Details

---

BUY M48T129Y-70PM1 https://www.utsource.net/itm/p/12611660.html

Parameter	Description
Device Type	Real-Time Clock (RTC) with Integrated SRAM
Part Number	M48T129Y-70PM1
Package Type	SOIC-8
Operating Voltage	VCC = 2.0V to 5.5V
Temperature Range	-40掳C to +85掳C
Clock Accuracy	卤200ppm at 25掳C
RAM Size	128 bytes of battery-backed SRAM
Oscillator Type	External 32.768 kHz crystal
Supply Current	< 500nA (typical) in backup mode
Interface	Two-wire I2C compatible interface
Addressing Mode	7-bit I2C address
Backup Supply	Supports VBAT for continuous operation during main power loss
Power-On Reset	Automatic reset on power-up or brown-out condition

Instructions:

1. Power Connections: Connect VCC to the main power supply and VBAT to a backup power source such as a lithium coin cell.
2. Crystal Connection: Attach a 32.768 kHz crystal between the X1 and X2 pins for accurate timekeeping.
3. I2C Communication: Ensure proper pull-up resistors are used on the SDA and SCL lines for reliable communication.
4. Initialization: After powering up, initialize the device by writing to the control registers as specified in the datasheet.
5. Time Setting: Set the time and date registers using the I2C interface.
6. Data Storage: Use the SRAM addresses to store and retrieve data as needed.
7. Reading Time: Read the current time and date from the respective registers via the I2C interface.
8. Battery Management: Ensure VBAT is always connected to maintain real-time data when VCC is not present.

(For reference only)