AD7745: 24-bit, 1 Channel Capacitance to Digital Converter
The AD7745/AD7746 are a high resolution, Σ-Δ capacitance-to-digital converter (CDC). The capacitance to be measured is connected directly to the device inputs. The architecture features inherent high ...More
Order the AD7746 Evaluation Board (EVAL-AD7746EB) which can also be used for the AD7745.
AD7745: 24-bit, 1 Channel Capacitance to Digital Converter
Product Description
The AD7745/AD7746 are a high resolution, Σ-Δ capacitance-to-digital converter (CDC). The capacitance to be measured is connected directly to the device inputs. The architecture features inherent high resolution (24-bit no missing codes, up to 21-bit effective resolution), high linearity (±0.01%), and high accuracy (±4 fF factory calibrated). The AD7745/AD7746 capacitance input range is ±4 pF (changing), while it can accept up to 17 pF common-mode capacitance (not changing), which can be balanced by a programmable on-chip, digital-to-capacitance converter (CAPDAC).
The AD7745 has one capacitance input channel, while the AD7746 has two channels. Each channel can be configured as single-ended or differential. The AD7745/AD7746 are designed for floating capacitive sensors. For capacitive sensors with one plate connected to ground, the AD7747 is recommended.
The parts have an on-chip temperature sensor with a resolution of 0.1°C and accuracy of ±2°C. The on-chip voltage reference and the on-chip clock generator eliminate the need for any external components in capacitive sensor applications. The parts have a standard voltage input, which together with the differential reference input allows easy interface to an external temperature sensor, such as an RTD, thermistor, or diode.
The AD7745/AD7746 have a 2-wire, I2C-compatible serial interface. Both parts can operate with a single power supply from 2.7 V to 5.25 V. They are specified over the automotive temperature range of –40°C to +125°C and are housed in a 16-lead TSSOP package.
Applications
Automotive, Industrial and Medical Systems for:
- Pressure Measurement
- Position Sensors
- Level Sensors
- Flowmeters
- Humidity Sensors
- Impurity Detection
Features
Capacitance-to-digital converter
- New standard in single chip solutions
- Interfaces to single or differential floating sensors
- Resolution down to 4 aF (that is, up to 21 ENOB)
- Accuracy: 4 fF
- Linearity: 0.01%
- Common-mode (not changing) capacitance up to 17 pF
- Full-scale (changing) capacitance range: ±4 pF
- Tolerant of parasitic capacitance to ground up to 60 pF
- Update rate: 10 Hz to 90 Hz
- Simultaneous 50 Hz and 60 Hz rejection at 16 Hz >
- Temperature sensor on-chip
▪ Resolution: 0.1°C, accuracy: ±2°C - Voltage input channel
- Internal clock oscillator
- 2-wire serial interface (I2C®-compatible)
- Power
▪ 2.7 V to 5.25 V single-supply operation
▪ 0.7 mA current consumption - Operating temperature: –40°C to +125°C
- 16-lead TSSOP package
Diagrams
- Enlarge
- Другие диаграммы
- Обозначения и трафареты для печатной платы
Functional Block Diagram for AD7745
24-bit, 1 Channel Capacitance to Digital Converter
Другие диаграммы для AD7745
24-bit, 1 Channel Capacitance to Digital Converter
AD7745 16-TSSOP
Functional Block Diagram for AD7745
Характеристики
| Resolution (Bits) | 24bit |
| T-Put Rate | 90SPS |
| # Chan | 1 |
| Supply V | Single(+2.7 to +5.25) |
| Pwr Diss (max) | 4.25mW |
| Sleep Pwr Diss | 10µW |
| Ain Range | (2Vref) p-p,± 4 pF (Delta C) |
| Ref Int/Ext | Int/Ext |
| Product Description | 24-Bit, Cap-to-Dig Conv. w/ 1 SE/Diff Capacitive Input Ch for Interface to Dual Electrode Cap Sensor |
AD7153 - 12-битный преобразователь емкостного сигнала в цифровой (1 входной емкостной канал)
AD7152 - 12-Bit Capacitance-to-Digital Converter (2 Capacitance Input Channels)
| Part# | Resolution (Bits) | T-Put Rate | # Chan | Supply V | Pwr Diss (max) | Input Base C (pF Max) | Cin Range (pF) | Pkg Type | Price* (1000-4999) | Product Description | Interface |
|---|---|---|---|---|---|---|---|---|---|---|---|
| AD7142 | 16 | 27.8SPS | 14 | Single(+2.6 to +3.6), Single(+2.7), Single(+3), Single(+3.3) | 3.6mW | 20 | ±2 | CSP | $1.37 | CAPTouch (TM) Programmable Controller for 2-Electrode Capacitance Sensor with SPI or I2C Interface | I²C/Ser 2-Wire, Ser, SPI |
| AD7143 | 16 | 43.5SPS | 8 | Single(+2.6 to +3.6) | 3.6mW | 20 | ±2 | CSP | $1.25 | CAPTouch (TM) Programmable Controller for 2-Electrode Capacitance Sensor with I2C Interface | I²C/Ser 2-Wire, Ser |
| AD7147 | 16 | 111SPS | 13 | Single(+3), Single(+3.3) | 3.6mW | 20 | ±8 | CSP | $1.30 | CAPTouch (TM) Programmable Controller w/ SPI or I2C Interface for Single-Electrode Cap Sensors | I²C/Ser 2-Wire, Ser, SPI |
| AD7150 | 12 | 100SPS | 2 | Single(+2.7 to +3.6) | 0.43mW | 10 | ±4 | SOP | $1.37 | Ultra-Lo Pwr, 2-Ch Capacitance Converter for Proximity Sensing Applications | I²C/Ser 2-Wire, Ser |
| AD7151 | 12 | 100SPS | 1 | Single(+2.7 to +3.6) | 0.3mW | 10 | ±4 | SOP | $1.37 | Ultra-Low Power, 1-Ch, Capacitance Converter for Proximity Sensing Applications | I²C/Ser 2-Wire, Ser |
| AD7745 | 24 | 90SPS | 1 | Single(+2.7 to +5.25) | 4.25mW | 17 | ±4 | SOP | $4.66 | 24-Bit, Cap-to-Dig Conv. w/ 1 SE/Diff Capacitive Input Ch for Interface to Dual Electrode Cap Sensor | I²C/Ser 2-Wire, Ser |
| AD7746 | 24 | 90SPS | 2 | Single(+2.7 to +5.25) | 4.25mW | 17 | ±4 | SOP | $5.01 | 24-bit, Cap-to-Dig Conv. w/ 2 SE/Diff Capacitive Input Ch for interface to Dual Electrode Cap Sensor | I²C/Ser 2-Wire, Ser |
| AD7747 | 24 | 45.5SPS | 1 | Single(+2.7 to +5.25) | 4.25mW | 17 | ±8 | SOP | $4.66 | 24-bit, Cap-to-Dig Conv w/1 SE/Diff Capacitive Input Ch for interface to Single Electrode Cap Sensor | I²C/Ser 2-Wire, Ser |
* The pricing listed here is provided only for budgetary purposes as recommended list price in U.S.
Dollars in the United States ex factor per unit for the stated volume. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.
** Pricing is currently unavailable. Click on the product number to see the Product Page for additional information.
AD7745 Model Options
| Модели | Статус | Корпуса | Pins | Температурный диапазон |
Цена* (1000 pcs.) |
Production** Availability |
ROHS Compliant | Samples Cart | Purchase Cart |
|---|---|---|---|---|---|---|---|---|---|
| AD7745ARUZ | Prodn | 16 ld TSSOP | 16 | Ind | $ 4,66 | 10/17/2008 |
Y
Material Declaration |
Add To Cart | Add To Cart |
| AD7745ARUZ-REEL | Prodn | 16 ld TSSOP | 16 | Ind | $ 4,66 | - |
Y
Material Declaration |
Обратная связь | Add To Cart |
| AD7745ARUZ-REEL7 | Prodn | 16 ld TSSOP | 16 | Ind | $ 4,66 | 10/17/2008 |
Y
Material Declaration |
Обратная связь | Add To Cart |
Help
Close- "Pre-Release": модель микросхемы еще не запущена в серийное производство, однако можно получить образцы.
- Производство: модель производится, доступна для покупки и заказа образцов.
- Завершение продаж: запланировано снятие модели микросхемы с производства, но в течение некоторого ограниченного времени покупка еще возможна.
- Снято с производства: Микросхема снята с производства и не доступна для приобретения. Другие варианты, указанные в таблице, все еще производятся (если их статус любой, кроме "снято с производства")
Для более подробного описания корпуса и материалов - см. Package Site
- Коммерческое исполнение: 0…70°С
- Военное исполнение: от -55 до +125 градусов по Цельсию
- Индустриальное исполнение: диапазоны рабочих температур могут быть разные у разных моделей. См. техническое описание (datasheet)
- Automotive: -40 to +125 °С
Sample availability may be better than production availability. Please enter samples into your cart to check sample availability.
*Приведенные цены действительны в США и указаны только для примерного бюджетного рассчета. Цены указаны в долларах США (за штуку в указанном размере партии) и могут быть изменены. Цены в других регионах могут отличаться в зависимости от местных пошлин, налогов, сборов и курсов валют. Для уточн