AD7789:24位、单通道、超低功耗Σ-Δ型ADC

AD7789: 24位、单通道、超低功耗Σ-Δ型ADC

AD7788/AD7789均为适合低频测量应用的低功耗、完整模拟前端。采用3 V电源时,二者的典型功耗为65 µA；采用5 V电源时,典型功耗为75 µA。AD7789内置一个24位Σ-Δ型ADC,其中含有一个无缓冲差分输入。AD7788是AD7789的16位版本。AD7788具有16位峰－峰值分辨率,而AD7789则具有19位峰－峰值分辨率,相当于21.5位有效分辨率。AD7788/AD7789均采用内部时钟工作,因此,用户不必为其提供时钟源。输出数据速率为16.6 Hz,此时具有50 Hz/60 Hz同时抑制特性。两款器件也可用来进行电源监控。AD7788/AD7789可在单次转换模式下使用,即上电后执行单次转换,然后返回省电模式。或者,也可以选择连续模式工作。在连续转换模式下,可将两款器件配置为连续读取,即假设已将串行时钟作用于这些器件,则一旦完成一次转换,便会自动将转换结果置于串行总线上（用户无需写入ADC以读取数据）。AD7788/AD7789采用10引脚MSOP封装。

The AD7788/AD7789 are low-power, complete analog front ends for low frequency measurement applications. The device consumes 65 µA of current typically when operated with a 3 V power supply and 75 µA typical when operated with a 5 V power supply. The AD7789 contains a 24-bit S-D ADCwith one differential input, which is unbuffered. The AD7788 is a 16-bit version of the AD7789. The AD7788 has a peak-to-peak resolution of 16 bits while the AD7789 has a peak to peak resolution of 19 bits, which is equivalent to an effective resolution of 21.5 bits.

The device operates from an internal clock. Therefore, the user does not have to supply a clock source to the device. The output data rate is 16.6 Hz which gives simultaneous 50 Hz/60 Hz rejection. Power supply monitoring can also be performed with the part.

The part can be used in single conversion mode whereby the device powers up, performs a single conversion and then returns to powerdown mode. Alternatively, it can be operated in continuous mode. In continuous conversion mode, the part can be configured to continuously read i.e. the conversions are placed on the serial bus automatically as soon as a conversion is complete (the user does not need to write to the ADC to read the data), assuming that the serial clock is applied to the device.

AD7789 特点

24位分辨率
电源：
- 工作电压：2.5 V至5.25 V
- 正常模式：最大75 µA
- 省电模式：最大1 µA
均方根（RMS）噪声：1.5 µV
19位峰－峰值分辨率（21.5位有效分辨率）
积分非线性：3.5 ppm（典型值）
50 Hz和60 Hz同时抑制
内部时钟振荡器
VDD监控通道
10引脚MSOP封装
24-bit resolution
Power
- Supply: 2.5 V to 5.25 V operation
- Normal: 75 µA maximum
- Power-down: 1 µA maximum
RMS noise: 1.5 µV
19-bit p-p resolution (21.5 bits effective)
Integral nonlinearity: 3.5 ppm typical
Simultaneous 50 Hz and 60 Hz rejection
Internal clock oscillator
VDD monitor channel
10-lead MSOP

AD7789 技术指标

Resolution (Bits): 24bit
# Chan: 1
Sample Rate: n/a
Interface: Ser,SPI
Analog Input Type: Diff-Uni
Ain Range: (2Vref) p-p
ADC Architecture: Sigma-Delta
Pkg Type: SOP

AD7789 功能框图

AD7789 芯片订购指南

产品型号	产品状态	封装	引脚	温度范围
AD7789BRM	Prodn	10 ld MSOP	10	工业
AD7789BRM-REEL	Prodn	10 ld MSOP	10	工业
AD7789BRMZ	Prodn	10 ld MSOP	10	工业
AD7789BRMZ-REEL	Prodn	10 ld MSOP	10	工业
EVAL-AD7789EB	Prodn	EVALUATION BOARDS	-	待定