TI ADS8201低功耗单片数据采集方案

TI 公司的ADS8201是低功耗单片数据采集系统,包括12位采用电容的SAR模数转换器(ADC),高性能连续时间可编增益放大器(PGA)以及全自动扫描8:1复接器,模拟电压2.2V到5.5V,高达100kSPS吞吐量速率, SCLK 高达25MHz (VD = 5V),主要用在手提通信,传感器接口,手提医疗仪表,数据采集系统和GPS芯片组.本文介绍ADS8201主要特性, 功能方框图以及精密定位应用电路图和桥式传感器应用电路图.

The ADS8201 is a low-power, complete on-chip data acquisition system optimized for portable applications that require direct connections, wide dynamic range, and automatic operation with very low power consumption. The device includes a 12-bit, capacitor-based, successive approximation register (SAR) analog-to-digital converter (ADC); a high-performance, continuous-time programmable gain amplifier (PGA); and a fully automatic scan, 8-to-1 multiplexer (mux) with breakout to allow for system design flexibility.

Many other features are included to further optimize system operation. Conversion results may be saved in an onboard first-in/first-out (FIFO) buffer and read out at a later time. Each channel has a gain setting that can be loaded automatically when it is selected.

ADS8201主要特性:

• Multi-Chip Ready and Fully Enabled:234

• Low-Power, Flexible Supply Range:

– 2.2V to 5.5V Analog Supply

– 1.32mW (100kHz, +VA = 2.2V, +VD = 2.2V)

– 4.5mW (100kHz, +VA = 5V, +VD = 5V)

• Up to 100kSPS Throughput Rate

• Excellent DC Performance:

• Transducer Interfaces

– ±0.5 LSB typ, ±1.5 LSB max INL

• Portable Medical Instruments

– ±0.5 LSB typ, ±1.0 LSB max DNL • Data Acquisition Systems

– ±6 LSB Offset Error at +VA =5V • GPS Chipsets

– ±0.1%FS Gain Error at +VA = 5V SPACE

• Flexible Analog Inputs:

– True Differential Input

– Differential/Unipolar Input Range (0 to VREF)

– TAG Bit Output

– Programmable Averaging Function

– Onboard, Eight Single-Ended/Four Differential Channel Mux:

– High Input Impedance

– High-Performance PGA (Gain = 1/2/4/8)

– PGA Breakout

– Auto/Manual Channel Select with Gain.

– Auto/Manual Trigger

– Mixed Type Partial Scan

• Built-in Hardware Features:

– On-chip Conversion Clock (CCLK)

– Hardware/Software Reset

– Programmable Status/Polarity for BUSY/INT

• Flexible I/O:

– SPI-/ DSP™-Compatible Serial Interface

– Separate I/O Supply (2.2V to 5.5V)

– Onboard 8×1 FIFO Buffer

– SCLK up to 25MHz (VD = 5V)

• Multi-Chip Ready and Fully Enabled:

– Global CONVST (Independent of CS)

• Power-Down Mode

• 24-Pin 4×4 QFN Package

ADS8201应用:

• Portable Communications

• Transducer Interfaces

• Portable Medical Instruments

• Data Acquisition Systems

• GPS Chipsets

图1.ADS8201功能方框图

图2.ADS8201精密定位应用电路图


图3.ADS8201桥式传感器应用电路图