The DS1287 and DS1187 are real-time clock (RTC) chips manufactured by Dallas Semiconductor (now part of Maxim Integrated). Below are their specifications, descriptions, and features:
DS1287 Specifications:
- Manufacturer: Dallas Semiconductor (Maxim Integrated)
- Type: Real-Time Clock (RTC) with Non-Volatile RAM
- Memory: 114 bytes of general-purpose RAM, 14 bytes of clock/control registers
- Timekeeping: Seconds, minutes, hours, day, date, month, year (with leap-year compensation)
- Power Supply:
- Operating Voltage: 4.5V to 5.5V
- Battery Backup Voltage: 3V to 5.5V (supports external battery backup)
- Interface: Parallel (Intel/Motorola bus-compatible)
- Accuracy: ±1 minute per month at 25°C
- Temperature Range: 0°C to 70°C
- Package: 24-pin DIP
DS1187 Specifications:
- Manufacturer: Dallas Semiconductor (Maxim Integrated)
- Type: Real-Time Clock (RTC) with Non-Volatile RAM
- Memory: 114 bytes of general-purpose RAM, 14 bytes of clock/control registers
- Timekeeping: Seconds, minutes, hours, day, date, month, year (with leap-year compensation)
- Power Supply:
- Operating Voltage: 4.5V to 5.5V
- Battery Backup Voltage: 3V to 5.5V (supports external battery backup)
- Interface: Parallel (Intel/Motorola bus-compatible)
- Accuracy: ±1 minute per month at 25°C
- Temperature Range: 0°C to 70°C
- Package: 24-pin DIP
Descriptions:
- The DS1287 and DS1187 are real-time clock (RTC) chips with integrated non-volatile RAM.
- They provide timekeeping functions (seconds, minutes, hours, day, date, month, year) with automatic leap-year compensation.
- Both include battery backup support to maintain timekeeping and RAM data during power loss.
- They are compatible with Intel and Motorola bus interfaces.
Features:
- Integrated RTC and RAM: Combines clock/calendar functions with non-volatile RAM storage.
- Battery Backup: Maintains timekeeping and RAM data during power failures.
- Leap-Year Compensation: Automatically adjusts for leap years until 2100.
- Programmable Square-Wave Output: Can generate a clock signal for external use.
- Bus Compatibility: Works with Intel (multiplexed) and Motorola (non-multiplexed) bus interfaces.
- Low Power Consumption: Efficient power usage in battery-backup mode.
These chips were commonly used in embedded systems, industrial controls, and computing applications requiring accurate timekeeping with data retention.