Analog Devices

The AD7237A / AD7247A is an enhanced version of the industry standardAD7237/ 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 theWRinput 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 asynchronousLDACsignal 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 kΩ 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 AD7245A/AD7248A is an enhanced version of the industry standard AD7245/AD7248. Improvements include operation from 12 V to 15 V supplies, a ±1/2 LSB linearity grade, faster interface times and better full scale and reference variations with VDD. Additional features include extended temperature range operation for commercial and industrial grades.The AD7245A/AD7248A is a complete, 12-bit, voltage output, digital-to-analog converter with output amplifier 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 double-buffered interface logic. The AD7245A accepts 12-bit parallel data which is loaded into the input latch on the rising edge of CS or WR. The AD7248A has an 8-bit wide data bus with data loaded to the input latch in two write operations. For both parts, an asynchronous LDAC signal transfers data from the input latch to the DAC latch and updates the analog output. The AD7245A also has a CLR signal on the DAC latch which allows features such as power-on reset to be implemented.The on-chip 5 V buried Zener diode provides a low noise, temperature compensated reference for the DAC. 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 kOhm load to GND.The AD7245A/AD7248A is fabricated in linear compatible CMOS (LC2MOS), an advanced, mixed technology process that combines precision bipolar circuits with low power CMOS logic. The AD7245A is available in a small, 0.3" wide, 24-pin DIP and SOIC and in 28-terminal surface mount packages. The AD7248A is packaged in a small, 0.3" wide, 20-pin DIP SOIC and in 20-terminal surface mount packages.

The AD725 is a very low cost general purpose RGB to NTSC/ PAL encoder that converts red, green and blue color component signals into their corresponding luminance (baseband amplitude) and chrominance (subcarrier amplitude and phase) signals in accordance with either NTSC or PAL standards. These two outputs are also combined on-chip to provide a composite video output. All three outputs are available separately at voltages of twice the standard signal levels as required for driving 75 Ω, reverse-terminated cables.An evaluation board is available for this product and may be ordered using the following product number: AD725-EB.

The AD7265 is a dual, 12-bit, high speed, low power, successive approximation ADC that operates from a single 2.7 V to 5.25 V power supply and features throughput rates of up to 1 MSPS. The device contains two ADCs, each preceded by a 3-channel multiplexer, and a low noise, wide bandwidth track-and-hold amplifier that can handle input frequencies in excess of 30 MHz.The conversion process and data acquisition use standard control inputs allowing easy interfacing to microprocessors or DSPs. The input signal is sampled on the falling edge ofCS; conversion is also initiated at this point. The conversion time is determined by the SCLK frequency. The AD7265 uses advanced design techniques to achieve very low power dissipation at high throughput rates. With 5 V supplies and a 1 MSPS throughput rate, the part consumes 4 mA maximum. The part also offers flexible power/throughput rate management when operating in normal mode, because the quiescent current consumption is so low.The analog input range for the part can be selected to be a 0 V to VREF(or 2 × VREF) range, with either straight binary or twos complement output coding. The AD7265 has an on-chip 2.5 V reference that can be overdriven when an external reference is preferred. This external reference range is 100 mV to VDD. The AD7265 is available in 32-lead LFCSP and 32-lead TQFP.PRODUCT HIGHLIGHTSTwo Complete ADC Functions Allow Simultaneous Sampling and Conversion of Two Channels.Each ADC has three fully/pseudo differential pairs, or six single-ended channels, as programmed. The conversion result of both channels is simultaneously available on separate data lines, or in succession on one data line if only one serial port is available.High Throughput with Low Power Consumption.The AD7265 offers a 1 MSPS throughput rate with 9 mW maximum power dissipation when operating at 3 V.The AD7265 offers both a standard 0 V to VREFinput range and a 2 × VREFinput range.No Pipeline Delay.The part features two standard successive approximation ADCs with accurate control of the sampling instant via aCSinput and once off conversion control.

The AD7273 is a 10-bit, high speed, low power, successive-approximation ADC. The part operates from a single 2.35V to 3.6 V power supply and features throughput rates up to 3 MSPS. The part contains a low-noise, wide bandwidth track/hold amplifier which can handle input frequencies in excess of 30 MHz.The conversion process and data acquisition are controlled usingCSand the serial clock, allowing the devices to interface with microprocessors or DSPs. The input signal is sampled on the falling edge ofCSand the conversion is also initiated at this point. The conversion rate is determined by the SCLK. There are no pipeline delays associated with the part.The AD7273 uses advanced design techniques to achieve very low power dissipation at high throughput rates.The reference for the part is applied externally and can be in the range of 1.2 V to VDD. This allows the widest dynamic input range to the ADC.PRODUCT HIGHLIGHTS3 MSPS ADCs in an 8-lead TSOT package.High throughput with low power consumption.Flexible power/serial clock speed management.Allows maximum power efficiency at low throughput rates.Reference can be driven up to the power supply.No pipeline delay.The parts feature a standard successive approximation ADC with accurate control of the sampling instant via aCSinput and once-off conversion control.APPLICATIONSBattery-Powered SystemsPersonal Digital AssistantsMedical InstrumentsMobile CommunicationsInstrumentation and Control SystemsData Acquisition SystemsHigh-Speed ModemsOptical Sensors

The AD7274 is a 12-bit, high speed, low power, successive-approximation ADC. The part operates from a single 2.35V to 3.6 V power supply and features throughput rates up to 3 MSPS. The part contains a low-noise, wide bandwidth track/hold amplifier which can handle input frequencies in excess of 30 MHz.The conversion process and data acquisition are controlled usingCSand the serial clock, allowing the devices to interface with microprocessors or DSPs. The input signal is sampled on the falling edge ofCSand the conversion is also initiated at this point. The conversion rate is determined by the SCLK. There are no pipeline delays associated with the part.The AD7274 uses advanced design techniques to achieve very low power dissipation at high throughput rates.The reference for the part is applied externally and can be in the range of 1.2 V to VDD. This allows the widest dynamic input range to the ADC.APPLICATIONSBattery-Powered SystemsPersonal Digital AssistantsMedical InstrumentsMobile CommunicationsInstrumentation and Control SystemsData Acquisition SystemsHigh-Speed ModemsOptical SensorsAll Members of the AD727x FamilyPart #Resolution (Bits)Package TypePriceAD7274128-LEAD TSOT/MSOP$6.50AD7276126-LEAD TSOT/8-LEAD MSOP$6.25AD7277106-LEAD TSOT/8-LEAD MSOP$3.60AD7273108-LEAD TSOT/MSOP$3.75AD727886-LEAD TSOT/8-LEAD MSOP$1.85