OCTAL SMBus SERIAL-PARALLEL I/O EXPANDER
SUNNYVALE, CA—February 10, 2000—Maxim Integrated Products introduces the MAX1608/MAX1609 input/output (I/O) expanders, designed to provide remote I/O expansion via an SMBus serial interface. Each device has eight high-voltage open-drain outputs that also serve as TTL-compatible logic inputs, enabling bidirectional capability. Typical applications include high-side MOSFET load-switch drivers in power-management systems, pushbutton switch monitors, and general purpose I/Os.
The eight I/Os are continuously monitored and can be used as inputs. Two internal 8-bit latches allow the outputs to be toggled between two states using the SMBus suspend input without the inherent latency of reprogramming the inputs and outputs over the serial bus.
The MAX1608's outputs, intended for driving N-channel MOSFETs, are low at power-up. The MAX1609’s outputs, intended for driving P-channel MOSFETs, are in the high-impedance state at power-up. These conditions enable power-plane sequencing by ensuring that the MOSFETs are off at power-up.
Other features include thermal-overload and output overcurrent protection, a wide +2.7V to +5.5V input supply range, and ultra-low supply current. An evaluation kit (MAX1608EVKIT) is available to speed the design cycle. The MAX1608/MAX1609 come in space-saving 16-pin QSOP packages, priced from $2.61 (1000-up, FOB USA).
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