Datasheet AD7896 (Analog Devices)

2.7 V to 5.5 V, 12-Bit, 8
␮
s ADC in 8-Lead SOIC/PDIP AD7896 FEATURES FUNCTIONAL BLOCK DIAGRAM 100 kHz Throughput Rate Fast 12-Bit Sampling ADC with 8
␮
s Conversion Time VDD 8-Lead PDIP and SOIC Single 2.7 V to 5.5 V Supply Operation AD7896 High Speed, Easy-to-Use Serial Interface TRACK-AND-HOLD On-Chip Track-and-Hold Amplifier Analog Input Range Is 0 V to Supply VIN 12-BIT High Input Impedance ADC Low Power: 9 mW Typ OUTPUT CONVST REGISTER CLOCK AGND DGND BUSY SCLK SDATA GENERAL DESCRIPTION PRODUCT HIGHLIGHTS
The AD7896 is a fast, 12-bit ADC that operates from a single 1. Complete, 12-bit ADC in an 8-Lead Package. 2.7 V to 5.5 V supply and is housed in small 8-lead PDIP and The AD7896 contains an 8 µs ADC, a track-and-hold ampli- 8-lead SOIC packages. The part contains an 8 µs successive fier, control logic, and a high speed serial interface, all in an approximation ADC, an on-chip track-and-hold amplifier, an 8-lead PDIP. The VDD input is used as the reference for the on-chip clock, and a high speed serial interface. part, so no external reference is needed. This offers consider- Output data from the AD7896 is provided via a high speed, able space saving over alternative solutions. serial interface port. This 2-wire serial interface has a serial 2. Low Power, Single-Supply Operation. clock input and a serial data output with the external serial The AD7896 operates from a single 2.7 V to 5.5 V supply clock accessing the serial data from the part. and consumes only 9 mW typical. The automatic power- In addition to the traditional dc accuracy specifications, such as down mode, where the part goes into power down once linearity, full-scale, and offset errors, the AD7896 is also speci- conversion is complete and “wakes up” before the next con- fied for dynamic performance parameters, including harmonic version cycle, makes the AD7896 ideal for battery-powered distortion and signal-to-noise ratio. or portable applications. The part accepts an analog input range of 0 V to V 3. High Speed Serial Interface. DD and operates from a single 2.7 V to 5.5 V supply, consuming only 9 mW The part provides high speed serial data and serial clock lines typical. The V allowing for an easy, 2-wire serial interface arrangement. DD input is also used as the reference for the part so that no external reference is required. The AD7896 features a high sampling rate mode and, for low power applications, a proprietary automatic power-down mode where the part automatically goes into power-down once conver- sion is complete and “wakes up” before the next conversion cycle. The part is available in a small, 8-lead, 0.3'' wide, plastic or hermetic dual-in-line package (PDIP) and in an 8-lead, small outline IC (SOIC). Rev. D Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. No license is granted by implication or otherwise
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
under any patent or patent rights of Analog Devices. Trademarks and
Tel: 781/329-4700 www.analog.com
registered trademarks are the property of their respective companies.
Fax: 781/461-3113 ©1994–2011 Analog Device, Inc. All rights reserved.
Document Outline FEATURES GENERAL DESCRIPTION FUNCTIONAL BLOCK DIAGRAM PRODUCT HIGHLIGHTS SPECIFICATIONS TIMING CHARACTERISTICS ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION PIN FUNCTION DESCRIPTIONS TERMINOLOGY Relative Accuracy Differential Nonlinearity Unipolar Offset Error Positive Full-Scale Error Track-and-Hold Acquisition Time Signal-to-(Noise + Distortion) Ratio Total Harmonic Distortion Peak Harmonic or Spurious Noise Intermodulation Distortion CONVERTER DETAILS CIRCUIT DESCRIPTION Analog Input Section Track-and-Hold Section Timing and Control OPERATING MODES Mode 1 Operation (High Sampling Performance) Mode 2 Operation (Auto Sleep after Conversion) Serial Interface MICROPROCESSOR/MICROCONTROLLER INTERFACE AD7896–8051 Interface AD7896–68HC11/L11 Interface AD7896–ADSP-2103/ADSP-2105 Interface AD7896–DSP56002/L002 Interface AD7896 PERFORMANCE Linearity Noise Dynamic Performance (Mode 1 Only) Effective Number of Bits Power Considerations OUTLINE DIMENSIONS ORDERING GUIDE Revision History