- The MAXREFDES1152 provides a complete system solution for industrial voltage and current measurement
- This reference design can be used in any application that requires high-accuracy analogue-to-digital conversion
Maxim has released the reference design for a voltage/current sensor module. The MAXREFDES1152 is a four-channel universal analogue input module that measures voltage or current signals. Each channel can be configured for voltage input at 0 to 10V. The current input can also be sensed between 0 to 20mA. It can be operated through a 24V power supply that power an external 2-Wire, 3-Wire, or 4-Wire sensor. It targets applications that require multiple channels of sensing at low power.
Switch based front-end interface
The MAXREFDES1152 provides a complete system solution for industry voltage and current measurement. The analogue front end includes multiple analogue switches. It also includes operational amplifiers that are used to achieve voltage/ current input selection and signal conditions.
Integrated 24-bit ADC converter
The 24-bit MAX11270 analogue-to-digital converter (ADC) helps the system to achieve accurate measurements. The microcontroller communicates with the MAX11270 and the MAX7317 10-port I/O expander. This expander controls the analogue front end and accepts the ADC conversion results.
Powered by a USB power supply
The 24V field input power supply is isolated with the analogue front end and the microcontroller. The system is powered by a USB power supply. This isolated design enhances system robustness in harsh industrial applications.
Integrated dual-channel analogue multiplexer
The MAXREFDES1152 have five single-pole/double-throw (SPDT) analogue switches. It also integrates a dual-channel 4:1 analogue multiplexer. Additionally, it also have two low-noise op-amps and a 2.75kVRMS data isolation sensor. The device runs on STMicroelectronics STM32F1 microcontroller.
Uses a USB-UART bridge for Serial interface
The device is programmable through an FTDI Chip that uses a USB-UART bridge. It uses an iso-buck DC-DC converter that provides different power rails for +5V and +3.3V supplies. The entire system typically operates at a power consumption of up to 500mW. The design also features small dimensions of 5cm × 10.6cm.
This reference design can be used in any application that requires high-accuracy analogue-to-digital conversion. Hence, it can be used in devices working for industrial and PLC applications. All the design-related documents can be downloaded here.
