppm / Volt Counter for seconds, minutes, hours, day of week, date months, years in BCD format and alarm Leap year compensation 16-bits timer with 2 working modes Two low voltage detection levels VLow1, VLow2 Automatic supply switchover 2 Serial communication via I2C (I C-bus specification Rev. 03 compatible – see §10.2) or SPI (3-line SPIbus with separate combinable data input and output) Thermometer readable by the host Trickle charger to maintain battery charge Integrated oscillator capacitors Two EEPROM and 8 RAM data bytes for application Digital Self-Recovery system No busy states and no risk of corrupted data while accessing One hour periodical configuration registers refresh Support for standard UL1642 for Lithium batteries Standard temperature range: -40°C to +85°C Extended temperature range: -40°C to +125°C Packages: TSSOP8, TSSOP14, SO8. Block Diagram EM3027 Temperature Sensor X1 Oscillator X2 VCC VREG VBack SCL/SCK SDA/SO SI CS CLKOUT INT or IRQ CLKOE Watch & Alarm - Seconds - Minutes - Hours - Days - Weekdays - Months - Years Timer Power Management I2C or SPI Output Control EEPROM Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 1 www.emmicroelectronic.com R EM3027 Table of contents Table of contents..................................................................................................................................................................... 2 1 Packages / Pin Out Configuration .................................................................................................................................... 3 2 Absolute Maximum Ratings.............................................................................................................................................. 4 2.1 Handling Procedures................................................................................................................................................. 4 2.2 Operating Conditions ................................................................................................................................................ 4 2.3 Crystal characteristics ............................................................................................................................................... 4 2.4 EEPROM Characteristics .......................................................................................................................................... 4 3 Electrical Characteristics .................................................................................................................................................. 4 4 EM3027 Block Diagram and Application Schematic......................................................................................................... 6 4.1 Block Diagram........................................................................................................................................................... 6 4.2 Application Schematic ............................................................................................................................................... 6 4.3 Crystal Thermal Behaviour........................................................................................................................................ 7 4.4 Crystal Calibration..................................................................................................................................................... 8 5 Memory Mapping.............................................................................................................................................................. 9 6 Definitions of terms in the memory mapping .................................................................................................................. 10 7 Serial communication ..................................................................................................................................................... 12 7.1 How to perform data transmission through I2C ....................................................................................................... 12 7.2 How to perform data transmission through SPI....................................................................................................... 13 8 Functional Description.................................................................................................................................................... 15 8.1 Start after power-up ................................................................................................................................................ 15 8.2 Normal Mode function ............................................................................................................................................. 15 8.3 Watch and Alarm function ....................................................................................................................................... 15 8.4 Timer function ......................................................................................................................................................... 16 8.5 Temperature measurement..................................................................................................................................... 16 8.6 Frequency compensation ........................................................................................................................................ 16 8.7 EEPROM memory................................................................................................................................................... 17 8.8 RAM User Memory.................................................................................................................................................. 18 8.9 Status Register........................................................................................................................................................ 18 8.10 Interrupts ............................................................................................................................................................ 18 8.11 Self-Recovery System (SRS) ............................................................................................................................. 19 8.12 Register Map ...................................................................................................................................................... 19 8.13 Crystal Oscillator and Prescaler ......................................................................................................................... 19 9 Power Management ................................................................................................................................................ 20 9.1 Power Supplies, Switchover and Trickle Charger ................................................................................................... 20 9.2 Low Supply Detection ............................................................................................................................................. 21 10 AC Characteristics .................................................................................................................................................. 22 10.1 AC characteristics – I2C ..................................................................................................................................... 22 10.2 I2C Specification compliance ............................................................................................................................. 23 10.3 AC characteristics – SPI..................................................................................................................................... 24 11 Package Information ............................................................................................................................................... 26 11.1 TSSOP-08/14 ..................................................................................................................................................... 26 11.2 SO-8................................................................................................................................................................... 27 12 Ordering Information ............................................................................................................................................... 28 Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 2 www.emmicroelectronic.com R EM3027 1 Packages / Pin Out Configuration Pin 1 2 3 4 5 6 7 8 Table 1 Name X1 X2 VBack VSS SDA SCL IRQ/CLKOUT VCC Function 32.768 kHz crystal input 32.768 kHz crystal output Backup Supply Ground Supply Serial Data Serial Clock Interrupt Request/Clock output Positive Supply SO8-TSSOP8 X1 X2 VBack Vss Vcc IRQ/CLKOUT EM3027 SCL SDA I2C TSSOP14 X1 X2 SI NC CLKOE VCC Pin 1 2 3 4 5 6 7 8 9 10 11 12 13 Name X1 X2 SI VReg VBack INT VSS SO SCK CS IRQ/CLKOUT VCC CLKOE VReg VBack INT Vss EM3027 IRQ/CLKOUT CS SCK SO SPI 14 NC Table 2 Function 32.768 kHz crystal input 32.768 kHz crystal output Serial Data input Regulated Voltage – Reserved for test purpose (This output must be left unconnected) Backup Supply Interrupt Request output (Open Drain active low) Ground Supply Serial Data output Serial Clock input Chip Select input Interrupt Request/Clock output Positive Supply Clock Output Enable CLKOE = ‘0’ CLKOUT is low CLKOE = ‘1’ CLKOUT is output Not Connected Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 3 www.emmicroelectronic.com R EM3027 2 Absolute Maximum Ratings Symbol VCCmax VCCmin Vmax Vmin TSTOmax TSTOmin VSmax Conditions VSS + 6.0V VSS – 0.3V VCC + 0.3V VSS – 0.3V +150°C -65°C 2000V Operating Conditions Parameter Symbol Min Typ Max Unit TA Operating Temp. -40 Supply voltage VCC, 1.4 5.0 VBack (Note 1) Capacitor at VCC, CD 100 VBack Table 4 Note 1: Refer to paragraphs 9.1 and 9.2 Parameter Maximum voltage at VCC Minimum voltage at VCC Maximum voltage at any signal pin Minimum voltage at any signal pin Maximum storage temperature Minimum storage temperature Electrostatic discharge maximum to MIL-STD-883C method 3015.7 with ref. to VSS Table 3 +125 5.5 °C V nF 2.3 Crystal characteristics Symbol Min Typ Max Unit Parameter Stresses above these listed maximum ratings may cause permanent damages to the device. Exposure beyond specified operating conditions may affect device reliability or cause malfunction. Frequency Load capacitance Series resistance Table 5 f CL RS 7 32.768 kHz 8.2 12.5 pF 70 110 kΩ Crystal Reference : Micro Crystal CC5V-T1A web: www.microcrystal.com 2.4 EEPROM Characteristics Symbol Min Typ Max Unit Parameter 2.1 Handling Procedures This device has built-in protection against high static voltages or electric fields; however, anti-static precautions must be taken as for any other CMOS component. Unless otherwise specified, proper operation can only occur when all terminal voltages are kept within the voltage range. Unused inputs must always be tied to a defined logic voltage level. 2.2 Read voltage Programming Voltage EEPROM Programming Time Write/Erase Cycling Table 6 VRead VProg TProg 1.4 2.2 30 5000 V V ms cycles 3 Electrical Characteristics Symbol Parameter Total supply current with Crystal ICC Test Conditions All outputs open, Rs < 70 kΩ, VBack = 0V I2C: SDA, SCL at VCC, Clk/Int=’0’ SPI: All inputs at VSS All outputs open, Rs < 70 kΩ, VCC = 0V I2C: SDA, SCL at VBack, Clk/Int=’0’ SPI: All inputs at VSS VBack 1.4 3.3 5.0 VCC 1.4 3.3 5.0 Temp. °C -40 to 85 -40 to 125 -40 to 85 -40 to 125 -40 to 85 -40 to 125 Min Typ 0.6 0.8 0.9 Max 1.5 4.6 2.0 5.2 2.2 5.5 Unit µA Total supply current with Crystal IBack 0 Dynamic current I2C IDD SCL = 100kHz (See Note 1) SCL = 400kHz (See Note 1) SCL = 400kHz (See note 1) 1.4 3.3 5.0 -40 to 85 -40 to 125 -40 to 85 -40 to 125 -40 to 85 -40 to 125 -40 to 85 -40 to 125 -40 to 85 -40 to 125 -40 to 85 -40 to 125 0.6 0.8 0.9 1.5 4.6 2.0 5.2 2.2 5.5 12 15 35 40 50 60 µA µA Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 4 www.emmicroelectronic.com R EM3027 Parameter Dynamic current SPI Interface Symbol IDD Test Conditions SCK = 200 kHz (See Note 2) SCK = 1 MHz (See Note 2) SCK = 1 MHz (See Note 2) Relative to VCC Relative to VCC VCC with respect to VBack = 3.0V CS, CLKOE, SI, SCL/SCK, SDA 0.0 < VIN < VCC IOL = 0.4 mA IOH = 0.1 mA IOL = 1.5 mA IOH = 1.5 mA IOL = 5.0 mA IOH = 2.0 mA 1.4 to 5.0 1.4 to 5.0 -40 to 85 -40 to 125 -40 to 125 VCC 1.4 3.3 5.0 Temp. °C -40 to 85 -40 to 125 -40 to 85 -40 to 125 -40 to 85 -40 to 125 -40 to 125 -40 to 125 -40 to 125 Min Typ Max 14 18 50 55 65 75 2.1 1.4 20 0.2VCC 0.8VCC -1 -1.5 1 1.5 0.2 1.4 1.0 0.25 3.3 -40 to 125 2.7 0.8 5.0 -40 to 125 4.5 -1 -1.5 1.2 0.5 1 0.5 13.5 pF 25 25 25 25 25 -40 to 85 -40 to 125 13.5 80 20 5.0 1.5 +/- 1 +/- 1 +/- 3 +/- 6 3 3 2 1 1.5 V V V Unit µA Low supply detection level1 Low supply detection level2 Switchover hysteresis Input Parameters Low level input voltage High level input voltage Input Leakage Output Parameters Low level output voltage High level output voltage Low level output voltage High level output voltage Low level output voltage High level output voltage Output HiZ leakage on INT Oscillator Start-up voltage Start-up time Vlow1 Vlow2 Vhyst VIL VIH IIN VOL VOH VOL VOH VOL VOH ILEAK_OUT VSTA TSTA 1.8 1.0 V V mV V 1.4 to 5.0 µA INT not active TSTA < 10s 1.4 to 5.0 -40 to 85 -40 to 125 -40 to 125 -40 to 85 -40 to 125 25 25 µA V s s ppm/ V 5.0 1.8V ≤ VCC ≤ 5.5V, TA = +25°C TA = +25°C, f = 32.768kHz, Vmeas = 0.3V (Note 3) TA = +25°C, f = 32.768kHz, Vmeas = 0.3V (Note 3) VCC =5.0V, VBack=3.0V VCC =5.0V, VBack=3.0V VCC =5.0V, VBack=3.0V VCC =5.0V, VBack=3.0V Vlow1 < VCC ≤ 5.5V Frequency stability over voltage Input capacitance on X1 Output capacitance on X2 Trickle Charger Current limiting Resistors Δf/(f ΔV) CIN COUT R80k R20k R5k R1.5k TE kΩ Thermometer Precision Table 7 The following parameters are tested during production test: IDD, Vlow1, Vlow2, VIL, VIH, VOL, VOH, IIN, ILEAK_OUT The parameters ICC, Vhyst, VSTA, TSTA, CIN, COUT, Δf/(f*ΔV), TE are characterised during the qualification of the IC. Notes: 1. SDA = VSS, continuous clock applied at SCL (VIL_SCL < 0.05V, VIH_SCL > 0.95VCC) 2. CS, SI = VCC, continuous clock applied at SCK, SO not connected. (VIL_SCK < 0.05VCC, VIH_SCK > 0.95VCC) Note that there is a 100kΩ pull-down resistor on CS. 3. Vmeas : Peak to peak amplitude during capacitance measurement Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D °C 5 www.emmicroelectronic.com R EM3027 4 4.1 EM3027 Block Diagram and Application Schematic Block Diagram VBack Vcc Vss Switchover VHigh Voltage Regulator Voltage Monitoring VREG X1 X2 Xtal Oscillator Prescaler RTC RAM 32.768 kHz EEPROM Control Inputs Stages I2C SPI SCL/SCK SI CS SDA/SO Thermometer Output Buffers CLKOE SDA/SO INT CLKOUT 4.2 Application Schematic Crystal Layout Example VCC Supply CD VCC X1 for application use CLKOUT X2 X2 X1 Crystal EM3027 CLKOE INT CS, SCL/SCK SDA/SO SI VSS VCC VBack Protection Resistor * Lithium Battery or Super Cap CD µController Serial Interface VSS VSS = 0V * optional for Lithium batteries ( VCC_min and VCC > VBack . 8.3 Watch and Alarm function The Watch part provides timing information in BCD format. The timing data is composed of seconds, minutes, hours, date, weekdays, months and years. The corresponding values are updated every second. The Watch part setup is provided by Write transmission into the Watch Page (Address 0x08h to 0x0Eh). After the transmission, the Watch is restarted from the setup values after one second. The Alarm function is activated by setting and enabling the alarm registers (Address 0x10h to 0x16h). Each Alarm byte has its own enable bit. It is the bit 7. Recommended combinations of enabled bits are described in the table below. SecEq 1 1 1 1 1 1 MinEq 0 1 1 1 1 1 HrsEq DateEq DaysEq MonthEq 0 0 0 0 0 0 0 0 1 0 0 0 1 1 0 0 1 1 0 1 1 0 1 0 Table 9: Alarm Period Selection YearEq 0 0 0 0 0 0 Al_period min hrs day month year week - Both Watch and Alarm parts must be set by an application before use - The bits SecEq to YearEq enable the comparison of the corresponding registers Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 15 www.emmicroelectronic.com R EM3027 8.4 Timer function The 16-bit count down timer can be enabled/disabled by TiOn bit. The timer input frequency is selected by TD1, TD0 bits according to the following table: TD1 TD0 Timer frequency 0 0 32 Hz 0 1 8 Hz 1 0 1 Hz 1 1 0.5 Hz Table 10: Timer Frequency Selection The timer can run in Zero-Stop or Auto-Reload mode (TROn bit: ‘0’ = Zero-Stop mode, ‘1’ = Auto-Reload mode). When TROn = ‘0’, then it is possible to read current value of the timer. If TROn = ‘1’, then last written value is read from cache memory. The value in the cache memory is used as the new value for reloading (Auto-Reload mode). Frequency selection (TD1, TD0) and mode selection (TROn) can be written only when the timer is stopped (TiOn = ‘0’). Timer values (TimLow, TimHigh) can be written only when TiOn = ’0’ and TROn = ‘0’. NOTE: The “Timer Page” can also be used as a general purpose register when the timer function is not used. 8.5 Temperature measurement The integrated thermometer has a resolution of 1°C. The thermometer is disabled when ThEn = ’0’ and enabled when ThEn = ’1’. By default, the thermometer is enabled. Thermometer period is selectable by ThPer bit according to the table below: ThPer Period in Seconds 0 1s 1 16 s Table 11: Thermometer Period The thermometer is automatically disabled when VLOW1 status bit is at ‘1’. When the thermometer is disabled (ThEn = ’0’), the Temp register can be written. Temp register uses a cache memory to keep stable value during a whole transaction (read/write). 8.6 Frequency compensation There is a frequency compensation unit (FCU) inside EM3027. FCU compensates quartz crystal native frequency in dependency on actual compensation value (COMP_val). FCU is always running. During chip power-up, if ThEn = ’1’ and VLOW1 = ‘0’ temperature measurement is enabled and COMP_val is computed. Otherwise, COMP_val is set to 0 ppm. In Normal mode, new compensation value is computed each 32 seconds. The only exception is when ThEn = ‘1’ and VLOW1 = ‘1’. In this case, temperature measurement and COMP_val computation are blocked and FCU uses the last computed compensation value. For the evaluation of COMP_val, actual content of Temp register (0x20) is used. The compensation value is computed according to the equation described in paragraph 4.3. Content of Temp register is updated either after a temperature measurement (when ThEn = '1' and VLOW1 = '0') or after Temp register write transaction (when ThEn = '0'). After power-up content of Temp register is undefined. If thermometer is disabled (ThEn = '0') user is advised to periodically update Temp register with actual ambient temperature in order to have correct input data for COMP_val computation. Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 16 www.emmicroelectronic.com R EM3027 8.7 EEPROM memory Before any EEPROM access (read/write), the bit EERefOn has to be cleared by the application to prevent from access collision with the Configuration Registers. Then the application has to read EEBusy bit and if EEBusy = ‘0’, then EEPROM access can be started. After the write command (at “Transmission STOP”) the current state of EEPROM writing is monitored by EEBusy register bit at ‘1’. EEBusy goes to ‘0’ when EEPROM writing is finished. NOTE: VCC must be applied during the whole EEPROM write (i.e. until EEBusy = ‘0’) and must be higher than Vprog. Clear EERefOn Clear EERefOn No EEBusy = 0 ? No EEBusy = 0 ? Yes Read EEPROM Yes Write EEPROM Yes Next read ? No EEBusy = 0 ? No Set EERefOn Yes Yes Next Write ? No Set EERefOn 8.7.1 EEPROM Control Page This part is composed of 4 bytes purposed for miscellaneous function control and for crystal compensation constants. EEctrl byte contains: trickle charger selectors (R80k, R20k, R5k, R1.5k); output clock frequency selector (FD1, FD0); thermometer enable and thermometer period selector. 8.7.2 Clock Output Output clock frequency is selected by FD1, FD0 bits in EEctrl register. FD1 0 0 1 1 FD0 0 1 0 1 Select Clock Output 32.768 kHz Description From crystal oscillator, without frequency compensation 1024 Hz With frequency compensation 32 Hz 1 Hz Table 12: Output Clock frequency selection Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 17 www.emmicroelectronic.com R EM3027 8.7.3 Configuration Registers All the configuration data from EEPROM (i.e. EEctrl, XTalOffset, Qcoef, TurnOver, EEData) is hold in configuration registers. Data from EEPROM is loaded to these registers during power-up sequence and is refreshed each hour, if ‘Configuration Registers refresh’ feature is enabled (EERefOn = ‘1’). Regular refresh of Configuration Registers prevents their content to be corrupted by strongly polluted electrical environment (EMC problems, disturbed power supply, etc.). It is recommended to enable ‘Configuration Registers refresh’ feature. 8.7.4 EEPROM User Memory Two bytes of the memory are dedicated for the application (addresses 0x28 and 0x29). 8.8 RAM User Memory RAM user memory size is 8 bytes (addresses 0x38 to 0x3F). The state of the RAM data after power-up is undefined. 8.9 Status Register The purpose of EEBusy bit is to inform the user about current status of the EEPROM operations. EEBusy – status of EEPROM controller (if EEBusy = ‘1’, then Configuration Registers refresh or EEPROM write is in progress) The purpose of the following status bits is to record status of power supply voltage and Self-Recovery system/System reset behaviour. PON VLOW1 VLOW2 SR – status of Power-ON – status of Vlow1 voltage detection – status of Vlow2 voltage detection – status of the Self-Recovery system/System reset If one of these status bits is set, it can be cleared only by writing ‘0’, there is no automatic reset if the set condition disappears. 8.10 Interrupts There are five interrupt sources which can output an interrupt on (INT and/or IRQ/CLKOUT) pins. The request is generated when at least one of IRQflags goes to ‘1’ (OR function). AF TF V1F V2F SRF – interrupt is provided when Watch time reaches Alarm time settings and comparison is enabled – interrupt is provided when Timer reaches ZERO – interrupt is provided when supply voltage is below Vlow1 (when VLOW1 status bit is set) – interrupt is provided when supply voltage is below Vlow2 (when VLOW2 status bit is set) – interrupt is provided when Self-Recovery system invoked internal reset (when SR status bit is set) Each interrupt source has its own interrupt enable (AIntE, TIntE, V1IntE, V2IntE, SRIntE). When the interrupt enable is ‘1’ then the appropriate interrupt source is enabled. Interrupt flags (IRQflags) are cleared by ‘0’ writing into the appropriate bit. In case of V1F, V2F and SRF bits, it is necessary to clear also the corresponding status bits (Status) after interrupt bit. Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 18 www.emmicroelectronic.com R EM3027 8.11 Self-Recovery System (SRS) The purpose of the Self-Recovery System (SRS) is to generate an internal reset in case the on-chip state machine goes into a deadlock. The function is based on an internal counter that is periodically reset by the control logic. If the counter is not reset on time, this reset will take place. It is executed after two voltage monitoring periods at the latest, i.e. 2s or 32s (ThPer bit). A possible source of a deadlock could be disturbed electrical environment (EMC problem, disturbed power supply, etc.). SRS sets status bit SR and resets the internal logic, except Watch, Alarm and Timer parts (i.e. time informations are not affected). Furthermore, if the SRS interrupt is enabled (SRIntE='1'), the SRF flag is set after the internal chip reset. Note, that SROn = '1' and SRIntE = '0' after the reset. After the internal reset, the device starts with the power-up sequence (see paragraph 8.1). SRS is automatically enabled after power-up (SROn bit). It can be disabled by writing '0' into the SROn bit in the Control Page. 8.12 Register Map The address range of the EM3027 is divided into pages. The page is addressed by the five most significant bits of the address (bits 6 … 3). The three low significant bits of the address provide selection of registers inside the page. During address incrementing the three low significant bits (2 … 0) are changed. The page address part is fixed during the whole data transmission. 8.13 Crystal Oscillator and Prescaler The 32.768 kHz crystal oscillator and the clock divider provide the timing signals for the functional blocks. The prescaler block is responsible for frequency division of the 32.768 kHz clock signal from the crystal oscillator. Divided frequency is then distributed between other blocks inside the chip, including Watch, Timer and control logic. Two capacitors CIN and COUT are integrated on chip – see Figure 5. X2 X1 CIN COUT Figure 5: Oscillator Capacitors Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 19 www.emmicroelectronic.com R EM3027 9 Power Management VCC I/O Switchover V H igh V Back V Reg Logic, EEPROM, Thermometer, Voltage Monitor Regulator 2.9V Xtal Oscillator 4x Trickle charger resistors Figure 6: Power Management 9.1 Power Supplies, Switchover and Trickle Charger In this way, a rechargeable battery or a super-cap can be charged from the VCC voltage, as long as VCC > VBack. There are 4 selectable resistors connected in parallel with typical values of 80kΩ, 20kΩ, 5kΩ and 1.5kΩ. One or more resistors can be selected by EEctrl bits setting. If a Lithium battery shall be connected to VBack pin, a protection resistor of value up to 1kΩ can be connected in series with it. In this way, in case of EM3027 device damage resulting in short between both supply pins, charging current from the VCC supply can be reduced to its allowed maximum level as required by UL1642 standard. The device can be supplied from the VCC pin or from the VBack pin. The switchover block implemented inside the chip compares VCC and VBack voltages and connects the higher of them to the internal VHigh net that supplies the chip. Nevertheless, the communication pins (SCL, SDA or CS, SCK, SI, SO) are supplied from the VCC pin. For that reason, when serial interface (I2C or SPI) is used, the chip has to be supplied from VCC. (i.e. VCC > VBack). By setting of a trickle charger bit in register EEctrl, a resistor can be inserted between VBack and VHigh voltage. Clock operating with thermocompensation using either previously in fully operating mode measured or by user stored temperature value; no EEPROM write min max min max Serial communication is enabled, if VCC > VCCmin and VCC > Vback Vlow2 VCCmin Vlow1 EM3027 fully operating according datasheet (clock, thermometer, thermocompensation) Vprog EEPROM write if VCC > Vprog 2.2V 2.0V 3.0V 4.0V 5.0V VCCmax 1.4V 0V 1.0V 5.5V Supply Voltage Figure 7: EM3027 operating Voltage Areas Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 20 www.emmicroelectronic.com R EM3027 9.2 Low Supply Detection To leave the VLOW1 status, the supply voltage must be increased above the Vlow1 level and a ‘0’ value must be written into the VLOW1 status bit via the serial interface. When the supply voltage drops below the Vlow2 level, the VLOW2 status bit is set by the voltage monitoring system. The VLOW2 status bit disables the read out of the EEPROM. To leave the VLOW2 status, the supply voltage must be increased above the Vlow2 level and a ‘0’ value must be written into the VLOW2 status bit via the serial interface. Below Vlow2 level, device functionality is not guaranteed and register contents can be corrupted. Therefore, if VLOW2 status bit is set, it is recommended to perform system reset by writing of ‘1’ into SYSRes bit in RstCtrl page and afterwards update content of Watch, Alarm and Timer registers. The supply voltage level is monitored periodically versus Vlow1 and Vlow2 levels. The monitoring rate is one second. When the voltage monitoring is running, a higher current consumption for few milliseconds occurs. At the power-up of the device, as long as the supply voltage stays below Vlow2, the monitoring rate is accelerated. To enable normal operation, the chip must be supplied with a voltage above Vlow2, to enable the readout of initialization data from EEPROM and to stop the higher current consumption. When the supply voltage drops from the normal range (from 2.1V to 5.5V) below Vlow1, the VLOW1 status bit is set to ‘1’ by the voltage monitoring system. When bit VLOW1 is at ‘1’, the thermometer is disabled and the automatic computation of the thermal compensation value (COMP_val) for frequency correction is inhibited. In this case, the last computed compensation value is used. Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 21 www.emmicroelectronic.com R EM3027 10 AC Characteristics 10.1 AC characteristics – I2C VSS = 0V and TA=-40 to +125°C, unless otherwise specified PARAMETER SYMBOL CONDITIONS Vcc ≥ 3.0V SCL Clock Frequency fSCL Vcc >1.8V Vcc>1.4V Bus Free Time Between STOP and START Condition Vcc ≥ 3.0V tBUF Vcc >1.8V Vcc>1.4V Hold Time (Repeated) START Condition Vcc ≥ 3.0V tHD:STA Vcc >1.8V Vcc>1.4V Vcc ≥ 3.0V LOW Period of SCL Clock tLOW Vcc >1.8V Vcc>1.4V Vcc ≥ 3.0V HIGH Period of SCL Clock tHIGH Vcc >1.8V Vcc>1.4V Vcc ≥ 3.0V Setup Time START Condition tSU:STA Vcc >1.8V Vcc>1.4V Vcc ≥ 3.0V Data Hold Time tHD:DAT Vcc >1.8V Vcc>1.4V Vcc ≥ 3.0V Data Setup Time tSU:DAT Vcc >1.8V Vcc>1.4V Vcc ≥ 3.0V Data Valid Time tVD:DAT Vcc >1.8V Vcc>1.4V Vcc ≥ 3.0V Data Valid Acknowledge Time tVD:ACK Vcc >1.8V Vcc>1.4V Rise Time of Both SDA and SCL Signals Vcc ≥ 3.0V tR Vcc >1.8V Vcc>1.4V Fall Time of Both SDA and SCL Signals (See note 1) Vcc ≥ 3.0V tF Vcc >1.8V Vcc>1.4V Setup Time (Repeated) STOP Condition Length of spikes suppressed by the input filter on SCL and SDA Capacitive Load For Each Bus Line I/O Capacitance (SDA, SCL) Vcc ≥ 3.0V tSU:STO Vcc >1.8V Vcc>1.4V tSP CB CI/O 20 30 50 50 200 10 ns pF pF ns 1.3 1.7 4.5 0.4 0.5 0.6 20 30 50 20 30 50 50 80 100 1.2 1.5 4.0 0.9 1.1 3.5 200 300 1000 200 300 400 ns ns μs μs ns ns ns μs μs 0.2 μs 0.4 0.5 1.0 μs MIN TYP MAX 400 300 100 kHz UNITS Table 13: I2C AC characteristics Parameters are guaranteed by design. They are not tested in production. Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 22 www.emmicroelectronic.com R EM3027 Calculation of external pull–up resistor The following conditions have to be met: Rise time is equal to 0.847 RPU (CB + N * CI/O) ⇒ RPU < tR max / (0.847 (CB + N CI/O)), where N is total number of I/O pins connected to the corresponding bus line. (tR in ns, C in pF, R in kΩ) The minimum value of the pullup resistor value can be calculated with the IOL value of the SDA output: RPU = (Vcc – VOL) / IOL ( IOL: see Table 7, page 5, Output Parameters; e.g. 5mA at VCC = 5.0V, with VOL = 0.8V ) Start SDA tBUF Stop tLOW tR tHIGH SCL tHD:STA tHD:DAT tF tSU:DAT tSU:STO tSU:STA Figure 8: I2C Timing 10.2 I2C Specification compliance There are, however, the following discrepancies between I2C specification and EM3027 interface: 1) Falling time on SDA driven by EM3027 can be shorter than 20 + 0.1* CB ns. (CB is total capacitive load for SDA bus line in pF) In other words, slope control of falling edges on SDA is missing. Some timing parameters differ from the original I2C specification – refer to Table 13. EM3027 device with I2C serial interface was designed 2 in compliance with Philips Semiconductors I C-bus specification UM10204 (Rev. 03 – 19 June 2007), Fastmode class (up to 400kbit/s). Device address consists of 7 bits. Clock stretching is not supported. Brief manual to I2C interface read and write transmissions is to be found in §7.1. 2) Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 23 www.emmicroelectronic.com R EM3027 10.3 AC characteristics – SPI VSS = 0V and TA=-40 to +125°C, unless otherwise specified PARAMETER SCK Clock Frequency SYMBOL fSCK CONDITIONS Vcc ≥ 3.0V Vcc >1.8V Vcc >1.4V Data to SCK setup tDC Vcc ≥ 3.0V Vcc >1.8V Vcc >1.4V SCK to Data Hold tCDH Vcc ≥ 3.0V Vcc >1.8V Vcc >1.4V SCK to Data Valid tCDD Vcc ≥ 3.0V Vcc >1.8V Vcc >1.4V SCK Low Time tCL Vcc ≥ 3.0V Vcc >1.8V Vcc >1.4V SCK High Time tCH Vcc ≥ 3.0V Vcc >1.8V Vcc >1.4V SCK Rise and Fall tR , tF Vcc ≥ 3.0V Vcc >1.8V Vcc >1.4V CS to SCK Setup tCC Vcc ≥ 3.0V Vcc >1.8V Vcc >1.4V SCK to CS Hold tCCH Vcc ≥ 3.0V Vcc >1.8V Vcc >1.4V CS Inactive Time tCWL Vcc ≥ 3.0V Vcc >1.8V Vcc >1.4V CS to Output High Impedance tCDZ Vcc ≥ 3.0V Vcc >1.8V Vcc >1.4V 200 300 500 200 300 400 50 100 200 ns ns ns 100 ns 400 700 1500 400 700 1500 200 800 ns ns ns 200 300 500 350 650 1300 ns ns 20 ns MIN TYP MAX 1 600 200 UNITS MHz kHz Table 14: SPI AC characteristics Parameters are guaranteed by design. They are not tested in production. 1) Max. bus capacitance on SO line shall be lower than 100pF when Vcc > 1.8V and lower than 50pF when Vcc < 1.8V. 2) Spikes on SCK signal shorter than 20ns are suppressed. Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 24 www.emmicroelectronic.com R EM3027 CS tCC tCH tF tCL t tCCH tCWL SCK tDC tCDH A0 SI data are don't care when SO outputs data SI R/W SPI Master writes address, EM3027 outputs data: SO HiZ D7 tCDD tCDZ D0 Figure 9: SPI Read Timing CS tCC tCH tF tCL t tCCH tCWL SCK tDC tCDH A0 D7 D0 SI R/W SPI Master writes address and data: SO HiZ Figure 10: SPI Write Timing Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 25 www.emmicroelectronic.com R EM3027 11 Package Information 11.1 TSSOP-08/14 4 B 32 1 B E/2 1.00 E E1 5 C L B 1.00 1.00 DIA. C A4 TOP VIEW b bbb M C A-B A2 D9 0.05 C 3 e D 5 A1 SEATING PLANE S Y M B O L A A1 A2 aaa b b1 bbb c c1 D E1 e E L N P P1 COMMON DIMENSIONS MIN. NOM. 0.05 0.85 0.90 0.076 0.19 0.19 0.22 0.10 0.09 0.09 0.127 SEE VARIATIONS 4.30 4.40 0.65 BSC 6.40 BSC 0.50 0.60 SEE VARIATIONS SEE VARIATIONS SEE VARIATIONS 0° MAX. 1.10 0.15 0.95 0.30 0.25 0.20 0.16 4.50 0.70 N VARIO T E ATIONS NOTE MIN. 2.90 4.90 9 NOTES: 1. DIE THICKNESS ALLOWABLE IS 0.279±0.0127 2. DIMENSIONING & TOLERANCES PER ASME. Y14.5M-1994. 3. DATUM PLANE H LOCATED AT MOLD PARTING LINE AND COINCIDENT WITH LEAD, WHERE LEAD EXITS PLASTIC BODY AT BOTTOM OF PARTING LINE. 4. DATUM A-B AND D TO BE DETERMINED WHERE CENTERLINE BETWEEN LEADS EXITS PLASTIC BODY AT DATUM PLANE H. 5 5 6 7 5. "D" & "E1" ARE REFERENCE DATUM AND DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS, AND ARE MEASURED AT THE BOTTOM PARTING LINE. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.15mm ON D AND 0.25mm ON E PER SIDE. 6. DIMENSION IS THE LENGTH OF TERMINAL FOR SOLDERING TO A SUBSTRATE. 7. TERMINAL POSITIONS ARE SHOWN FOR REFERENCE ONLY. 8. FORMED LEADS SHALL BE PLANAR WITH RESPECT TO ONE ANOTHER WITHIN 0.076mm AT SEATING PLANE. 9. THE LEAD WIDTH DIMENSION DOES NOT INCLUDE DAMBAR PROTRUSION. ALLOWABLE DAMBAR PROTRUSION SHALL BE 0.07mm TOTAL IN EXCESS OF THE LEAD WIDTH DIMENSION AT MAXIMUM MATERIAL CONDITION. DAMBAR CANNOT BE LOCATED ON THE LOWER RADIUS OR THE FOOT. MINIMUM SPACE BETWEEN PROTRUSIONS AND AN ADJACENT LEAD SHOULD BE 0.07mm 8° ALL DIMENSIONS IN MILLIMETERS Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D C C D 0.20 C A-B D 2X N/2 TIPS N e/2 7 4 SEE DETAIL "A" END VIEW X EVEN LEAD SIDES TOPVIEW (14°) X X = A AND B ODD LEAD SIDES TOPVIEW 0.25 A H aaa 8 L6 (1.00) DETAIL 'A' (VIEW ROTATED 90° C.W.) (14°) PARTING LINE H 5 D NOM. 3.00 5.00 MAX. 3.10 5.10 P MAX. 1.59 3.1 P1 MAX. 3.2 3.0 7 N 8 14 26 www.emmicroelectronic.com R EM3027 11.2 SO-8 Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 27 www.emmicroelectronic.com R EM3027 12 Ordering Information EM3027 I D X SO8B Part Number EM3027 = Interface I2C bus = SPI bus = I S RTC SO8B= TP8B= TP14= WS11= 8 pin SO8 tape 8 pin TSSOP8 tape 14 pin TSSOP14 tape Wafer sawn 11 MILS Package Temperature compensation Default Temp. Compensation = (Factory Standard) D Functional Temperature Standard temperature= S Extended temperature= X Standard Versions Part Number EM3027IDSTP8A+ EM3027IDSTP8B+ EM3027IDXTP8B+ EM3027IDSSO08A+ EM3027IDSSO08B+ EM3027IDXSO08B+ EM3027SDSTP14A+ EM3027SDSTP14B+ EM3027SDXTP14B+ Package TSSOP8 TSSOP8 TSSOP8 SO8 SO8 SO8 TSSOP14 TSSOP14 TSSOP14 Functional Temperature -40 +85°C -40 +85°C -40 +125°C -40 +85°C -40 +85°C -40 +125°C -40 +85°C -40 +85°C -40 +125°C Interface I2C I2C I2C I2C I2C I2C SPI SPI SPI Delivery Form Stick , 100 pcs Tape & Reel, 4000 pcs Tape & Reel, 4000 pcs Stick, 97 pcs Tape & Reel, 2500 pcs Tape & Reel, 2500 pcs Stick, 96 pcs Tape & Reel, 3500 pcs Tape & Reel, 3500 pcs Marking 3027S5 3027S5 3027X5 3027S5 3027S5 3027X5 3027S6 3027S6 3027X6 Please contact Sales office for other versions not shown here and for availability of non standard versions. EM Microelectronic-Marin SA (EM) makes no warranty for the use of its products, other than those expressly contained in the Company's standard warranty which is detailed in EM's General Terms of Sale located on the Company's web site. EM assumes no responsibility for any errors which may appear in this document, reserves the right to change devices or specifications detailed herein at any time without notice, and does not make any commitment to update the information contained herein. No licenses to patents or other intellectual property of EM are granted in connection with the sale of EM products, expressly or by implications. EM's products are not authorized for use as components in life support devices or systems. Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 28 www.emmicroelectronic.com