Linear Technology’s 16-Bit Octal SPI DAC Achieves ±4LSB INL

(Product News, 1 Jul 2009)

Linear Technology Corp. introduces the LTC2656, a 16-bit octal digital-to-analog converter (DAC) that offers ±4LSB INL maximum over temperature, a factor of three times better than the nearest octal competitor. The combination of low 0.1 percent (max) gain error and low ±2mV (max) offset error ensure that LTC2656 remains accurate near the supply rails and provides the user with a wider effective output range. The LTC2656's precision specifications makes it ideal for multichannel open loop and closed loop systems typically found in communication systems, industrial process control, automated test equipment (ATE) and programmable logic controllers.

The LTC2656 integrates a precision reference that achieves 2ppm/°C typical and 10ppm/°C maximum temperature coefficient. By integrating the reference in its tiny 20-pin 4mm x 5mm QFN and TSSOP packages, the LTC2656 offers further space reduction for densely packed circuit boards. Operating from a single 2.7V to 5.5V supply, supply current is a low 375uA per DAC with the reference activated. AC performance also stands out, as the LTC2656 offers 8.5us settling time for a half-scale step and <1nV•s crosstalk, resulting in minimal disturbance between DAC channels. The LTC2656 communicates via a 4-wire SPI-compatible interface up to 50MHz.

The LTC2656 offers a wide range of options to meet application specific requirements. Designers can choose between 16-bit or 12-bit resolution and an internal 1.25V or 2.048V reference, which produce a full-scale output voltage of 2.5V or 4.096V. Alternatively, an external reference up to half the supply voltage can be for rail-to-rail operation. The LTC2656 also includes a hardware option to power up the DAC outputs at zero-scale or midscale.

The LTC2656 is available, along with the LTC2657, an I2C-compatible 16-bit octal DAC. The LTC2656 16-bit and 12-bit DACs and demo boards are now available.