PDF AD9281 Data sheet ( Hoja de datos )

Número de pieza	AD9281
Descripción	Dual Channel 8-Bit Resolution CMOS ADC
Fabricantes	Analog Devices
Logotipo
Hay una vista previa y un enlace de descarga de AD9281 (archivo pdf) en la parte inferior de esta página. Total 16 Páginas
No Preview Available ! a FEATURES Complete Dual Matching ADC Low Power Dissipation: 225 mW (+3 V Supply) Single Supply: 2.7 V to 5.5 V Differential Nonlinearity Error: 0.1 LSB On-Chip Analog Input Buffers On-Chip Reference Signal-to-Noise Ratio: 49.2 dB Over Seven Effective Bits Spurious-Free Dynamic Range: –65 dB No Missing Codes Guaranteed 28-Lead SSOP Dual Channel 8-Bit Resolution CMOS ADC AD9281 IINA IINB IREFB IREFT QREFB QREFT VREF REFSENSE QINB QINA FUNCTIONAL BLOCK DIAGRAM AVDD AVSS CLOCK DVDD DVSS "I" ADC I REGISTER AD9281 REFERENCE BUFFER ASYNCHRONOUS MULTIPLEXER 1V THREE- STATE OUTPUT BUFFER "Q" ADC Q REGISTER SLEEP SELECT DATA 8 BITS CHIP SELECT PRODUCT DESCRIPTION The AD9281 is a complete dual channel, 28 MSPS, 8-bit CMOS ADC. The AD9281 is optimized specifically for applica- tions where close matching between two ADCs is required (e.g., I/Q channels in communications applications). The 28 MHz sampling rate and wide input bandwidth will cover both narrow- band and spread-spectrum channels. The AD9281 integrates two 8-bit, 28 MSPS ADCs, two input buffer amplifiers, an internal voltage reference and multiplexed digital output buffers. Each ADC incorporates a simultaneous sampling sample-and- hold amplifier at its input. The analog inputs are buffered; no external input buffer op amp will be required in most applica- tions. The ADCs are implemented using a multistage pipeline architecture that offers accurate performance and guarantees no missing codes. The outputs of the ADCs are ported to a multi- plexed digital output buffer. The AD9281 is manufactured on an advanced low cost CMOS process, operates from a single supply from 2.7 V to 5.5 V, and consumes 225 mW of power (on 3 V supply). The AD9281 input structure accepts either single-ended or differential signals, providing excellent dynamic performance up to and beyond 14 MHz Nyquist input frequencies. PRODUCT HIGHLIGHTS 1. Dual 8-Bit, 28 MSPS ADC A pair of high performance 28 MSPS ADCs that are opti- mized for spurious free dynamic performance are provided for encoding of I and Q or diversity channel information. 2. Low Power Complete CMOS Dual ADC function consumes a low 225 mW on a single supply (on 3 V supply). The AD9281 operates on supply voltages from 2.7 V to 5.5 V. 3. On-Chip Voltage Reference The AD9281 includes an on-chip compensated bandgap voltage reference pin programmable for 1 V or 2 V. 4. On-chip analog input buffers eliminate the need for external op amps in most applications. 5. Single 8-Bit Digital Output Bus The AD9281 ADC outputs are interleaved onto a single output bus saving board space and digital pin count. 6. Small Package The AD9281 offers the complete integrated function in a compact 28-lead SSOP package. 7. Product Family The AD9281 dual ADC is pin compatible with a dual 10-bit ADC (AD9201). REV. F 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 which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781/329-4700 World Wide Web Site: http://www.analog.com Fax: 781/461-3113 ©1999-2011 Analog Devices, Inc. All rights reserved. 1 page AD9281 ABSOLUTE MAXIMUM RATINGS* Parameter With Respect to Min Max Units AVDD AVSS DVDD DVSS AVSS DVSS AVDD DVDD CLK AVSS Digital Outputs DVSS AINA, AINB AVSS VREF AVSS REFSENSE AVSS REFT, REFB AVSS Junction Temperature Storage Temperature Lead Temperature 10 sec –0.3 –0.3 –0.3 –6.5 –0.3 –0.3 –1.0 –0.3 –0.3 –0.3 –65 +6.5 +6.5 +0.3 +6.5 AVDD + 0.3 DVDD + 0.3 AVDD + 0.3 AVDD + 0.3 AVDD + 0.3 AVDD + 0.3 +150 +150 V V V V V V V V V V °C °C +300 °C *Stresses above those listed under Absolute Maximum Ratings may cause perma- nent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum ratings for extended periods may effect device reliability. PIN CONFIGURATION DVSS DVDD DNC DNC (LSB) D0 D1 D2 D3 D4 D5 D6 (MSB) D7 SELECT CLOCK AD9281 TOP VIEW (Not to Scale) CHIP-SELECT INA-Q INB-Q REFT-Q REFB-Q AVDD VREF REFSENSE AVSS REFB-I REFT-I INB-I INA-I SLEEP NC = NO CONNECT PIN FUNCTION DESCRIPTIONS Pin No. Name Description 1 DVSS Digital Ground 2 DVDD Digital Supply 3 DNC Do not connect 4 DNC Do not connect 5 D0 Bit 0 (LSB) 6 D1 Bit 1 7 D2 Bit 2 8 D3 Bit 3 9 D4 Bit 4 10 D5 Bit 5 11 D6 Bit 6 12 D7 Bit 7 (MSB) 13 SELECT Hi I Channel Out, Lo Q Channel Out 14 CLOCK Clock 15 SLEEP Hi Power Down, Lo Normal Operation 16 INA-I I Channel, A Input 17 INB-I I Channel, B Input 18 REFT-I Top Reference Decoupling, I Channel 19 REFB-I Bottom Reference Decoupling, I Channel 20 AVSS Analog Ground 21 REFSENSE Reference Select 22 VREF Internal Reference Output 23 AVDD Analog Supply 24 REFB-Q Bottom Reference Decoupling, Q Channel 25 REFT-Q Top Reference Decoupling, Q Channel 26 INB-Q Q Channel B Input 27 INA-Q Q Channel A Input 28 CHIP-SELECT Hi-High Impedance, Lo-Normal Operation DEFINITIONS OF SPECIFICATIONS INTEGRAL NONLINEARITY (INL) Integral nonlinearity refers to the deviation of each individual code from a line drawn from “zero” through “full scale.” The point used as “zero” occurs 1/2 LSB before the first code transi- tion. “Full scale” is defined as a level 1 1/2 LSBs beyond the last code transition. The deviation is measured from the center of each particular code to the true straight line. DIFFERENTIAL NONLINEARITY (DNL, NO MISSING CODES) An ideal ADC exhibits code transitions that are exactly 1 LSB apart. DNL is the deviation from this ideal value. It is often specified in terms of the resolution for which no missing codes (NMC) are guaranteed. CAUTION ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human body and test equipment and can discharge without detection. Although the AD9281 features proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality. –4– WARNING! ESD SENSITIVE DEVICE REV. F 5 Page AD9281 REFERENCE AND REFERENCE BUFFER The reference and buffer circuitry on the AD9281 is configured for maximum convenience and flexibility. An illustration of the equivalent reference circuit is show in Figure 26. The user can select from five different reference modes through appropriate pin-strapping (see Table I below). These pin strapping options cause the internal circuitry to reconfigure itself for the appropri- ate operating mode. Table I. Table of Modes Mode 1V 2V Programmable External Input Span REFSENSE Pin Figure 1V 2V 1 + (R1/R2) = External Ref VREF AGND See Figure AVDD 22 23 24 25 1 V Mode (Figure 22)—provides a 1 V reference and 1 V input full scale. Recommended for applications wishing to optimize high frequency performance, or any circuit on a supply voltage of less than 4 V. The part is placed in this mode by shorting the REFSENSE pin to the VREF pin. 1V 1V 0V 5k⍀ 10␮F 0.1␮F IINA IINB QINA QINB 0V 10␮F 5k⍀ AD9281 1V VREF REFSENSE 0.1␮F I OR QREFT 0.1␮F 0.1␮F 10␮F I OR QREFB 0.1␮F Figure 22. 0 V to 1 V Input 2 V Mode (Figure 23)—provides a 2 V reference and 2 V input full scale. Recommended for noise sensitive applications on 5 V supplies. The part is placed in 2 V reference mode by ground- ing (shorting to AVSS) the REFSENSE pin. 2V 2V 0V IINA QINA 5k⍀ IINB QINB 10␮F 0.1␮F 5k⍀ AD9281 0V 10␮F 0.1␮F VREF I OR QREFT 0.1␮F 0.1␮F 10␮F I OR QREFB REFSENSE 0.1␮F Externally Set Voltage Mode (Figure 24)—this mode uses the on-chip reference, but scales the exact reference level though the use of an external resistor divider network. VREF is wired to the top of the network, with the REFSENSE wired to the tap point in the resistor divider. The reference level (and input full scale) will be equal to 1 V × (R1 + R2)/R1. This method can be used for voltage levels from 0.7 V to 2.5 V. 1␮F 0.1␮F R2 R1 VREF = 1 + R2 R1 VREF 1V + +– – REFSENSE AD9281 AVSS I OR QREFT I OR QREFB 0.1␮F 0.1␮F 10␮F 0.1␮F Figure 24. Programmable Reference External Reference Mode (Figure 25)—in this mode, the on- chip reference is disabled, and an external reference applied to the VREF pin. This mode is achieved by tying the REFSENSE pin to AVDD. 1V 0V 5k⍀ 10␮F 1V EXT REFERENCE 10␮F 0.1␮F 5k⍀ 0.1␮F AVDD IINA IINB QINA QINB AD9281 VREF I OR QREFT I OR QREFB REFSENSE 1V 0V 0.1␮F 0.1␮F 10␮F 0.1␮F Figure 25. External Reference Reference Buffer—The reference buffer structure takes the voltage on the VREF pin and level-shifts and buffers it for use by various sub-blocks within the two A/D converters. The two converters share the same reference buffer amplifier to maintain the best possible gain match between the two converters. In the interests of minimizing high frequency crosstalk, the buffered references for the two converters are separately decoupled on the IREFB, IREFT, QREFB and QREFT pins, as illustrated in Figure 26. Figure 23. 0 V to 2 V Input –10– REV. F 11 Page

Páginas	Total 16 Páginas
PDF Descargar	[ Datasheet AD9281.PDF ]

Hoja de datos destacado

Número de pieza	Descripción	Fabricantes
AD9280	CMOS A/D Converter	Analog Devices
AD9281	Dual Channel 8-Bit Resolution CMOS ADC	Analog Devices
AD9283	3V A/D Converter	Analog Devices
AD9284	1.8 V Dual Analog-to-Digital Converter (ADC)	Analog Devices

Número de pieza	Descripción	Fabricantes
SLA6805M	High Voltage 3 phase Motor Driver IC.	Sanken
SDC1742	12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters.	Analog Devices

DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares,
permitiéndote verlos en linea o descargarlos en PDF.

DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar