MAX1608

19-1639; Rev 0; 1/00 Octal SMBus-to-Parallel I/O Expanders General Description The MAX1608/MAX1609 provide remote input/output (I/O) expansion through an SMBus™ 2-wire serial interface. Each device has eight high-voltage open-drain outputs that double as TTL-level logic inputs, providing continuous bidirectional capabilities. The open-drain outputs tailor the MAX1608/MAX1609 for use in load-switching and other level-shifting applications as well as general-purpose I/O applications. Two complete sets of registers allow the device and its outputs to be toggled between two states using the SMBSUS input, without the inherent latency of reprogramming outputs over the serial bus. The eight I/O lines are continuously monitored and can be used as inputs. Each line can generate asynchronous maskable interrupts on the falling edge, the rising edge, or both edges. For load-switching applications, the MAX1608 is designed to drive N-channel MOSFETs, and its outputs are low upon power-up; the MAX1609 is designed to drive Pchannel MOSFETs, and its I/Os are high impedance upon power-up. Other features of both devices include thermaloverload and output-overcurrent protection, ultra-low supply current, and a wide +2.7V to +5.5V supply range. The MAX1608/MAX1609 are available in space-saving 16-pin QSOP packages. o 8 General-Purpose Digital I/O Pins (withstand +28V) o SMBus 2-Wire Serial Interface o Supports SMBSUS Asynchronous Suspend o 9 Pin-Selectable Slave Addresses o Outputs High Impedanc...