Datasheet AD7866 (Analog Devices) - 10

AD7866 PERFORMANCE CURVES
Pf = power at frequency f in ADC output, and PfS = power at TPC 1 shows a typical FFT plot for the AD7866 at 1 MHz frequency fS coupled onto the ADC AVDD supply. Here, a 100 mV sample rate and 300 kHz input frequency. TPC 2 shows the peak-to-peak sine wave is coupled onto the AVDD supply while the signal-to-(noise + distortion) ratio performance versus input digital supply is left unaltered. TPCs 3a and 3b show the PSRR frequency for various supply voltages while sampling at 1 MSPS of the AD7866 when there is no decoupling on the supply, while with an SCLK of 20 MHz. TPCs 4a and 4b show the PSRR with decoupling capacitors of 10 µF and 0.1 µF on the supply. TPCs 3a to 4b show the power supply rejection ratio versus AV TPCs 5 and 6 show typical DNL and INL plots for the AD7866. DD supply ripple frequency for the AD7866 under different conditions. The power supply rejection ratio (PSRR) is defined TPC 7 shows a graph of the total harmonic distortion versus as the ratio of the power in the ADC output at full-scale fre- analog input frequency for various source impedances. quency f, to the power of a 100 mV sine wave applied to the TPC 8 shows a graph of total harmonic distortion versus analog ADC AVDD supply of frequency fS: input frequency for various supply voltages. See the Analog PSRR dB 10 log Pf Pf ( ) = ( ) S Input section.
Typical Performance Characteristics 0 0 4098 POINT FFT 100mV p-p SINE WAVE ON AV f DD SAMPLE = 1MSPS –10 2.5V EXT REFERENCE ON V –15 REF fIN = 300kHz TA = 25
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C SNR = 70.31dB –20 THD = –85.47dB –35 SFDR = –86.64dB –30 –40 –55 –50 VDD = 2.7V VDD = 5.25V SNR – dB PSRR – dB –60 –75 –70 –95 –80 VDD = 4.75V –90 VDD = 3.6V –115 –100 0 50 100 150 200 250 300 350 400 450 500 1k 10k 100k 1M FREQUENCY – kHz AVDD RIPPLE FREQUENCY – Hz
TPC 1. Dynamic Performance TPC 3a. PSRR vs. Supply Ripple Frequency, without Supply Decoupling
–61 T 0 A = 25 C 100mV p-p SINE WAVE ON AVDD –10 2.5V EXT REFERENCE ON D –63 CAPA, DCAPB TA = 25
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C –20 –65 VDD = VDRIVE = 2.7V –30 –67 V –40 DD = VDRIVE = 3.6V –50 VDD = 5.25V –69 SINAD – dB V PSRR – dB –60 DD = 2.7V –71 V –70 DD = VDRIVE = 5.25V VDD = VDRIVE = 4.75V –80 –73 –90 VDD = 4.75V VDD = 3.6V –7510k 100k 1M –100 1k 10k 100k 1M INPUT FREQUENCY – Hz AVDD RIPPLE FREQUENCY – Hz
TPC 2. SINAD vs. Input Frequency TPC 3b. PSRR vs. Supply Ripple Frequency, without Supply Decoupling REV. A –9– Document Outline FEATURES GENERAL DESCRIPTION PRODUCT HIGHLIGHTS FUNCTIONAL BLOCK DIAGRAM SPECIFICATIONS TIMING SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS ORDERING GUIDE PIN CONFIGURATION PIN FUNCTION DESCRIPTIONS TERMINOLOGY Integral Nonlinearity Differential Nonlinearity Offset Error Offset Error Match Gain Error Gain Error Match Zero Code Error Zero Code Error Match Positive Gain Error Negative Gain Error Track-and-Hold Acquisition Time Signal-to-(Noise + Distortion) Ratio (SNDR) Total Harmonic Distortion (THD) Peak Harmonic or Spurious Noise Intermodulation Distortion Channel-to-Channel Isolation PSR (Power Supply Rejection) PERFORMANCE CURVES Typical Performance Characteristics CIRCUIT INFORMATION CONVERTER OPERATION ANALOG INPUT Analog Input Ranges Handling Bipolar Input Signals Transfer Functions Digital Inputs REFERENCE CONFIGURATION OPTIONS MODES OF OPERATION Normal Mode Partial Power-Down Mode Full Power-Down Mode POWER-UP TIMES POWER VS. THROUGHPUT RATE SERIAL INTERFACE MICROPROCESSOR INTERFACING AD7866 to ADSP-218x AD7866 to TMS320C541 AD7866 to DSP-563xx APPLICATION HINTS Grounding and Layout Evaluating the AD7866 Performance OUTLINE DIMENSIONS Revision History