14-Bit, 3 MSPS SAR ADC
The conversion process is a proprietary algorithmic successive approximation technique that results in no pipeline delays. The input signal is sampled, and a conversion is initiated on the falling edge of the CONVST signal. The conversion process is controlled by an internally trimmed oscillator. Interfacing is via standard parallel signal lines, making the part directly compatible with microcontrollers and DSPs.
The AD7484 provides excellent ac and dc performance specifica-tions. Factory trimming ensures high dc accuracy, resulting in very low INL, offset, and gain errors.
The part uses advanced design techniques to achieve very low power dissipation at high throughput rates. Power consumption in the normal mode of operation is 90 mW. There are two power saving modes: a nap mode, which keeps the reference circuitry alive for a quick power-up while consuming 2.5 mW, and a standby mode that reduces power consumption to a mere 10 μW.
The AD7484 features an on-board 2.5 V reference but can also accommodate an externally provided 2.5 V reference source. The nominal analog input range is 0 V to 2.5 V, but an offset shift capability allows this nominal range to be offset by ±200 mV. This allows the user considerable flexibility in setting the bottom end reference point of the signal range, a useful feature when using single-supply op amps.
The AD7484 also provides an 8% overrange capability via a 15th bit. Therefore, if the analog input range strays outside the nominal range by up to 8%, the user can still accurately resolve the signal by using the 15th bit.
The AD7484 is powered by a 4.75 V to 5.25 V supply. The part also provides a VDRIVE pin that allows the user to set the voltage levels for the digital interface lines. The range for this VDRIVE pin is 2.7 V to 5.25 V. The part is housed in a 48-lead LQFP package and is specified over a −40°C to +85°C temperature range.
Data Sheet, Rev. B, 8/08
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
The EVAL-AD7484CBZ is a fully featured evaluation kit for the AD7484. This board operates in stand alone mode or in conjunction with the Evaluation Controller board . When operated with the Evaluation Controller board, software is provided enabling the user to perform detailed analysis of the ADC's performance. This software includes the technical note describing the operation and set up of the evaluation board in standalone operation or when operated with the Evaluation Controller board.
Recommended Input Buffer Amplifiers
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.