AD7781: 20-Bit, Pin-Programmable, Ultralow Power Sigma-Delta ADC |
The AD7781 is a complete low power front-end solution for bridge sensor products, including weigh scales, strain gages, and pressure sensors. It contains a precision low power 20-bit sigma-delta (Σ-Δ) ADC, an on-chip, low noise programmable gain amplifier (PGA), and an on-chip oscillator.
Consuming only 330 μA, the AD7781 is particularly suitable for portable or battery-operated products ...More
The AD7781 is a complete low power front-end solution for bridge sensor products, including weigh scales, strain gages, and pressure sensors. It contains a precision low power 20-bit sigma-delta (Σ-Δ) ADC, an on-chip, low noise programmable gain amplifier (PGA), and an on-chip oscillator.
Consuming only 330 μA, the AD7781 is particularly suitable for portable or battery-operated products where very low power is required. The AD7781 also has a power-down mode that allows the user to switch off the power to the bridge sensor and power down the AD7781 when not converting, thus increasing the battery life of the product.
For ease of use, all the features of the AD7781 are controlled by dedicated pins. Each time that a data read occurs, eight status bits are appended to the 20-bit conversion. These status bits contain a pattern sequence that can be used to confirm the validity of the serial transfer.
The on-chip PGA has a gain of 1 or 128, supporting a full-scale differential input of ±5 V or ±39 mV. The device has two filter response options. The filter response at the 16.7 Hz update rate provides superior dynamic performance. The settling time is 120 ms at this update rate. At the 10 Hz update rate, the filter response provides better than -45 dB of stop-band attenuation. In load cell applications, this stop-band rejection is useful to reject low frequency mechanical vibrations of the load cell. The settling time is 300 ms at this update rate. Simultaneous 50 Hz/60 Hz rejection occurs at both the 10 Hz and 16.7 Hz update rates.
The AD7781 operates with a power supply from 2.7 V to 5.25 V. It is available in a narrow body, 14-lead SOIC package and in a 16-lead TSSOP package.
Applications
| Part# | Bits | Throughput Rate | # of Inputs | Operating Pwr Diss |
|---|---|---|---|---|
| AD7781 | 20 | 16.7SPS | 1 | 2.1mW |
| AD7790 | 16 | 120SPS | 1 | 800µW |
| AD7796 | 16 | 123SPS | 1 | 1.6mW |
| AD7466 | 12 | 200KSPS | 1 | 900µW |
| AD7791 | 24 | 120SPS | 1 | 800µW |
| AD7151 | 12 | 100SPS | 1 | 300µW |
| AD7797 | 24 | 123SPS | 1 | 1.6mW |
| AD7153 | 12 | 200SPS | 1 | 432µW |
| AD7467 | 10 | 200KSPS | 1 | 630µW |
| AD7468 | 8 | 200KSPS | 1 | 570µW |
| AD7703 | 20 | 4KSPS | 1 | 37mW |
| 产品型号 | 产品状态 | 封装 | 引脚 | 温度范围 | 报价* (1000 pcs.) |
生产供货情况** | 符合ROHS规定 | 查看PCN | 样片车 | 购物车 |
|---|---|---|---|---|---|---|---|---|---|---|
| AD7781BRUZ | 量产 | 16 ld TSSOP | 16 | 工业 | $ 2.30 | 11/13/2009 | Y 材料声明 | - | 添加到样片车 | 添加到购物车 |
| AD7781BRUZ-REEL | 量产 | 16 ld TSSOP | 16 | 工业 | $ | - | Y 材料声明 | - | 联络ADI | 添加到购物车 |
| AD7781BRZ | 量产 | 14 ld SOIC | 14 | 工业 | $ 2.30 | 11/13/2009 | Y 材料声明 | - | 添加到样片车 | 添加到购物车 |
| AD7781BRZ-REEL | 量产 | 14 ld SOIC | 14 | 工业 | $ | 01/15/2010 | Y 材料声明 | - | 联络ADI | 添加到购物车 |
| AD7781CRUZ | 量产 | 16 ld TSSOP | 16 | 工业 | $ 2.60 | 11/13/2009 | Y 材料声明 | - | 联络ADI | 添加到购物车 |
| AD7781CRUZ-REEL | 量产 | 16 ld TSSOP | 16 | 工业 | $ | - | Y 材料声明 | - | 联络ADI | 添加到购物车 |
| AD7781CRZ | 量产 | 14 ld SOIC | 14 | 工业 | $ 2.60 | 11/13/2009 | Y 材料声明 | - | 联络ADI | 添加到购物车 |
| AD7781CRZ-REEL | 量产 | 14 ld SOIC | 14 | 工业 | $ | - | Y 材料声明 | - | 联络ADI | 添加到购物车 |
| EVAL-AD7781EBZ | 量产 | 评估板 | - | 待定 | $ 65.00 | 11/13/2009 | Y | - | 联络ADI | 添加到购物车 |
*这里所列出的美国报价单仅供预算参考，指美元报价（规定订量的每片美元，美国离岸价），如有修改不再另行通知。由于地区关税、商业税、汇率及手续费原因，国际报价可能不同。对于特殊批量报价，请与您当地的ADI公司办事处或代理商联络。对于评估板和套件的报价是指一个单位价格。
**样片供货情况可能好于生产供货，请将样片放入购物车，以查看样片供货情况。
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