Microchip: How to simplify your next Thermocouple design

Market Overview

Thermocouples are widely used today because of their ruggedness and simplicity (two different wire types connected), making them well-suited for a wide variety of different application areas—from harsh industrial environments like boilers, petrochemical, smelters, and automotive to consumer products, such as coffee/espresso machines, cooktops, ovens, and many others.

Thermocouples are a popular customer design-in choice today because of their many advantages:

Wide temperature range
Below -250°C to over 1800°C
Fast thermal response
Accurately capture temperature spikes
Rugged against vibration and dirt
Simple design
Self-powered
No voltage or current excitation required

Client challenges

Unfortunately, in addition to all the advantages that thermocouples provide, there are a few challenges. Most clients today develop their thermocouple systems using discrete analog components requiring up to 15 or more components, depending on their precision accuracy requirements. Thermocouple systems can be very complex and require long system development times, cost, and resources to develop and support.

Another challenge is that the long thermocouple wires can act as an antenna that can pick up all sorts of electrical noise. Ideally, this noise will couple onto both wires of the thermocouple and hence be common, but this high level of common mode noise can affect the signal conditioning circuitry. The actual voltage created across the thermocouple is very small, in the order of tens of millivolts across a wide temperature range. It is a significant challenge in attempting to measure this very low voltage in the presence of potentially large common mode noise and requires a high-performance front-end solution. Not only does the thermocouple produce a relatively low voltage output, but it also is not linear across the temperature range. Therefore, extracting a small voltage change in the presence of a large common mode voltage can be challenging.

Why change?

In many cases, a single-chip solution to replace all these components will not only save board space, but will likely cost less compared to using discrete analog components depending on the precision level of discrete analog components used. The MCP9600 and MCP9601 products integrate the complete analog signal chain which includes a precision high-resolution Analog-to-Digital Converter (ADC), a high-accuracy temperature sensor, and a preprogrammed math engine to signal process in real-time and correct the thermocouple’s non-linearity error characteristics to provide customers with an accurate temperature measurement in degrees Celsius, which can be simply read on the I2C bus. Now, that is easy.

Why now?

MCP9600 and MCP9601 products solve the performance, integration, power, and cost challenges for today’s thermocouple system analog design engineers. You might be thinking, how is this possible? The MCP9600 and MCP9601 thermocouple conditioning Integrated Circuits (ICs) are the most complete plug-and-play, single-chip solutions on the market today.

Why Microchip?

Let’s face it, developing discrete precision analog circuitry to accurately condition the thermocouple signal is not a trivial task and Microchip has this taken care of for you. Microchip offers complete thermocouple conditioning products available today that you should check out.

While there are a few competitor thermocouple conditioning ICs, they are inferior to the complete plug-and-play thermocouple conditioning solution that the MCP9600 and MCP9601 products offer. Microchip is unique in this product category with its advanced features and functionality. These products reduce the required expertise in analog, mixed-signal, thermal management, and microcontroller design. Our innovative portfolio of highly integrated thermocouple conditioning IC solutions simplifies the client’s development and speeds up their product’s time to market.

Additionally, the MCP9600 and MCP9601 thermocouple conditioning ICs connect a thermocouple and measure precision temperature measurements in degrees Celsius temperature data via a standard I2C interface. How simple is that? It is because these devices integrate the complete analog signal chain that includes a precision high-resolution ADC, a high-accuracy temperature sensor, and a pre-programmed math engine to correct the thermocouple nonlinear error characteristics of eight different thermocouple types used today.

Please check out Microchip’s thermocouple conditioning products if you are looking for flexible, easy-to-use, and complete thermocouple conditioning products that will reduce your development risk and speed up your product’s time to market. The benefits of using MCP9601 products:

Provides a complete plug-and-play thermocouple conditioning solution
Simplifies design, reduces development time, lowers overall system cost
Integrated thermocouple open-circuit and short-circuit detection
Temperature data digital filter
Minimizes effects of system noise and Electromagnetic Interference (EMI)
Shutdown modes
Reduces overall system power consumption
Four user-programmable Temperature Alert outputs
Reduces microcontroller overhead, reduces code space, simplifies design, and enhances product performance
Small Package: 20-lead QFN (5 mm x 5 mm)
Reduces board space and lowers manufacturing costs