The AD8400/AD8402/AD8403 provide a single, dual or quad channel, 256 position digitally controlled variable resistor (VR) device. These devices perform the same electronic adjustment function as a potentiometer or variable resistor. The AD8400 contains a single variable resistor in the compact SO-8 package. The AD8402 contains two independent variable resistors in saving SO-14 surface mount package. The AD8403 contains four independent variable resistors in 24-lead PDIP, SOIC and TSSOP packages. Each part contains a fixed resistor with a wiper contact that taps the fixed resistor value at a point determined by a digital code loaded into the controlling serial input register. The resistance between the wiper and either endpoint of the fixed resistor varies linearly with respect to the digital code transferred into the VR latch. Each variable resistor offers a completely programmable value of resistance, between the A terminal and the wiper or the B terminal and the wiper. The fixed A to B terminal resistance of 1 kOhm, 10 kOhm, 50 kOhm or 100 kOhm has a ±1% channel-to-channel matching tolerance with a nominal temperature coefficient of 500 ppm/°C. A unique switching circuit minimizes the high glitch inherent in traditional switched resistor designs avoiding any make-before-break or break-before-make operation.Each VR has its own VR latch that holds its programmed resistance value. These VR latches are updated from an SPI compatible serial-to-parallel shift register that is loaded from a standard 3-wire serial-input digital interface. Ten data bits make up the data word clocked into the serial input register. The data word is decoded where the first two bits determine the address of the VR latch to be loaded, the last eight bits are data. A serial data output pin at the opposite end of the serial register allows simple daisy-chaining in multiple VR applications without additional external decoding logic.

The AD9835 is a numerically-controlled oscillator employing a phase accumulator, a COS lookup table, and a 10-bit digital-to-analog converter integrated on a single CMOS chip. Modulation capabilities are provided for phase modulation and frequency modulation.Clock rates of up to 50 MHz are supported. Frequency accuracycan be controlled to one part in 4 billion. Modulation is effected by loading registers through the serial interface. A power-down bit allows the user to power down the AD9835 when it is not in use, the power consumption reduces to 1.75 mW.The part is available in a 16-lead TSSOP package.APPLICATIONS Frequency stimulus/waveform generation Frequency phase tuning and modulation Low power RF/communications systems Liquid and gas flow measurement Sensory applications: proximity, motion, and defect detection Test and medical equipment

The AD5231 is a nonvolatile memory, digitally controlled potentiometer with 1024-step resolution. The device performs the same electronic adjustment function as a mechanical potentiometer with enhanced resolution, solid state reliability, and remote controllability. The AD5231 has versatile programming that uses a standard 3-wire serial interface for 16 modes of operation and adjustment, including scratchpad programming, memory storing and restoring, increment/decrement, ±6 dB/step log taper adjustment, wiper setting readback, and extra EEMEM for user-defined information, such as memory data for other components, look-up table, or system identification information.In scratchpad programming mode, a specific setting can be programmed directly to the RDAC register that sets the resistance between Terminals W–A and Terminals W–B. This setting can be stored into the EEMEM and is transferred automatically to the RDAC register during system power-on.The EEMEM content can be restored dynamically or through external PR strobing, and a WP function protects EEMEM contents. To simplify the programming, the linear-step increment or decrement commands can be used to move the RDAC wiper up or down, one step at a time. The ±6 dB step commands can be used to double or half the RDAC wiper setting.The AD5231 is available in a 16-lead TSSOP. The part is guaranteed to operate over the extended industrial temperature range of −40°C to +85°C.APPLICATIONS Mechanical potentiometer replacement Instrumentation: gain, offset adjustment Programmable voltage to current conversion Programmable filters, delays, time constants Programmable power supply Low resolution DAC replacement Sensor calibration

The AD5231 is a nonvolatile memory, digitally controlled potentiometer with 1024-step resolution. The device performs the same electronic adjustment function as a mechanical potentiometer with enhanced resolution, solid state reliability, and remote controllability. The AD5231 has versatile programming that uses a standard 3-wire serial interface for 16 modes of operation and adjustment, including scratchpad programming, memory storing and restoring, increment/decrement, ±6 dB/step log taper adjustment, wiper setting readback, and extra EEMEM for user-defined information, such as memory data for other components, look-up table, or system identification information.In scratchpad programming mode, a specific setting can be programmed directly to the RDAC register that sets the resistance between Terminals W–A and Terminals W–B. This setting can be stored into the EEMEM and is transferred automatically to the RDAC register during system power-on.The EEMEM content can be restored dynamically or through external PR strobing, and a WP function protects EEMEM contents. To simplify the programming, the linear-step increment or decrement commands can be used to move the RDAC wiper up or down, one step at a time. The ±6 dB step commands can be used to double or half the RDAC wiper setting.The AD5231 is available in a 16-lead TSSOP. The part is guaranteed to operate over the extended industrial temperature range of −40°C to +85°C.APPLICATIONS Mechanical potentiometer replacement Instrumentation: gain, offset adjustment Programmable voltage to current conversion Programmable filters, delays, time constants Programmable power supply Low resolution DAC replacement Sensor calibration

The AD5258 provides a compact, nonvolatile 3 mm × 4.9 mm packaged solution for 64-position adjustment applications. These devices perform the same electronic adjustment function as mechanical potentiometers or variable resistors, but with enhanced resolution and solid-state reliability.The wiper settings are controllable through an I2C-compatible digital interface that is also used to read back the wiper register and EEPROM content in addition, resistor tolerance is stored within EEPROM, providing an end-to-end tolerance accuracy of 0.1%. There is also a software write protection function that ensures data cannot be written to the EEPROM register.A separate VLOGIC pin delivers increased interface flexibility. For users who need multiple parts on one bus, Address Bit AD0 and Address Bit AD1 allow up to four devices on the same bus.APPLICATIONS LCD panel VCOM adjustment LCD panel brightness and contrast control Mechanical potentiometer replacement in new designs Programmable power supplies RF amplifier biasing Automotive electronics adjustment Gain control and offset adjustment Fiber to the home systems Electronics level settings

The AD5258 provides a compact, nonvolatile 3 mm × 4.9 mm packaged solution for 64-position adjustment applications. These devices perform the same electronic adjustment function as mechanical potentiometers or variable resistors, but with enhanced resolution and solid-state reliability.The wiper settings are controllable through an I2C-compatible digital interface that is also used to read back the wiper register and EEPROM content in addition, resistor tolerance is stored within EEPROM, providing an end-to-end tolerance accuracy of 0.1%. There is also a software write protection function that ensures data cannot be written to the EEPROM register.A separate VLOGIC pin delivers increased interface flexibility. For users who need multiple parts on one bus, Address Bit AD0 and Address Bit AD1 allow up to four devices on the same bus.APPLICATIONS LCD panel VCOM adjustment LCD panel brightness and contrast control Mechanical potentiometer replacement in new designs Programmable power supplies RF amplifier biasing Automotive electronics adjustment Gain control and offset adjustment Fiber to the home systems Electronics level settings

The AD637 is a complete, high accuracy, rms-to-dc converter that computes the true rms value of any complex waveform. It offers performance that is unprecedented in integrated circuit rms-to-dc converters and comparable to discrete and modular techniques in accuracy, bandwidth, and dynamic range. The AD637 computes the true root mean square, mean square, or absolute value of any complex ac (or ac plus dc) input waveform and gives an equivalent dc output voltage. The true rms value of a waveform is more useful than an average rectified signal because it relates directly to the power of the signal. The rms value of a statistical signal relates to the standard deviation of the signal.Superior crest factor compensation permits measurements of signals with crest factors of up to 10 with less than 1% additional error. The wide bandwidth of the AD637 permits the measurement of signals up to 600 kHz with inputs of 200 mV rms and up to 8 MHz when the input levels are above 1 V rms.Direct dB value of the rms output with a range of 60 dB is available on a separate pin. An externally programmed reference current allows the user to select the 0 dB reference voltage to correspond to any level between 0.1 V and 2.0 V rms.A chip select connection on the AD637 permits the user to decrease the supply current from 2.2 mA to 350 µA during periods when the rms function is not in use. This feature facilitates the addition of precision rms measurement to remote or handheld applications where minimum power consumption is critical. In addition, when the AD637 is powered down, the output goes to a high impedance state. This allows several AD637s to be tied together to form a wideband true rms multiplexer.The input circuitry of the AD637 is protected from overload voltages in excess of the supply levels. The inputs are not damaged by input signals if the supply voltages are lost.The AD637 is laser wafer trimmed to achieve rated performance without external trimming. The only external component required is a capacitor that sets the averaging period. The value of this capacitor also determines low frequency accuracy, ripple level, and settling time.The on-chip buffer amplifier is used either as an input buffer or in an active filter configuration. The filter can be used to reduce the amount of ac ripple, thereby increasing accuracy.The AD637 is available in accuracy Grade J and Grade K for commercial temperature range (0°C to 70°C) applications, accuracy Grade A and Grade B for industrial range (−40°C to +85°C) applications, and accuracy Grade S rated over the −55°C to +125°C temperature range. All versions are available in hermetically sealed, 14-lead SBDIP, 14-lead CERDIP, and 16-lead SOIC_W packages.

The AD7142 and AD7142-1 are integrated capacitance-to-digital converters (CDCs) with on-chip environmental calibration for use in systems requiring a novel user input method. The AD7142 and AD7142-1 can interface to external capacitance sensors implementing functions such as capacitive buttons, scroll bars, or wheels.The CDC has 14 inputs channeled through a switch matrix to a 16-bit, 250 kHz sigma-delta (∑-Δ) capacitance-to-digital 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 AD7142 and AD7142-1 have on-chip calibration logic to account for changes in the ambient environment. The calibration sequence is performed automatically and at continuous intervals, when the sensors are not touched. This ensures that there are no false or nonregistering touches on the external sensors due to a changing environment.The AD7142 has an SPI-compatible serial interface, and the AD7142-1 has an I2C-compatible serial interface. Both parts have an interrupt output, as well as a general-purpose input/ output (GPIO). The AD7142 and AD7142-1 are available in a 32-lead, 5 mm × 5 mm LFCSP_VQ and operate from a 2.6 V to 3.6 V supply. The operating current consumption is less than 1 mA, falling to 50 μA in low power mode (conversion interval of 400 ms).ApplicationsPersonal music and multimedia playersCell phonesDigital still camerasSmart hand-held devicesTelevision, A/V, and remote controlsGaming consoles

The AD5291 and AD5292 are single-channel, 256-/1024-position digital potentiometers that combine industry leading variable resistor performance with nonvolatile memory (NVM) in a compact package. These devices are capable of operating across a wide voltage range, supporting both dual supply operation at ±10.5 V to ±16.5 V and single supply operation at +21 V to +33 V, while ensuring less than 1% end-to-end resistor tolerance error and offering 20-time programmable (20-TP) memory.The guaranteed industry leading low resistor tolerance error feature simplifies open-loop applications as well as precision calibration and tolerance matching applications.The AD5291 and AD5292 device wiper settings are controllable through the SPI digital interface. Unlimited adjustments are allowed before programming the resistance value into the 20-TP memory. The AD5291 and AD5292 do not require any external voltage supply to facilitate fuse blow, and there are 20 opportunities for permanent programming. During 20-TP activation, a permanent blow fuse command freezes the wiper position (analogous to placing epoxy on a mechanical trimmer).The AD5291 and AD5292 are available in a compact 14-lead TSSOP package. The part is guaranteed to operate over the extended industrial temperature range of −40°C to +105°C.APPLICATIONS Mechanical potentiometer replacement Instrumentation: gain and offset adjustment Programmable voltage-to-current conversion Programmable filters, delays, and time constants Programmable power supply Low resolution DAC replacement Sensor calibration

The AD5560 is a high performance, highly integrated device power supply consisting of programmable force voltages and measure ranges. This part includes the required DAC levels to set the programmable inputs for the drive amplifier, as well as clamping and comparator circuitry. Offset and gain correction is included on-chip for DAC functions. A number of programmable measure current ranges are available: five internal fixed ranges and two external customer-selectable ranges (EXTFORCE1 and EXTFORCE2) that can supply currents up to ±1.2 A and ±500 mA, respectively. The voltage range possible at this high current level is limited by headroom and the maximum power dissipation. Current ranges in excess of ±1.2 A or at high current and high voltage combinations can be achieved by paralleling or ganging multiple DPS devices. Open-drain alarm outputs are provided in the event of overcurrent, overtemperature, or Kelvin alarm on either the SENSE or DUTGND line.The DPS functions are controlled via a simple 3-wire serial interface compatible with SPI, QSPI™, MICROWIRE™, and DSP interface standards running at clock speeds of up to 50 MHz.APPLICATIONS Automatic test equipment (ATE) Device power supply