ADI 公司的AD5791是單路20位電壓輸出數模轉換器(DAC),雙極工作電壓高達33V,正基準電壓從5V到VDD-2.5V,負基準電壓從VSS+2.5V到0V,精度1ppm,噪音頻譜密度7.5 nV/√Hz,溫度漂移0.05 ppm/°C,主要用在醫療儀器,測試測量,工業控制和高端科學和航空儀表.本文介紹了AD5791產品亮點和主要特性, 方框圖和菊花鏈接方框圖,以及典型應用電路圖和EVAL-AD5791評估板電路圖,材料清單和PCB元件布局圖.

The AD5791 is a single 20-bit, unbuffered voltage-output DAC that operates from a bipolar supply of up to 33 V. The AD5791 accepts a positive reference input in the range 5 V to VDD − 2.5 V and a negative reference input in the range VSS + 2.5 V to 0 V. The AD5791 offers a relative accuracy specification of ±1 LSB max, and operation is guaranteed monotonic with a ±1 LSB DNL maximum specification.

The part uses a versatile 3-wire serial interface that operates at clock rates up to 35 MHz and that is compatible with standard SPI, QSPI™, MICROWIRE™, and DSP interface standards. The part incorporates a power-on reset circuit that ensures the DAC output powers up to 0 V and in a known output impedance state and remains in this state until a valid write to the device takes place. The part provides an output clamp feature that places the output in a defined load state.

AD5791產品亮點:

1 ppm Accuracy.

Wide Power Supply Range up to ±16.5 V.

Operating Temperature Range: −40℃ to +125℃.

Low 7.5 nV/√Hz Noise Spectral Density.

Low 0.05 ppm/℃ Temperature Drift.

AD5791主要特性:

1 ppm resolution

1 ppm INL

7.5 nV/√Hz noise spectral density

0.19 LSB long term linearity stability

<0.05 ppm/℃ temperature drift

1 μs settling time

1 nV-sec glitch impulse

Operating temperature range:−40℃ to +125℃

20-lead TSSOP package

Wide power supply range up to ±16.5 V

35 MHz Schmitt triggered digital interface

1.8 V compatible digital interface

AD5791應用:

Medical instrumentation

Test and measurement

Industrial control

High end scientific and aerospace instrumentation


圖1.AD5791方框圖

圖2.AD5791菊花鏈接方框圖

圖3.AD5791典型應用電路圖

EVAL-AD5791評估板

The EVAL-AD5791 is a full-featured evaluation board, designed to allow the user to easily evaluate all features of the AD5791 voltage output, 20-bit DAC. The AD5791 pins are accessible at on-board connectors for external connection. The board can be controlled by two means, via the on-board connector (J6) or via the system development platform connector (J3). The SDP board allows the evaluation board to be controlled through the USB port of a Windows® XP (SP2 or later) or Vista (32-bit) based PC using the AD5791 evaluation software.

EVAL-AD5791評估板主要特性:

Full-featured evaluation board for the AD5791

Link options

PC control in conjunction with Analog Devices, Inc., system development platform

PC software for control

圖4.EVAL-AD5791評估板連接框圖

EVALUATION BOARD SCHEMATICS AND ARTWORK

圖5.EVAL-AD5791評估板電路圖(1)

圖6.EVAL-AD5791評估板基準電壓電路圖

圖7.EVAL-AD5791評估板SDP板連接器電路

圖8.EVAL-AD5791評估板元件布局圖
EVAL-AD5791評估板材料清單(BOM):

詳情請見:
http://www.analog.com/static/imported-files/data_sheets/AD5791.pdf
和
http://www.analog.com/static/imported-files/user_guides/UG-185.pdf