PDF AD677 Data sheet ( Hoja de datos )

Número de pieza	AD677
Descripción	16-Bit 100 kSPS Sampling ADC
Fabricantes	Analog Devices
Logotipo
Hay una vista previa y un enlace de descarga de AD677 (archivo pdf) en la parte inferior de esta página. Total 16 Páginas
No Preview Available ! a FEATURES Autocalibrating On-Chip Sample-Hold Function Serial Output 16 Bits No Missing Codes ؎1 LSB INL –99 dB THD 92 dB S/(N+D) 1 MHz Full Power Bandwidth 16-Bit 100 kSPS Sampling ADC AD677 FUNCTIONAL BLOCK DIAGRAM VIN 10 AGND SENSE 9 VREF 11 AGND 8 INPUT BUFFERS 16-BIT DAC CAL DAC A CHIP COMP LOGIC TIMING LEVEL TRANSLATORS CAL 16 CLK 2 SAMPLE 1 MICROCODED CONTROLLER SAR ALU RAM D CHIP 15 BUSY 14 SCLK 3 SDATA AD677 PRODUCT DESCRIPTION The AD677 is a multipurpose 16-bit serial output analog-to- digital converter which utilizes a switched-capacitor/charge redistribution architecture to achieve a 100 kSPS conversion rate (10 µs total conversion time). Overall performance is opti- mized by digitally correcting internal nonlinearities through on-chip autocalibration. The AD677 circuitry is segmented onto two monolithic chips— a digital control chip fabricated on Analog Devices DSP CMOS process and an analog ADC chip fabricated on our BiMOS II process. Both chips are contained in a single package. The AD677 is specified for ac (or “dynamic”) parameters such as S/(N+D) Ratio, THD and IMD which are important in sig- nal processing applications. In addition, dc parameters are specified which are important in measurement applications. The AD677 operates from +5 V and ± 12 V supplies and typi- cally consumes 450 mW using a 10 V reference (360 mW with 5 V reference) during conversion. The digital supply (VDD) is separated from the analog supplies (VCC, VEE) for reduced digi- tal crosstalk. An analog ground sense is provided to remotely sense the ground potential of the signal source. This can be use- ful if the signal has to be carried some distance to the A/D con- verter. Separate analog and digital grounds are also provided. The AD677 is available in a 16-pin narrow plastic DIP, 16-pin narrow side-brazed ceramic package, or 28-lead SOIC. A paral- lel output version, the AD676, is available in a 28-pin ceramic or plastic DIP. All models operate over a commercial tempera- ture range of 0°C to +70°C or an industrial range of –40°C to +85°C. PRODUCT HIGHLIGHTS 1. Autocalibration provides excellent dc performance while eliminating the need for user adjustments or additional exter- nal circuitry. 2. ± 5 V to ± 10 V input range (± VREF). 3. Available in 16-pin 0.3" skinny DIP or 28-lead SOIC. 4. Easy serial interface to standard ADI DSPs. 5. TTL compatible inputs/outputs. 6. Excellent ac performance: –99 dB THD, 92 dB S/(N+D) peak spurious –101 dB. 7. Industry leading dc performance: 1.0 LSB INL, ± 1 LSB full scale and offset. REV. A 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: 617/329-4700 Fax: 617/326-8703 1 page ORDERING GUIDE Model Temperature Range S/(N+D) Max INL AD677JN AD677KN AD677JD AD677KD AD677JR AD677KR AD677AD AD677BD 0°C to +70°C 0°C to +70°C 0°C to +70°C 0°C to +70°C 0°C to +70°C 0°C to +70°C –40°C to +85°C –40°C to +85°C 89 dB 90 dB 89 dB 90 dB 89 dB 90 dB 89 dB 90 dB Typ Only ± 1.5 LSB Typ Only ± 1.5 LSB Typ Only ± 1.5 LSB Typ Only ± 1.5 LSB D = Ceramic DIP; N = Plastic DIP; R = Small Outline IC (SOIC). AD677 Package Description Plastic 16-Pin DIP Plastic 16-Pin DIP Ceramic 16-Pin DIP Ceramic 16-Pin DIP Plastic 28-Lead SOIC Plastic 28-Lead SOIC Ceramic 16-Pin DIP Ceramic 16-Pin DIP Package Option N-16 N-16 D-16 D-16 R-28 R-28 D-16 D-16 ABSOLUTE MAXIMUM RATINGS* VCC to VEE . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +26.4 V VDD to DGND . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +7 V Vcc to AGND . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +18 V VEE to AGND . . . . . . . . . . . . . . . . . . . . . . . . . . –18 V to +0.3 V AGND to DGND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +0.3 V Digiul Inputs to DGND . . . . . . . . . . . . . . . . . . . . . . 0 to +5.5 V Analog Inputs, VREF to AGND . . . . . . . . . . . . . . . . . . . . . . . . . . . . (VCC +0.3 V) to (VEE –0.3 V) Soldering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +300°C, 10 sec Storage Temperature . . . . . . . . . . . . . . . . . . . . . –65°C to +150°C *Stresses greater than those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. 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 AD677 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. WARNING! ESD SENSITIVE DEVICE REV. A –5– 5 Page AD677 made for selecting one with low noise. A capacitor connected between REF IN and AGND will reduce the demands on the reference by decreasing the magnitude of high frequency com- ponents required to be sourced by the reference. Figures 6 and 7 represent typical design approaches. +12V CN 1.0µF 2 VIN 86 AD586 4 10µF VREF 0.1µF AD677 AGND Figure 6. Figure 6 shows a voltage reference circuit featuring the 5 V out- put AD586. The AD586 is a low cost reference which utilizes a buried Zener architecture to provide low noise and drift. Over the 0°C to +70°C range, the AD586M grade exhibits less than 1.0 mV output change from its initial value at +25°C. A noise reduction capacitor, CN, reduces the broadband noise of the AD586 output, thereby optimizing the overall performance of the AD677. It is recommended that a 10 µF to 47 µF high qual- ity tantalum capacitor and a 0.1 µF capacitor be tied between the VREF input of the AD677 and ground to minimize the im- pedance on the reference. Using the AD677 with ± 10 V input range (VREF = 10 V) typi- cally requires ± 15 V supplies to drive op amps and the voltage reference. If ± 12 V is not available in the system, regulators such as 78L12 and 79L12 can be used to provide power for the AD677. This is also the recommended approach (for any input range) when the ADC system is subjected to harsh environ- ments such as where the power supplies are noisy and where voltage spikes are present. Figure 7 shows an example of such a system based upon the 10 V AD587 reference, which provides a 300 µV LSB. Circuitry for additional protection against power supply disturbances has been shown. A 100 µF capacitor at each 10Ω 10µF 0.1µF AD587 2 VIN VO 6 GND NR 8 4 1µF +15V 100µF 78L12 +5V 100µF –15V 100µF 79L12 10Ω 0.01µF 10Ω 10Ω 0.01µF 10µF 0.1µF 0.1µF VCC VDD VREF AD677 VEE VIN 10µF 0.1µF 10µF 0.1µF VIN Figure 7. regulator prevents very large voltage spikes from entering the regulators. Any power line noise which the regulators cannot eliminate will be further filtered by an RC filter (10 Ω/10 µF) having a –3 dB point at 1.6 kHz. For best results the regulators should be within a few centimeters of the AD677. ANALOG INPUT As previously discussed, the analog input voltage range for the AD677 is ± VREF. For purposes of ground drop and common mode rejection, the VIN and VREF inputs each have their own ground. VREF is referred to the local analog system ground (AGND), and VIN is referred to the analog ground sense pin (AGND SENSE) which allows a remote ground sense for the input signal. The AD677 analog inputs (VIN, VREF and AGND SENSE) ex- hibit dynamic characteristics. When a conversion cycle begins, each analog input is connected to an internal, discharged 50 pF capacitor which then charges to the voltage present at the corre- sponding pin. The capacitor is disconnected when SAMPLE is taken LOW, and the stored charge is used in the subsequent conversion. In order to limit the demands placed on the external source by this high initial charging current, an internal buffer amplifier is employed between the input and this capacitance for a few hundred nanoseconds. During this time the input pin ex- hibits typically 20 kΩ input resistance, 10 pF input capacitance and ± 40 µA bias current. Next, the input is switched directly to the now precharged capacitor and allowed to fully settle. During this time the input sees only a 50 pF capacitor. Once the sample is taken, the input is internally floated so that the external input source sees a very high input resistance and a parasitic input capacitance of typically only 2 pF. As a result, the only domi- nant input characteristic which must be considered is the high current steps which occur when the internal buffers are switched in and out. In most cases, these characteristics require the use of an external op amp to drive the input of the AD677. Care should be taken with op amp selection; even with modest loading conditions, most available op amps do not meet the low distortion require- ments necessary to match the performance capabilities of the AD677. Figure 8 represents a circuit, based upon the AD845, which will provide excellent overall performance. For applications optimized more for low distortion and low noise, the AD845 of Figure 8 may be replaced by the AD743. 1k Ω ±5V INPUT 1k Ω 499 Ω +12V 27 AD845 34 0.1µF 6 0.1µF –12V AD677 VIN AGND AGND SENSE Figure 8. REV. A –11– 11 Page

Páginas	Total 16 Páginas
PDF Descargar	[ Datasheet AD677.PDF ]

Hoja de datos destacado

Número de pieza	Descripción	Fabricantes
AD670	Low Cost Signal Conditioning 8-Bit ADC	Analog Devices
AD671	Monolithic 12-Bit 2 MHz A/D Converter	Analog Devices
AD673	8-Bit A/D Converter	Analog Devices
AD674B	Complete 12-Bit A/D Converters	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