Analog Devices Inc./Maxim Integrated

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 AD7249 DACPORT®contains a pair of 12-bit, voltage-output, digital-to-analog converters with output amplifiers and Zener voltage reference on a monolithic CMOS chip. No external trims are required to achieve full specified performance.The output amplifiers are capable of developing +10 V across a 2 kΩload. The output voltage ranges with single supply operation are 0 V to +5 V or 0 V to +10 V, while an additional bipolar ±5V output range is available with dual supplies. The ranges are selected using the internal gain resistor.Interfacing to the AD7249 is serial, minimizing pin count and allowing a small package size. Standard control signals allow interfacing to most DSP processors and microcontrollers. The data stream consists of 16 bits, DB15 to DB13 are don't care bits, the 13th bit (DB12) is used as the channel select bit and the remaining 12 bits (DB11 to DB0) contain the data to update the DAC. The 16-bit data word is clocked into the input register on each falling SCLK edge.The data format is natural binary in both unipolar ranges, while either offset binary or twos complement format may be selected in the bipolar range. ACLRfunction is provided which sets the output to 0 V in both unipolar ranges and in the twos 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 outputs to be set to a known voltage level.The AD7249 features a 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 2 MHz allowing a DAC update rate of 125 kHz.The AD7249 is fabricated on linear compatible CMOS (LC2MOS), an advanced, mixed technology process. It is packaged in 16-pin DIP and 16-pin SOIC packages.DACPORT is a registered trademark of Analog Devices, Inc.

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 AD7262/AD7262-5 are dual, 12-bit, high speed, low power, successive approximation ADCs that operate from a single 5 V power supply. The AD7262 features throughput rates of up to 1 MSPS per on-chip ADC. The AD7262-5 features throughput rates of up to 500 kSPS. Two complete ADC functions allow simultaneous sampling and conversion of two channels. Each ADC is preceded by a true differential analog input with a PGA. There are 14 gain settings available: ×1, ×2, ×3, ×4, ×6, ×8, ×12, ×16, ×24, ×32, ×48, ×64, ×96, and ×128.The AD7262/AD7262-5 contain four comparators. Comparator A and Comparator B are optimized for low power, while Comparator C and Comparator D have fast propagation delays. The AD7262/AD7262-5 feature a calibration function to remove any device offset error and programmable gain adjust registers to allow for input path (for example, sensor) offset and gain compensation. The AD7262/AD7262-5 have an on-chip 2.5 V reference that can be disabled if an external reference is preferred.The AD7262/AD7262-5 are ideally suited for monitoring small amplitude signals from a variety of sensors. They include all the functionality needed for monitoring the position feedback signals from a variety of analog encoders used in motor control systems.Product HighlightsIntegrated PGA with a variety of flexible gain settings to allow detection and conversion of low level analog signals.Each PGA is followed by a dual simultaneous sampling ADC, featuring throughput rates of 1 MSPS per ADC for the AD7262. The conversion results of both ADCs are simultaneously available on separate data lines or in succession on one data line if only one serial port is available.Four integrated comparators that can be used to count signals from pole sensors in motor control applications.Internal 2.5 V reference.

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.