TI DAC8734高精度四路16位数模转换方案

TI 公司的DAC8734是高精度四路16位数模转换器(DAC),工作电压从±5V 到±18V,或单极电压从±5V 到+24V/-12V. DAC8734的噪音为60nV/Hz,建立时间为6us,可配置增益为X2/X4,模拟输出监视和降功耗模式,主要用在自动测试设备,仪表,工业过程控制和通信.本文介绍了DAC8734的主要特性,方框图和典型应用电路.

The DAC8734 is a high-accuracy, quad-channel, 16-bit digital-to-analog converter (DAC) that operates from supply voltages of ±5V to ±18V in bipolar output mode, and from ±5V to +24V/-12V in unipolar mode. With a 5V reference, the DAC8734 can be configured to output ±10V, ±5V, 0V to 20V, or 0V to 10V. The DAC8734 provides 16-bit monotonicity, excellent integral nonlinearity (INL) error of ±1 LSB, low glitch, and low noise over the operating temperature range of -40°C to +105°C. This device is trimmed in production for very low zero and gain errors. In addition, the DAC8734 implements a user-programmable system-level calibration function to achieve ±0.125 LSB zero error and ±1 LSB gain error.

The DAC8734 has integrated reference buffers and output buffers. It features a standard high-speed 1.8V, 3V, or 5V serial peripheral interface (SPI) that operates at clock rates of up to 50MHz to communicate with a DSP or microprocessor. The four DAC channels and the auxiliary registers are addressed with four address bits. The device features double-buffered interface logic for simultaneous updates of all DACs. An asynchronous load input (LDAC) transfers data from the input data register to the DAC latch, and the contents of the DAC latch set the output voltage. The asynchronous RST input sets the output of all four DACs to 0V. The V_MON pin is an analog monitor output that multiplexes the individual DAC outputs or the AIN pin.

The DAC8734 is pin-compatible with the DAC8234 (14-bit) and the DAC7716 (12-bit).

DAC8734主要特性:

Bipolar Output:Up to ±16V

Unipolar Output:0V to +20V

16-Bit Monotonic

Relative Accuracy: 1 LSB Max

Low Zero and Gain Errors Before User Calibration: 4 LSB After User Calibration:0.125 LSB Zero Error, 1 LSB Gain Error

Low Noise: 60nV/Hz

Settling Time: 6µs

Configurable Gain: x2/x4

Analog Output Monitor

Power-Down Mode

SPI: Up to 50MHz, 1.8V/3V/5V Logic

Daisy-Chain Mode

Operating Temperature: -40℃ to +105℃

Packages: QFN-40 (6x6mm), TQFP-48 (7x7mm)

DAC8734应用:

Automatic Test Equipment

Instrumentation

Industrial Process Control

Communications

图1.DAC8734方框图

The DAC8734 is a highly-integrated device with high-performance reference buffers and output buffers, greatly reducing the printed circuit board (PCB) area and cost. On-chip reference buffers eliminate the need for a negative external reference. Configurable on-chip output buffers support four different output modes.

图2.DAC8734基本应用电路