The circuit pictured here is a custom control device for an automotive application. While the detail of the application is confidential, some common knowledge facts are significant to note for anyone interested in the current state of the art in this field. It encompasses several recent advancements in Embedded Control System integration. At the heart of the circuit is the Microchip PIC32MX360F512L, a 32 bit MCU implementing the MIPS 32 architecture in a highly integrated single IC. The system includes a full compliment of analog and digital I/O with a minimum of external circuitry.
For example: The Power Outputs are a good example of the simplicity available today. The large double sided copper lands at center right are actually all the heatsink needed by the power MOSFET output drivers to support output currents of 3A per channel. Those Power FETs are driven directly by the MCU.
While the PIC32MX is a 3.3v device, the outputs are “5v Tolerant”. This feature facilitates things like driving the Power FETs directly.
Another nice feature is the capability to perform some DSP style filtering. This allows the electronic signal filtering on the Analog Inputs to also be minimized.
The PIC32MX is provides an excellent mix of full features and low cost. While it may cost a bit more than the venerable 8 bit MCUs that still dominate the sector, I am finding a general ability to design with fewer external support components that offsets some of the cost. It also helps to have more headroom for programming. In some cases that turns out to be a more significant cost factor than the parts.
Vernon Johnson, Engineer LLC