1 Features

• Automatic Switchover to Backup Supply
• I²C Interface Supports Serial Clock
  up to 400 kHz
• Uses 32.768-kHz Crystal With
  –63-ppm to +126-ppm Adjustment
• Integrated Oscillator-Fail Detection
• 8-Pin SOIC Package
• –40°C to +85°C Ambient Operating Temperature

2 Applications

General Consumer Electronics

3 Description

The BQ32002 device is a compatible replacement for industry standard real-time clocks.

The BQ32002 features an automatic backup supply that can be implemented using a capacitor or non-rechargeable battery. The BQ32002 has a programmable calibration adjustment from –63 ppm to +126 ppm. The BQ32002 registers include an OF (oscillator fail) flag indicating the status of the RTC oscillator, as well as a STOP bit that allows the host processor to disable the oscillator. The time registers are normally updated once per second, and all the registers are updated at the same time to prevent a timekeeping glitch. The BQ32002 includes automatic leap-year compensation.

1. For all available packages, see the orderable addendum at the end of the data sheet.

Application Circuit

NOTE:

All pullup resistors should be connected to V_CC such that no pullup is applied during backup supply operation.

Simplified Schematic