System Monitoring Oscillator with Watchdog and Power Fail

The MAX7387/MAX7388 provide a clock source together with integrated reset, watchdog, and power-fail functions. The watchdog timer is pin programmable and provides watchdog timeout values in the 16ms to 2048ms range. The power-fail output provides early warning of power failure. The power-fail threshold on the MAX7388 is internally set. The MAX7387 also provides a separate watchdog output that is used as a status indicator or to control safety-critical system elements.

The MAX7387/MAX7388 clock outputs are factory programmed to a frequency in the 1MHz to 16MHz range. Four standard frequencies are available. Other frequencies are available upon request. The maximum operating supply current is 5.5mA (max) with a clock frequency of 12MHz.

Unlike typical crystal and ceramic resonator oscillator circuits, the MAX7387/MAX7388 are resistant to EMI, vibration, and operate reliably at high temperatures. The high-output drive current and absence of high-impedance nodes make the oscillator invulnerable to dirty or humid operating conditions.

The MAX7387/MAX7388 are available in 10-pin and 8-pin µMAX® packages. The MAX7387/MAX7388 standard operating temperature range is from -40°C to +125°C.