Data converters shrink to reduce footprint and add intelligence

ADCs and DACs from Texas Instruments reduce the overall system footprint in industrial, communications and personal electronics applications, claims the company. The four precision data converters, are each claimed to be the industry’s smallest in its class.

The DAC80508 and DAC70508 are eight-channel precision digital-to-analogue converters (DACs) that provide true 16- and 14-bit resolution, respectively. The ADS122C04 and ADS122U04 are 24-bit precision analogue-to-digital converters (ADCs) that feature a two-wire, I2C-compatible interface and a two-wire, UART-compatible interface, respectively.

The new data converters enable designers to add more intelligence and functionality, while shrinking system board space, says Texas Instruments.

They join a portfolio of precision ADCs and DACs optimised for a variety of small-size, high-performance or cost-sensitive industrial, communications and personal electronics applications, such as optical modules, field transmitters, battery-powered systems, building automation and wearables.

The DAC80508 and DAC70508 include a 2.5V, 5-ppm/ degrees C internal reference, eliminating the need for an external precision reference. Available in a 2.4 x 2.4mm die-size ball-grid array (DSBGA) package or wafer chip-scale package (WCSP), and a 3.0 x 3.0mm quad flat no-lead (QFN)-16 package, these DACs are up to 36 per cent smaller than the competition. They eliminate the typical trade-off between high performance and small size, enabling engineers to achieve the best system accuracy, while reducing board size or increasing channel density.

They also maximise system accuracy and achieve higher reliability, says TI. Despite their compact size, the DAC80508 and DAC70508 provide true, one least significant bit (LSB) integral nonlinearity to achieve the highest level of accuracy at 16- and 14-bit resolution. This is up to 66 per cent better linearity than the competition, says TI. They are specified over a -40 to +125 degrees C extended temperature range and provide features such as cyclic redundancy check (CRC) to increase system reliability.

The ADS122C04 and ADS122U04 24-bit precision ADCs are available in 3.0 x 3.0mm very thin QFN (WQFN)-16 and 5.0 x 4.4mm thin-shrink small-outline package (TSSOP)-16 options. The two-wire interface requires fewer digital isolation channels than a standard serial peripheral interface (SPI), reducing the overall cost of an isolated system. The precision ADCs also eliminate the need for external circuitry by integrating a flexible input multiplexer, a low-noise programmable gain amplifier, two programmable excitation current sources, an oscillator and a precision temperature sensor.

Both devices feature a low-drift 2.048V, 5-ppm/ degress C internal reference. Their internal two per cent accurate oscillators help designers improve power-line cycle noise rejection, enabling higher accuracy in noisy environments, explains TI. With gains from one to 128 and noise as low as 100nV, designers can measure both small-signal sensors and wide input ranges with one ADC. These device families, which also include pin-to-pin-compatible 16-bit options, enabling designers to meet various system requirements by scaling performance up or down.

Texas Instruments is also releasing the DAC80508 evaluation module, the ADS122C04 evaluation module and the ADS122U04 evaluation module.

Engineers can jump-start their designs using the DAC80508 with the reference design for laser diode applications with precisely controlled current requirements and the ADS122C04 and ADS122U04 with the high-precision temperature measurement for heat and cold meters reference design.

Designers can simulate their designs and predict circuit behaviour for these data converters by downloading the DACx0508 input/output buffer information specification (IBIS) model, the ADS122C04 IBIS model and the ADS122U04 IBIS model.

http://www.ti.com