SERIAL I/O CALENDAR & CLOCK CMOS LSI The UPD4990AG is a real-time clock (RTC) IC manufactured by NEC (now part of Renesas Electronics). Below are its key specifications, descriptions, and features:
### **Manufacturer:** NEC (Renesas Electronics)
### **Part Number:** UPD4990AG
### **Description:**
The UPD4990AG is a CMOS real-time clock (RTC) IC designed for timekeeping applications. It includes a built-in calendar function and supports serial data transfer for interfacing with microcontrollers or other digital systems.
### **Key Features:**
- **Timekeeping Functions:**
- Seconds, minutes, hours, day, month, year, and day of the week.
- Leap year compensation (up to 2099).
- **Serial Interface:**
- 3-wire serial communication (data input, data output, and clock).
- **Low Power Consumption:**
- CMOS technology ensures low power operation.
- **Operating Voltage:**
- Typically **2.7V to 5.5V**, making it suitable for battery-backed applications.
- **Oscillator:**
- Built-in oscillator circuit (requires an external 32.768 kHz crystal).
- **Alarm Function:**
- Programmable alarm with interrupt output.
- **Temperature Compensation:**
- Some variants may include temperature compensation for improved accuracy.
- **Package Type:**
- Available in **DIP (Dual In-line Package)** or **SOP (Small Outline Package)**.
### **Applications:**
- Embedded systems requiring accurate timekeeping.
- Consumer electronics (e.g., digital clocks, appliances).
- Industrial automation and data logging systems.
This information is based on the manufacturer's datasheet and technical documentation. For detailed electrical characteristics and timing diagrams, refer to the official NEC/Renesas datasheet.
