| Part Number | M41ST85WMX6TR | M41ST87WMX6TR | 
|---|---|---|
| Manufacturer | STMicroelectronics | STMicroelectronics | 
| Category | Clock/Timing - Real Time Clocks | Clock/Timing - Real Time Clocks | 
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| Product Status | Active | Active | 
| Type | Clock/Calendar | Clock/Calendar | 
| Features | Alarm, Leap Year, NVSRAM, Square Wave Output, Supervisor, Watchdog Timer | Alarm, Leap Year, NVSRAM, Square Wave Output, Supervisor, Watchdog Timer | 
| Memory Size | 44B | 128B | 
| Time Format | HH:MM:SS:hh (24 hr) | HH:MM:SS:hh (24 hr) | 
| Date Format | YY-MM-DD-dd | YY-MM-DD-dd | 
| Interface | I²C, 2-Wire Serial | I²C, 2-Wire Serial | 
| Voltage - Supply | 2.7V ~ 3.6V | 2.7V ~ 3.6V | 
| Voltage - Supply, Battery | 2.5V ~ 3.5V | 2.5V ~ 3.6V | 
| Current - Timekeeping (Max) | 0.5mA @ 2.7V ~ 3.6V | 0.5mA @ 2.7V ~ 3.6V | 
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C | 
| Mounting Type | Surface Mount | Surface Mount | 
| Package / Case | 28-SOIC (0.295", 7.50mm Width) | 28-SOIC (0.295", 7.50mm Width) | 
| Supplier Device Package | 28-SO | 28-SO |