ISL1209 Intersil Corporation, ISL1209 Datasheet

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... Data Sheet Low Power RTC with Battery Backed SRAM and Event Detection The ISL1209 device is a low power real time clock with Event Detect function, timing and crystal compensation, clock/calendar, power fail indicator, periodic or polled alarm, intelligent battery backup switching and battery-backed user SRAM ...

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... Serial Clock (SCL). The SCL input is used to clock all serial data into and out of the device. 9 IRQ/F Interrupt Output IRQ, /Frequency Output F OUT output pin. The function is set via the configuration register Power supply. DD DD. 2 ISL1209 CONTROL INTERFACE LOGIC RTC DIVIDER POR FREQUENCY ALARM OUT ...

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... Test Conditions:V SYMBOL PARAMETER V SDA and SCL input buffer LOW IL voltage V SDA and SCL input buffer HIGH IH voltage 3 ISL1209 Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . .-65°C to +150°C Lead Temperature (Soldering, 10s 300°C ESD Rating (Human Body Model >±2kV + 0.5 (V Mode 0.5 (V Mode) BAT BAT Test Conditions:V = +2.7 to +5.5V, Temperature = -40° ...

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... In order to ensure proper timekeeping, the V 4. Typical values are for T = 25°C and 3.3V supply voltage Mode SUP DD DD SUP BAT 4 ISL1209 = +2.7 to +5.5V, Temperature = -40°C to +85°C, unless otherwise specified. DD TEST CONDITIONS 3mA 25° 1MHz 5V ...

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... SDA (OUTPUT TIMING) Symbol Table WAVEFORM INPUTS Must be steady May change from LOW to HIGH May change from HIGH to LOW Don’t Care: Changes Allowed N/A 5 ISL1209 HIGH LOW t SU:DAT t HD:DAT OUTPUTS Will be steady Will change from LOW to HIGH Will change ...

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... TEMPERATURE (°C) FIGURE TEMPERATURE DD1 2.1E-6 2.0E-6 1.9E-6 1.8E-6 1.7E-6 1.6E-6 1.5E-6 1.4E-6 1.3E-6 1.2E-6 F OUT (Hz) FIGURE DD1 OUT 6 ISL1209 Temperature is 25°C unless otherwise specified 000E+0 4.5 5.0 5.5 BAT 800.0E-9 600.0E-9 400.0E 3.3V DD 1E-6 800E-9 600E-9 400E-9 200E-9 -40 - TEMPERATURE (°C) FIGURE TEMPERATURE AT V BAT 2 ...

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... An external 32.768kHz quartz crystal AND I = 3mA OL is used with the ISL1209 to supply a timebase for the real time clock. Internal compensation circuitry provides high accuracy over the operating temperature range from -40°C to +85°C. This oscillator compensation network can be used to calibrate the crystal timing accuracy over ...

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... Many types of batteries can be used with Intersil RTC products. For example, 3.0V or 3.6V Lithium batteries are appropriate, and battery sizes are available that can power the ISL1209 for years. Another option is to use a Super Cap for applications where month. See the Applications Section for more information ...

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... For example, battery-backed RTCs are commonly packaged on a board with a battery connected. In order to preserve battery life, the ISL1209 will not draw any power from the battery source until after the device is first powered up from the V source ...

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... The frequency output can be enabled/disabled during battery backup mode using the FOBATB bit. General Purpose User SRAM The ISL1209 provides 2 bytes of user SRAM. The SRAM will continue to operate in battery backup mode. However, it should be noted that the I , the clock will BAT backup mode ...

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... C serial bus protocols using a bidirectional data signal (SDA) and a clock signal (SCL). Oscillator Compensation The ISL1209 provides the option of timing correction due to temperature variation of the crystal oscillator for either manufacturing calibration or active calibration. The total possible compensation is typically -94ppm to +140ppm. Two compensation mechanisms that are available are as follows: 1 ...

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... HRA EHRA Alarm 0Fh DTA EDTA 10h MOA EMOA 11h DWA EDWA 12h USR1 USR17 User 13h USR2 USR27 12 ISL1209 TABLE 5. REGISTER MEMORY MAP BIT SC22 SC21 SC20 SC13 MN22 MN21 MN20 MN13 0 HR21 HR20 HR13 0 DT21 DT20 ...

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... Years divisible by 100 are not leap years, unless they are also divisible by 400. This means that the year 2000 is a leap year, the year 2100 is not. The ISL1209 does not correct for the leap year in the year 2100. ...

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... These two bits select the rate of sampling of the EVIN pin trigger an event detection. For example, a 2Hz sampling rate would configure the ISL1209 to check the status of the pin twice a second. Slower sampling significantly reduces the supply current drain. ...

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... EVENT DETECT ENABLE BIT (EVEN) This bit enables/disables the Event Detect function of the ISL1209. When this bit is set to “1”, the Event Detect is active. When this bit is cleared to “0”, the Event Detect is disabled. RTC HALT ON EVENT DETECT BIT (RTCHLT) This bit sets the RTC registers to continue or halt counting upon an Event Detect triggered by the EV pin ...

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... Interrupt Mode is enabled by setting the ALME bit to “1”, the IM bit to “1”, and disabling the frequency output. The 16 ISL1209 IRQ output will now be pulsed each time an alarm occurs. This means that once the interrupt mode alarm is set, it will continue to alarm for each occurring match of the alarm and present time ...

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... Data states on the SDA line can change only during SCL DESCRIPTION LOW periods. SDA state changes during SCL HIGH are reserved for indicating START and STOP conditions (See enabled Figure 12). On power up of the ISL1209, the SDA pin is in the input mode. 2 All I C interface operations must begin with a START condition, which is a HIGH to LOW transition of SDA while SCL is HIGH ...

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... TRANSMITTER HIGH IMPEDANCE SDA OUTPUT FROM RECEIVER START FIGURE 13. ACKNOWLEDGE RESPONSE FROM RECEIVER SIGNALS FROM S THE MASTER T IDENTIFICATION SIGNAL AT SDA 1 SIGNALS FROM THE ISL1209 FIGURE 14. BYTE WRITE SEQUENCE 18 ISL1209 DATA DATA DATA STABLE CHANGE STABLE 1 8 WRITE ADDRESS BYTE BYTE 1 ...

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... Identification byte with the R/W bit set to “1”. After each of the three bytes, the ISL1209 responds with an ACK. Then the ISL1209 transmits Data Bytes as long as the master responds with an ACK during the SCL cycle following the eighth bit of each byte. The master terminates the read operation (issuing a STOP condition) following the last bit of the last Data Byte (See Figure 16) ...

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... Application Section Event Detection The event detection feature of the ISL1209 is intended to be used for recording the time of single events that involve the opening of an enclosure, door, etc. The normal method of detection is with normally closed switch function that opens to initiate the event. This mechanism is ideal for applications such as set top boxes, utility meters, security alarm and camera systems or vending machines ...

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... In addition to the analog compensation afforded by the adjustable load capacitance, a digital compensation feature is available for the ISL1209. There are 3 bits known as the Digital Trimming Register (DTR). The range provided is ±60ppm in increments of 20ppm. DTR operates by adding or skipping pulses in the clock counter very useful for ...

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... A Super Capacitor can be used as an alternative to a battery in cases where shorter backup times are required. Since the battery backup supply current required by the ISL1209 is extremely low possible to get months of backup operation using a Super Capacitor. Typical capacitor values are a few µ Farad or more depending on the application ...

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... BAT voltage from fully charged to loss of operation. Note that I is the total of the supply current of the ISL1209 (I TOT plus the leakage current of the capacitor and the diode these calculations assumed to be extremely small LKG and will be ignored ...

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... However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries. For information regarding Intersil Corporation and its products, see www.intersil.com 24 ISL1209 M10.118 (JEDEC MO-187BA) 10 LEAD MINI SMALL OUTLINE PLASTIC PACKAGE SYMBOL ...