The MAX7391 replaces ceramic resonators, crystals,
and supervisory functions for microcontrollers in 3.3V
and 5V applications.
The MAX7391 provides a clock source, reset, and
power-fail functions. The programmable power-fail function
provides early warning of power failure and is configurable
to detect either an external voltage or the VCC
supply to the device.
The clock output can be switched between normal and
half-speed operation. This functionality allows the microcontroller
to operate at reduced power and may be
used to extend the time available to perform housekeeping
tasks, such as writing data to flash during a
power failure. Connecting the power-fail output to the
SPEED input reduces clock speed automatically during
power-fail events.
The MAX7391 clock output is 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 (typ) with a clock frequency of 12MHz.
Unlike typical crystal and ceramic resonator oscillator
circuits, the MAX7391 is resistant to EMI and vibration,
and operates 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 MAX7391 is available in an 8-pin µMAX® package.
The MAX7391 standard operating temperature range is from -40°C to +125°C.
Applications
- Appliances and Controls
- Handheld Products
- Microcontroller Systems
- Portable Equipment
- White Goods
