Equivalent Circuits–AD6640tAAINNANALOGINPUTSN + 1AINENCODE INPUTS(ENCODE)DIGITAL OUTPUTSN – 2N – 1N(D11–D0)tOD Figure 1. Timing Diagram VCH AVCCDVCCAINBUFT/HCURRENTMIRROR450 ⍀ VCLBUFVREFVCH AVCC450 ⍀ DVCCAINBUFT/HVREFD0–D11VCL Figure 2. Analog Input Stage AVCCCURRENTMIRRORAVCCAVCCR1R1 Figure 5. Digital Output Stage 17k ⍀ 17k ⍀ ENCODEENCODETIMINGR2CIRCUITSR2AV8k ⍀ 8k ⍀ CCAVCC2.4VV Figure 3. ENCODE Inputs REF0.5mAAVCC Figure 6. 2.4 V Reference VREFAVCCAVCCCURRENTMIRRORC1 Figure 4. Compensation Pin, C1 REV. A –7– Document Outline FEATURES APPLICATIONS GENERAL DESCRIPTION FUNCTIONAL BLOCK DIAGRAM PRODUCT HIGHLIGHTS SPECIFICATIONS DC SPECIFICATIONS DIGITAL SPECIFICATIONS SWITCHING SPECIFICATIONS AC SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS EXPLANATION OF TEST LEVELS ORDERING GUIDE PIN FUNCTION DESCRIPTIONS PIN CONFIGURATION DEFINITION OF SPECIFICATIONS Analog Bandwidth (Small Signal) Aperture Delay Aperture Uncertainty (Jitter) Differential Nonlinearity Encode Pulsewidth/Duty Cycle Integral Nonlinearity Minimum Conversion Rate Maximum Conversion Rate Output Propagation Delay Power Supply Rejection Ratio Signal-to-Noise-and-Distortion (SINAD) Signal-to-Noise Ratio (SNR) Spurious-Free Dynamic Range (SFDR) Two-Tone Intermodulation Distortion Rejection Two-Tone SFDR Worst Harmonic Equivalent Circuits Typical Performance Characteristics THEORY OF OPERATION APPLYING THE AD6640 Encoding the AD6640 Driving the Analog Input Power Supplies Output Loading Layout Information Evaluation Boards DIGITAL WIDEBAND RECEIVERS Introduction System Description System Requirements Noise Floor and SNR Processing Gain Overcoming Static Nonlinearities with Dither Receiver Example IF Sampling Using the AD6640 as a Mix-Down Stage RECEIVE CHAIN FOR A PHASED-ARRAY CELLULAR BASE STATION OUTLINE DIMENSIONS Revision History