AD6640 Analog Devices, AD6640 Datasheet
AD6640
Specifications of AD6640
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AD6640 Summary of contents
Page 1
... All necessary functions, including track-and-hold (T/H) and reference, are included on-chip to provide a complete conversion solution. The AD6640 runs on a single 5 V supply and provides CMOS compatible digital outputs at 65 MSPS. Specifically designed to address the needs of multichannel, multimode receivers, the AD6640 maintains 80 dB spurious- free dynamic range (SFDR) over a bandwidth of 25 MHz ...
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... V) CC Output Coding NOTES Best dynamic performance is obtained by driving ENCODE and ENCODE differentially. See Encoding the AD6640 section for more details. Performance versus ENCODE/ENCODE 1 power is shown in TPC 12. 2 For dc-coupled applications, the ENCODE input common-mode range specifies the common-mode range the ENCODE inputs can tolerate when driven differentially by the minimum differential input voltage of 0 ...
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... V –3– AD6640 = – +85 C, MIN MAX AD6640AST Min Typ Max Unit 65 MSPS 6.5 MSPS 400 ps 0.3 ps rms 6.5 ns 6.5 ns 8.5 10.5 12 – +85 C, MIN MAX AD6640AST Min Typ Max Unit 67 63.5 67.2 dB 67 dBc 74 80 dBc 79.5 dBc 78.5 dBc 85 ...
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... 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 AD6640 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 ...
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... Function 3.3 V/5 V Power Supply (Digital). Powers output stage only. Encode Input. Data conversion initiated on rising edge. Complement of ENCODE. Drive differentially with ENCODE or bypass to ground for single-ended clock mode. See Encoding the AD6640 section. Ground Analog Input Complement of Analog Input Internal Voltage Reference. Nominally 2.4 V. Bypass to ground with 0.1 µ ...
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... AD6640 DEFINITION OF SPECIFICATIONS Analog Bandwidth (Small Signal) The analog input frequency at which the spectral power of the fundamental frequency (as determined by the FFT analysis) is reduced by 3 dB. Aperture Delay The delay between a differential crossing of ENCODE and ENCODE and the instant at which the analog input is sampled. ...
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... INPUTS AIN (ENCODE) N – 2 (D11–D0 Figure 1. Timing Diagram T/H V REF T 17k ENCODE –7– –7– Equivalent Circuits–AD6640 N – CURRENT MIRROR REF D0–D11 CURRENT MIRROR Figure 5. Digital Output Stage 2.4V V REF 0.5mA ...
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... AD6640 –Typical Performance Characteristics 0 ENCODE = 65MSPS AIN = 2.2MHz 100 120 dc 6.5 13.0 19.5 FREQUENCY – MHz TPC 1. Single Tone at 2.2 MHz 100 120 dc 6.5 13.0 19.5 FREQUENCY – MHz TPC 2. Single Tone at 15.5 MHz 0 ENCODE = 65MSPS AIN = 31.0MHz ...
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... TPC 11. SNR, Worst Spurious vs. Duty Cycle –20 –10 0 –15 TPC 12. SNR, Worst Spurious vs. ENCODE Power –9– AD6640 AIN = 19.5MHz WORST SPUR SNR SAMPLE RATE – MSPS ENCODE = 65MSPS AIN = 2.2MHz WORST SPUR SNR 30 35 ...
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... AD6640 0 ENCODE = 65MSPS AIN = 19.5MHz @ –36dBFS –20 NO DITHER –40 –60 –80 –100 –120 dc 6.5 13.0 19.5 FREQUENCY – MHz TPC 13. 16K FFT without Dither 100 90 ENCODE = 65MSPS 80 AIN = 19.5MHz NO DITHER SFDR = 80dB 10 REFERENCE LINE 0 –80 –70 –60 –50 –40 –30 ANALOG INPUT POWER LEVEL – dBFS TPC 14 ...
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... The result is a 12-bit parallel digital CMOS compatible word, coded as twos complement. APPLYING THE AD6640 Encoding the AD6640 A valid ENCODE clock must be present on the AD6640 before the application V). Best performance is obtained by CC driving the ENCODE pins differentially. However, the AD6640 is also designed to interface with TTL and CMOS logic families ...
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... Therefore, the analog source driving the AD6640 should be ac-coupled to the input pins. Since the differential input impedance of the AD6640 is 0.9 kΩ, the analog input power requirement is only –3 dBm, simplifying the drive amplifier in many cases ...
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... AD6640 (see Driving the Analog Input section). The onboard termination resistor is 270 Ω. This resistor, in parallel with the AD6640’s input resistance (900 Ω), provides a 50 Ω load to the analog source driving the 1:4 transformer different input impedance is required, replace R16 by using the equation where Z is desired input impedance (200 Ω ...
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... Data is latched in a pipeline configuration; a rising edge generates the new AD6640 data sample, latches the previous data at the con- verter output, and strobes the external data register over J3. Note that power and ground must be applied power the digital logic section of the evaluation board ...
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... D4 29 DUT D3 28 AD6640 (LSB GND 348 CONNECT 348 C13 C15 C16 0.1 F 0.1 F 0.1 F Figure 18. AD6640ST/PCB Schematic –15– AD6640 74LCX574 ( 348 348 348 348 ...
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... AD6640 Figure 19. AD6640ST/PCB Top Side Silkscreen Figure 20. AD6640ST/PCB Bottom Side Silkscreen NOTE: Evaluation boards are often updated; consult factory for latest version. Figure 21. AD6640ST/PCB Top Side Copper Figure 22. AD6640ST/PCB Bottom Side Copper (Positive) –16– REV. A ...
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... Figure 23. AD6640ST/PCB Ground Layer (Negative) REV. A Figure 24. AD6640ST/PCB “Split” Power Layer (Negative) –17– AD6640 ...
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... System Requirements Figure 28 shows a typical wideband receiver subsystem based around the AD6640. This strip consists of a wideband IF filter, amplifier, ADC, latches, channelizer, and interface to a digital signal processor. This design shows a typical clocking scheme used in many receiver designs ...
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... CLOCK band-pass filter will remove harmonics generated within the amplifier, but intermods should be better than the performance of the A/D converter. In the case of the AD6640, amplifier intermods must be better than –80 dBFS when driving full- scale power. As mentioned earlier, there are several amplifiers to choose from and the specifications depend on the end application ...
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... For example kHz AMPS signal is being digitized with an AD6640 sampling at 65 MSPS, the ratio would be 0.015 MHz/32.5 MHz. Expressed in log form, the processing gain is –10 × log (0.015 MHz/32.5 MHz) or 33.4 dB. ...
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... IF Sampling Using the AD6640 as a Mix-Down Stage Since performance of the AD6640 extends beyond the baseband region into the third Nyquist zone, the converter has many uses as a mix-down converter in both narrow-band and wideband applications. This application is called band-pass sampling. Doing – ...
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... RECEIVE CHAIN FOR A PHASED-ARRAY CELLULAR BASE STATION The AD6640 is an excellent digitizer for beam forming in phased- array antenna systems. The price performance of the AD6640 and AD6620 channelizers allows for a very competitive solution. Phased-array base stations allow better coverage by focusing the receivers’ ...
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... ANTENNA 1 AD6640 COMMON LO ANTENNA 2 AD6640 ANTENNA 3 AD6640 ANTENNA 4 AD6640 ANTENNA 5 AD6640 ANTENNA 6 AD6640 ANTENNA 7 AD6640 ANTENNA 8 AD6640 Figure 34. Receive Chain for a Phased-Array Cellular Base Station with Eight Antennas and 32 Channels REV. A SYNC 1 AD6620 (1) AD6620 (2) AD6620 (3) AD6620 (30) AD6620 (31) AD6620 (32) AD6620s (32 CHANNELS) SYNC 1 ...
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... Sheet changed from REV REV. A. Updated Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Universal Changed to 44-Lead Plastic Quad Flatpack (LQFP Universal Changes to ABSOLUTE MAXIMUM RATINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Updated TPCs 13 and Text inserted in Encoding the AD6640 section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Updated OUTLINE DIMENSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 OUTLINE DIMENSIONS 44-Lead Plastic Quad Flatpack [LQFP] (ST-44) Dimensions shown in millimeters 0 ...