M48T129Y-70PM1: Top Choice in United States (USA) Utsource Holding Company Limited

Description

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°C to +85°C
Clock Accuracy	±200ppm at 25°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

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

(For reference only)