content here.
content here.

AD7148:  CapTouch® Programmable Controller for Single-Electrode Capacitance Sensors

The AD7148 CapTouch® Programmable Controller is designed for use with capacitance sensors implementing functions such as buttons, scroll bars, and wheels. The sensors need only one PCB layer, enabling ultra thin applications.

The AD7148 is an integrated capacitance-to-digital converter (CDC) with on-chip environmental calibration. The CDC has 8 inputs channeled through a switch matrix to a ...More

AD7148:  CapTouch® Programmable Controller for Single-Electrode Capacitance Sensors

Product Description

The AD7148 CapTouch® Programmable Controller is designed for use with capacitance sensors implementing functions such as buttons, scroll bars, and wheels. The sensors need only one PCB layer, enabling ultra thin applications.

The AD7148 is an integrated capacitance-to-digital converter (CDC) with on-chip environmental calibration. The CDC has 8 inputs channeled through a switch matrix to a 16-bit, 250 kHz sigma-delta (Σ-Δ) converter. The CDC is capable of sensing changes in the capacitance of the external sensors and uses this information to register a sensor activation. The external sensors can be arranged as a series of buttons, as a scroll bar or wheel, or as a combination of sensor types. By programming the registers, the user has full control over the CDC setup.

High resolution sensors require minor software to run on the host processor.

The AD7148 is designed for single electrode capacitance sensors (grounded sensors.) There is an active shield output to minimize noise pick-up in the sensor. For floating, or two electrode sensors, use the AD7143.

The AD7148 has on-chip calibration logic to account for changes in the ambient environment. The calibration sequence is performed automatically and at continuous intervals, while the sensors are not active. This ensures that there are no false or non-registering touches on the external sensors due to a changing environment.

The AD7148 has an I2C-compatible serial interface, as well as interrupt output. There is a VDRIVE pin to set the voltage level for the serial interface independently from VCC.

The AD7148 is available in a 16-lead, 4 mm × 4 mm LFCSP and operates from a 2.6 V to 3.6 V supply. The operating current consumption in low power mode is typically 26 μA.

Applications

  • Cell Phones
  • Personal Music and Multimedia Players
  • Smart Hand-held Devices
  • Television, A/V and Remote Controls
  • Gaming Consoles
  • Digital Still Cameras

RESOURCES & TOOLS

What is your task? Try Lead the Way AdvisorTM BETA
  • Programmable capacitance to digital converter
    Femto Farad resolution
    8 capacitance sensor inputs
    25ms update rate, all 8 sensor inputs
    No external RC components required
    Automatic conversion sequencer
  • On-chip automatic calibration logic
    Automatic compensation for environmental changes
    Automatic adaptive threshold and sensitivity levels
    Register map compatible with AD7143
  • On-chip RAM to store calibration data
  • I2C®-compatible serial interface
  • Separate VDRIVE level for serial interface
  • Interrupt Output
  • 16-lead, 4 mm x 4 mm LFCSP_VQ
  • 2.6 to 3.3V supply voltage
  • Low operating current
    Full power mode: 1 mA
    Low power mode: 21.5 µA
  • Resolution (Bits): 16bit
  • T-Put Rate: 4SPS
  • # Chan: 8
  • Supply V: Multi(+3.3Anlg, +3.3Dig)
  • Pwr Diss: 3.3mW
  • Sleep Pwr Diss: 24.8µW
  • Ain Range: ± 8 pF (Delta C)
  • Ref Int/Ext: Int
  • Product Description: Octal Input, Programmable-Touch Controller for Single Electrode Capacitance Sensors

Functional Block Diagram for AD7148

OF NOTE ...

Demo

Similar Products

arrow View Full Interactive Product Selection Table
Part# Resolution (Bits) T-Put Rate # Chan Supply V Pwr Diss 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 $1.28 CAPTouch (TM) Programmable Controller w/ SPI or I2C Interface for Single-Electrode Cap Sensors I²C/Ser 2-Wire, Ser, SPI
AD7147A 16 111SPS 13 Single(+3), Single(+3.3) 3.6mW 20 ±8 CSP $1.25 CapTouch® Programmable Controller for Single-Electrode Capacitance Sensors I²C/Ser 2-Wire, Ser, SPI
AD7148 16 4SPS 8 Multi(+3.3Anlg, +3.3Dig) 3.3mW 20 ±8 CSP $1.21 Octal Input, Programmable-Touch Controller for Single Electrode Capacitance Sensors I²C/Ser 2-Wire, Ser
AD7150 12 200SPS 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
AD7152 12 200SPS 2 Single(+2.7 to +3.6) 432µW 10 ±0.25 SOP $1.97 12-Bit Capacitance-to-Digital Converter (2 Capacitance Input Channels) I²C/Ser 2-Wire, Ser
AD7153 12 200SPS 1 Single(+2.7 to +3.6) 432µW 10 ±0.25 SOP $1.77 12-Bit Capacitance-to-Digital Converter I²C/Ser 2-Wire, Ser
AD7156 12 100SPS 2 Single(+1.8), Single(+2.5), Single(+2.7), Single(+3), Single(+3.3), Single(+3.6) 306µW 10 ±0.5 CSP $1.25 Ultralow Power, 1.8 V, 3 mm × 3 mm, 2-Channel Capacitance Converter 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
back to top

* 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.

Pricing, Packaging & Availability

Print Table
back to top

Help

Model
The model number is a specific version of a generic that can be purchased or sampled.

Status
Status indicates the current lifecycle of the product. This can be one of 4 stages:
  • Pre-Release: The model has not been released to general production, but samples may be available.
  • Production: The model is currently being produced, and generally available for purchase and sampling.
  • Last Time Buy: The model has been scheduled for obsolescence, but may still be purchased for a limited time.
  • Obsolete: The specific part is obsolete and no longer available. Other models listed in the table may still be available (if they have a status that is not obsolete).
Package Description
The package for this IC (i.e. DIP, SOIC, BGA). An Evaluation Board is a board engineered to show the performance of the model, the part is included on the board.

For detailed drawings and chemical composition please consult our  Package Site

Pin Count
Pin Count is the number of pins, balls, or pads on the device. Pin-out diagrams & pin function descriptions may be found in the datasheet.

Temperature Range
This is the acceptable operating range of the device. The various ranges specified are as follows:
  • Commercial: 0 to +70 degrees Celsius
  • Military : -55 to +125 degrees Celsius
  • Industrial: Temperature ranges may vary by model. Please consult the datasheet for more information.
  • Automotive: -40 to +125 degrees Celsius
Price
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.

Production Availability
This is the date Analog Devices, Inc. anticipates that the product will ship from the warehouse. Most orders ship within 48 hours of this date.Once an order has been placed, Analog Devices, Inc. will send an Order Acknowledgement email to confirm your delivery date. It is important to note the scheduled dock date on the order entry screen. We do take orders for items that are not in stock, so delivery may be scheduled at a future date. Also, please note the warehouse location for the product ordered. We have warehouses in the United States, Europe and Southeast Asia. Transit times from these sites may vary.
Sample availability may be better than production availability. Please enter samples into your cart to check sample availability.

RoHS Compliant
Due to environmental concerns, ADI offers many of our products in lead-free versions. For more information about lead-free parts, please consult our Pb (Lead) free information page.

View PCN
This is the list of Product Change Notifications (PCN) published on the web for this model. Click on the link to access PCN Information.Only select pre-2009 PCN�s are available on-line. To obtain a pre-2009 PCN, contact your ADI Sales Rep. For more information on ADI's PCN process, please visit our PCN Policy Statement page

*The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.
**Sample availability may be better than production availability. Please enter samples into your cart to check sample availability.