Datasheet AD7482 (Analog Devices)

3 MSPS, 12-Bit SAR ADC AD7482 FEATURES FUNCTIONAL BLOCK DIAGRAM Fast throughput rate: 3 MSPS AVDD AGND CBIAS DVDD VDRIVE DGND Wide input bandwidth: 40 MHz No pipeline delays with SAR ADC Excellent dc accuracy performance 2.5V REFOUT REFERENCE BUF 2 parallel interface modes REFSEL REFIN Low power: 90 mW (full power) and 2.5 mW (nap mode) Standby mode: 2 µA maximum 12-BIT Single 5 V supply operation ALGORITHMIC VIN T/H SAR Internal 2.5 V reference Full-scale overrange mode (using 13th bit) AD7482 System offset removal via user access offset register D12 Nominal 0 V to 2.5 V input with shifted range capability MODE1 D11 MODE2 14-bit pin compatible upgrade AD7484 available D10 CLIP CONTROL D9 NAP LOGIC AND I/O REGISTERS D8 STBY D7 RESET D6 CONVST D5 Y CS RD D0 D1 D2 D3 D4 ITE
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GENERAL DESCRIPTION
The AD7482 is a 12-bit, high speed, low power, successive alive for a quick power-up while consuming 2.5 mW, and a approximation ADC. The part features a paral el interface with standby mode that reduces power consumption to a mere 10 μW. throughput rates up to 3 MSPS. The part contains a low noise, The AD7482 features an on-board 2.5 V reference but can also wide bandwidth track-and-hold that can handle input frequencies accommodate an externally provided 2.5 V reference source. in excess of 40 MHz. The nominal analog input range is 0 V to 2.5 V, but an offset The conversion process is a proprietary algorithmic successive shift capability al ows this nominal range to be offset by ±200 mV. approximation technique that results in no pipeline delays. The This al ows the user considerable flexibility in setting the bottom input signal is sampled, and a conversion is initiated on the fal ing end reference point of the signal range, a useful feature when edge of the CONVST signal. The conversion process is controlled using single-supply op amps. via an internally trimmed oscil ator. Interfacing is via standard The AD7482 also provides an 8% overrange capability via a parallel signal lines, making the part directly compatible with 13th bit. Therefore, if the analog input range strays outside the microcontrollers and DSPs. nominal by up to 8%, the user can stil accurately resolve the The AD7482 provides excellent ac and dc performance specifica- signal by using the 13th bit. tions. Factory trimming ensures high dc accuracy, resulting in The AD7482 is powered by a 4.75 V to 5.25 V supply. The part very low INL, offset, and gain errors. also provides a VDRIVE pin that allows the user to set the voltage The part uses advanced design techniques to achieve very low levels for the digital interface lines. The range for this VDRIVE pin power dissipation at high throughput rates. Power consumption is 2.7 V to 5.25 V. The part is housed in a 48-lead LQFP package in the normal mode of operation is 90 mW. There are two power and is specified over a −40°C to +85°C temperature range. saving modes: a nap mode, which keeps the reference circuitry
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