TI ADS1675 4MSPS Delta-Sigma ADC方案

TI 公司的ADS1675 是高速(4MSPS)高精度ADC,采用先进的delta-sigma (ΔΣ)架构,速度高达4MSPS,具有杰出的AC性能和DC精度.在4MSPS时动态范围为103dB, 125kSPS时动态范围为111dB,THDwei1-107,INL为3ppm,失调漂移为4μV/℃,增益漂移为4ppm/℃. ADS1675的工作电压为5V,可直接与各种微控制器(MCU),数字信号处理器(DSP)或FPGA接口.本文介绍了的主要特性,方框图, 模拟信号基本连接图, 差分和单端输入信号接口连接图。

The ADS1675 is a high-speed, high-precision analog-to-digital converter (ADC). Using an advanced delta-sigma (ΔΣ) architecture, it operates at speeds up to 4MSPS with outstanding ac performance and dc accuracy.

The ADS1675 ADC is comprised of a low-drift modulator with out-of-range detection and a dual-path programmable digital filter. The dual filter path allows the user to select between two post-processing filters: Low-Latency or Wide-Bandwidth. The Low-Latency filter settles quickly (as fast as 2.65μs) for applications with large instantaneous changes, such as a multiplexer. The Wide-Bandwidth path provides an optimized frequency response for ac measurements with a passband ripple of less than ±0.00002dB, stop band attenuation of 115dB, and a bandwidth of 1.7MHz.

The device offers two speed modes with distinct interface, resolution, and feature set. In the high-speed mode the device can be set to operate at either 4MSPS or 2MSPS. In the low-speed mode, it can be set to operate at either 1MSPS, 500KSPS, 250KSPS or 125KSPS.

The ADS1675 is controlled through I/O pins—there are no registers to program. A dedicated START pin allows for direct control of conversions: toggle the START pin to begin a conversion, and then retrieve the output data. The flexible serial interface supports data readback with either standard CMOS and LVDS logic levels, allowing the ADS1675 to directly connect to a wide range of microcontrollers, digital signal processors (DSPs), or field-programmable grid arrays (FPGAs).

The ADS1675 operates from an analog supply of 5V and digital supply of 3V, and dissipates 575mW of power. When not in use, the PDWN pin can be used to power down all device circuitry. The device is fully specified over the industrial temperature range and is offered in a TQFP-64 package.

ADS1675主要特性:

AC Performance:

103dB of Dynamic Range at 4MSPS

111dB of Dynamic Range at 125kSPS

-107dB THD

DC Accuracy:

3ppm INL

4μV/℃ Offset Drift

4ppm/℃ Gain Drift

Programmable Digital Filter with User-Selectable Path:

Low-Latency: Completely settles in 2.65μs

Wide-Bandwidth: 1.7MHz BW with flat passband

Flexible Read-Only Serial Interface:

Standard CMOS

Serialized LVDS

Easy Conversion Control with START Pin

Out-of-Range Detection

Supply: Analog +5V, Digital +3V

Power: 575mW