M41ST85WMX6TR
Real Time Clock (RTC) IC Clock/Calendar 44B I2C, 2-Wire Serial 28-SOIC (0.295", 7.50mm Width)
Brands: STMicroelectronics
Mfr.Part #: M41ST85WMX6TR
Datasheet: M41ST85WMX6TR Datasheet (PDF)
Package/Case: 28-SOIC(0.295",7.50mmWidth)
RoHS Status:
Stock Condition: 8866 pcs, New Original
Warranty: 1 Year Ovaga Warranty - Find Out More
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Add To BomM41ST85WMX6TR General Description
The M41ST85W is a combination serial real-time clock, microprocessor supervisor, and NVRAM supervisor. It is built in a low-power CMOS SRAM process and has a 64-byte memory space with 44 bytes of NVRAM and 20 memory-mapped RTC registers. The RTC registers are configured in binary coded decimal (BCD) format.The M41ST85W combines a 400 kHz I2C serial RTC with an automatic backup battery switchover circuit for powering an external LPSRAM as well as the internal RTC. When power begins to fail, the switchover automatically connects to the backup battery to keep the RTC and external LPSRAM alive in the absence of system power. Access to the LPSRAM is also cut off via a chip-enable gate function, thereby write-protecting the memory. A programmable watchdog and power-on reset/low voltage detect function are the key elements in the microprocessor supervisor section.The real-time clock includes a built-in 32.768 kHz oscillator (crystal-controlled), which provides the time base for the timekeeping and calendar functions. Eight of the 20 clock registers provide the basic clock/calendar functions while the other 12 bytes provide status/control for the alarm, watchdog, and squarewave functions.RTC addresses and data are transferred serially via the two-line, bidirectional I2C interface. The built-in address register is incremented automatically after each WRITE or READ data byte.The M41ST85W has a built-in power sense circuit which detects power failures and automatically switches to the backup battery when a power failure occurs. During an outage, the power to sustain the SRAM and clock operations is typically supplied by a small lithium button-cell battery as is the case when using the SNAPHAT®package option.Functions available to the user include a non-volatile, time-of-day clock/calendar, alarm interrupts, watchdog timer, and programmable squarewave generator. Other features include a power-on reset as well as two additional debounce reset inputs (RSTIN1andRSTIN2) which can also generate an output reset (RST).The eight registers for basic clock/calendar functions contain the century, year, month, date, day, hour, minute, second, and tenths/hundredths of a second in 24-hour BCD format. Corrections for 28, 29 (leap year - valid until year 2100), 30 and 31 day months are made automatically.The M41ST85W is offered in two 28-lead SOIC packages. The 300 mil SOH28 SNAPHAT®IC package mates with ST’s SNAPHAT battery/crystal top (ordered separately). SNAPHAT battery options include 48 mAh and 120 mAh. ST’s 300 mil SOX28 embedded crystal IC includes the 32 KHz crystal and is perfect for applications where a low profile is a must.The SOH28 SNAPHAT SOIC includes sockets with gold plated contacts at both ends for direct connection to the SNAPHAT top. The SNAPHAT battery/crystal top is inserted atop the IC package after the completion of the surface mount assembly process which avoids potential battery and crystal damage due to the high temperatures required for device surface-mounting. The unique design allows the battery to be replaced, thus extending the life of the RTC and NVRAM indefinitely.The SNAPHAT top is keyed to prevent reverse insertion. The SNAPHAT IC and SNAPHAT tops are shipped separately. The ICs are available in plastic anti-static tubes or in tape & reel form. The SNAPHAT tops are shipped in plastic anti-static tubes. The part numbers are M4T28-BR12SH1 (48 mAh) and M4T32-BR12SH1 (120 mAh). For the extended temperature requirement, the 120 mAh M4T32-BR12SH6 is available.
Features
- Automatic battery switchover and WRITE protect for:
- Internal serial RTC and
- External low power SRAM (LPSRAM)
- 400 kHz I2C serial interface
- 3.0/3.3 V operating voltage
- VCC= 2.7 to 3.6 V
- Ultralow battery supply current of 500 nA (max)
- RoHS compliant
- Lead-free second level interconnect
- Serial RTC features
- 400 kHz I2C
- 44 bytes of general purpose NVRAM
- Counters for:
- Seconds, minutes, hours, day, date, month, and year
- Century
- Tenths/hundredths of seconds
- Clock calibration register allows compensation for crystal variations over temperature
- Programmable alarm with repeat modes
- Functions in battery back-up mode
- Power-down timestamp (HT bit)
- 2.5 to 5.5 V oscillator operating voltage
- Microprocessor supervisor features
- Programmable watchdog
- 62.5 ms to 128 s time-out period
- Early power-fail warning circuit (PFI/PFO) with 1.25 V precision reference
- Power-on reset/low voltage detect
- Open drain reset output
- Reset voltage, VPFD= 2.60 V (nom)
- Two reset input pins
- Watchdog can be steered to reset output
- Programmable watchdog
- NVRAM supervisor features
- Non-volatizes external LPSRAM
- Automatically switches to back-up battery and deselects (write-protects) external LPSRAM via chip-enable gate
- Power-fail deselect (write protect) voltage, VPFD= 2.60 V (nom)
- Switchover, VSO= 2.50 V (nom)
- Battery monitor (battery low flag)
- Non-volatizes external LPSRAM
- Other features
- Programmable squarewave generator (1 Hz to 32 KHz)
- –40°C to +85°C operation
- Package options:
- 28-lead SNAPHAT®IC (SOH28) SNAPHAT battery/crystal top to be ordered separately
- 28-lead
Specifications
Parameter | Value | Parameter | Value |
---|---|---|---|
Product Status | Active | Programmabe | Not Verified |
Type | Clock/Calendar | Features | Alarm, Leap Year, NVSRAM, Square Wave Output, Supervisor, Watchdog Timer |
Memory Size | 44B | Time Format | HH:MM:SS:hh (24 hr) |
Date Format | YY-MM-DD-dd | Interface | I2C, 2-Wire Serial |
Voltage - Supply | 2.7V ~ 3.6V | Voltage - Supply, Battery | 2.5V ~ 3.5V |
Current - Timekeeping (Max) | 0.5mA @ 2.7V ~ 3.6V | Operating Temperature | -40°C ~ 85°C |
Mounting Type | Surface Mount | Package / Case | 28-SOIC (0.295", 7.50mm Width) |
Supplier Device Package | 28-SO |
Shipping
Shipping Type | Ship Fee | Lead Time | |
---|---|---|---|
DHL | $20.00-$40.00 (0.50 KG) | 2-5 days | |
Fedex | $20.00-$40.00 (0.50 KG) | 2-5 days | |
UPS | $20.00-$40.00 (0.50 KG) | 2-5 days | |
TNT | $20.00-$40.00 (0.50 KG) | 2-5 days | |
EMS | $20.00-$40.00 (0.50 KG) | 2-5 days | |
REGISTERED AIR MAIL | $20.00-$40.00 (0.50 KG) | 2-5 days |
Processing Time:Shipping fee depend on different zone and country.
Payment
Terms of payment | Hand Fee | |
---|---|---|
Wire Transfer | charge US$30.00 banking fee. | |
Paypal | charge 4.0% service fee. | |
Credit Card | charge 3.5% service fee. | |
Western Union | charge US.00 banking fee. | |
Money Gram | charge US$0.00 banking fee. |
Guarantees
1.The electronic components you purchase include 365 Days Warranty, We guarantee product quality.
2.If some of the items you received aren't of perfect quality, we would resiponsibly arrange your refund or replacement. But the items must remain their orginal condition.
Packing
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Step5 :Packaging boxes
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All the products will packing in anti-staticbag. Ship with ESD antistatic protection.
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We will inspect all the goods before shipment,ensure all the products at good condition and ensure the parts are new originalmatch datasheet.
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