M41T66Q6F STMicroelectronics, M41T66Q6F Datasheet
M41T66Q6F
Specifications of M41T66Q6F
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M41T66Q6F Summary of contents
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Features ■ Counters for tenths/hundredths of seconds, seconds, minutes, hours, day, date, month, year, and century ■ 32 KHz crystal oscillator integrating load capacitance and high crystal series resistance operation ■ Oscillator stop detection monitors clock operation 2 ■ Serial ...
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Contents Contents 1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...
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M41T66 List of tables Table 1. Signal names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...
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List of figures List of figures Figure 1. M41T66 logic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...
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M41T66 1 Description The M41T66 serial access TIMEKEEPER 32.768 kHz oscillator (external crystal controlled). Eight registers (see are used for the clock/calendar function and are configured in binary coded decimal (BCD) format. An additional 8 registers provide status/control of alarm, ...
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Description Figure 2. M41T66 connections 1. SQW output defaults to 32 KHz upon power-up 2. Open drain Table 1. Signal names XI Oscillator input XO Oscillator output SDA Serial data input/output SCL Serial clock input IRQ/OUT Interrupt or OUT output ...
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M41T66 Figure 4. Hardware hookup for SuperCap™ backup operation 1. Open drain 2. For a crystal with a load capacitance (C must be added to achieve better clock accuracy can also be connected to another power supply. 4. ...
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Operation 2 Operation The M41T66 clock operates as a slave device on the serial bus. Access is obtained by implementing a start condition followed by the correct slave address (D0h). The 16 bytes contained in the device can then be ...
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M41T66 2.1.4 Data valid The state of the data line represents valid data when after a start condition, the data line is stable for the duration of the high period of the clock signal. The data on the line may ...
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Operation Figure 6. Acknowledgement sequence 2.2 READ mode In this mode the master reads the M41T66 slave after setting the slave address (see Figure 8 on page bit, the word address 'An' is written to the on-chip address pointer. Next ...
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M41T66 Figure 7. Slave address location Figure 8. READ mode sequence Figure 9. Alternative READ mode sequence Operation 11/33 ...
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Operation 2.3 WRITE mode In this mode the master transmitter transmits to the M41T66 slave receiver. Bus protocol is shown in Figure 10. Following the START condition and slave address, a logic '0' (R/W=0) is placed on the bus and ...
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M41T66 3 Clock operation The M41T66 is driven by a quartz-controlled oscillator with a nominal frequency of 32.768 kHz. The accuracy of the real-time clock depends on the frequency of the quartz crystal that is used as the time-base for ...
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Clock operation 3.1 TIMEKEEPER The M41T66 offers 16 internal registers which contain clock, calibration, alarm, watchdog, flags, and square wave. The clock registers are memory locations which contain external (user accessible) and internal copies of the data (usually referred to ...
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M41T66 Table 2. M41T66 register map Addr D7 00h 01h ST 02h OFIE 03h 0 04h RS3 05h 0 06h CB1 07h 08h OUT 09h RB2 BMB4 BMB3 0Ah AFE SQWE 0Bh RPT4 RPT5 0Ch RPT3 0Dh RPT2 0Eh RPT1 ...
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Clock operation 3.2 Calibrating the clock The M41T66 is driven by a quartz controlled oscillator with a nominal frequency of 32,768 Hz. The accuracy of the real-time clock depends on the frequency of the quartz crystal that is used as ...
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M41T66 Figure 11. Crystal accuracy across temperature Figure 12. Calibration waveform Clock operation 17/33 ...
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Clock operation 3.3 Setting alarm clock registers Address locations 0Ah-0Eh contain the alarm settings. The alarm can be configured to go off at a prescribed time on a specific month, date, hour, minute, or second, or repeat every year, month, ...
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M41T66 3.4 Watchdog timer The watchdog timer can be used to detect an out-of-control microprocessor. The user programs the watchdog timer by setting the desired amount of time-out into the Watchdog Register, address 09h. Bits BMB4-BMB0 store a binary multiplier ...
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Clock operation 3.5 Square wave output The M41T66 offers the user a programmable square wave function which is output on the SQW pin. RS3-RS0 bits located in 04h establish the square wave output frequency. These frequencies are listed in completed, ...
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M41T66 3.7 Output driver pin When the OFIE bit, AFE bit, and watchdog register are not set to generate an interrupt, the IRQ/OUT pin becomes an output driver that reflects the contents the calibration register. In other ...
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Clock operation 3.9 Initial power-on defaults Upon application of power to the device, the register bits will initially power-on in the state indicated in Table Table 5. Initial power-on default values Condition (1) Initial power-up 1. All other control bits ...
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... These are stress ratings only and operation of the device at these or any other conditions above those indicated in the operating sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Refer also to the STMicroelectronics SURE Program and other relevant quality documents. Table 7. ...
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DC and AC parameters 5 DC and AC parameters This section summarizes the operating and measurement conditions, as well as the DC and AC characteristics of the device. The parameters in the following DC and AC Characteristic tables are derived ...
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M41T66 Table 9. Capacitance Symbol C Input capacitance IN (3) C Output capacitance OUT t Low-pass filter input time constant (SDA and SCL Effective capacitance measured with power supply at 3.6 V; sampled only, not 100% tested. 2. ...
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... C Load capacitance L 1. Externally supplied if using the QFN16 package. STMicroelectronics recommends the Citizen CFS-145 (1 mm) and the KDS DT- mm) for thru-hole, or the KDS DMX-26S (3 mm) for surface-mount, tuning fork-type quartz crystals. KDS can be contacted at http://www.kds.info/index_en.htm. Citizen can be contacted at http://www.citizencrystal.com. ...
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M41T66 Table 13. AC characteristics Sym f SCL clock frequency SCL t Clock low period LOW t Clock high period HIGH t SDA and SCL rise time R t SDA and SCL fall time F START condition hold time t ...
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Package mechanical data 6 Package mechanical data In order to meet environmental requirements, ST offers these devices in ECOPACK packages. These packages have a Lead-free second level interconnect. The category of second Level Interconnect is marked on the package and ...
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M41T66 Table 14. QFN16 – 16-lead, quad, flat package, no lead body size, mech. data Symb ddd Ch N Figure 18. QFN16 – 16-lead, quad, ...
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Package mechanical data Figure 19. 32 KHz crystal + QFN16 vs. VSOJ20 mechanical data 1. Dimensions shown are in millimeters (mm). 30/33 M41T66 ...
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M41T66 7 Part numbering Table 15. Ordering information scheme Example: Device family M41T Device type and supply voltage 1 4 Package Q = QFN16 ( mm) Temperature range 6 ...
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Revision history 8 Revision history Table 16. Document revision history Date 22-Oct-2008 32/33 Revision 1 Initial release M41T66 Changes ...
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... M41T66 Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any time, without notice. All ST products are sold pursuant to ST’s terms and conditions of sale. ...