Datasheet AD7829-1 (Analog Devices)

link to page 18
3 V/5 V, 2 MSPS, 8-Bit, 8-Channel ADC AD7829-1 FEATURES FUNCTIONAL BLOCK DIAGRAM 8-bit half-flash ADC with 420 ns conversion time CONVST EOC A0 A1 A2 VDD Eight single-ended analog input channels Available with input offset adjust CONTROL COMP LOGIC 2.5V On-chip track-and-hold REF SNR performance given for input frequencies up to10 MHz VIN1 BUF V V REF IN/OUT On-chip reference (2.5 V) IN2 VIN3 8-BIT Automatic power-down at the end of conversion VIN4 INPUT T/H HALF V MUX FLASH Wide operating supply range IN5 V ADC PARALLEL DB7 IN6 3 V ± 10% and 5 V ± 10% PORT V DB0 IN7 Input ranges VIN8
1 00
0 V to 2 V p-p, V
9-
DD = 3 V ± 10% V
17
MID AGND DGND CS RD
06
0 V to 2.5 V p-p, VDD = 5 V ± 10%
Figure 1.
Flexible parallel interface with EOC pulse to allow stand-alone operation APPLICATIONS Data acquisition systems, DSP front ends Disk drives Mobile communication systems, subsampling applications GENERAL DESCRIPTION
The AD7829-1 is a high speed 8-channel, microprocessor- The AD7829-1 is available in a 28-lead, wide body, small outline compatible, 8-bit analog-to-digital converter with a maximum IC (SOIC_W) and a 28-lead thin shrink small outline package throughput of 2 MSPS. The AD7829-1 contains an on-chip (TSSOP). reference of 2.5 V (2% tolerance); a track-and-hold amplifier;
PRODUCT HIGHLIGHTS
a 420 ns, 8-bit half-flash ADC; and a high speed parallel interface. The converter can operate from a single 3 V ± 10% 1. Fast Conversion Time. The AD7829-1 has a conversion and 5 V ± 10% supply. time of 420 ns. Faster conversion times maximize the DSP processing time in a real-time system. The AD7829-1 combines the convert start and power-down 2. Analog Input Span Adjustment. The VMID pin allows the functions at one pin, that is, the CONVST pin. This allows a user to offset the input span. This feature can reduce the unique automatic power-down at the end of a conversion to be requirements of single-supply op amps and take into implemented. The logic level on the CONVST pin is sampled account any system offsets. after the end of a conversion when an EOC (end of conversion) 3. FPBW (Full Power Bandwidth) of Track-and-Hold. The signal goes high, and if it is logic low at that point, the ADC is track-and-hold amplifier has excellent high frequency powered down. The parallel interface is designed to allow easy performance. The AD7829-1 is capable of converting full- interfacing to microprocessors and DSPs. Using only address scale input signals up to a frequency of 10 MHz, making decoding logic, the parts are easily mapped into the microprocessor the parts ideally suited to subsampling applications. address space. 4. Channel Selection. Channel selection is made without the The EOC pulse allows the ADCs to be used in a stand-alone necessity of writing to the part. manner (see the Parallel Interface section).
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 CHARACTERISTICS TIMING DIAGRAM ABSOLUTE MAXIMUM RATINGS ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TERMINOLOGY CIRCUIT INFORMATION CIRCUIT DESCRIPTION TYPICAL CONNECTION DIAGRAM ADC TRANSFER FUNCTION ANALOG INPUT POWER-UP TIMES POWER VS. THROUGHPUT OPERATING MODES PARALLEL INTERFACE MICROPROCESSOR INTERFACING AD7829-1 TO 8051 AD7829-1 TO PIC16C6x/PIC16C7x AD7829-1 TO ADSP-21xx INTERFACING MULTIPLEXER ADDRESS INPUTS OUTLINE DIMENSIONS ORDERING GUIDE