August 2010A design team at a major manufacturer of office automation equipment is using the ProcessorPM (ispPAC-POWR605) and the MachXO (LCMXO640) to perform stand-by system power-up with rail sequencing, voltage monitoring, reset distribution and RMII-to-MII translation.
This manufacturer chose the ProcessorPM and MachXO in a subsystem power management scenario for a line of universal copier/scanner/printer devices for the European market. The design team indicated that the network card subsystem could be adopted as a standard for all digital Multi Function Devices (MFDs) in the future.
Multi-Function Devices (MFDs) provide a number of services such as monochrome or color printing, copying, sorting, scanning, and emailing. It is also possible to print a document or transmit a scanned image through an Ethernet connection. These systems consume 50-200 Watts or more.
Multi-function devices are made up of three main blocks:
Generally, in an office environment, MFDs are not always printing or scanning. There are long periods when these systems are not in use. To minimize power dissipation, these systems go into stand-by mode. During stand-by mode, only the network interface and the man-machine interface are operational. When a request arrives from the network or from the keyboard, the system is powered on and responds to the command.
The ProcessorPM Power Manager IC is used to provide the ordered turn-on of a scanner subsystem through simple sequencing and monitoring. The MachXO is used to manage IC resets and integrate glue logic. The low stand-by current of the ProcessorPM (10 micro-amperes) coupled with the MachXO’s sleep mode of operation (85 micro-amperes) provides a solution that is ideally suited for control and supervisory functions.
When a packet is received from the network, the network controller wakes the ProcessorPM device. The ProcessorPM then turns on the main DC-DC converters including minimal sequencing and reset generation. After the supply voltages are stable, the ProcessorPM wakes up the MachXO. Once the MachXO device is operational, the CPU reset is released. The MachXO then releases resets for the remaining devices on the circuit board. The MachXO can also implement a conversion bus bridge interface between a standard and reduced media independent interface (RMII/MII) channeling packets from the network board to the MFD subsystem. Using this method of conditional powering of subsystems, the stand-by power can be reduced to less than 1W.
The diagram below illustrates a portion of the MFD system interface between a network card and scanner subsystem.
The MachXO and ProcessorPM based solution is not unique to the MFD market. Variations of this circuit can be used across systems such as patient health monitoring systems, lab instrumentation, or numerical control (NC) systems that can be turned on remotely from a network or by the touch of a button.
For more information about the MachXO and ProcessorPM devices, visit the Lattice web site or contact your local Lattice sales representative.
© Lattice Semiconductor Corporation 2012
