CXAS42303 is a high-performance, low-power dual channel analog front-end chip designed for low-frequency signal measurement in electronic scale systems. This chip is capable of directly receiving weak differential signals from sensors and converting them into high-precision digital signals through a 24 bit ∑ - Δ analog-to-digital converter for output. It integrates a programmable gain amplifier internally, supporting three gain options of 32, 64, and 128, suitable for sensor inputs of different ranges. The chip also has excellent power supply rejection ratio and common mode rejection ratio, which can effectively suppress 50Hz/60Hz power frequency interference and ensure the stable operation of the system in complex environments.
-
[ CXAS42303 ]"
CXAS42303 high-precision electronic scale simulation front-end chip: dual channel 24 bitΣ -Δ ADC Detailed Explanation
In today's high-precision electronic scale systems, the performance of the analog front-end chip directly determines the measurement accuracy, stability, and cost of the entire system. CXAS42303, as a dual channel analog front-end chip designed specifically for low-frequency measurement of electronic scales, has become an ideal choice in electronic scale design due to its high integration, excellent anti-interference ability, and extremely low power consumption. This article will provide a detailed introduction to the functional features, technical parameters, application scenarios, and system design suggestions of CXAS42303, helping engineers better understand and apply the chip to improve the overall performance of electronic scale systems.
1、 Chip Overview
CXAS42303 is a high-performance, low-power dual channel analog front-end chip designed for low-frequency signal measurement in electronic scale systems. This chip can directly receive weak differential signals from sensors and use 24 bitΣ -Δ The analog-to-digital converter converts it into a high-precision digital signal output. It integrates a programmable gain amplifier internally, supporting three gain options of 32, 64, and 128, suitable for sensor inputs of different ranges. The chip also has excellent power supply rejection ratio and common mode rejection ratio, which can effectively suppress 50Hz/60Hz power frequency interference and ensure the stable operation of the system in complex environments.
2、 Main functional features
· Dual channel differential inputSupports two differential signal inputs, suitable for multi-sensor systems.
· 24Σ -Δ ADCRealize high-precision and code free data conversion.
· Programmable gainGain options include 32, 64, and 128, allowing for flexible adaptation to different input ranges.
· Ultra high linearityNonlinear error as low as± 0.001%, ensuring measurement accuracy.
· Optional data update rate10Hz or 80Hz, suitable for different response speed requirements.
· Multiple clock sourcesSupports internal clock, external clock, or crystal oscillator.
· low-power designExtremely low power consumption in standby mode, suitable for battery powered devices.
· Wide voltage operating range：2.6V~5.5V， Compatible with multiple power systems.
· Standard packagingProvide two packaging forms, SOP16 and DIP16, for easy system integration.
3、 Pin function and system connection
The pin design of CXAS42303 is simple and clear, making it easy for system layout and debugging. Among them, INPA/INNA and INPB/INNB are the positive and negative differential inputs of channels A and B, respectively; PD_SCK is for standby control and serial clock input; DOUT is the data output terminal; RATE is used to select the data update rate; XI/XO is the clock input/output terminal, supporting external clock or crystal oscillator access. In practical applications, if the comparator function is not needed, the BASE pin can be floating and the VFB pin can be grounded to simplify circuit design.
4、 Electrical characteristics and performance parameters
Under recommended working conditions (voltage 2.6V~5.5V, temperature -40 ℃~+85 ℃), CXAS42303 exhibits excellent performance:
· significant digitsAt a gain of 128 and a rate of 10Hz, it can reach 19.7 bits.
· Noise-Free BitsUnder the same conditions, it is 17.3 bits.
· Input noiseIn gain 128 and 10Hz mode, it is only 50nV (RMS).
· zero driftWhen the gain is 128, it is only 0.1mV, and when the gain is 64, it is 0.2mV.
· temperature coefficientInput zero drift as low as± 12nV/℃, gain drift is± 7ppm/℃.
· Power supply rejection ratio and common mode rejection ratioAll are better than 100dB.
These parameters ensure the reliability and stability of CXAS42303 in high-precision measurement scenarios.
5、 Serial Communication and Data Reading
CXAS42303 achieves serial data communication through PD_SCK and DOUT. Users can select channels and gain configurations by inputting 25-27 clock pulses into PD_SCK: 25 pulses select channel A and gain 128; 26 pulses select channel B and gain 32; Select channel A with 27 pulses and gain of 64. The DOUT pin will pull low when the data is valid, indicating that the host can read the data. In communication timing, attention should be paid to time parameters such as T1~T4 to ensure signal stability and data accuracy.
6、 System clock and data update rate configuration
The chip supports three clock modes:
6.1. Internal clock modeWhen the XI pin is grounded, the data update rate is 10Hz (RATE=0) or 80Hz (RATE=DVDD).
6.2. External clock modeThe XI pin is connected to an external clock signal, with a typical frequency of 11.0592MHz.
6.3. Crystal oscillator modeConnect a crystal oscillator between XI and XO.
Users can flexibly choose clock sources and data output rates according to system requirements.
7、 Standby mode and power management
CXAS42303 has intelligent standby function. When PD_SCK remains high for more than 60 seconds, the chip enters standby mode. At this time, the analog current is only 1.5mA, and the digital current is as low as 0.01mA, greatly reducing system power consumption. After lowering PD_SCK again, the chip resumed normal operation with default configuration of channel A and gain 128, and stable output of valid data after 4 data output cycles.
8、 Typical application scenarios
CXAS42303 is widely used in various high-precision electronic scale systems, including:
· Platform scale, cutting scale, pricing scale
· Industrial weighing system
· Medical weighing apparatus
· Pressure measurement and sensor signal conditioning
Its high integration and low external component requirements significantly reduce system costs and PCB area, enhancing the overall competitiveness of the machine.
9、 Packaging and Supply Information
CXAS42303 offers two packaging forms, SOP16 and DIP16, with standard size and strong compatibility, suitable for surface mount and plug-in processes. JTM-IC, as a reliable integrated circuit supplier, provides a full range of chip supply and technical support. Welcome to visit our official websitejtm-ic.comLearn more about product details and design resources.
10、 Conclusion
CXAS42303 has become the preferred chip for analog front-end in electronic scale systems due to its high precision, low power consumption, strong anti-interference and flexible configuration capabilities. Whether in traditional commercial scales or emerging intelligent measuring devices, it can provide stable and reliable signal processing capabilities. Choosing CXAS42303 means choosing the perfect balance between high performance and cost-effectiveness.
11、 Download the relevant chip selection guide; ► More similar products ...
