AD7795 6通道、低噪声、低功耗、16位Σ-Δ型ADC,内置片内仪表放大器和基准电压源

AD7795: 6通道、低噪声、低功耗、16位Σ-Δ型ADC,内置片内仪表放大器和基准电压源

AD7794/AD7795均为适合高精度测量应用的低功耗、低噪声、完整模拟前端,内置一个低噪声24位/16位Σ-Δ型ADC,其中含有6个差分输入,还集成了片内低噪声仪表放大器,因而可直接输入小信号。每款器件均内置一个精密低噪声、低漂移内部带隙基准电压源,也可采用最多两个外部差分基准电压。其它片内特性包括可编程激励电流源、熔断电流控制和偏置电压产生器,利用偏置电压产生器可将某一通道的共模电压设置为AVDD/2。低端电源开关可用来在两次转换之间关断桥式传感器,从而使系统功耗降至最低。AD7794/AD7795可以采用内部时钟或外部时钟工作,输出数据速率可在4.17 Hz至470 Hz的范围内变化。两款器件均采用2.7 V至5.25 V电源供电。B级器件（AD7794和AD7795）的额定温度范围为−40°C至+105°C,而C级器件（AD7794）的额定温度范围为−40°C至+125°C,这些器件的典型功耗为400 µA,采用24引脚TSSOP封装。

The AD7794/AD7795 are low power, low noise, complete analog front ends for high precision measurement applications. They contain a low noise, 24-/16-bit Σ-Δ ADC with six differential inputs. The on-chip low noise instrumentation amplifier means that signals of small amplitude can be interfaced directly to the ADC.

Each device contains a precision, low noise, low drift internal band gap reference, and can also accept up to two external differential references. Other on-chip features include programmable excitation current sources, burnout currents, and a bias voltage generator that is used to set the common-mode voltage of a channel to AVDD/2. The low-side power switch can be used to power down bridge sensors between conversions, minimizing the system’s power consumption. The AD7794/AD7795 can operate with either an internal clock or an external clock. The output data rate from each part can vary from 4.17 Hz to 470 Hz.Both parts operate with a power supply from 2.7 V to 5.25 V. The B-grade parts (AD7794 and AD7795) are specified for a temperature range of −40°C to +105°C while the C-grade part (AD7794) is specified for a temperature range of −40°C to +125°C. They consume a current of 400 μA typical and are housed in a 24-lead TSSOP.

技术特性

最高23位有效分辨率
均方根（RMS）噪声：40 nV（4.17 Hz时），85 nV（16.7 Hz时）
功耗：400 µA（典型值）
省电模式：最大1 µA
低噪声可编程增益仪表放大器
带隙基准电压源，典型漂移值为4 ppm/°C
更新速率：4.17 Hz至470 Hz
6个差分模拟输入
内部时钟振荡器
50 Hz/60 Hz同时抑制
基准电压检测
可编程电流源

技术指标

Resolution (Bits): 16bit
# Chan: 6
Sample Rate: n/a
Interface: Ser,SPI
Analog Input Type: Diff-Uni
Ain Range: (2Vref/PGA Gain) p-p
ADC Architecture: Sigma-Delta
Pkg Type: SOP

应用领域

温度测量
压力测量
电子秤
应变计传感器
气体分析

功能框图

建议配套产品

Recommended High Accuracy, Precision References - 2.5V for the AD7795
- For low noise and and low power applications, we recommend the ADR381 or ADR391.
Recommended Digital Isolators for the AD7795
- For process control applications, we recommend the ADuM1400 and the ADuM1200 icoupler.
- For cost sensitive designs, we recommend the ADuM7440, ADuM7441 or ADuM7442.
- For digital isolators with integrated isolated power, we suggest the ADuM5401, ADuM5402 or the ADuM5403.
- For isolated USB designs in healthcare and industrial control, we recommend the ADuM4160.
Recommended Power Solutions
- For selecting voltage regulator products, use ADIsimPower.
- For selecting supervisor products, use the Supervisor Parametric Search.

订购指南

产品型号	产品状态	封装	Pins	温度范围
AD7795BRUZ	Prodn	24 ld TSSOP	24	工业
AD7795BRUZ-REEL	Prodn	24 ld TSSOP	24	工业
EVAL-AD7795EB	Prodn	EVALUATION BOARDS	-	待定