GENERAL DESCRIPTION

The DS1677 portable system controller is a circuit that incorporates many of the functions necessary for low-power portable products integrated into one chip. The device provides a real-time clock (RTC), NV RAM controller, microprocessor monitor, power-fail warning, and a 3-channel, 8-bit analog-to-digital converter (ADC). Communication with the DS1677 is established through a simple 3-wire interface.

FEATURES

■ Provides Real-Time Clock

Counts Seconds, Minutes, Hours, Date of the Month, Month, Day of the Week, and Year with Leap Year Compensation Valid Up to 2100

Power Control Circuitry Supports System Power-On from Day/Time Alarm

■ Microprocessor Monitor

Halts Microprocessor During Power-Fail

Automatically Restarts Microprocessor After Power Failure

Monitors Pushbutton for External Override

Halts and Resets an Out-of-Control Microprocessor

■ NV RAM Control

Automatic Battery Backup and Write Protection to External SRAM

■ 3-Channel, 8-Bit ADC

■ Simple 3-Wire Interface

■ +5.0V Operation

■ 1.25V Threshold Detector for Power-Fail Warning

■ UL Recognized