Analog Devices

The AD7538 is a 14-bit monolithic CMOS digital-to-analog converter (DAC) that uses laser trimmed thin-film resistors to achieve excellent linearity.The DAC is loaded by a single 14-bit wide word using standard chip select and memory write logic. Double buffering, which is optional usingLDAC, allows simultaneous updates in a system containing multiple AD7538s.A novel low leakage configuration enables the AD7538 to exhibit excellent output leakage current characteristics over the specified temperature range.The AD7538 is manufactured using the linear-compatible CMOS (LC2MOS) process. It is speed compatible with most microprocessors and accepts TTL or CMOS logic level inputs.

The AD7541A is a high performance, 12-bit monolithic multiplying digital-to-analog converter (DAC). It is fabricated using advanced, low noise, thin film, complementary metal-oxide semiconductor (CMOS) technology. The AD7541A is available in 18-lead PDIP, 18-lead PLCC, and 18-lead SOIC packages.The AD7541A is functionally and pin compatible with the industry standard AD7541, and it offers improved specifications and performance over the obsolete product, AD7541. The improved design ensures that the AD7541A is latch-up free; therefore, no output protection Schottky diodes are required.The AD7541A uses laser wafer trimming to provide full 12-bit endpoint linearity with several high performance grades.Product HighlightsCompatibility—The AD7541A can be used as a direct replacement for any AD7541 type device. As with the AD7541, The digital inputs on the AD7541A are TTL/CMOS compatible. They have a ±1 μA maximum input current requirement so that they do not load the driving circuitry.Improvements—The AD7541A offers the following improved specifications over the AD7541:Gain error for all grades are reduced with premium grade versions having a maximum gain error of ±3 LSB.Gain error temperature coefficient are reduced to 2 ppm/°C typical and 5 ppm/°C maximum.Digital-to-analog charge injection energy for the AD7541A is typically 20% less than the standard AD7541.Latch-up proof.Laser wafer trimming provides 1/2 LSB maximum differential nonlinearity for top grade devices over the operating temperature range (vs. 1 LSB on previous AD7541 devices).All grades are guaranteed monotonic to 12 bits over the operating temperature range.ApplicationsWaveform generatorsAnalog processingInstrumentation applicationsProgrammable amplifiers and attenuatorsDigitally controlled calibrationProgrammable filters and oscillatorsComposite videoUltrasoundGain, offset, and voltage trimming

The AD7542 is a precision 12-bit CMOS multiplying DAC designed for direct interface to 4- or 8-bit microprocessors.The functional diagram shows the AD7542 to consist of three 4-bit data registers, a 12-bit DAC register, address decoding logic and a 12-bit CMOS multiplying DAC. Data is loaded into the data registers in three 4-bit bytes, and subsequently transferred to the 12-bit DAC register. All data loading or data transfer operations are identical to the WRITE cycle of a static RAM. A clear input allows the DAC register to be easily reset to all zeros when powering up the device.

The AD7548 is a 12-monolithic CMOS D/A converter for use with 8-bit bus microprocessors. Data is loaded in two bytes to input holding registers as shown in the block diagram opposite. The AD7548 can be configured to accept either left- or right-justified data, least significant byte or most significant byte first, using standard TTL compatible control inputs.A separate load DAC control input allows the user the choice of updating the analog output coincident with loading new data to the DAC input register or at any time after the data loading event. This feature is especially important in multi-DAC systems where simultaneous update of all DACs is required.APPLICATIONS8-bit microprocessor based control systemsProgrammable amplifiersFunction generationServo Control