The LTC2668-16 from Linear Technology Corp. is a 16-channel, 16-bit voltage output digital-to-analog converter (DAC) with SoftSpan™ outputs, each of which can be independently configured for one of five selectable unipolar and bipolar output ranges up to ±10 V. Each rail-to-rail DAC output is capable of sourcing or sinking 10 mA with guaranteed load regulation and is stable driving capacitive loads as large as 1000 pF. This makes the LTC2668 ideal for driving a variety of demanding loads in applications such as optical modules, programmable logic controllers (PLCs), MRI and X-ray imaging, automatic test equipment, laser etch equipment, spectrum analyzers and oscilloscopes.
The LTC2668 offers many space-saving features in a compact 6mm x 6mm QFN package, nearly 50% smaller footprint than alternative 16-channel DACs. The LTC2668 can be operated from a single 5 V supply, or from dual bipolar supplies depending on the output voltage range requirement. The device includes a precision 2.5 V 10 ppm/°C max reference to generate the five SoftSpan output ranges, or it can be driven with an external reference. A convenient 16:1 high voltage analog multiplexer enables the user to monitor circuit integrity or perform in-circuit calibration, saving significant board real estate. The LTC2668 also supports an A/B toggle function for generating an AC bias or for applying dither to a system. Configuration of the LTC2668 is handled via an SPI-compatible serial interface which can be powered from an independent 1.8V to 5V digital supply.
The LTC2668 is offered in both 16-bit and 12-bit versions and is available today in commercial, industrial and automotive (-40 °C to 125 °C) temperature grades. Pricing begins at $31.25 each for the LTC2668-16 and $25.75 each for the LTC2668-12 in 1,000-piece quantities. The DC2025A evaluation board for the LTC2668 family is available at www.linear.com/demo or via a local Linear Technology sales office. The demo board is supported by the Linduino™ firmware development system, using the DC2026A.
