EVALUATION MODULE LM3643

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 ?-? 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 ?W 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 AD7741/AD7742 are a new generation of synchronous voltage-to-frequency converters (VFCs). The AD7741 is a single-channel version in an 8-lead package (SOIC/DIP) and the AD7742 is a multichannel version in a 16-lead package (SOIC/DIP). No user trimming is required to achieve the specified performance.The AD7741 has a single buffered input whereas the AD7742 has four buffered inputs that may be configured as two fully-differential inputs or three pseudo-differential inputs. Both parts include an on-chip +2.5 V bandgap reference that provides the user with the option of using this internal reference or an external reference.The AD7741 has a single-ended voltage input range from 0 V to REFIN. The AD7742 has a differential voltage input range from ?VREF to +VREF. Both parts operate from a single +5 V supply consuming typically 6 mA, and also contain a power down feature that reduces the current consumption to less than 35 ?A.Applications Low Cost Analog-to-Digital Conversion Signal Isolation AD7742 is obsolete

The AD7747 is a high-resolution, ?-? capacitance-to-digital converter (CDC). The capacitance to be measured is connected directly to the device inputs. The architecture features inherent high resolution (24-bit no missing codes, up to 19.5-bit effective resolution), high linearity (?0.01%), and high accuracy (?10 fF factory calibrated). The AD7747 capacitance input range is ?8 pF (changing), and it can accept up to 17 pF common-mode capacitance (not changing), which can be balanced by a programmable on-chip digital-to-capacitance converter (CAPDAC).The AD7747 is designed for single-ended or differential capacitive sensors with one plate connected to ground. For floating (not grounded) capacitive sensors, the AD7745 or AD7746 are recommended.The part has an on-chip temperature sensor with a resolution of 0.1?C and accuracy of ?2?C. The on-chip voltage reference and the on-chip clock generator eliminate the need for any external components in capacitive sensor applications. The part has a standard voltage input that, together with the differential reference input, allows easy interface to an external temperature sensor, such as an RTD, thermistor, or diode.The AD7747 has a 2-wire, I2C-compatible serial interface. The part can operate with a single power supply of 2.7 V to 5.25 V. It is specified over the automotive temperature range of ?40?C to +125?C and is housed in a 16-lead TSSOP package.ApplicationsAutomotive, industrial, and medical systems for:Pressure measurementPosition sensingProximity sensingLevel sensingFlowmetersImpurity detections

The AD7765 is a high performance, 24-bit sigma-delta (?-?) analog-to-digital converter (ADC). It combines wide input bandwidth, high speed, and performance of 112 dB dynamic range at a 156 kHz output data rate. With excellent dc specifications, the converter is ideal for high speed data acquisition of ac signals where dc data is also required.Using the AD7765 eases front-end antialias filtering requirements, simplifying the design process significantly. The AD7765 offers pin-selectable decimation rates of 128? and 256?. Other features include an integrated buffer to drive the reference, as well as a fully differential amplifier to buffer and level shift the input to the modulator.An overrange alert pin indicates when an input signal exceeds the acceptable range. The addition of internal gain and internal overrange registers makes the AD7765 a compact, highly integrated data acquisition device requiring minimal peripheral components.The AD7765 also offers a low power mode, significantly reducing power dissipation without reducing the output data rate or available input bandwidth.The differential input is sampled at up to 40 MSPS by an analog modulator. The modulator output is processed by a series of low-pass filters. The external clock frequency applied to the AD7765 determines the sample rate, filter corner frequencies, and output word rate.The AD7765 device boasts a full band on-board FIR filter. The full stop-band attenuation of the filter is achieved at the Nyquist frequency. This feature offers increased protection from signals that lie above the Nyquist frequency being aliased back into the input signal bandwidth.The reference voltage supplied to the AD7765 determines the input range. With a 4 V reference, the analog input range is ?3.2768 V differential, biased around a common mode of 2.048 V. This common-mode biasing is achieved using the on-chip differential amplifier, further reducing the external signal conditioning requirements.The AD7765 is available in a 28-lead TSSOP package and is specified over the industrial temperature range of ?40?C to +85?C.APPLICATIONS Data acquisition systems Vibration analysis Instrumentation

The AD7770 is an 8-channel, simultaneous sampling ADC. Eightfull sigma-delta (?-?) ADCs are on chip. The AD7770 providesa low input current to allow direct sensor connection. Each inputchannel has a programmable gain stage allowing gains of 1, 2, 4,and 8 to map lower amplitude sensor outputs into the full-scaleADC input range, maximizing the dynamic range of the signalchain. The AD7770 accepts a VREF voltage from 1 V up to 3.6 V.The analog inputs accept unipolar (0 V to VREF) or true bipolar(?VREF/2) analog input signals with 3.3 V or ?1.65 V analogsupply voltages, respectively for PGAGAIN = 1. The analog inputscan be configured to accept true differential, pseudo differential,or single-ended signals to match different sensor outputconfigurations.Each channel contains a PGA, an ADC modulator and asinc3, low latency digital filter. An SRC is provided to allow fineresolution control over the AD7770 ODR. This control can beused in applications where the ODR resolution is required tomaintain coherency with 0.01 Hz changes in the line frequency.The SRC is programmable through the serial port interface (SPI).The AD7770 implements two different interfaces: a data outputinterface and SPI control interface. The ADC data output interfaceis dedicated to transmitting the ADC conversion results fromthe AD7770 to the processor. The SPI writes to and reads fromthe AD7770 configuration registers and for the control andreading of data from the SAR ADC. The SPI can also beconfigured to output the ?-? conversion data.The AD7770 includes a 12-bit SAR ADC. This ADC can beused for AD7770 diagnostics without having to decommissionone of the ?-? ADC channels dedicated to system measurementfunctions. With the use of an external multiplexer, which can becontrolled through the three general-purpose input/output pins(GPIOs), and signal conditioning, the SAR ADC can validatethe ?-? ADC measurements in applications where functionalsafety is required. In addition, the AD7770 SAR ADC includesan internal multiplexer to sense internal nodes.The AD7770 contains a 2.5 V reference and reference buffer. Thereference has a typical temperature coefficient of 10 ppm/?C.The AD7770 offers two modes of operation: high resolution modeand low power mode. High resolution mode provides a higherdynamic range while consuming 10.75 mW per channel; lowpower mode consumes just 3.37 mW per channel at a reduceddynamic range specification.The specified operating temperature range is ?40?C to +105?C,although the device is operational up to +125?C.Applications Protection relays General-purpose data acquisition Industrial process control

The?AD7794/AD7795 are low power, low noise, complete analog front ends for high precision measurement applications. They contain a low noise, 24-/16-bit ?-? ADC with six differential inputs. The on-chip low noi se instrumentation amplifier means that signals of small amplitude can be interfaced directly to the ADC.Each device contains a precision, low noise, low drift internal band gap reference, and can also accept up to two external differential references. Other on-chip features include programmable excitation current sources, burnout currents, and a bias voltage generator that is used to set the common-mode voltage of a channel to AVDD/2. The low-side power switch can be used to power down bridge sensors between conversions, minimizing the system?s power consumption. The AD7794/AD7795 can operate with either an internal clock or an external clock. The output data rate from each part can vary from 4.17 Hz to 470 Hz.Both parts operate with a power supply from 2.7 V to 5.25 V. The B-grade parts (AD7794 and AD7795) are specified for a temperature range of ?40?C to +105?C while the C-grade part (AD7794) is specified for a temperature range of ?40?C to +125?C. They consume a current of 400 ?A typical and are housed in a 24-lead TSSOP.Applications Temperature measurement Pressure measurement Weigh scales Strain gage transducers Gas analysis

The AD7798 /?AD7799 are low power, low noise, complete analog front ends for high precision measurement applications. The AD7798 / AD7799 contains a low noise, 16-/24-bit ?-? ADC with three differential analog inputs. The on-chip, low noise instrumentation amplifier means that signals of small amplitude can be interfaced directly to the ADC. With a gain setting of 64, the rms noise is 27 nV for the AD7799 and 40 nV for the AD7798 when the update rate equals 4.17 Hz.On-chip features include a low-side power switch, reference detect, programmable digital output pins, burnout currents, and an internal clock oscillator. The output data rate from the part is software-programmable and can be varied from 4.17 Hz to 470 Hz.The part operates with a power supply from 2.7 V to 5.25 V. The AD7798 consumes a current of 300 ?A typical, whereas the AD7799 consumes 380 ?A typical. Both devices are housed in a 16-lead TSSOP package.APPLICATIONS Weigh scales Pressure measurement Strain gauge transducers Gas analysis Industrial process control Instrumentation Portable instrumentation Blood analysis Smart transmitters Liquid/gas chromotography 6-digit DVM

The LT5528 is a direct I/Q modulator designed for high performance wireless applications, including wireless infrastructure. It allows direct modulation of an RF signal using differential baseband I and Q signals. It supports PHS, GSM, EDGE, TD-SCDMA, CDMA, CDMA2000, W-CDMA and other systems. It may also be con? gured as an image reject up-converting mixer, by applying 90? phase-shifted signals to the I and Q inputs. The I/Q baseband inputs consist of voltage-to-current converters that in turn drive double-balanced mixers. The outputs of these mixers are summed and applied to an on-chip RF transformer, which converts the differential mixer signals to a 50? single-ended output. The four balanced I and Q baseband input ports are intended for DC coupling from a? source with a common-mode voltage level of about 0.5V. The LO path consists of an LO buffer with single-ended input, and precision quadrature generators that produce the LO drive for the mixers. The supply voltage range is 4.5V to 5.25V.Applications Infrastructure Tx for DCS, PCS and UMTS Bands Image Reject Up-Converters for PCS and UMTS Bands Low-Noise Variable Phase-Shifter for 1.5GHz to 2.4GHz Local Oscillator Signals

The LTC4063 is a standalone linear charger for single cell lithium-ion batteries with an adjustable low dropout linear regulator (LDO). The adjustable LDO regulates an output voltage between 1.2V to 4.2V at up to 100mA load current. When the input supply (wall adapter or USB supply) is removed, the LDO regulates the output voltage without interruption. The battery charger and LDO regulator can be enabled individually.No external sense resistor or external blocking diode is required for charging due to the internal MOSFET architecture. Internal thermal feedback regulates the charge current to maintain a constant die temperature during high power operation or high ambient temperature conditions. The float voltage is fixed at 4.2V and the charge current is programmed with an external resistor. Charge termination methods include minimum charge current or maximum time. With power applied, the LTC4063 can be put into shutdown mode to reduce the supply current to 35?A and the battery drain current to less than 2?A.Other features include smart recharge, undervoltage lockout, LDO current limiting and a charge status pin to indicate when the charge cycle has completed.Applications Handheld Computers Portable MP3 Players Digital Cameras