Dallas Semiconductor/Maxim brings the memory shopping mall to you. With a 2-kbit (256 by 8) EEPROM, 12 user-programmable I/O channels, a
real-time clock/calendar/alarm, CPU reset
monitor, 64-bit factory-programmed ROM ID, battery monitor, and watchdog timer, the DS28DG02 () offers one-stop shopping.
The I/O channels may be configured as inputs, outputs, open drains, or push-pulls. The EEPROM registers allow the I/Os to power up in a defined state. If your system includes a battery backup, the DS28DG02 "actively" monitors the "health" of the battery by applying a 10-µA (typical) test load with a 1-second duration to the
battery each hour. It then follows with a programmable battery
terminal voltage comparison to a programmable test point. An
interrupt output is generated if the terminal voltage is below the
programmed threshold.
The voltage monitor is factory-programmed to generate a 328-ms
(typical) reset at 3.3 V, with a 2.5% accuracy threshold over the operating range. The monitor's reset output can also be
used as a pushbutton I/O with debounce. The watchdog is user-programmable with timeout options
ranging from 0.2 to 1.64 s (typical).
Since the device replaces four or
more discrete ICs, Dallas Semiconductor estimates it will typically
save around 20% printed-circuit-board (PCB) space and reduce bill of materials costs by about 30%. If
you consider the overall hardware design
aspects of a discrete implementation, typical
complications include multidevice bus interfacing,
power-supply bypass filtering, and increased PCB layout
effort. Communications with the device are performed via
the serial peripheral interface (SPI).
All this can be yours for only $1.81 in quantities of 1000. The
device is available in a small thin-shrink small-outline package
(TSSOP) or quad flat no-lead (QFN) package.
Dallas Semiconductor
www.maxim-ic.com/Memory-IC