Reduce Your Risk of Redesigns
Adaptive ADC Design for Maximum Flexibility
In the realm of embedded systems and electronics design, Analog-to-Digital Converters (ADCs) play a crucial role in translating analog signals into digital data for microcontrollers (MCUs) to process. Many modern MCUs come equipped with onboard ADCs. When leading-edge performance is a goal, it may be unclear whether the onboard ADC will provide sufficient performance. This article focuses on this scenario.
Designs will always have risk/reward dilemmas to confront. Each time the wrong choice is made in the face of such a dilemma, a price is paid. Reducing the number of such dilemmas faced is good design practice.
The solution described below eliminates one potential dilemma, enabling a design decision even after the initial board layout and manufacture. Designers can create a Printed Circuit Board (PCB) with the option to either populate an external ADC socket and route the signal through it or bypass the external ADC and rely on the MCU's onboard ADC based on post-production testing and performance evaluations. This flexibility means that if the onboard ADC proves sufficient during testing, it can be omitted, saving costs. Conversely, if higher precision or better performance is needed, the external ADC can be easily integrated without requiring a redesign of the PCB.
One of the unique advantages of the MCP3465R is its compact size, making it an excellent option to use for this. Additionally, this approach enables the introduction of tiered offerings. If the system utilizing the MCP3465R provides end users with a meaningful performance boost, the supplier can market two solutions from the same development—one lower price, the other higher performance (and higher price). This approach further enables a path to an even higher performance system built around the MCP3565R, a device which is higher performance still than the MCP3465R, but pin and software compatible.
Three specific areas of improved performance are worth noting:
Enhanced Performance and Precision
A primary reason to consider a dedicated ADC is the superior performance and precision it offers. At 16 bits, the MCP3465R (the MCP3565R supports 24 bits) provides a level of precision higher than what is available on most MCUs, making it ideal for applications requiring accurate and reliable data conversion, such as medical instrumentation, industrial automation and high-fidelity audio processing.Improved Signal Integrity
Dedicated ADC chips are designed with a focus on minimizing noise and interference, which can significantly impact signal integrity. The MCP3465R/MCP3565R, for example, feature advanced filtering and noise reduction techniques that help maintain the integrity of the analog signal during conversion. External ADCs can be isolated from the switching and thermal noise inherent on an MCU; integrated ADCs are much more exposed to these noise sources. This is particularly important in environments with high electromagnetic interference (EMI) or when dealing with low-amplitude signals.Offloading Processing Tasks
By offloading the analog-to-digital conversion task to a dedicated ADC chip, the MCU is freed up to handle other processing tasks. This can lead to more efficient use of the MCU's resources and potentially lower power consumption, as the MCU can enter low-power modes more frequently. The MCP3465R/MCP3565R, with its low-power operation and efficient data handling, complements this approach by reducing the overall power footprint of the system.
While onboard ADCs in microcontrollers offer convenience and integration at a good price, dedicated ADC chips like the MCP3465R provide enhanced performance, precision and flexibility that can be invaluable. By considering a dedicated ADC as a Plan B alternative, designers can achieve higher signal integrity, better resource management, and greater system lexibility.
