DS12C887+ - English Editing Encyclopedia Entry

Product Overview

Category: Integrated Circuit (IC)

Use: Real-Time Clock (RTC) with Non-Volatile RAM (NVRAM)

Characteristics: - Low-power CMOS technology - 12-hour or 24-hour format clock/calendar - Battery backup for continuous timekeeping - 114 bytes of non-volatile RAM - Programmable square wave output - Automatic power-fail detect and switch circuitry

Package: DIP (Dual In-line Package)

Essence: The DS12C887+ is a highly integrated real-time clock IC that combines a clock/calendar, non-volatile RAM, and various other features in a single package.

Packaging/Quantity: The DS12C887+ is typically available in a DIP package and is sold individually or in bulk quantities.

Specifications

• Supply Voltage: 4.5V to 5.5V
• Operating Temperature Range: -40°C to +85°C
• Clock Accuracy: ±2 minutes per month at 25°C
• Data Retention: >10 years
• Battery Backup Voltage: 2.0V to 5.5V

Detailed Pin Configuration

The DS12C887+ has a total of 24 pins, which are assigned specific functions. Here is the detailed pin configuration:

1. VCC - Power supply voltage
2. GND - Ground
3. X1 - Crystal oscillator input
4. X2 - Crystal oscillator output
5. RS0 - Register select bit 0
6. RS1 - Register select bit 1
7. I/O - Input/output data bus
8. R/W - Read/write control signal
9. A0 - Address bit 0
10. A1 - Address bit 1
11. A2 - Address bit 2
12. IRQ - Interrupt request output
13. SQW/OUT - Square wave output
14. VBAT - Battery backup voltage input
15. VCC - Power supply voltage
16. GND - Ground
17. NC - No connection
18. NC - No connection
19. NC - No connection
20. NC - No connection
21. NC - No connection
22. NC - No connection
23. NC - No connection
24. NC - No connection

Functional Features

1. Real-Time Clock: Provides accurate timekeeping in both 12-hour and 24-hour formats.
2. Non-Volatile RAM: Stores critical data even when the power is disconnected.
3. Battery Backup: Ensures continuous timekeeping during power outages.
4. Programmable Square Wave Output: Generates square wave signals with adjustable frequency.
5. Automatic Power-Fail Detect and Switch Circuitry: Allows seamless transition between main power and battery backup.

Advantages and Disadvantages

Advantages: - Highly integrated solution for real-time clock and non-volatile RAM requirements. - Low-power CMOS technology ensures efficient operation. - Battery backup provides uninterrupted timekeeping. - Programmable square wave output allows for various applications.

Disadvantages: - Limited non-volatile RAM capacity (114 bytes). - Requires an external crystal oscillator for clock operation.

Working Principles

The DS12C887+ utilizes a combination of internal registers, counters, and a crystal oscillator to accurately keep track of time. The crystal oscillator generates clock pulses, which are divided and processed by the internal circuitry to maintain the current time and date. The non-volatile RAM stores critical data, such as alarm settings and system configuration, ensuring their retention even during power loss.

Detailed Application Field Plans

The DS12C887+ finds applications in various fields, including:

1. Embedded Systems: Used in microcontroller-based systems to provide real-time clock functionality.
2. Industrial Automation: Enables accurate timekeeping and scheduling in industrial control systems.
3. Medical Devices: Utilized in medical equipment for time-sensitive operations and data logging.
4. Automotive Electronics: Integrated into automotive systems for timekeeping and event logging purposes.
5. Consumer Electronics: Found in devices like digital cameras, printers, and home appliances that require accurate timekeeping.

Detailed and Complete Alternative Models

1. DS1307 - Real-Time Clock IC with I2C interface
2. PCF8563 - Low-power Real-Time Clock IC with I2C-bus interface
3. MCP7940N - Real-Time Clock/Calendar with I2C interface and SRAM

These alternative models offer similar functionalities to the DS12C887+ and can be considered as alternatives based on specific requirements.

In conclusion, the DS12C887+ is a highly integrated real-time clock IC that combines timekeeping, non-volatile RAM, and other features in a single package. Its low-power CMOS technology, battery backup, and programmable