The AD7705 / AD7706 are complete analog front ends for low frequency measurement applications. These 2-/3-channel devices can accept low level input signals directly from a transducer and produce serial digital output. The devices employ a Σ-Δ conversion technique to realize up to 16 bits of no missing codes performance. The selected input signal is applied to a proprietary, programmable-gain front end based around an analog modulator. The modulator output is processed by an on-chip digital filter. The first notch of this digital filter can be programmed via an on-chip control register, allowing adjustment of the filter cutoff and output update rate. The AD7705 / AD7706 devices operate from a single 2.7 V to 3.3 V or 4.75 V to 5.25 V supply. The AD7705 features two fully differential analog input channels; the AD7706 features three pseudo differential input channels. Both devices feature a differential reference input. Input signal ranges of 0 mV to 20 mV through 0 V to 2.5 V can be incorporated on both devices when operating with a VDD of 5 V and a reference of 2.5 V. They can also handle bipolar input signal ranges of ±20 mV through ±2.5 V, which are referenced to the AIN(−) inputs on the AD7705 and to the COMMON input on the AD7706.The AD7705 / AD7706 devices, with a 3 V supply and a 1.225 V reference, can handle unipolar input signal ranges of 0 mV to 10 mV through 0 V to 1.225 V. The devices can accept bipolar input ranges of ±10 mV through ±1.225 V. Therefore, the AD7705 / AD7706 devices perform all signal conditioning and conversion for a 2-channel or 3-channel system. The AD7705 / AD7706 are ideal for use in smart, microcontroller, or DSP-based systems. The devices feature a serial interface that can be configured for 3-wire operation. Gain settings, signal polarity, and update rate selection can be configured in software using the input serial port. The parts contains self-calibration and system calibration options to eliminate gain and offset errors on the part itself or in the system. CMOS construction ensures very low power dissipation, and the power-down mode reduces the standby power consumption to 20 μW typ. These parts are available in a 16-lead, wide body (0.3 inch), plastic dual in-line package (DIP); a 16-lead, wide body (0.3 inch), standard small outline (SOIC) package; and a low profile, 16-lead, thin shrink small outline package (TSSOP).

The AD7740 is a low-cost, ultrasmall synchronous Voltage-to-FrequencyConverter (VFC). It works from a single 3.0 V to3.6 V or 4.75 V to 5.25 V supply consuming 0.9 mA. The AD7740is available in an 8-lead SOT-23 and also in an 8-lead MSOPpackage. Small package, low cost and ease of use were majordesign goals for this product. The part contains an on-chip 2.5 Vbandgap reference but the user may overdrive this using anexternal reference. This external reference range includes VDD.The full-scale output frequency is synchronous with the clocksignal on the CLKIN pin. This clock can be generated with theaddition of an external crystal (or resonator) or supplied from aCMOS-compatible clock source. The part has a maximuminput frequency of 1 MHz.For an analog input signal that goes from 0 V to VREF, the outputfrequency goes from 10% to 90% of fCLKIN. In buffered mode,the part provides a very high input impedance and accepts arange of 0.1 V to VDD – 0.2 V on the VIN pin. There is alsoan unbuffered mode of operation that allows VIN to go from–0.15 V to VDD + 0.15 V. The modes are interchangeable usingthe BUF pin.The AD7740 (Y Grade) is guaranteed over the automotivetemperature range of –40°C to +105°C. The AD7740 (K Grade)is guaranteed from 0°C to 85°C.Product Highlights The AD7740 is a single channel, single-ended VFC. It is available in 8-lead SOT-23 and 8-lead MSOP packages, and is intended for low-cost applications. The AD7740 offers considerable space saving over alternative solutions. The AD7740 operates from a single 3.0 V to 3.6 V or 4.75 V to 5.25 V supply and consumes typically 0.9 mA when the input is unbuffered. It also contains an automatic power-down function. The AD7740 does not require external resistors and capacitors to set the output frequency. The maximum output frequency is set by a crystal or a clock. No trimming or calibration is required. The analog input can be taken to 150 mV below GND for true bipolar operation. The specified voltage reference range on REFIN is from 2.5 V to the supply voltage, VDD.Applications Isolation of high common-mode voltages Low-cost analog-to-digital conversion Battery monitoring Automotive sensing

The AD7740 is a low-cost, ultrasmall synchronous Voltage-to-FrequencyConverter (VFC). It works from a single 3.0 V to3.6 V or 4.75 V to 5.25 V supply consuming 0.9 mA. The AD7740is available in an 8-lead SOT-23 and also in an 8-lead MSOPpackage. Small package, low cost and ease of use were majordesign goals for this product. The part contains an on-chip 2.5 Vbandgap reference but the user may overdrive this using anexternal reference. This external reference range includes VDD.The full-scale output frequency is synchronous with the clocksignal on the CLKIN pin. This clock can be generated with theaddition of an external crystal (or resonator) or supplied from aCMOS-compatible clock source. The part has a maximuminput frequency of 1 MHz.For an analog input signal that goes from 0 V to VREF, the outputfrequency goes from 10% to 90% of fCLKIN. In buffered mode,the part provides a very high input impedance and accepts arange of 0.1 V to VDD – 0.2 V on the VIN pin. There is alsoan unbuffered mode of operation that allows VIN to go from–0.15 V to VDD + 0.15 V. The modes are interchangeable usingthe BUF pin.The AD7740 (Y Grade) is guaranteed over the automotivetemperature range of –40°C to +105°C. The AD7740 (K Grade)is guaranteed from 0°C to 85°C.Product Highlights The AD7740 is a single channel, single-ended VFC. It is available in 8-lead SOT-23 and 8-lead MSOP packages, and is intended for low-cost applications. The AD7740 offers considerable space saving over alternative solutions. The AD7740 operates from a single 3.0 V to 3.6 V or 4.75 V to 5.25 V supply and consumes typically 0.9 mA when the input is unbuffered. It also contains an automatic power-down function. The AD7740 does not require external resistors and capacitors to set the output frequency. The maximum output frequency is set by a crystal or a clock. No trimming or calibration is required. The analog input can be taken to 150 mV below GND for true bipolar operation. The specified voltage reference range on REFIN is from 2.5 V to the supply voltage, VDD.Applications Isolation of high common-mode voltages Low-cost analog-to-digital conversion Battery monitoring Automotive sensing

The AD7814 is a complete temperature monitoring system in aSOT-23 package or 8-lead MSOP package. It contains a bandgap temperature sensor and 10-bit ADC to monitor and digitizethe temperature reading to a resolution of 0.25°CThe AD7814 has a flexible serial interface that allows easy interfacing to most microcontrollers. The interface is compatiblewith SPI®, QSPI™, and MICROWIRE™ protocol, and is alsocompatible with DSPs. The part features a standby mode that iscontrolled via the serial interface.The AD7814’s wide supply voltage range, low supply current,and SPI-compatible interface make it ideal for a variety ofapplications, including personal computers, office equipment,and domestic appliances.PRODUCT HIGHLIGHTS The AD7814 has an on-chip temperature sensor that allows an accurate measurement of the ambient temperature. The measurable temperature range is –55°C to +125°C, with a ±2°C temperature accuracy. Supply voltage of 2.7 V to 5.5 V Space-saving 6-lead SOT-23 package and 8-lead MSOP package 10-bit temperature reading to 0.25°C resolution Standby mode that reduces the current consumption to 1 µAAPPLICATIONS Hard Disk Drives Personal Computers Electronic Test Equipment Office Equipment Domestic Appliances Process Control

The AD7887 is a high speed, low power, 12-bit analog-to-digital converter (ADC) that operates from a single 2.7 V to 5.25 V power supply. The AD7887 is capable of 125 kSPS throughput rate. The input track-and-hold acquires a signal in 500 ns and features a single-ended sampling scheme. The output coding for the AD7887 is straight binary, and the part is capable of converting full power signals of up to 2.5 MHz.The AD7887 can be configured for either dual- or single-channel operation via the on-chip control register. There is a default single-channel mode that allows the AD7887 to be operated as a read-only ADC. In single-channel operation, there is one analog input (AIN0) and the AIN1/VREF pin assumes its VREF function. This VREF pin allows the user access to the part’s internal 2.5 V reference, or the VREF pin can be overdriven by an external reference to provide the reference voltage for the part. This external reference voltage has a range of 2.5 V to VDD. The analog input range on AIN0 is 0 to VREF.In dual-channel operation, the AIN1/VREF pin assumes its AIN1 function, providing a second analog input channel. In this case, the reference voltage for the part is provided via the VDD pin. As a result, the input voltage range on both the AIN0 and AIN1 inputs is 0 to VDD.CMOS construction ensures low power dissipation of typically 2 mW for normal operation and 3 μW in power-down mode. The part is available in an 8-lead, 0.15-inch-wide narrow body SOIC and an 8-lead MSOP package.Product HighlightsSmallest 12-bit dual-/single-channel ADC; 8-lead MSOP package.Lowest power 12-bit dual-/single-channel ADC.Flexible power management options, including automatic power-down after conversion.Read-only ADC capability.Analog input range from 0 V to VREF.Versatile serial input/output port (SPI/QSPI/MICROWIRE/ DSP compatible).ApplicationsBattery-powered systems (personal digital assistants, medical instruments, mobile communications)Instrumentation and control systemsHigh speed modems

The AD7908 / AD7918 / AD7928 are, respectively, 8-bit, 10-bit, and 12-bit, high speed, low power, 8-channel, successive approximation ADCs. The parts operate from a single 2.7 V to 5.25 V power supply and feature throughput rates up to 1 MSPS. The parts contain a low noise, wide bandwidth track-and-hold amplifier that can handle input frequencies in excess of 8 MHz.The conversion process and data acquisition are controlled using CS and the serial clock signal, allowing the device to easily interface with microprocessors or DSPs. The input signal is sampled on the falling edge of CS and conversion is also initiated at this point. There are no pipeline delays associated with the part.The AD7908 / AD7918 / AD7928 use advanced design techniques to achieve very low power dissipation at maximum throughput rates. At maximum throughput rates, the AD7908 / AD7918 / AD7928 consume 2 mA maximum with 3 V supplies; with 5 V supplies, the current consumption is 2.7 mA maximum.Through the configuration of the control register, the analog input range for the part can be selected as 0 V to REFIN or 0 V to 2 × REFIN, with either straight binary or twos complement output coding. The AD7908 / AD7918 / AD7928 each feature eight single-ended analog inputs with a channel sequencer to allow a preprogrammed selection of channels to be converted sequentially.The conversion time for the AD7908 / AD7918 / AD7928 is determined by the SCLK frequency, which is also used as the master clock to control the conversion.PRODUCT HIGHTLIGHTS High Throughput with Low Power Consumption. The AD7908 / AD7918 / AD7928 offer up to 1 MSPS throughput rates. At the maximum throughput rate with 3 V supplies, the AD7908 / AD7918 / AD7928 dissipate just 6 mW of power maximum. Eight Single-Ended Inputs with a Channel Sequencer. A sequence of channels can be selected, through which the ADC cycles and converts on. Single-Supply Operation with VDRIVE Function. The AD7908 / AD7918 / AD7928 operate from a single 2.7 V to 5.25 V supply. The VDRIVE function allows the serial interface to connect directly to either 3 V or 5 V processor systems independent of AVDD. Flexible Power/Serial Clock Speed Management. The conversion rate is determined by the serial clock, allowing the conversion time to be reduced through the serial clock speed increase. The parts also feature various shutdown modes to maximize power efficiency at lower throughput rates. Current consumption is 0.5 μA max when in full shutdown. No Pipeline Delay. The parts feature a standard successive approximation ADC with accurate control of the sampling instant via a CS input and once off conversion control.

The AD7923 is a 12-bit, high speed, low power, 4-channel, successive-approximation (SAR) ADC. It operates from a single 2.7 V to 5.25 V power supply and features throughput rates up to 200 kSPS. It contains a low noise, wide bandwidth track-and-hold amplifier that can handle input frequencies in excess of 8 MHz.The conversion process and data acquisition are controlled by CS and the serial clock signal, allowing the device to easily interface with microprocessors or DSPs. The input signal is sampled on the falling edge of CS and conversion is also initiated at this point.The AD7923 uses advanced design techniques to achieve very low power dissipation at maximum throughput rates. At maximum throughput rates, it consumes 1.2 mA maximum with 3 V supplies and 1.5 mA maximum with 5 V supplies.Through the configuration of the control register, the analog input range can be selected as 0 V to REFIN or 0 V to 2 × REFIN, with either straight binary or twos complement output coding. The AD7923 features four single-ended analog inputs with achannel sequencer to allow a preprogrammed selection of channels to be converted sequentially.The conversion time for the AD7923 is determined by the serial clock, SCLK, frequency, since this is used as the master clock to control the conversion. The conversion time can be as short as 800 ns with a 20 MHz SCLK.

The AD603 is a low noise, voltage-controlled amplifier for use in RF and IF AGC systems. It provides accurate, pin-selectable gains of −11 dB to +31 dB with a bandwidth of 90 MHz or +9 dB to 51+ dB with a bandwidth of 9 MHz. Any intermediate gain range may be arranged using one external resistor. The input referred noise spectral density is only 1.3 nV/√Hz, and power consumption is 125 mW at the recommended ±5 V supplies.The decibel gain is linear in dB, accurately calibrated, and stable over temperature and supply. The gain is controlled at a high impedance (50 MΩ), low bias (200 nA) differential input; the scaling is 25 mV/dB, requiring a gain control voltage of only 1 V to span the central 40 dB of the gain range. An overrange and underrange of 1 dB is provided whatever the selected range. The gain control response time is less than 1 μs for a 40 dB change.The differential gain control interface allows the use of either differential or single-ended positive or negative control voltages. Several of these amplifiers may be cascaded and their gain control gains offset to optimize the system SNR.The AD603 can drive a load impedance as low as 100 Ω with low distortion. For a 500 Ω load in shunt with 5 pF, the total harmonic distortion for a ±1 V sinusoidal output at 10 MHz is typically −60 dBc. The peak specified output is ±2.5 V minimum into a 500 Ω load.The AD603 uses a patented proprietary circuit topology—the X-AMP®. The X-AMP comprises a variable attenuator of 0 dB to −42.14 dB followed by a fixed-gain amplifier. Because of the attenuator, the amplifier never has to cope with large inputs and can use negative feedback to define its (fixed) gain and dynamic performance. The attenuator has an input resistance of 100 Ω, laser trimmed to ±3%, and comprises a 7-stage R-2R ladder network, resulting in an attenuation between tap points of 6.021 dB. A proprietary interpolation technique provides a continuous gain control function that is linear in dB.The AD603 is specified for operation from −40°C to +85°C.Applications RF/IF AGC amplifiers Video gain controls A/D range extensions Signal measurements

The AD603 is a low noise, voltage-controlled amplifier for use in RF and IF AGC systems. It provides accurate, pin-selectable gains of −11 dB to +31 dB with a bandwidth of 90 MHz or +9 dB to 51+ dB with a bandwidth of 9 MHz. Any intermediate gain range may be arranged using one external resistor. The input referred noise spectral density is only 1.3 nV/√Hz, and power consumption is 125 mW at the recommended ±5 V supplies.The decibel gain is linear in dB, accurately calibrated, and stable over temperature and supply. The gain is controlled at a high impedance (50 MΩ), low bias (200 nA) differential input; the scaling is 25 mV/dB, requiring a gain control voltage of only 1 V to span the central 40 dB of the gain range. An overrange and underrange of 1 dB is provided whatever the selected range. The gain control response time is less than 1 μs for a 40 dB change.The differential gain control interface allows the use of either differential or single-ended positive or negative control voltages. Several of these amplifiers may be cascaded and their gain control gains offset to optimize the system SNR.The AD603 can drive a load impedance as low as 100 Ω with low distortion. For a 500 Ω load in shunt with 5 pF, the total harmonic distortion for a ±1 V sinusoidal output at 10 MHz is typically −60 dBc. The peak specified output is ±2.5 V minimum into a 500 Ω load.The AD603 uses a patented proprietary circuit topology—the X-AMP®. The X-AMP comprises a variable attenuator of 0 dB to −42.14 dB followed by a fixed-gain amplifier. Because of the attenuator, the amplifier never has to cope with large inputs and can use negative feedback to define its (fixed) gain and dynamic performance. The attenuator has an input resistance of 100 Ω, laser trimmed to ±3%, and comprises a 7-stage R-2R ladder network, resulting in an attenuation between tap points of 6.021 dB. A proprietary interpolation technique provides a continuous gain control function that is linear in dB.The AD603 is specified for operation from −40°C to +85°C.Applications RF/IF AGC amplifiers Video gain controls A/D range extensions Signal measurements

The AD604 is an ultralow noise, very accurate, dual-channel, linear-in-dB variable gain amplifier (VGA) optimized for time-based variable gain control in ultrasound applications; however, it supports any application requiring low noise, wide bandwidth, variable gain control. Each channel of the AD604 provides a 300 kΩ input resistance and unipolar gain control for ease of use. User determined gain ranges, gain scaling (dB/V), and dc level shifting of output further optimize performance.Each channel of the AD604 utilizes a high performance preamplifier that provides an input referred noise voltage of 0.8 nV/√Hz. The very accurate linear-in-dB response of the AD604 is achieved with the differential input exponential amplifier (DSX-AMP) architecture. Each of the DSX-AMPs comprise a variable attenuator of 0 dB to 48.36 dB followed by a high speed fixed gain amplifier. The attenuator is a 7-stage R-1.5R ladder network. The attenuation between tap points is 6.908 dB and 48.36 dB for the ladder network.The equation for the linear-in-dB gain response isG(dB) = (Gain Scaling (dB/V) × VGN (V))+ (Preamp Gain (dB) – 19 dB)Preamplifier gains between 5 and 10 (14 dB and 20 dB) provide overall gain ranges per channel of 0 dB through 48 dB and 6 dB through 54 dB. The two channels of the AD604 can be cascaded to provide greater levels of gain range by bypassing the second channel’s preamplifier. However, in multiple channel systems, cascading the AD604 with other devices in the AD60x VGA family that do not include a preamplifier may provide a more efficient solution. The AD604 provides access to the output of the preamplifier, allowing for external filtering between the preamplifier and the differential attenuator stage.Note that scale factors up to 40 dB/V are achievable with reduced accuracy for scales above 30 dB/V. The gain scales linearly-in-dB with control voltages of 0.4 V to 2.4 V with the 20 dB/V scale. Below and above this gain control range, the gain begins to deviate from the ideal linear-in-dB control law. The gain control region below 0.1 V is not used for gain control. In fact when the gain control voltage is <50 mV, the amplifier channel is powered down to 1.9 mA.The AD604 is available in 24-lead SSOP, SOIC, and PDIP packages and is guaranteed for operation over the −40°C to +85°C temperature range.Applications Ultrasound and sonar time gain control High performance AGC systems Signal measurement