ADC for Medical and Industrial Applications
ADI has today revealed the introduction of the first product in a series of ultra-low-power, 12-bit, 1-MSPS SAR analogue-to-digital converters with internal 2.5-V reference. The new A/D converter is designed for USB or battery powered data acquisition modules, handheld meters, field instruments, energy harvesting applications and medical devices such as portable electrocardiograms and heart rate monitors.
The most power-efficient converter in its class, the device dissipates over 70 percent lower power than the closest SAR A/D converter competitor, in a package that is 33 percent smaller than competing 12-bit converters with internal reference.
“The AD7091R operates at over 3.5 times the power efficiency of competing A/D converters, and of discrete ADC and reference two-chip alternatives,” said Mike Britchfield, vice president, Industrial and Instrumentation Group, Analog Devices. “The significant power performance advantage was designed specifically for system engineers working within stringent system power constraints.”
The AD7091R core draws 349 μA typical at 3 V when operating at 1-MSPS. The device’s power automatically scales with throughput. It draws 264-nA power down current and 21.6µA standby current, which allows designers to further optimise energy consumption for intermittent or one-shot conversions. The new device also achieves a 4.5 ppm/˚C reference temperature coefficient.
Key AD7091R 12-bit A/D Converter Features:
• Low power:
o 349 µA typical at 3 V and 1 MSPS
o 264-nA power-down current
o 21.6 µA standby current
• Flexible power/throughput rate management
• Fast throughput: 1 MSPS
• Power supply: 2.7 V to 5.25 V
• DC Accuracy: +/-1 LSB INL
• 4.5 ppm/˚C 2.5V internal reference
• High-speed serial interface: SPI-/QSPI-/MICROWIRE-/DSP-compatible
• Serial interface voltage: 1.65V to 5.25V
Pricing, Availability and Complementary Products
The AD7091R is available now for sampling and production quantities, with a temperature range of –40°C to +125°C. The AD7091R is available in a 10-lead MSOP 5-mm × 3-mm package or in a 10-lead LFCSP 3-mm × 2-mm package, priced at $2.15 (USD) per unit in 1,000 quantities.
The EVAL-AD7091RSDZ evaluation board for the AD7091R is now available and priced at $59.00. The EVAL-SDP-CB1Z controller board must be ordered with the evaluation board and is priced at $99.00.
For ease of design in, IBIS models and software drivers are also now available. When coupled with low-power amplifiers, the AD7091R A/D converter is part of a chipset that reduces signal chain power dissipation. When used with the AD8031 op amp with rail-to-rail inputs and output, power is reduced by over 45 percent compared to previous offerings. For low-bandwidth applications, the AD8420 instrumentation amplifier used together with the AD7091R A/D converter provides a cost-sensitive solution that dissipates more than 60 percent lower power than previous solutions.