M41ST85WMX6 STMicroelectronics, M41ST85WMX6 Datasheet - Page 5

• Manufacturer Part Number: M41ST85WMX6
• Description: IC RTC 3.0V NVRAM 28SOIC
• Manufacturer: STMicroelectronics
• Type: Clock/Calendar/Supervisorr

Specifications of M41ST85WMX6

• Memory Size: 64B
• Time Format: HH:MM:SS:hh (24 hr)
• Date Format: YY-MM-DD-dd
• Interface: I²C, 2-Wire Serial
• Voltage - Supply: 2.7 V ~ 3.6 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 28-SOIC, 28-SOH (8.48mm Width)
• Function: Clock/Calendar/Supervisor/Alarm
• Rtc Memory Size: 64 Byte
• Supply Voltage (max): 3.6 V
• Supply Voltage (min): 2.7 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Rtc Bus Interface: Serial (2-Wire, I2C)
• Memory Configuration: 64 X 8
• Nvram Features: RTC, Internal Battery, XTAL
• Interface Type: I2C, Serial, 2-Wire
• Supply Voltage Range: 2.7V To 3.6V
• Memory Case Style: SO
• No. Of Pins: 28
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-2805-5

M41ST85W
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Logic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
28-pin SOIC connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
28-pin, 300 mil SOIC (MX) connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Hardware hookup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Serial bus data transfer sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Acknowledgement sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Write cycle timing: RTC & external SRAM control signals . . . . . . . . . . . . . . . . . . . . . . . . . 14
Slave address location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Read mode sequence. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Alternate read mode sequence. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Write mode sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Crystal accuracy across temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Calibration waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Alarm interrupt reset waveform. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Backup mode alarm waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
RSTIN1 & RSTIN2 timing waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
AC testing input/output waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Bus timing requirements sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Power down/up mode AC waveforms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
SOH28 – 28-lead plastic small outline, battery SNAPHAT
SH – 4-pin SNAPHAT
SH – 4-pin SNAPHAT
SOX28 – 28-lead plastic small outline, 300 mils, embedded crystal, package outline . . . . 37
Recycling symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
®
®
housing for 48 mAh battery & crystal, package outline. . . . . . . . . 35
housing for 120 mAh battery & crystal, package outline. . . . . . . . 36
®
, package outline . . . . . . . . . . 34
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