The threat of used batteries to human living environment has become a social consensus. Reducing battery usage by reducing power consumption is becoming the choice of many electronics companies. With the advancement of solar cell technology and the development of low-power semiconductor design technology, the application of solar cells to replace traditional batteries has gradually emerged. This article will introduce a solar scale design based on the low power CSU11 series scale SoC chip. Low-power solar scale design points For scale products that use traditional battery power, they are usually limited by volume and cost. If solar panels are used, the area is limited, which limits the power supply of the solar panels. In addition, the solar panel generates a low amount of power (indoor μA level), and there is a problem that the current is unstable due to the difference in light intensity. Therefore, the scale solution powered by solar panels needs to solve the following problems: increase the energy storage circuit and store the power generated by the solar panel (only 200 watts in 200 lumens); reduce power consumption, The whole machine and working current must be at nA and μA levels respectively. The main power consumption of the electronic weighing instrument is the sensor, ADC and MCU. To this end, the usual solution requires the following methods to achieve overall low power consumption: intermittent or power supply to the sensor to reduce power consumption of the sensor; high impedance strain sensor; increase ADC output rate, reduce each sampling Time reduces sampling power consumption; increases ADC effective bits to ensure instrument accuracy at high speed; increases SoC operation speed to reduce power consumption per MHz; reduces LCD driver circuit power consumption; improves integration and reduces peripheral devices. The high-precision 24-bit ADC chip CS1242 introduced by Core Technology has filled the gap in the field of high-end electronic weighing instruments in China. While meeting the high-precision requirements, the company has introduced the CSU11 series of weighing instrument SoC chips with excellent low-power characteristics for the current trend of low-power applications. The biggest advantage is that it also meets the automatic weighing scales and solar energy. The human body scale requires low power consumption and the high precision requirements of the pocket scale. This series of products takes into account the above-mentioned low-power design factors and achieves excellent low-power characteristics. With the CSU11 series SoC designed automatic weighing scales, the average standby power consumption can be as low as 3μA, and the solar body scale is weighed. The current is less than 20μA, and the pocket scale can be divided into 30,000. The CSU11 Series SoC integrates 8-bit RISC MCUs, 4K*16 OTP (available as user data PROM), 256 RAM, 4*18 LCD, and 16 I/O ports (except for these 16 I/O ports, all " The Seg port can be multiplexed to output, allowing up to 26 IO totals. Dual-channel high-speed, high-precision ADCs with a maximum data output rate of 16kHz (12-bit accuracy, 32 gain) and 18-bit maximum accuracy ( The gain is 128 and the rate is 32 Hz). In order to meet the requirements of low power consumption and high precision on one chip, CSU11 series SoC also provides the option of “power-accuracy-speed†balancing, that is, users can achieve low by configuring lower ADC operating current. Power consumption, but the linearity is poor in this case. It can only be used for scales below 5000 points. It can also be configured with a large operating current to achieve 30,000-degree accuracy and linearity. The type of solution development is convenient, and only needs to be slightly modified in configuration to meet different market needs. The emergence of solar human scales is mainly to avoid the environmental hazards of ordinary batteries and achieve environmental protection. However, current solar scales on the market require expensive sensors and PS08 master chips. The high cost of construction has greatly limited the market share of solar scales. The CSU11 series offers features specifically designed for solar body scales, designed with an 1KHz AD output rate and a fourth AD sample. Weighing once every second, the required dynamic power consumption is 4 times *2.5mA* (1/1000 seconds) = 10μA, and the LCD shows the required power consumption of 5μA (drive circuit operating current) + 5μA (glass consumption) ) = 20 μA. At present, a large domestic weighing instrument enterprise has successfully developed solar electronic scale products using CSU1101B chip, and realized mass production, and has successfully realized bulk export to the European and American markets. With an average operating current of 25μA or less, the product can be scaled at 55 lumens of light, making it suitable for a wide range of indoor environments, including bathrooms. It has an accuracy of 2,000 divisions and features an automatic start-up function with an average shutdown current of less than 3μA. The threat of used batteries to human living environment has become a social consensus. Reducing battery usage by reducing power consumption is becoming the choice of many electronics companies. With the advancement of solar cell technology and the development of low-power semiconductor design technology, the application of solar cells to replace traditional batteries has gradually emerged. This article will introduce a solar scale design based on the low power CSU11 series scale SoC chip. Low-power solar scale design points For scale products that use traditional battery power, they are usually limited by volume and cost. If solar panels are used, the area is limited, which limits the power supply of the solar panels. In addition, the solar panel generates a low amount of power (indoor μA level), and there is a problem that the current is unstable due to the difference in light intensity. Therefore, the scale solution powered by solar panels needs to solve the following problems: increase the energy storage circuit and store the power generated by the solar panel (only 200 watts in 200 lumens); reduce power consumption, The whole machine and working current must be at nA and μA levels respectively. The main power consumption of the electronic weighing instrument is the sensor, ADC and MCU. To this end, the usual solution requires the following methods to achieve overall low power consumption: intermittent or power supply to the sensor to reduce power consumption of the sensor; high impedance strain sensor; increase ADC output rate, reduce each sampling Time reduces sampling power consumption; increases ADC effective bits to ensure instrument accuracy at high speed; increases SoC operation speed to reduce power consumption per MHz; reduces LCD driver circuit power consumption; improves integration and reduces peripheral devices. The high-precision 24-bit ADC chip CS1242 introduced by Core Technology has filled the gap in the field of high-end electronic weighing instruments in China. While meeting the high-precision requirements, the company has introduced the CSU11 series of weighing instrument SoC chips with excellent low-power characteristics for the current trend of low-power applications. The biggest advantage is that it also meets the automatic weighing scales and solar energy. The human body scale requires low power consumption and the high precision requirements of the pocket scale. This series of products takes into account the above-mentioned low-power design factors and achieves excellent low-power characteristics. With the CSU11 series SoC designed automatic weighing scales, the average standby power consumption can be as low as 3μA, and the solar body scale is weighed. The current is less than 20μA, and the pocket scale can be divided into 30,000. The CSU11 Series SoC integrates 8-bit RISC MCUs, 4K*16 OTP (available as user data PROM), 256 RAM, 4*18 LCD, and 16 I/O ports (except for these 16 I/O ports, all " The Seg port can be multiplexed to output, allowing up to 26 IO totals. Dual-channel high-speed, high-precision ADCs with a maximum data output rate of 16kHz (12-bit accuracy, 32 gain) and 18-bit maximum accuracy ( The gain is 128 and the rate is 32 Hz). In order to meet the requirements of low power consumption and high precision on one chip, CSU11 series SoC also provides the option of “power-accuracy-speed†balancing, that is, users can achieve low by configuring lower ADC operating current. Power consumption, but the linearity is poor in this case. It can only be used for scales below 5000 points. It can also be configured with a large operating current to achieve 30,000-degree accuracy and linearity. The type of solution development is convenient, and only needs to be slightly modified in configuration to meet different market needs. The emergence of solar human scales is mainly to avoid the environmental hazards of ordinary batteries and achieve environmental protection. However, current solar scales on the market require expensive sensors and PS08 master chips. The high cost of construction has greatly limited the market share of solar scales. The CSU11 series offers features specifically designed for solar body scales, designed with an 1KHz AD output rate and a fourth AD sample. Weighing once every second, the required dynamic power consumption is 4 times *2.5mA* (1/1000 seconds) = 10μA, and the LCD shows the required power consumption of 5μA (drive circuit operating current) + 5μA (glass consumption) ) = 20 μA. At present, a large domestic weighing instrument enterprise has successfully developed solar electronic scale products using CSU1101B chip, and realized mass production, and has successfully realized bulk export to the European and American markets. With an average operating current of 25μA or less, the product can be scaled at 55 lumens of light, making it suitable for a wide range of indoor environments, including bathrooms. It has an accuracy of 2,000 divisions and features an automatic start-up function with an average shutdown current of less than 3μA. Design recommendations to improve system performance At present, solar electronic scales are positioned in the high-end market, and are mainly exported to Europe and the United States. In order to improve the performance of the whole machine and meet the strict electromagnetic compatibility test standards in Europe and America, the following recommendations are given for product design based on CSU11 series SoC. Design practice has practical guiding significance for Other SoCs based on the core technology and general electronic product design: 1. Improve product anti-ESD performance The most important thing for product ESD performance is the product housing design, which must ensure that the electrostatic energy is not introduced into the PCB of the product. However, buttons and battery compartments are sometimes not avoided in the design of the enclosure due to ESD events. Therefore, the key to improving the ESD performance of the circuit is to take the ESD measures of the button and power supply parts. Buttons that may be exposed to ESD events require an RC circuit to direct the ESD energy to ground. The typical capacitance is 0.1μF and the resistance is 10K. It is best to fill the ground around the buttons (using solid paving, not meshing). Near the power supply access point on the PCB (the solder joint between the battery compartment and the PCB), a 105 capacitor must be placed immediately after the power line solder joint (104 capacitors are also available, but 105 capacitors can increase the ESD limit). The capacitor is mainly used to discharge static energy to the ground when the battery compartment is opened and the ESD is opened. The land here should be paved with a piece of land. In addition to the above two measures, if you want to further improve the ESD performance, the ground on the PCB should be spread as much as possible on a solid ground, and do not use the way of grid laying. Moreover, the connection between the ground and the ground should be good, and it is forbidden to use a thin wire connection between the ground and the ground. In addition, the ground connection design of the sensor is also beneficial to improve the anti-ESD performance. In principle, the ground wire solder joint of the sensor should be placed as close as possible to the power supply solder joint so that the electrostatic energy does not need to pass through the board winding to reach the sensor, thereby reducing the impact on the chip. 2. Improve AD performance For high-precision palm scales, especially for palm scales with an accuracy of more than 20,000 points, circuit and PCB design are essential, and a reasonable design can effectively improve the performance of the scale. The capacitance on the sensor should be as close as possible to the chip pins, and the traces should be as parallel as possible. Between AVDD and AGND, connect a 105 capacitor as close as possible to the chip. When developing a scale with a clock function or a scale that requires a communication function, it is usually necessary to use an external crystal oscillator. The crystal oscillator should be as close as possible to the chip, the traces should be parallel, the bottom of the crystal oscillator should not be routed, and the ground wire should be applied. Summary of this article The company's product development ideas for integrating high-performance ADCs with MCUs provide a highly competitive solution for the weighing instrument industry. Currently, ICs are widely used in more than 1,000 companies in China, and low-power solar electronic solutions are available. The launch has followed the general trend of the current global low carbon economy. The CSU11 series chip introduced in this article has won the "Electronic Engineering Album" 2010 Hot Product Award, which once again highlights innovative product design ideas and cost-effective features. In fact, in addition to solar scale applications, the CSU11XX series is also widely used in industrial applications such as industrial process control, liquid/other chemical analysis, portable products, smart converters, solar human scales, and portable medical equipment smart meters. In order to shorten the time-to-market of customers' products and reduce the cost of research and development, Xinhai Technology provides application support for end customers or solution providers with “IC+ System Standard Program†from the beginning of the product launch, and provides complete development tools and rich application software packages. . Chemical Float Ball Valve,Gas Station Ball Valve,Buried Ball Valve East Well Valve Co., Ltd. , http://www.shballvalve.com