Pin- and Software-Compatible, Multichannel DACs from Maxim

Today, power conservation is critical in all systems, not just battery-powered devices. In sleep mode, the MAX5134-MAX5137 family draws less than 300nA. Four 12- or 16-bit DACs can operate on an average current of 2.5microamps. Featuring an integrated, high-precision voltage reference, these DACs also give designers unmatched flexibility to change channel count and resolution with little or no design rework. Consequently, each DAC channel can be powered down individually for better control of power consumption.

The high linearity (±8LSB INL for the 16-bit DAC and ±1LSB INL for the 12-bit DAC) and flexibility of these DACs make them ideal for industrial process control and portable instrumentation applications, such as communication systems, programmable logic controllers, servo loops, and automatic test equipment. Other broad-based applications include automatic tuning, gain and offset adjustment, power amplifier control, data acquisition, programmable voltage, and current sources.

For production efficiency, inventory control, and time to market considerations, designers of today's industrial precision equipment employ a modular approach with multiple channels. Designers demand the flexibility to change resolution and channel count quickly, depending on their customer needs.

Using conventional converter solutions, designers had to redesign their board and rework the software to change resolution or channel count. With the MAX5134-MAX5137 family of pin- and software-compatible DACs, Designers can now switch between quad- and dual-channel 12-bit and 16-bit DACs without redesigning their board or control software, said Jeremy Tole, Maxim's Director of Business Development for Data Converters.

The MAX5134-MAX5137 DACs are unique in the industry because they offer the combination of better accuracy, greater integration, and a smaller package than competitive devices. The integrated voltage reference has a temperature coefficient of 10ppm/degree Celsius and the devices deliver ±8LSB INL for the 16-bit and ±1LSB for 12-bit DACs. This high accuracy is a marked improvement over the ±16LSB INL of the competition. All DAC outputs are buffered. The internal buffers provide improved load regulation and transition glitch suppression for the DAC outputs, Tole explained.

A pin-programmable zero/midscale DAC output ensures that the DAC output powers up to the desired state, even during a loss-of-power event. This output provides additional safety for applications that drive valves or other transducers that need to be off during power-up.

Each DAC features a software-controlled power-down mode for each channel. To conserve power when all four channels are powered down, the internal reference and biasing circuits also power down to consume only 300nA shutdown current.

The devices accept a 3-wire SPI(TM)-/QSPI(TM)-/MICROWIRE(TM)-/DSP-compatible serial interface, which saves board space and reduces the complexity of optically-isolated and transformer-isolated applications. To reduce number of optocouplers in isolated applications, the serial interface features a READY output for easy daisy chaining of several MAX5134-MAX5137 devices and/or other compatible devices.

These parts are offered in an ultra-small 4mm x 4mm TQFN package and are guaranteed monotonic to 16 bits.

The pin- and software-compatibility among these DACs saves significant design time and reduces time-to-market. The DACs operate over a wide +2.7V to +5.25V supply range to accommodate most low-power and low-voltage applications. The devices' low gain error (less than ±0.5%FS) and offset (less than ±10mV) provide the high precision necessary for process-control applications. These devices are offered in an ultra-small (4mm x 4mm) 24-pin TQFN package and are specified over the -40 degrees Celsius to +105 degrees Celsius extended industrial temperature range.