1. General Introduction

A thermostat is a device that can accurately adjust and control the environmental temperature. It has a built-in sensor to monitor the temperature in real time. Once the temperature deviates from the preset value, it automatically activates the heating or cooling device for adjustment. Thermostats are widely used in industrial production, scientific research experiments, and smart homes. They ensure the stability of the industrial environment and regulate the indoor temperature at home. By maintaining a constant temperature, thermostats provide a suitable temperature condition for various activities, improving production efficiency and living comfort.

 

2. Urgent Need to Overcome Technical Bottlenecks

Although thermostats are required to control the temperature precisely, in actual use, they are often affected by various factors and it is difficult to achieve high precision and stability. On the one hand, the accuracy and response speed of sensors affect the accuracy of temperature measurement. For example, sensors such as thermistors and thermocouples have their own errors and performance drifts after long - term use. On the other hand, environmental factors such as surrounding electromagnetic interference, air flow, and uneven heat source distribution interfere with temperature measurement, resulting in deviations in thermostat control. Moreover, when the temperature approaches the set value, the thermostat needs to make fine adjustments to avoid frequent device on - off, which requires high - sensitivity control algorithms and actuators.

In the general trend of energy conservation, thermostats need to reduce energy consumption as much as possible while ensuring comfort. Traditional thermostats, due to their lack of flexibility, are difficult to adjust in a timely manner according to user behavior patterns and environmental conditions, resulting in unnecessary energy waste. For example, when there is no one in the room, the set temperature cannot be adjusted in time, or it cannot be adjusted intelligently according to seasonal and day - night changes. It is difficult to balance the user experience and energy consumption. Therefore, more intelligent algorithms and networking functions are needed for better prediction and adjustment.

With the development of smart home systems, thermostats need to be compatible with different devices and systems. They may need to communicate and collaborate with air conditioners, floor heating systems, smart speakers, mobile applications, etc. However, devices from different manufacturers follow different protocols, which brings difficulties to the integration of thermostats. In addition, the expandability of thermostats is also crucial. Users often expect to add functions such as remote monitoring and zoned control in the future, which undoubtedly poses more stringent requirements for hardware and software architectures.

4. Corebai Solution

In the face of the technical bottlenecks of thermostats, Corebai has introduced a targeted product solution after in - depth research. It lays a solid foundation for the stable operation of thermostats and injects strong impetus into their performance improvement.

 DAC (Digital - to - Analog Converter): It is used to convert the digital temperature set value into an analog signal to precisely control the power of heating or cooling devices, achieving more precise temperature regulation.

 LDO (Low Dropout Linear Regulator): It supplies a stable power source for the electronic components of the thermostat. This ensures that the internal circuit can operate smoothly under various input voltage conditions and effectively reduces the negative impact of voltage fluctuations on temperature control.

 OPA (Operational Amplifier): It can amplify the weak signals of temperature sensors, improving the signal strength and accuracy, which is helpful for more accurate comparison and processing of temperature signals.

 RS - 485 Chip: It realizes long - distance and anti - interference communication between the thermostat and other devices (such as remote monitoring systems and host computers), facilitating remote control and data collection.

 

Recommended DACs: CBM53D24, CBM128S085

CBM53D24 is a DAC with the following characteristic parameter advantages:

 

 Low Power Consumption: Under a 3V power supply, the current consumption is only 500μA. After entering the sleep mode, the current can be further reduced to 80nA (@3V), making it suitable for battery - powered applications or those with low - power requirements.

 High Resolution: With a 12 - bit resolution, it can provide precise analog output, meeting the requirements of applications with high - precision requirements.

 Multi - channel Output: It has 4 - channel buffered voltage output, which can control multiple analog signals simultaneously, increasing the flexibility of applications.

 Wide Voltage Range: The power supply voltage range is 2.5V to 5.5V, which can adapt to different power supply conditions and reduces the requirements for the power supply.

 Strong Compatibility: The 3 - wire serial interface is compatible with communication protocols such as SPI, QSPI, MICROWIRE, and DSP, facilitating connection with various microcontrollers and processors and enabling easy system integration.

 Reset Circuit: It contains a startup reset circuit. When the power supply voltage rises to the effective voltage, the DAC output voltage is 0V and remains in this state until a new status update command is received, enhancing the system's stability and reliability.

 High Conversion Rate: The voltage conversion rate is 0.7V/μs, which can convert digital signals into analog signals relatively quickly and meet certain real - time requirements.

CBM128S085 is a DAC with the following characteristic parameter advantages:

 

 Multi - channel Output: A single chip integrates an 8 - channel 12 - bit voltage - output digital - to - analog converter with output buffer drive, which can meet the needs of multiple analog signals in various application scenarios.

 High Resolution: The 12 - bit resolution can provide high - precision analog output and is suitable for applications with high - precision requirements, such as industrial control and data acquisition fields.

 Wide Voltage Range: The normal operating power supply voltage range is 2.7V - 5.5V, which can adapt to a variety of power supply conditions, reducing the requirements for the power supply and improving the chip's applicability.

 Low Power Consumption: Without load, the overall current consumption is only 540μA@3V and 600μA@5V. The low - power consumption feature makes it very suitable for portable devices or scenarios with strict power consumption requirements.

 Flexible Interface: It uses a three - wire serial interface with a maximum clock of 40MHz, is compatible with interface standards such as SPI, QSPI, MICROWIRE, and DSP, and is convenient for connection with various microcontrollers and processors. It also supports the daisy - chain working mode, allowing a single interface to control multiple chips simultaneously and ensuring that multiple chips can update their status at the same time.

 Flexible Output Configuration: The multi - channels of the chip can be flexibly configured. Each channel can work independently, and it supports three different output impedance sleep modes. When all digital - to - analog converters enter the sleep mode, the chip is at the μW - level power consumption.

Recommended LDO: CBM1117

CBM1117 is an LDO product with the following characteristic parameter advantages:

    

 High Output Current: It can provide an output current of up to 0.8A, meeting the power supply requirements of complex functional modules that require a large current and having a strong load - driving capacity.

 Wide Input Voltage Range: It supports a wide input voltage range from 2.6V to 15V, which can adapt to various power supply conditions. It has good compatibility with both battery - powered and other power - supplied devices.

 Multiple Output Voltage Options: There are two types of output voltages: fixed and adjustable. Fixed output voltages include common values such as 1.5V, 1.8V, 2.5V, 3.3V, and 5.0V. The adjustable output voltage range is 1.2V - 13.8V, which can meet the different voltage requirements of different devices.

 Thermal Overload Protection and Current Limiting: When the chip temperature reaches approximately 150°C, the thermal shutdown circuit will disable the output to prevent the device from being damaged by overheating. The built - in current - limiting circuit limits the current when the output or adjustment terminal is short - circuited, protecting the device's safety.

Recommended OPAs: CBM27, CBM2904

CBM27 is a precision operational amplifier with the following characteristic parameter advantages:

     

 

 Low Noise: At 10Hz, en = 3.5nV/√Hz, and the low 1/f noise corner frequency is 2.7Hz. When processing low - level signals, it can effectively reduce noise interference, improve the purity and accuracy of the signal, and is suitable for application scenarios with extremely high noise requirements, such as professional audio circuits and precision measuring instruments.

 High - Precision Amplification Performance: The open - loop gain is as high as 1800V/mV. It can amplify weak signals significantly and accurately while maintaining signal integrity, which is helpful for accurate signal amplification and processing in various circuits that require high - precision signal processing.

 Wide Voltage Supply Range: It supports a wide voltage supply range from ±4V to ±18V and can also operate with a single power supply from 8V to 36V. It can adapt to a variety of power supply conditions, providing greater flexibility in circuit design and facilitating use in devices with different power supply environments.

 High - Speed Performance: With a gain - bandwidth product of 8MHz and a slew rate of 2.8V/μs, it can achieve excellent dynamic accuracy in high - speed data acquisition systems, quickly tracking and processing changing signals, and is suitable for applications that require high signal - processing speed.

 Low Input Offset Voltage: The offset voltage is as low as 26μV, with a drift of 0.2μV/°C. Even in a changing temperature environment, it can maintain stable performance, ensuring the accuracy and stability of the amplified signal. It is very suitable for precision instruments and other applications that require long - term stable operation.

 Good Load - Driving Capability: The output stage has good load - driving capability, with a ±10V guaranteed swing (600Ω load) and low output distortion. It can provide a stable signal drive for subsequent loads and can directly drive some loads that require a large driving capacity, such as speakers, and performs well in professional audio applications.

 High Power Supply Rejection Ratio and Common - Mode Rejection Ratio: Both the power supply rejection ratio (PSRR) and the common - mode rejection ratio (CMRR) exceed 120dB, which can effectively suppress power supply voltage fluctuations and common - mode signal interference, improving the anti - interference ability and stability of the circuit.

CBM2904 is a high - voltage operational amplifier with the following characteristic parameter advantages:

 

 High DC Voltage Gain: CBM2904 has a DC voltage gain of up to 100dB, enabling it to accurately extract and enhance weak voice signals during long - distance transmission or in noisy environments.

 Wide Power Supply Range: The chip supports a wide input power supply voltage range from 3V to 32V (or ±1.5V to ±16V), making it suitable for various power supply conditions and allowing for flexible use in different application environments.

 Low Power Consumption: The power supply current is within 1.5mA, making it suitable for battery - powered devices and extending the usage time after a single charge. This feature is particularly important for battery - powered devices that need to operate for a long time.

 Internal Frequency Compensation: CBM2904 contains two independent high - gain operational amplifiers with internal frequency compensation, which helps to improve the system's stability and performance.

Recommended RS - 485 Chips: CBM3085, CBM485

CBM3085 is an RS - 485 interface chip with the following characteristic parameter advantages:

 Low - Power Design: CBM3085 adopts a low - power design, which is very suitable for energy - saving application scenarios. This feature is of great significance for extending the battery life of devices or reducing overall energy consumption.

 Data Transmission Rate: The data rate of this chip can reach 500kbps, meeting most data transmission requirements. This enables CBM3085 to process data efficiently and is suitable for communication scenarios with high real - time requirements.

 High Stability: CBM3085 can maintain the stability of the output voltage when the input voltage or load current changes, which is crucial for electronic devices that require precise voltage control. This stability helps to ensure the reliable operation of devices under various working conditions.

 ESD Protection: The chip provides ESD protection of up to 2000V (TTL/CMOS level) and 15000V (RS - 485 level), ensuring normal operation in harsh environments. This strong ESD protection capability helps to improve the reliability and durability of devices.

 Wide Operating Temperature Range: The operating temperature range of CBM3085 is from - 40°C to + 125°C, allowing it to maintain stable performance in various extreme environments. This feature makes CBM3085 suitable for a variety of harsh industrial environments.

CBM485 is an RS - 485 interface chip with the following characteristic parameter advantages:

 High - Speed Transmission Capability: CBM485 supports a data transmission rate of up to 10Mbps, which can meet the high - speed transmission requirements of most applications.

 Low - Power Design: When the driver is unloaded or disabled under full load, the power supply current consumed by these transceivers is only 120µA to 500µA, which helps to extend the usage time of battery - powered devices and is suitable for long - term operation scenarios.

 Hardware Space Saving: CBM485 supports connecting multiple devices on a single cable and various topological structures (such as ring, star, etc.), further saving hardware space.

 Low Cost: CBM485 has the advantage of low cost, which can meet the budget requirements of different customers, reduce system costs, and improve competitiveness.

6. Application Scenarios

The products launched by Corebai with its professional technical R & D have powerful performance and adaptability, and can be widely used in various scenarios such as homes, industries, commerce, healthcare, and scientific research laboratories, providing strong support for precise temperature control in these scenarios.

(1) Indoor Temperature Control

Thermostats are a key part of smart home systems. They can be connected to air conditioners and heating equipment. By setting the ideal temperature, such as maintaining 20°C - 22°C in winter and 24°C - 26°C in summer, the indoor environment can always be kept comfortable. This not only improves the living comfort but also reduces energy waste caused by temperature fluctuations.

(2) Warehousing Facilities

Many products have strict temperature requirements during storage. For example, red wine needs to be stored in an environment of 12°C - 18°C. Thermostats can precisely control the temperature of wine cellars or warehouses, extending the shelf life of red wine and improving its quality. For warehouses storing precision instruments and electronic products, thermostats can prevent instrument damage or performance degradation caused by temperature changes.

(3) Shopping Malls and Supermarkets

To provide a comfortable shopping environment for customers, shopping malls and supermarkets install thermostats to adjust the indoor temperature. At the same time, in the fresh food area, dairy product area, and other areas where refrigeration is required, thermostats can accurately control the temperature of refrigerators and freezers to ensure food freshness and safety. For electronic product warehouses, thermostats can also prevent instrument damage or performance degradation caused by temperature changes.

(4) Hospital Wards

In hospital wards, thermostats can provide a comfortable rehabilitation environment for patients. For some special wards, such as neonatal wards and intensive care units (ICUs), thermostats are even more crucial. Newborns need to live in an environment with a stable temperature of 24°C - 26°C. Thermostats can precisely control the room temperature to ensure their healthy growth.