M41T94MH6F STMicroelectronics, M41T94MH6F Datasheet
M41T94MH6F
Specifications of M41T94MH6F
M41T94MH6F
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M41T94MH6F Summary of contents
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Serial real-time clock with 44 bytes NVRAM and reset Features ■ Counters for tenths/hundredths of seconds, seconds, minutes, hours, day, date, month, year, and century ■ 32 KHz crystal oscillator integrating load capacitance (12.5 pF) providing exceptional oscillator stability and ...
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Contents Contents 1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...
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M41T94 8 Part numbering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...
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List of figures List of figures Figure 1. Logic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...
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M41T94 List of tables Table 1. Signal names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...
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Description 1 Description The M41T94 is a serial real-time clock with 44 bytes of NVRAM and a RESET output. A built-in 32,768 Hz oscillator (external crystal controlled) and 8 bytes of the SRAM (see Table 4 on page 18) are ...
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M41T94 Figure 1. Logic diagram 1. For SO16 package only. Figure 2. 16-pin SOIC connections ( BAT (1) XI (1) XO SCL SDI M41T94 E RSTIN1 RSTIN2 WDI THS ...
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Description Table 1. Signal names E IRQ/FT/OUT RST RSTIN1 RSTIN2 SCL SDI SDO SQW THS WDI (1) XI (1) XO (1) V BAT For SO16 package only. Figure 3. 28-pin SOIC connections 8/41 Chip enable ...
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M41T94 Figure 4. Block diagram E SDO SDI INTERFACE SCL 32KHz Crystal OSCILLATOR WDI BAT RSTIN1 RSTIN2 1. Open drain output Figure 5. Hardware hookup SPI Interface with (CPOL, CPHA) (1) = ('0','0') or ('1','1') Master (ST6, ...
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Description Table 2. Function table Mode Disable reset WRITE READ 1. SDO remains at High Z until eight bits of data are ready to be shifted out during a READ. Figure 6. Data and clock timing CPOL CPHA 0 0 ...
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M41T94 2 Signal description 2.1 Serial data output (SDO) The output pin is used to transfer data serially out of the memory. Data is shifted out on the falling edge of the serial clock. 2.2 Serial data input (SDI) The ...
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Operation 3 Operation The M41T94 clock operates as a slave device on the SPI serial bus. Each memory device is accessed by a simple serial interface that is SPI bus compatible. The bus signals are SCL, SDI and SDO (see ...
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M41T94 3.1 SPI bus characteristics The serial peripheral interface (SPI) bus is intended for synchronous communication between different ICs. It consists of four signal lines: serial data input (SDI), serial data output (SDO), serial clock (SCL) and a chip enable ...
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Operation Figure 8. Output timing requirements E SCL tCLQV tCLQX MSB OUT SDO ADDR. LSB IN SDI Table 3. AC characteristics Symbol f Serial clock input frequency SCL (2) t Clock high CH (3) t Clock transition (fall time) CHCL ...
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M41T94 3.2 Read and write cycles Address and data are shifted MSB first into the serial data input (SDI) and out of the serial data output (SDO). Any data transfer considers the first bit to define whether a READ or ...
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Operation Figure 9. Read mode sequence SCL W/R BIT 7 BIT ADDRESS SDI MSB SDO HIGH IMPEDANCE Figure 10. Write mode sequence SCL 7 BIT ADDR W/R ...
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M41T94 4 Clock operations The eight byte clock register (see read the date and time from the clock binary coded decimal format. Tenths/hundredths of seconds, seconds, minutes, and hours are contained within the first four registers. Bits D6 ...
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Clock operations Table 4. Clock register map Addr D7 00h 01h ST 02h 0 03h CEB 04h TR 05h 0 06h 0 07h 08h OUT 09h WDS BMB4 BMB3 0Ah AFE SQWE 0Bh RPT4 RPT5 0Ch RPT3 0Dh RPT2 0Eh ...
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M41T94 4.3 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, day, ...
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Clock operations Figure 12. Backup mode alarm waveforms PFD V SO ABE, AFE Bits in Interrupt Register AF bit in Flags Register IRQ/FT/OUT 20/41 HIGH-Z M41T94 tREC HIGH-Z AI03920 ...
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M41T94 4.4 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 operations Table 6. Square wave output frequency RS3 4.6 Power-on reset The M41T94 continuously monitors V the RST pulls low (open drain) and ...
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M41T94 Figure 13. RSTIN1 and RSTIN2 timing waveforms RSTIN1 RSTIN2 (1) RST Table 7. Reset AC characteristics Symbol (2) t RLRH1 (3) t RLRH2 (4) t R1HRH (4) t R2HRH 1. Valid for ambient operating temperature Pulse width ...
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Clock operations Therefore, each calibration step has the effect of adding 512 or subtracting 256 oscillator cycles for every 125,829,120 actual oscillator cycles, that is +4.068 or –2.034 ppm of adjustment per calibration step in the calibration register. Assuming that ...
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M41T94 Figure 14. Crystal accuracy across temperature Frequency (ppm –20 –40 –60 –80 –100 –120 –140 –160 –40 –30 Figure 15. Calibration waveform NORMAL POSITIVE CALIBRATION NEGATIVE CALIBRATION 4.9 Century bit Bits D7 and D6 of clock register ...
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Clock operations 4.10 Output driver pin When the FT bit, AFE bit and watchdog register are not set, the IRQ/FT/OUT pin becomes an output driver that reflects the contents the control register. In other words, when D7 ...
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M41T94 4.13 Initial power-on defaults Upon initial application of power to the device, the following register bits are set to a '0' state: Watchdog register, TR, FT, AFE, ABE, and SQWE. The following bits are set to a '1' state: ...
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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 10. ...
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M41T94 6 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 from tests performed ...
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... RF generating signals should be taken into account. These characteristics are externally supplied. 2. STMicroelectronics recommends the KDS DT-38: 1TA/1TC252E127, Tuning Fork Type (thru-hole) or the DMX-26S: 1TJS125FH2A212, (SMD) quartz crystal for industrial temperature operations. For contact information on this crystal type, ...
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M41T94 Figure 17. Power down/up mode AC waveforms PFD (max) V PFD (min INPUTS RST OUTPUTS (PER CONTROL INPUT) Table 15. Power down/up AC characteristics Symbol ( PFD ( ...
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Package mechanical data 7 Package mechanical data In order to meet environmental requirements, ST offers these devices in different grades of ® ECOPACK packages, depending on their level of environmental compliance. ECOPACK specifications, grade definitions and product status are available ...
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M41T94 Figure 18. SO16 – 16-lead plastic small outline package outline Note: Drawing is not to scale. Table 16. SO16 – 16-lead plastic small outline package mechanical data Symbol ...
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Package mechanical data Figure 19. SOH28 – 28-lead plastic small outline, battery SNAPHAT outline Note: Drawing is not to scale. Table 17. SOH28 – 28-lead plastic small outline, battery SNAPHAT mechanical data Symbol ...
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M41T94 Figure 20. SH – 4-pin SNAPHAT outline Note: Drawing is not to scale. Table 18. SH – 4-pin SNAPHAT mechanical data Symbol ® housing for 48 mAh battery & ...
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Package mechanical data Figure 21. SH – 4-pin SNAPHAT outline Note: Drawing is not to scale. Table 19. SH – 4-pin SNAPHAT mech. data Symbol 36/41 ® housing for 120 ...
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M41T94 8 Part numbering Table 20. Ordering information scheme Example: Device type M41T Supply voltage and write protect voltage 2 THS = THS = V ; 2.55 ...
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Environmental information 9 Environmental information Figure 22. Recycling symbols This product contains a non-rechargeable lithium (lithium carbon monofluoride chemistry) button cell battery fully encapsulated in the final product. Recycle or dispose of batteries in accordance with the battery manufacturer's instructions ...
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M41T94 10 References The crystal supplier KDS as cited in supplied) on page 30 Table 14: Crystal electrical characteristics (externally can be contacted at kouhou@kdsj.co.jp or http://xxx.kdsj.co.jp. References 39/41 ...
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Revision history 11 Revision history Table 22. Document revision history Date Revision Apr-2002 25-Apr-2002 03-Jul-2002 06-Nov-2002 26-Mar-2003 28-Apr-2003 15-Jun-2004 29-Aug-2006 09-Nov-2007 13-Jan-2009 40/41 1 First edition Adjust graphic (Figure 4 on page 1.1 Table 20 on page 37); adjust characteristics ...
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... M41T94 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. ...