Serial to Parallel Parallel to Serial Converters and Load Switch Controllers with SMBus Interface
19-1306; Rev 0; 10/97
AVAILABLE Serial-to-Parallel/Parallel-to-Serial Converters and
Load-Switch Controllers with SMBus Interface
____________________________Features The MAX1661/MAX1662/MAX1663 serial-to-parallel/
parallel-to-serial converters are intended to control external
power MOSFETs in power-plane switching applications.
These small, low-cost devices can be used on a system
motherboard to control point-of-load switching from a 2wire SMBusTM serial interface. Each device has three highvoltage open-drain outputs that double as TTL-level logic
inputs, giving them bidirectional capabilities. The I/O pins
can withstand +28V, so they can control battery voltagedistribution switches in notebook computers.
The MAX1661 is intended for driving N-channel MOSFETs
and its outputs are low upon power-up. The MAX1662/
MAX1663 are intended for P-channel MOSFETs, and their
outputs are high-impedance upon power-up. This ensures
that the MOSFETs are off at power-up, so the system can
enforce power-plane sequencing.
The SMBSUS control input selects control data between
two separate data registers. This feature allows the system
to select between two different power-plane configurations
asynchronously, eliminating latencies introduced by the
serial bus. Other features include thermal-overload and
overcurrent protection, ultra-low supply current, and both …