This device is a 7th order sigma-delta modulator that converts the analog input signal into a high speed 1-bit data stream. The part operates from a +5 V supply and accepts a differential input range of 0 V to +2.5 V or ±1.25 V centered about a common-mode bias. The analog input is continuously sampled by the analog modulator, eliminating the need for external sample and hold circuitry. The input information is contained in the output stream as a density of ones. The original information can be reconstructed with an appropriate digital filter.

The AD7722 is a complete low power, 16-bit, sigma-delta ADC. The part operates from a +5 V supply and accepts a differential input voltage range of 0 V to +2.5 V or ±1.25 V centered around a common-mode bias. The AD7722 provides 16-bit performance for input bandwidths up to 90.625 kHz. The part provides data at an output word rate of 195.3 kHz.The analog input is continuously sampled by an analog modulator eliminating the need for external sample-and-hold circuitry. The modulator output is processed by two Finite Impulse Response (FIR) digital filters in series. The on-chip filtering reduces the external antialias requirements to first order, in most cases. The group delay for the filter is 215.5 µs, while the settling time for a step input is 431 µs. The sample rate, filter corner frequency, and output word rate are set by an external clock that is nominally 12.5 MHz.Use of a single bit DAC in the modulator guarantees excellent linearity and dc accuracy. Endpoint accuracy is ensured by on-chip calibration. This calibration procedure minimizes the zero-scale and full-scale errors.Conversion data is provided at the output register through a flexible serial port or a parallel port. This offers 3-wire, high speed interfacing to digital signal processors. The serial interface operates in an internal clocking (master) mode, whereby an internal serial data clock and framing pulse are device outputs. Additionally, two AD7722s can be configured with the serial data outputs connected together. Each converter alternately transmits its conversion data on a shared serial data line.The part provides an accurate on-chip 2.5 V reference. A reference input/output function is provided to allow either the internal reference or an external system reference to be used as the reference source for the part.The AD7722 is available in a 44-pin PQFP package and is specified over the industrial temperature range from –40°C to +85°C.

The AD7730 is a complete analog front end for weigh-scale and pressure measurement applications. The device accepts low-level signals directly from a transducer and outputs a serial digital word. The input signal is applied to a proprietary programmable gain front end based around an analog modulator.The modulator output is processed by a low pass programmable digital filter, allowing adjustment of filter cutoff, output rate and settling time.The part features two buffered differential programmable gain analog inputs as well as a differential reference input. The part operates from a single +5 V supply. It accepts four unipolar analog input ranges: 0 mV to ±10 mV, +20 mV, +40 mV and +80 mV and four bipolar ranges: ±10 mV, ±20 mV, ±40 mV and ±80 mV. The peak-to-peak resolution achievable directly from the part is 1 in 230,000 counts. An on-chip 6-bit DAC allows the removal of TARE voltages. Clock signals for synchronizing ac excitation of the bridge are also provided.The serial interface on the part can be configured for three-wire operation and is compatible with microcontrollers and digital signal processors. The AD7730 contains self-calibration and system calibration options, and features an offset drift of less than 5 nV/°C and a gain drift of less than 2 ppm/°C.The part is available in a 24-pin plastic DIP, a 24-lead SOIC and 24-lead TSSOP package.APPLICATIONS Weigh Scales Pressure Measurement

The AD7731 is a complete analog front-end for process controlapplications. The device has a proprietary programmable gainfront end that allows it to accept a range of input signal ranges,including low level signals, directly from a transducer. The sigma-deltaarchitecture of the part consists of an analog modulatorand a low pass programmable digital filter, allowing adjustmentof filter cutoff, output rate and settling time.The part features three buffered differential programmable gainanalog inputs (which can be configured as five pseudo-differentialinputs), as well as a differential reference input. The part operatesfrom a single +5 V supply and accepts seven unipolar analoginput ranges: 0 to +20 mV, +40 mV, +80 mV, +160 mV,+320 mV, +640 mV and +1.28 V, and seven bipolar ranges:±20 mV, ±40 mV, ±80 mV, ±160 mV, ±320 mV, ±640 mV and±1.28 V. The peak-to-peak resolution achievable directly fromthe part is 16 bits at an 800 Hz output rate. The part can switchbetween channels with 1 ms settling time and maintain a performancelevel of 13 bits of peak-to-peak resolution.The serial interface on the part can be configured for three-wireoperation and is compatible with microcontrollers and digitalsignal processors. The AD7731 contains self-calibration andsystem calibration options and features an offset drift of lessthan 5 nV/°C and a gain drift of less than 2 ppm/°C.The part is available in a 24-lead plastic DIP, a 24-lead SOICand 24-lead TSSOP package.APPLICATIONS Process Control PLCs/DCS Industrial Instrumentation

The AD7731 is a complete analog front-end for process controlapplications. The device has a proprietary programmable gainfront end that allows it to accept a range of input signal ranges,including low level signals, directly from a transducer. The sigma-deltaarchitecture of the part consists of an analog modulatorand a low pass programmable digital filter, allowing adjustmentof filter cutoff, output rate and settling time.The part features three buffered differential programmable gainanalog inputs (which can be configured as five pseudo-differentialinputs), as well as a differential reference input. The part operatesfrom a single +5 V supply and accepts seven unipolar analoginput ranges: 0 to +20 mV, +40 mV, +80 mV, +160 mV,+320 mV, +640 mV and +1.28 V, and seven bipolar ranges:±20 mV, ±40 mV, ±80 mV, ±160 mV, ±320 mV, ±640 mV and±1.28 V. The peak-to-peak resolution achievable directly fromthe part is 16 bits at an 800 Hz output rate. The part can switchbetween channels with 1 ms settling time and maintain a performancelevel of 13 bits of peak-to-peak resolution.The serial interface on the part can be configured for three-wireoperation and is compatible with microcontrollers and digitalsignal processors. The AD7731 contains self-calibration andsystem calibration options and features an offset drift of lessthan 5 nV/°C and a gain drift of less than 2 ppm/°C.The part is available in a 24-lead plastic DIP, a 24-lead SOICand 24-lead TSSOP package.APPLICATIONS Process Control PLCs/DCS Industrial Instrumentation

The AD7782 is a complete analog front end for low-frequency measurement applications. The 24-bit sigma-delta ADC contains two fully differential analog input channels that can be configured with a gain of 1 or 16 allowing full-scale input signal ranges of ±2.56 V or ± 160 mV from a +2.5 V differential reference input. The AD7782 has an extremely simple, read-only digital interface which can be operated in master mode or slave mode. There are no on-chip registers to be programmed. The input signal range and input channel selection are configured using two external pins.The device operates from a 32.768 kHz crystal with an on-chip PLL generating the required internal operating frequency. The output data rate from the part is fixed via the master clock at 19.79 Hz and provides simultaneous 50 Hz and 60 Hz rejection at this update rate. Eighteen-bit p-p resolution can be obtained at this update rate. The part operates from a single 3 V or 5 V supply. When operating from 3 V supplies, the power dissipation for the part is 3.9 mW. The AD7782 is available in a 16-lead TSSOP package. Another part in the AD778x family is the AD7783. It is similar to the AD7782 except it has two integrated current sources and only one differential input channel.APPLICATIONS Sensor Measurement Industrial Process Control Temperature Measurement Pressure Measurements Weigh Scales Portable Instrumentation

The AD7788/AD7789 are low power, low noise, analog frontends for low frequency measurement applications. The AD7789contains a low noise, 24-bit, ∑-∆ analog-to-digital converter(ADC) with one differential input. The AD7788 is a 16-bitversion of the AD7789.The devices operate from an internal clock. Therefore, the userdoes not have to supply a clock source to the devices. The outputdata rate is 16.6 Hz, which gives simultaneous 50 Hz/60 Hzrejection.The devices operate with a single power supply from 2.5 V to5.25 V. When operating from a 3 V supply, the power dissipationfor the device is 225 µW maximum. The AD7788/AD7789 areavailable in a 10-lead MSOP.Applications Smart transmitters Battery applications Portable instrumentation Sensor measurement Temperature measurement Pressure measurement Weigh scales 4 to 20 mA loops

The AD7788/AD7789 are low power, low noise, analog frontends for low frequency measurement applications. The AD7789contains a low noise, 24-bit, ∑-∆ analog-to-digital converter(ADC) with one differential input. The AD7788 is a 16-bitversion of the AD7789.The devices operate from an internal clock. Therefore, the userdoes not have to supply a clock source to the devices. The outputdata rate is 16.6 Hz, which gives simultaneous 50 Hz/60 Hzrejection.The devices operate with a single power supply from 2.5 V to5.25 V. When operating from a 3 V supply, the power dissipationfor the device is 225 µW maximum. The AD7788/AD7789 areavailable in a 10-lead MSOP.Applications Smart transmitters Battery applications Portable instrumentation Sensor measurement Temperature measurement Pressure measurement Weigh scales 4 to 20 mA loops

The AD7810 is a high speed, low power, 10-bit A/D converter that operates from a single 2.7 V to 5.5 V supply. The part contains a 2 µs successive approximation A/D converter, with inherent track/hold functionality, a pseudo differential input and a high speed serial interface that interfaces to most microcontrollers. The AD7810 is fully specified over a temperature range of -40°C to +105°C.By using a technique that samples the state of the CONVST (convert start) signal at the end of a conversion, the AD7810 may be used in an automatic power-down mode. When used in this mode, the AD7810 automatically powers down at the end of a conversion and 'wakes up' at the start of a new conversion. This feature significantly reduces the power consumption of the part at lower throughput rates. The AD7810 can also operate in a high speed mode where the part is not powered down between conversions. In this high speed mode of operation, the conversion time of the AD7810 is 2 µs. The maximum throughput rate is dependent on the speed of the serial interface of the microcontroller. The part is available in a small 8-pin, 0.3' wide, plastic dual-in-line package (mini-DIP); in an 8-lead, small outline IC (SOIC); and in an 8-lead microSOIC package.PRODUCT HIGHLIGHTS Complete, 10-Bit ADC in 8-Lead Package The AD7810 is a 10-bit 2.3 µs ADC with inherent track/hold functionality and a high speed serial interface—all in an 8-lead microSOIC package. VREF may be connected to VDD to eliminate the need for an external reference. The result is a high speed, low power, space saving ADC solution. Low Power, Single Supply Operation The AD7810 operates from a single 2.7 V to 5.5 V supply and typically consumes only 9 mW of power while converting. The power dissipation can be significantly reduced at lower throughput rates by using the automatic power-down mode, e.g., at a throughput rate of 10 kSPS the power consumption is only 270 µW. Automatic Power-Down The automatic power-down mode, whereby the AD7810 powers down at the end of a conversion and “wakes up” before the next conversion, means the AD7810 is ideal for battery powered applications. See Power vs. Throughput Rate section. Serial Interface An easy to use, fast serial interface allows connection to most popular microprocessors with no external circuitry.APPLICATIONS Low Power, Hand-Held Portable Applications that Require Analog-to-Digital Conversion with 10-Bit Accuracy; e.g., Battery Powered Test Equipment, Battery-Powered Communications Systems

The AD7821 is a high-speed, 8-bit, sampling, analog-to-digital converter that offers improved performance over the popular AD7820. It offers a conversion time of 660 ns (vs. 1.36 µs for the AD7820) and 100 kHz signal bandwidth (vs. 6.4 kHz). The sampling instant is better defined and occurs on the falling edge of WR or RD. The provision for a VSS pin (Pin 19) allows the part to operate from  ±5 V supplies and to digitize bipolar input signals. Alternatively, for unipolar inputs, the VSS pin can be grounded and the AD7821 will operate from a single +5 V supply, like the AD7820.The AD7821 has a built-in track-and-hold function capable of digitizing full-scale signals up to 100 kHz max. It also uses a half-flash conversion technique that eliminates the need to generate a CLK signal for the ADC.The AD7821 is designed with standard microprocessor control signals (CS, RD, WR, RDY, INT) and latched, three-state data outputs capable of interfacing to high-speed data buses. An overflow output (OFL) is also provided for cascading devices to achieve higher resolution.The AD7821 is fabricated in Linear-Compatible CMOS (LC2MOS), an advanced, mixed technology process combining precision bipolar circuits with low-power CMOS logic. The part features a low power dissipation of 50 mW.