The AD698 is a complete, monolithic Linear Variable Differential Transformer (LVDT) signal conditioning subsystem. It is used in conjunction with LVDTs to convert transducer mechanical position to a unipolar or bipolar dc voltage with a high degree of accuracy and repeatability. All circuit functions are included on the chip. With the addition of a few external passive components to set frequency and gain, the AD698 converts the raw LVDT output to a scaled dc signal. The device will operate with half-bridge LVDTs, LVDTs connected in the series opposed configuration (4-wire), and RVDTs.The AD698 contains a low distortion sine wave oscillator to drive the LVDT primary. Two synchronous demodulation channels of the AD698 are used to detect primary and secondary amplitude. The part divides the output of the secondary by the amplitude of the primary and multiplies by a scale factor. This eliminates scale factor errors due to drift in the amplitude of the primary drive, improving temperature performance and stability.The AD698 uses a unique ratiometric architecture to eliminate several of the disadvantages associated with traditional approaches to LVDT interfacing. The benefits of this new circuit are: no adjustments are necessary; temperature stability is improved; and transducer interchangeability is improved.The AD698 is available in two performance grades: Grade Temperature Range Package AD698AP –40°C to +85°C 28-Pin PLCC AD698SQ –55°C to +125°C 24-Pin Cerdip

The AD706 is a dual, low power, bipolar op amp that has thelow input bias current of a JFET amplifier, but which offers asignificantly lower IB drift over temperature. It utilizes superbetabipolar input transistors to achieve picoampere input bias currentlevels (similar to FET input amplifiers at room temperature),while its IB typically only increases by 5 at 125°C (unlike aJFET amp, for which IB doubles every 10°C for a 1000×increase at 125°C). The AD706 also achieves the microvoltoffset voltage and low noise characteristics of a precision bipolarinput amplifier.Since it has < 200 pA of bias current, the AD706 does notrequire the commonly used “balancing” resistor. Furthermore,the current noise is only 50 fA/√Hz, which makes this amplifierusable with very high source impedances. At 600 A max supplycurrent (per amplifier), the AD706 is well suited for today’shigh density boards.The AD706 is an excellent choice for use in low frequencyactive filters in 12-bit and 14-bit data acquisition systems, inprecision instrumentation, and as a high quality integrator. TheAD706 is internally compensated for unity gain and is availablein five performance grades. The AD706J is rated over thecommercial temperature range of 0°C to +70°C. The AD706A israted for the extended industrial temperature range of −40°Cto +85°C.The AD706 is offered in two varieties of an 8-lead package:PDIP and surface-mount (SOIC).PRODUCT HIGHLIGHTS The AD706 is a dual low drift op amp that offers JFET level input bias currents, yet has the low IB drift of a bipolar amplifier. It may be used in circuits using dual op amps such as the LT1024. The AD706 provides both low drift and high dc precision. The AD706 can be used in applications where a chopper amplifier would normally be required but without the chopper’s inherent noise.APPLICATIONS Low Frequency Active Filters Precision Instrumentation Precision Integrators

The AD706 is a dual, low power, bipolar op amp that has thelow input bias current of a JFET amplifier, but which offers asignificantly lower IB drift over temperature. It utilizes superbetabipolar input transistors to achieve picoampere input bias currentlevels (similar to FET input amplifiers at room temperature),while its IB typically only increases by 5 at 125°C (unlike aJFET amp, for which IB doubles every 10°C for a 1000×increase at 125°C). The AD706 also achieves the microvoltoffset voltage and low noise characteristics of a precision bipolarinput amplifier.Since it has < 200 pA of bias current, the AD706 does notrequire the commonly used “balancing” resistor. Furthermore,the current noise is only 50 fA/√Hz, which makes this amplifierusable with very high source impedances. At 600 A max supplycurrent (per amplifier), the AD706 is well suited for today’shigh density boards.The AD706 is an excellent choice for use in low frequencyactive filters in 12-bit and 14-bit data acquisition systems, inprecision instrumentation, and as a high quality integrator. TheAD706 is internally compensated for unity gain and is availablein five performance grades. The AD706J is rated over thecommercial temperature range of 0°C to +70°C. The AD706A israted for the extended industrial temperature range of −40°Cto +85°C.The AD706 is offered in two varieties of an 8-lead package:PDIP and surface-mount (SOIC).PRODUCT HIGHLIGHTS The AD706 is a dual low drift op amp that offers JFET level input bias currents, yet has the low IB drift of a bipolar amplifier. It may be used in circuits using dual op amps such as the LT1024. The AD706 provides both low drift and high dc precision. The AD706 can be used in applications where a chopper amplifier would normally be required but without the chopper’s inherent noise.APPLICATIONS Low Frequency Active Filters Precision Instrumentation Precision Integrators

NEWER ALTERNATIVES: AD5304 2.5 V to 5.5 V, 500 µA, Quad Voltage Output 8-Bit DAC in a 10-Lead Packages AD5307 2.5 V to 5.5 V, 400 µA, Quad Voltage Output 8-Bit DAC in a 16-Lead TSSOPThe AD7226 contains four 8-bit voltage-output digital-to-analog converters, with output buffer amplifiers and interface logic on a single monolithic chip. No external trims are required to achieve full specified performance for the part.Separate on-chip latches are provided for each of the four D/A converters. Data is transferred into one of these data latches through a common 8-bit TTL/CMOS (5 V) compatible input port. Control inputs A0 and A1 determine which DAC is loaded when WR goes low. The control logic is speed-compatible with most 8-bit microprocessors.Each D/A converter includes an output buffer amplifier capable of driving up to 5 mA of output current. The amplifiers’ offsets are laser-trimmed during manufacture, thereby eliminating any requirement for offset nulling.Specified performance is guaranteed for input reference voltages from 2 V to 12.5 V with dual supplies. The part is also specified for single supply operation at a reference of 10 V.The AD7226 is fabricated in an all ion-implanted high speed Linear Compatible CMOS (LC2MOS) process which has been specifically developed to allow high speed digital logic circuits and precision analog circuits to be integrated on the same chip.APPLICATIONS Process control Automatic Test Equipment Automatic Calibration of Large System Parameters

The AD7233 is a complete 12-bit, voltage-output, digital-to-analog converter with output amplifier and Zener voltage reference all in an 8-pin package. No external trims are required to achieve full specified performance. The data format is 2s complement, and the output range is -5V to +5V.The AD7233 features a fast, versatile serial interface which allows easy connection to both microcomputers and 16-bit digital signal processors with serial ports. When the SYNC input is taken low, data on the SDIN pin is clocked into the input shift register on each falling edge of SCLK. On completion of the 16-bit data transfer, bringing LDAC low updates the DAC latch with the lower 12 bits of data and updates the output. Alternatively, LDAC can be tied permanently low, and in this case the DAC register is automatically updated with the contents of the shift register when all sixteen data bits have been clocked in. The serial data may be applied at rates up to 5 MHz allowing a DAC update rate of 300 kHz.For applications which require greater flexibility and unipolar output ranges with single supply operation, please refer to the AD7243 data sheet.The AD7233 is fabricated on Linear Compatible CMOS (LC2MOS), an advanced, mixed-technology process. It is packaged in an 8-pin DIP package.

The AD7237A / AD7247A is an enhanced version of the industry standard AD7237 / AD7247. Improvements include operation from 12 V to 15 V supplies, faster interface times and better reference variations with VDD . Additional features include faster settling times.The AD7237A / AD7247A is a complete, dual, 12-bit, voltage output digital-to-analog converter with output amplifiers and Zener voltage reference on a monolithic CMOS chip. No external user trims are required to achieve full specified performance.Both parts are microprocessor compatible, with high speed data latches and interface logic. The AD7247A accepts 12-bit parallel data which is loaded into the respective DAC latch using the WR input and a separate Chip Select input for each DAC. The AD7237A has a double buffered interface structure and an 8-bit wide data bus with data loaded to the respective input latch in two write operations. An asynchronous LDAC signal on the AD7237A updates the DAC latches and analog outputs.A REF OUT/REF IN function is provided which allows either the on-chip 5 V reference or an external reference to be used as a reference voltage for the part. For single supply operation, two output ranges of 0 V to +5 V and 0 V to +10 V are available, while these two ranges plus an additional ±5 V range are available with dual supplies. The output amplifiers are capable of developing +10 V across a 2 k(Ω) load to GND.The AD7237A / AD7247A is fabricated in Linear Compatible CMOS (LC2MOS), an advanced, mixed technology process that combines precision bipolar circuits with low power CMOS logic. Both parts are available in a 24-pin, 0.3' wide plastic and hermetic dual-in-line package (DIP) and are also packaged in a 24-lead small outline (SOIC) package.

The AD7243 is a complete 12-bit, voltage output, digital-toanalog converter with output amplifier and Zener voltage reference on a monolithic CMOS chip. No external trims are required to achieve full specified performance.The output amplifier is capable of developing +10 V across a 2 kΩ load. The output voltage ranges with single supply operation are 0 V to +5 V or 0 V to +10 V, while an additional bipolar ±5 V output range is available with dual supplies. The ranges are selected using the internal gain resistor.The data format is natural binary in both unipolar ranges, while either offset binary or two’s complement format may be selected in the bipolar range. A CLR function is provided which sets the output to 0 V in both unipolar ranges and in the two’s complement bipolar range, while with offset binary data format, the output is set to –REFIN. This function is useful as a power-on reset as it allows the output to be set to a known voltage level.The AD7243 features a fast versatile serial interface which allows easy connection to both microcomputers and 16-bit digital signal processors with serial ports. The serial data may be applied at rates up to 5 MHz allowing a DAC update rate of 300 kHz. A serial data output capability is also provided which allows daisy chaining in multi-DAC systems. This feature allows any number of DACs to be used in a system with a simple 4-wire interface. All DACs may be updated simultaneously using LDAC.The AD7243 is fabricated on Linear Compatible CMOS (LC2 MOS), an advanced, mixed technology process. It is packaged in 16-lead DIP and 16-lead SOIC packages.DACPORT is a registered trademark of Analog Devices, Inc.APPLICATIONS Process Control Industrial Automation Digital Signal Processing Systems Input/Output Ports

The AD7242 / AD7244 is a fast, complete, dual 12-bit/14-bit voltage output D/A converter. It consists of a 12-bit/14-bit DAC, 3 V buried Zener reference, DAC output amplifiers and high speed serial interface logic.Interfacing to both DACs is serial, minimizing pin count and allowing a small package size. Standard control signals allow interfacing to most DSP processors and microcontrollers. Asynchronous control of DAC updating for both DACs is made possible with a separate LDAC input for each DAC.The AD7242 / AD7244 operates from ±5 V power supplies, providing an analog output range of ±3 V. A REF OUT/REF IN function allows the DACs to be driven from the on-chip 3 V reference or from an external reference source.The AD7242 / AD7244 is fabricated in Linear Compatible CMOS (LC2MOS), an advanced mixed technology process that combines precision bipolar circuits with low power CMOS logic. Both parts are available in a 24-pin, 0.3-inch wide, plastic or hermetic dual-in-line package (DIP) and in a 28-pin, plastic small outline (SOIC) package. The AD7242 and AD7244 are available in the same pinout to allow easy upgrade from 12-bit to 14-bit performance.PRODUCT HIGHLIGHTS Complete, Dual 12-Bit/14-Bit DACs The AD7242 / AD7244 provides the complete function for generating voltages to 12-bit/14-bit resolution. The part features an on-chip reference, output buffer amplifiers and two 12-bit/14-bit D/A converters. High Speed Serial Interface The AD7242 / AD7244 provides a high speed, easy-to-use, serial interface allowing direct interfacing to DSP processors and microcontrollers. A separate serial port is provided for each DAC. Small Package Size The AD7242 / AD7244 is available in a 24-pin DIP and a 28- pin SOIC package offering considerable space saving over comparable solutions.

The AD7302 is a dual, 8-bit voltage out DAC that operates from a single +2.7 V to +5.5 V supply. Its on-chip precision output buffers allow the DAC outputs to swing rail to rail. The AD7302 has a parallel microprocessor and DSP-compatible interface with high speed registers and double buffered interface logic. Data is loaded to the registers on the rising edge of CS or WR and the A/B pin selects either DAC A or DAC B.Reference selection for AD7302 can be either an internal reference derived from the VDD or an external reference applied at the REFIN pin. Both DACs can be simultaneously updated using the asynchronous LDAC input and can be cleared by using the asynchronous CLR input.The low power consumption of this part makes it ideally suited to portable battery operated equipment. The power consumption is less than 10 mW at 3.3 V, reducing to 3 µW in powerdown mode.The AD7302 is available in a 20-pin plastic dual-in-line package, 20-lead SOIC and a 20-lead TSSOP package.APPLICATIONS Portable Battery Powered Instruments Digital Gain and Offset Adjustment Programmable Voltage and Current Sources Programmable AttenuatorsPRODUCT HIGHLIGHTS Low Power, Single Supply Operation. This part operates from a single +2.7 V to +5.5 V supply and typically consumes 15 mW at 5 V, making it ideal for battery powered applications. The on-chip output buffer amplifiers allow the outputs of the DACs to swing rail to rail with a settling time of typically 1.2 µs. Internal or external reference capability. High speed parallel interface. Power-Down Capability. When powered down the DAC consumes less than 1 µA at 25°C. Packaged in 20-lead DIP, SOIC and TSSOP packages.

The AD7303 is a dual, 8-bit voltage out DAC that operates from a single +2.7 V to +5.5 V supply. Its on-chip precision output buffers allow the DAC outputs to swing rail to rail. This device uses a versatile 3-wire serial interface that operates at clock rates up to 30 MHz, and is compatible with QSPI, SPI, microwire and digital signal processor interface standards. The serial input register is sixteen bits wide; 8 bits act as data bits for the DACs, and the remaining eight bits make up a control register.The on-chip control register is used to address the relevant DAC, to power down the complete device or an individual DAC, to select internal or external reference and to provide a synchronous loading facility for simultaneous update of the DAC outputs with a software LDAC function.The low power consumption of this part makes it ideally suited to portable battery operated equipment. The power consumption is 7.5 mW max at 3 V, reducing to less than 3 µW in full power-down mode.The AD7303 is available in an 8-pin plastic dual in-line package, 8-lead SOIC and microSOIC packages.