Analog Devices Introduces Multichannel A/D Converters Designed For High-Voltage Industrial Applications

November 9, 2004 - Analog Devices, is augmenting its broad portfolio of data conversion products with the introduction of six 12-bit to 16-bit true bipolar, multichannel analog-to-digital converters (ADCs) for high-voltage applications. These ADCs provide higher speed and accuracy, reduce power consumption by 60 percent, and require fewer external components, making them ideal for industrial and instrumentation applications that use high-voltage (+/-10 V) signals, such as oscilloscope test functions, motor control, voltage drives, power line monitoring, and channel test tools for pipeline inspections. The converters, which are manufactured on Analog Devices' iCMOS industrial process technology, are designed to meet the industrial sector's growing demand for higher resolution and channel counts, faster conversion times, and lower power consumption. The flagship ADC products are:

• 12-bit True Bipolar Input, Multichannel ADC: The AD7328 13-bit (12-bit + Sign) ADC features the industry's fastest throughput rate (1 MSPS), eight-channel sampling, and power consumption of only 25 mW.
  
• 16-bit Simultaneous Sampling ADC: The AD7656 16-bit ADC offers simultaneous sampling on six channels and twice the accuracy of comparable devices (+/- 4 LSB max INL) at 250 KSPS per channel.
  

About the AD7328 - True Bipolar Input, Multichannel ADC
The AD7328 features 13-bit resolution (12-bit + Sign )-providing an extra bit of resolution for higher accuracy-and a high speed serial interface that can operate at throughput rates up to 1 MSPS. The AD7328 consumes only 25 mW powerв- 60 percent reduction over comparable devices-and has several power-down modes that reduce its power consumption at lower throughput rates.
The AD7328 combines a number of unique features that enable greater ease of use and design efficiencies over the closest comparable solutions. The device has high impedance analog inputs, easing driving requirements compared to ADCs that have resistive inputs. The increased input signal range of the ADC minimizes the effect of noise at the ADC input. Software selectable input ranges eliminate the need for level shifting or signal conditioning circuitry, reducing the cost and number of external components. Changing the analog input range can be accomplished without changing the hardware.
The AD7328 offers three bipolar input ranges: +/-10 V, +/-5 V, +/-2.5 V, and a 0 to 10 V unipolar input range, all of which are software selectable. In addition, application of a 3 V reference allows the ranges to be expanded by 20 percent. A channel sequencer enables multiple channels to be converted with minimum processor overhead. Each channel can be independently programmed to one of the input ranges using the on-board range registers. A four-channel part (AD7324) and two-channel part (AD7322) offering the same features as the AD7328 are also available.

About the AD7656 -Simultaneous Sampling ADC
The AD7656 is highly integrated, with six 16-bit successive-approximation ADCs offering 4 LSBS max INL and fast throughput rates (250 KSPS per channel)-plus a 2.5-V internal reference and reference buffers-all housed in one package. At 160 mW, the part also enables a 60 percent reduction in power consumption compared to the closest comparable bipolar ADC.
The AD7656 contains low noise, wide bandwidth track-and-hold amplifiers that can handle input frequencies up to 8 MHz. The AD7656 has high-speed parallel and serial interfaces, allowing the device to interface with microprocessors or DSPs. When in serial interface mode, the AD7656 has a daisy chain feature that allows multiple ADCs to connect to a single serial interface. The pin-compatible AD7657 and AD7658 offer the same features as the AD7656, but at 14-bit and 12-bit resolutions, respectively.

Pricing and Availability
The AD7328 and AD7656 ADCs and their derivatives, which are all sampling now, are scheduled for full production in May 2005 and July 2005, respectively.