DS1302 Trickle-Charge Timekeeping Chip DIP-8 (DS1302 IC)
The DS1302 DIP IC is a popular, low-power real-time clock (RTC) chip designed to provide accurate timekeeping for electronic systems. Housed in a compact 8-pin DIP package, it tracks seconds, minutes, hours, date, month, day of the week, and year, with automatic leap-year compensation valid up to the year 2100. A standout feature of this IC is its integrated trickle charger, which can maintain a backup rechargeable battery or supercapacitor, ensuring time and data are preserved even when the primary power source is removed.
This IC is widely utilized in telephones, fax machines, and portable battery-powered instruments. It is an exceptionally common choice for Arduino and robotics projects in India for building digital clocks, attendance systems, and data loggers that require a simple 3-wire serial interface and minimal power consumption (less than 1 microwatt).
Key Features
- Complete Timekeeping: Tracks seconds through years with leap-year adjustment.
- Nonvolatile RAM: Includes 31 bytes of battery-backed static RAM for user data storage.
- Dual Power Pins: Dedicated inputs for primary and backup power supplies with intelligent switching.
- Trickle Charging: Programmable charging capability for backup energy sources.
- Low Power: Consumes less than 300nA at 2.0V, extending battery life significantly.
- Simple Interface: Uses only three wires (CE, I/O, SCLK) for communication with microcontrollers.
- Burst Mode: Supports multiple-byte data transfers for faster read/write operations.
Specifications
- IC Type: Real-Time Clock (RTC) / Calendar
- Operating Voltage: 2.0V to 5.5V
- RAM Capacity: 31 x 8 bits (Static RAM)
- Oscillator Frequency: 32.768 kHz (External crystal required)
- Clock Formats: 12-hour (with AM/PM) or 24-hour
- Interface: 3-wire Serial (TTL compatible at 5V)
- Package Type: PDIP-8
- Mounting Type: Through-Hole
- Operating Temperature: 0 to 70 degrees Celsius
Interfaces
- Pin 1 (VCC2): Primary Power Supply Input
- Pin 2 (X1): 32.768 kHz Crystal Oscillator Input
- Pin 3 (X2): 32.768 kHz Crystal Oscillator Output
- Pin 4 (GND): Ground
- Pin 5 (CE): Chip Enable (Must be HIGH for communication)
- Pin 6 (I/O): Bidirectional Data Line
- Pin 7 (SCLK): Serial Clock Input
- Pin 8 (VCC1): Backup Power Source / Trickle Charge Output
