24-Bit, 250kSPS Single-Supply Data Acquisition System

Advantages and Features

　　24-bit 250kSPS ADC system

　　Industrial signal levels

　　Single power supply

　　application:

　　Instrumentation

　　Programmable logic control and distributed control systems

　　Electronic test and measurement

　　Circuit Function and Advantages

　　When sampling industrial level signals, fast, high-resolution conversion information must be provided. Typically, the resolution of the analog-to-digital converter (ADC) can be 14 to 18 bits when the sampling rate reaches 500kSPS. The circuit shown in Figure 1 is a single-supply system optimized for sampling industrial level signals, using a 24-bit, 250 kSPS ∑-△ ADC. Each of the two differential channels or four pseudo-differential channels can provide 17.2 bits of noise-free code resolution at a sampling rate of 50kSPS.

　　This circuit uses an innovative differential amplifier with built-in laser trimmed resistors to achieve attenuation and level conversion. It can solve the problem of obtaining and digitizing standard industrial level signals of ±5V, ±10V, and 0V to 10V using a precision ADC with a low supply voltage. This circuit can be applied to process control (PLC/DCS modules), medical and scientific multi-channel instruments, and chromatographs.