Datasheet AD7938-6 (Analog Devices) - 10

Data Sheet AD7938-6 TYPICAL PERFORMANCE CHARACTERISTICS
TA = 25°C, unless otherwise noted.
–60 0 100mV p-p SINE WAVE ON VDD AND/OR VDRIVE 4096 POINT FFT NO DECOUPLING –10 VDD = 5V –70 DIFFERENTIAL/SINGLE-ENDED MODE –20 FSAMPLE = 625kSPS FIN = 49.62kHz SINAD = 70.94dB INT REF –30 –80 THD = –90.09dB –40 DIFFERENTIAL MODE B) ) d B –50 –90 (d RR ( S –60 P EXT REF –70 –100 –80 –110 –90
7 09 00
–100
0 1- 1- 75 75
–120
04
–110
04
10 210 410 610 810 1010 0 SUPPLY RIPPLE FREQUENCY (kHz) 100 200 300 400 500 600 700 FREQUENCY (kHz)
Figure 4. PSRR vs. Supply Ripple Frequency Without Supply Decoupling Figure 7. AD7938-6 FFT @ VDD = 5 V
–70 1.0 INTERNAL/EXTERNAL REFERENCE VDD = 5V VDD = 5V 0.8 DIFFERENTIAL MODE –75 0.6 ) B d ) 0.4 ( B S ON –80 (L 0.2 TI R LA 0 O RO R IS E –85 L E –0.2 N OIS D N –0.4 –90 –0.6
1 0 02
–0.8
01 1- 1- 75 75
–195
04
–1.0
04
0 100 200 300 400 500 600 700 800 0 500 1000 1500 2000 2500 3000 3500 4000 NOISE FREQUENCY (kHz) CODE
Figure 5. AD7938-6 Channel-to-Channel Isolation Figure 8. AD7938-6 Typical DNL @ VDD = 5 V
80 1.0 V V DD = 5V DD = 5V 0.8 DIFFERENTIAL MODE 70 0.6 VDD = 3V 0.4 60 B) ) S B L 0.2 d R ( 50 0 RO R INAD ( S E –0.2 40 INL –0.4 –0.6 30 FSAMPLE = 625kSPS
8
–0.8
1 1 00
RANGE = 0 TO V
0
REF
1- 1-
DIFFERENTIAL MODE
75 75
20
04
–1.0
04
0 100 200 300 400 500 600 700 800 900 1000 0 500 1000 1500 2000 2500 3000 3500 4000 FREQUENCY (kHz) CODE
Figure 6. AD7938-6 SINAD vs. Analog Input Figure 9. AD7938-6 Typical INL @ VDD = 5 V Frequency for Various Supply Voltages Rev. D | Page 9 of 32 Document Outline FEATURES FUNCTIONAL BLOCK DIAGRAM GENERAL DESCRIPTION PRODUCT HIGHLIGHTS REVISION HISTORY SPECIFICATIONS TIMING SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS TERMINOLOGY ON-CHIP REGISTERS CONTROL REGISTER SEQUENCER OPERATION Writing to the Control Register to Program the Sequencer SHADOW REGISTER CIRCUIT INFORMATION CONVERTER OPERATION ADC TRANSFER FUNCTION TYPICAL CONNECTION DIAGRAM ANALOG INPUT STRUCTURE ANALOG INPUTS Single-Ended Mode Differential Mode Driving Differential Inputs Using an Op Amp Pair Pseudo Differential Mode ANALOG INPUT SELECTION Traditional Multichannel Operation (SEQ = 0, SHDW = 0) Using the Sequencer: Programmable Sequence (SEQ = 0, SHDW = 1 ) Consecutive Sequence (SEQ = 1, SHDW = 1) REFERENCE Digital Inputs VDRIVE Input PARALLEL INTERFACE Reading Data from the AD7938-6 Writing Data to the AD7938-6 POWER MODES OF OPERATION Normal Mode (PM1 = PM0 = 0) Autoshutdown (PM1 = 0; PM0 = 1) Autostandby (PM1 = 1; PM0 = 0) Full Shutdown Mode (PM1 =1; PM0 = 1) POWER vs. THROUGHPUT RATE MICROPROCESSOR INTERFACING AD7938-6 to ADSP-21xx Interface AD7938-6 to ADSP-21065L Interface AD7938-6 to TMS32020, TMS320C25, and TMS320C5x Interface AD7938-6 to 80C186 Interface APPLICATION HINTS GROUNDING AND LAYOUT PCB DESIGN GUIDELINES FOR CHIP SCALE PACKAGE EVALUATING THE AD7938-6 PERFORMANCE OUTLINE DIMENSIONS ORDERING GUIDE