Maxim Integrated MAX32600, Руководство пользователя

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MAX32600 User’s Guide Analog Front End 8.2 AFE Reconfiguration Matrix
Analog Matrix
The analog matrix is a set of interlinked switch arrays in the AFE which allows a large number of possible connections between different input and output ports of
various components in the AFE.
8.2 AFE Reconfiguration Matrix
8.2.1 AFE Reconfiguration Matrix Overview
A large analog reconfiguration matrix allows many of the input and output ports of the ADC, DAC, and various other analog and digital blocks to be dynamically
connected to each other using internal connection points and analog multiplexer blocks. This allows for the configuration of highly complex analog functions (e.g.,
voltage followers and other types of internal amplifiers and buffers), which include ADC or DAC voltages as an input or output, without having to add physical
connections external to the device.
Many of the analog front end functions on the
MAX32600
can be configured to run primarily without CPU intervention. The Peripheral Management Unit (PMU) on
the MAX32600 can be used instead of the CPU to perform tasks that must take place during long sequences of analog operations. This allows sequences of ADC
readings and/or sequences of DAC channel output voltages to run while the Cortex-M3 core is in a low-power sleep mode (reference Power Ecosystem for more
details about MAX32600 power modes). More specifically, this includes operations such as unloading samples from the ADC FIFO to the main data RAM or loading
new sample sequences into the DAC FIFO for output generation. The PMU’s functionality is particularly useful for analog functions (e.g., the ADC) that require a
low-noise environment to attain the highest possible precision during data collection operations; the PMU provides this environment by operating independent of the
Cortex-M3 core. The
Analog Reconfiguration Sub-Matrix Diagrams illustrate the configurability between the:
• Op amps
• Low-power comparators
• DAC outputs
• Op amp output pins
• SPST switch external pins
– NOTE : The number of available SPST switch external pins is package dependent; refer to the MAX32600 data sheet for the pin out configuration for each
of the available package types
• LED drive and observe ports pins
The multiplexers (mux) allow a variety of possible connections to implement features including an op amp follower to buffer a DAC output, a second-order Sallen-key
filter, an LED driver control loop, among many others. The flexibility of the analog configuration matrix enables maximum configuration options of the
MAX32600
Rev.1.3 April 2015 Maxim Integrated Page 342