m48t35ay STMicroelectronics, m48t35ay Datasheet
m48t35ay
Available stocks
Related parts for m48t35ay
m48t35ay Summary of contents
Page 1
... The monolithic chip is available in two spe- cial packages to provide a highly integrated bat- tery backed-up memory and real time clock solution. The M48T35AY/35AV is a non-volatile pin and function equivalent to any JEDEC standard 32Kb x8 SRAM. It also easily fits into many ROM, EPROM, and EEPROM sockets, providing the ...
Page 2
... V Ground SS The 28 pin 600mil DIP CAPHAT™ houses the M48T35AY/35AV silicon with a quartz crystal and a long life lithium button cell in a single package. The 28 pin 330mil SOIC provides sockets with gold plated contacts at both ends for direct con- nection to a separate SNAPHAT housing contain- ing the battery and crystal ...
Page 3
... The eight clock bytes are not the actual clock counters themselves; they are memory locations consisting of BiPORT™ read/write memory cells. The M48T35AY/35AV includes a clock control cir- cuit which updates the clock bytes with current in- formation once per second. The information can be accessed by the user in the same manner as any other location in the static memory array ...
Page 4
... AXQX Address Access. WRITE MODE The M48T35AY/35AV is in the Write Mode when- ever W and E are low. The start of a write is refer- enced from the latter occurring falling edge write is terminated by the earlier rising edge ...
Page 5
... CC SO switches power to the internal battery which pre- serves data and powers the clock. The internal button cell will maintain data in the M48T35AY/ 35AV for an accumulated period of at least 7 years when V is less than system power re- ...
Page 6
... M48T35AY, M48T35AV (1, 2) Table 5. Capacitance (T = 25° Symbol Parameter C Input Capacitance IN (3) Input / Output Capacitance C IO Note: 1. Effective capacitance measured with power supply at 5V. 2. Sampled only, not 100% tested. 3. Outputs deselected. Table 6A. DC Characteristics ( ° – ° ...
Page 7
... Fall Time CC M48T35AY Fall Time M48T35AV Rise Time CC Rise Time may result in deselection/write protection not occurring until 200µs after V F may cause corruption of RAM data. FB tFB tDR DON'T CARE HIGH-Z M48T35AY, M48T35AV Typ Max Unit 4.35 4.5 V 2.9 3 –100mV V PFD YEARS YEARS = 7 years (typ) ...
Page 8
... M48T35AY, M48T35AV Table 9. Read Mode AC Characteristics ( ° – ° Symbol Parameter t Read Cycle Time AVAV (1) Address Valid to Output Valid t AVQV (1) Chip Enable Low to Output Valid t ELQV (1) Output Enable Low to Output Valid t GLQV (2) Chip Enable Low to Output Transition ...
Page 9
... The STOP bit is the MSB of the seconds register. Setting '1' stops the oscillator. The M48T35AY/35AV is shipped from STMicroelectronics with the STOP bit set to a '1'. When reset to a '0', the M48T35AY/ 35AV oscillator starts within 1 second. M48T35AY, M48T35AV M48T35AV ...
Page 10
... M48T35AY, M48T35AV Figure 7. Write Enable Controlled, Write AC Waveform A0-A14 E W DQ0-DQ7 Figure 8. Chip Enable Controlled, Write AC Waveforms A0-A14 tAVEL E W DQ0-DQ7 10/19 tAVAV VALID tAVWH tAVEL tWLWH tAVWL tWLQZ tWHDX DATA INPUT tDVWH tAVAV VALID tAVEH tELEH tAVWL DATA INPUT tDVEH tWHAX ...
Page 11
... Calibrating the Clock The M48T35AY/35AV is driven by a quartz con- trolled oscillator with a nominal frequency of 32,768Hz. The devices are tested not to exceed 35 ppm (parts per million) oscillator frequency er- ror at 25°C, which equates to about ±1.53 minutes per month. With the calibration bits properly set, the accuracy of each M48T35AY/35AV improves to better than ± ...
Page 12
... M48T35AY, M48T35AV Table 11. Register Map Address 7FFFh 10 Years 7FFEh 7FFDh 0 0 7FFCh 0 FT CEB 7FFBh Hours 7FFAh 0 10 Minutes 7FF9h ST 10 Seconds 7FF8h Keys SIGN Bit FT = FREQUENCY TEST Bit (Must be set to ‘0’ upon power for normal operation) ...
Page 13
... MBRS120T3 is recommended for surface mount -0.038 ppm 10 Figure 12. Supply Voltage Protection bus. The energy (cathode SS ). Schottky diode M48T35AY, M48T35AV AI02124 V CC 0.1 F DEVICE V SS AI02169 13/19 ...
Page 14
... M48T35AY, M48T35AV Table 12. Ordering Information Scheme Example: Device Type M48T Supply Voltage and Write Protect Voltage 35AY = V = 4.5V to 5.5V 4.2V to 4.5V CC PFD 35AV = V = 3.0V to 3.6V 2.7V to 3.0V CC PFD Speed -70 = 70ns (35AY) -10 = 100ns (35AV) Package PC = PCDIP28 ( SOH28 Temperature Range °C ( – ° C ...
Page 15
... Drawing is not to scale. mm Min Max Typ 8.89 9.65 0.38 0.76 8.38 8.89 0.38 0.53 1.14 1.78 0.20 0.31 39.37 39.88 17.83 18.34 2.29 2.79 29.72 36.32 15.24 16.00 3.05 3. M48T35AY, M48T35AV inches Min Max 0.350 0.380 0.015 0.030 0.330 0.350 0.015 0.021 0.045 0.070 0.008 0.012 1.550 1.570 0.702 0.722 0.090 0.110 1.170 1.430 0.600 0.630 0.120 0.150 PCDIP 15/19 ...
Page 16
... M48T35AY, M48T35AV Table 15. SOH28 - 28 lead Plastic Small Outline, 4-socket battery SNAPHAT, Package Mechanical Data Symb Typ 1. Figure 14. SOH28 - 28 lead Plastic Small Outline, 4-socket battery SNAPHAT, Package Outline SOH-A Drawing is not to scale. 16/19 mm Min Max Typ 3 ...
Page 17
... Figure 15. M4T28-BR12SH SNAPHAT Housing for 48 mAh Battery & Crystal, Package Outline Drawing is not to scale. mm Min Max Typ 9.78 6.73 7.24 6.48 6.99 0.38 0.46 0.56 21.21 21.84 14.22 14.99 3.20 3.61 2.03 2. M48T35AY, M48T35AV inches Min Max 0.385 0.265 0.285 0.255 0.275 0.015 0.018 0.022 0.835 0.860 0.560 0.590 0.126 0.142 0.080 0.090 SHTK-A 17/19 ...
Page 18
... M48T35AY, M48T35AV Table 17. M4T32-BR12SH SNAPHAT Housing for 120 mAh Battery & Crystal, Package Mechanical Data Symb Typ Figure 16. M4T32-BR12SH SNAPHAT Housing for 120 mAh Battery & Crystal, Package Outline Drawing is not to scale. 18/19 mm Min Max Typ 10.54 8.00 8.51 7.24 8.00 0.38 0.46 0.56 21.21 21.84 17.27 18.03 3.20 3.61 2.03 2. ...
Page 19
... All other names are the property of their respective owners. Australia - Brazil - China - Finland - France - Germany - Hong Kong - India - Italy - Japan - Malaysia - Malta - Morocco - Singapore - Spain - Sweden - Switzerland - United Kingdom - U.S.A. 2000 STMicroelectronics - All Rights Reserved STMicroelectronics GROUP OF COMPANIES http://www.st.com M48T35AY, M48T35AV 19/19 ...