Datasheet AD7643 (Analog Devices)

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18-Bit, 1.25 MSPS PulSAR® ADC AD7643 FEATURES FUNCTIONAL BLOCK DIAGRAM Throughput: 1.25 MSPS TEMP REFBUFIN REF REFGND DVDD DGND INL: ±1.5 LSB typical, ±3 LSB maximum (±11 ppm of full scale) AGND 18-bit resolution with no missing codes AD7643 OVDD AVDD Dynamic range: 95 dB typical OGND REF SINAD: 93.5 dB typical @ 20 kHz (VREF = 2.5 V) REF AMP SERIAL THD: −113 dB t ypical @ 20 kHz (V PORT REF = 2.5 V) IN+ 18 SWITCHED D[17:0] 2.048 V internal reference: typical drift 8 ppm/°C; TEMP output IN– CAP DAC MODE0 PARALLEL Differential input range: ±VREF (VREF up to 2.5 V) INTERFACE MODE1 No pipeline delay (SAR architecture) PDREF CLOCK BUSY Parallel (18-, 16-, or 8-bit bus) and serial 5 V/3.3 V/2.5 V interface PDBUF RD CONTROL LOGIC AND SPI®/QSPI™/MICROWIRE™/DSP compatible PD CALIBRATION CIRCUITRY CS Single 2.5 V supply operation RESET D0/OB/2C Power dissipation
-001
65 mW t ypical @ 1.25 MSPS w ith internal REF CNVST
024 06
2 μW in power-down mode
Figure 1.
Pb-free, 48-lead LQFP and 48-lead LFCSP_VQ Table 1. PulSAR 48-Lead Selection Pin compatible with the AD7641 and other PulSAR ADC’s 100 to 500 to 650 to Type/kSPS 250 570 1000 >1000 APPLICATIONS
Pseudo AD7651, AD7650, AD7653,
Medical instruments
Differential AD7660, AD7652, AD7667 AD7661 AD7664,
High speed data acquisition/high dynamic data acquisition
AD7666
Digital signal processing
True Bipolar AD7610, AD7665 AD7612,
Spectrum analysis
AD7663 AD7671
Instrumentation
True AD7675 AD7676 AD7677 AD7621,
Communications
Differential AD7622,
ATE
AD7623 18-Bit AD7631, AD7679 AD7634, AD7641,
GENERAL DESCRIPTION
Multichannel/ AD7678 AD7674 AD7643 Simultaneous AD7654 AD7655 The AD7643 is an 18-bit, 1.25 MSPS, charge redistribution SAR, fully differential, analog-to-digital converter (ADC) that
PRODUCT HIGHLIGHTS
operates from a single 2.5 V power supply. The part contains a 1.
Fast Throughput.
high speed, 18-bit sampling ADC, an internal conversion clock, The AD7643 is a 1.25 MSPS, charge redistribution, an internal reference (and buffer), error correction circuits, and 18-bit SAR ADC. both serial and parallel system interface ports. The part has no 2.
Superior Linearity.
latency and can be used in asynchronous rate applications. The The AD7643 has no missing 18-bit code. AD7643 is hardware factory calibrated and tested to ensure ac 3.
Internal Reference.
parameters, such as signal-to-noise ratio (SNR), in addition to The AD7643 has a 2.048 V internal reference with a typical the more traditional dc parameters of gain, offset, and linearity. drift of ±8 ppm/°C and an on-chip TEMP sensor. The AD7643 is only available in Pb-free packages with 4.
Single-Supply Operation.
operation specified from −40°C to +85°C. The AD7643 operates from a 2.5 V single supply. 5.
Serial or Parallel Interface.
Versatile parallel (18-, 16-, or 8-bit bus) or 2-wire serial interface arrangement compatible with 2.5 V, 3.3 V, or 5 V logic.
Rev. 0 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 One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Tel: 781.329.4700 www.analog.com Trademarks and registered trademarks are the property of their respective owners. Fax: 781.461.3113 ©2006 Analog Devices, Inc. All rights reserved.
Document Outline FEATURES APPLICATIONS GENERAL DESCRIPTION FUNCTIONAL BLOCK DIAGRAM PRODUCT HIGHLIGHTS TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS TIMING SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TERMINOLOGY TYPICAL PERFORMANCE CHARACTERISTICS APPLICATIONS INFORMATION CIRCUIT INFORMATION CONVERTER OPERATION TRANSFER FUNCTIONS TYPICAL CONNECTION DIAGRAM ANALOG INPUTS MULTIPLEXED INPUTS DRIVER AMPLIFIER CHOICE Single-to-Differential Driver VOLTAGE REFERENCE INPUT Internal Reference (PDBUF = Low, PDREF = Low) External 1.2 V Reference and Internal Buffer (PDBUF = Low, PDREF = High) External 2.5 V Reference (PDBUF = High, PDREF = High) Reference Decoupling Temperature Sensor POWER SUPPLY Power Sequencing Power-Up CONVERSION CONTROL INTERFACES DIGITAL INTERFACE RESET PARALLEL INTERFACE Master Parallel Interface Slave Parallel Interface 16-Bit and 8-Bit Interface (Master or Slave) SERIAL INTERFACE MASTER SERIAL INTERFACE Internal Clock SLAVE SERIAL INTERFACE External Clock External Discontinuous Clock Data Read After Conversion External Clock Data Read During Previous Conversion MICROPROCESSOR INTERFACING SPI Interface (ADSP-219x) APPLICATION HINTS LAYOUT EVALUATING THE AD7643 PERFORMANCE OUTLINE DIMENSIONS ORDERING GUIDE