TI 公司的ADS8284是高性能模拟系统级芯片(SoC)器件,集成了18位1MSPS的模数转换器(ADC),4V的内部基准电压,片内的ADC驱动器,以及4路差分复接器. ADS8284具有18/16/8位并行接口,在2kHz I/P时的SNR为98.4dB,THD为-119dB,在1MSPS时包括ADC驱动器在内的功耗为331.25mW.这种模拟系统级芯片可用在医疗图像/CT扫描,自动测试设备,高速数据采集系统和高速闭环系统.本文介绍了ADS8284主要特性,方框图以及模拟和数字接口框图和应用电路图.

The ADS8284 is a high-performance analog system-on-chip (SoC) device with an 18-bit, 1-MSPS A/D converter, 4-V internal reference, an on-chip ADC driver (OPA), and a 4-channel differential multiplexer. The channel count of the multiplexer and auto/manual scan modes of the device are user selectable.

The ADC driver is designed to leverage the very high noise performance of the differential ADC at optimum power usage levels.

The ADS8284 outputs a buffered reference signal for level shifting of a ±4-V bipolar signal with an external resistance divider. A Vref/2 output signal is available to set the common-mode of a signal conditioning circuit. The device also includes an 18-/16-/8-bit parallel interface.

The ADS8284 is available in a 9 mm x 9 mm, 64-pin QFN package and is characterized from -40℃ to 85℃.

ADS8284主要特性:

MHz Sample Rate, Zero Latency at Full Speed

18-Bit Resolution

Supports Pseudo-Bipolar Differential Input Range: -4Vto+4V with 2-V Common-Mode

Built-In Four Channel, Differential Ended Multiplexer; with Channel Count Selection and Auto/Manual Mode

On-Board Differential ADC Driver (OPA)

Buffered Reference Output to Level Shift Bipolar ±4-V Input with External Resistance Divider

Reference/2 Output to Set Common-Mode for External Signal Conditioner

18-/16-/8-Bit Parallel Interface

SNR: 98.4dB Typ at 2-kHz I/P

THD: -119dB Typ at 2-kHz I/P

Power Dissipation: 331.25 mW at 1 MSPS Including ADC Driver

Internal Reference

Internal Reference Buffer

64-Pin QFN Package

ADS8284主要应用:

Medical Imaging/CT Scanners

Automated Test Equipment

High-Speed Data Acquisition Systems

High-Speed Closed-Loop Systems



图1.ADS8284方框图



图2.ADS8284模拟和数字接口框图



图3.ADS8284应用电路图