12-Bit, 105 MSPS/125 MSPS, IF Sampling ADC AD9433 IF sampling up to 350 MHz SNR: 67.5 dB, fIN up to Nyquist at 105 MSPS SFDR: 83 dBc, fIN = 70 MHz at 105 MSPS SFDR: 72 dBc, fIN = 150 MHz at 105 MSPS 2 V p-p analog input range On-chip clock duty cycle stabilization On-chip reference and track-and-hold SFDR optimization circuit Excellent linearity DNL: ±0.25 LSB (typical) INL: ±0.5 LSB (typical) 750 MHz full power analog bandwidth Power dissipation: 1.35 W (typical) at 125 MSPS Twos complement or offset binary data format 5.0 V analog supply operation 2.5 V to 3.3 V TTL/CMOS outputs APPLICATIONS Cellular infrastructure communication systems 3G single- and multicarrier receivers IF sampling schemes Wideband carrier frequency systems Point-to-point radios LMDS, wireless broadband MMDS base station units Cable reverse path Communications test equipment Radar and satellite ground systems FUNCTIONAL BLOCK DIAGRAM AIN ENCODE The ADC requires a 5 V analog power supply and a differential encode clock for full performance operation. No external reference or driver components are required for many applications. The digital outputs are TTL-/CMOS-compatible, and a separate output power supply pin supports interfacing with 3.3 V or 2.5 V logic. ENCODE TIMING GND PIPELINE ADC 12 REF OUTPUT STAGING 12 D11 TO D0 DFS SFDR MODE VREFOUT VREFIN Figure 1. A user-selectable, on-chip proprietary circuit optimizes spurious-free dynamic range (SFDR) vs. signal-to-noise and distortion (SINAD) ratio performance for different input signal frequencies, providing as much as 83 dBc SFDR performance over the dc to 70 MHz band. The encode clock supports either differential or single-ended input and is PECL-compatible. The output format is userselectable for offset binary or twos complement and provides an overrange (OR) signal. Fabricated on an advanced BiCMOS process, the AD9433 is available in a 52-lead thin quad flat package (TQFP_EP) that is specified over the industrial temperature range of −40°C to +85°C. The AD9433 is pin-compatible with the AD9432. PRODUCT HIGHLIGHTS 1. GENERAL INTRODUCTION The AD9433 is a 12-bit, monolithic sampling analog-to-digital converter (ADC) with an on-chip track-and-hold circuit and is designed for ease of use. The product operates up to a 125 MSPS conversion rate and is optimized for outstanding dynamic performance in wideband and high IF carrier systems. T/H AIN ENCODE VDD AD9433 VCC 2. 3. 4. IF Sampling. The AD9433 maintains outstanding ac performance up to input frequencies of 350 MHz. Suitable for 3G wideband cellular IF sampling receivers. Pin-Compatibility with the AD9432. The AD9433 has the same footprint and pin layout as the AD9432 12-bit 80 MSPS/105 MSPS ADC. SFDR Performance. A user-selectable, on-chip circuit optimizes SFDR performance as much as 83 dBc from dc to 70 MHz. Sampling Rate. At 125 MSPS, the AD9433 is ideally suited for wireless and wired broadband applications such as LMDS/MMDS and cable reverse path. 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 that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 www.analog.com Fax: 781.461.3113 ©2001–2009 Analog Devices, Inc. All rights reserved. 01977-001 FEATURES AD9433 TABLE OF CONTENTS Features .............................................................................................. 1 Typical Performance Characteristics ..............................................8 Applications ....................................................................................... 1 Terminology .................................................................................... 14 General Introduction ....................................................................... 1 Equivalent Circuits ......................................................................... 16 Functional Block Diagram .............................................................. 1 Theory of Operation ...................................................................... 17 Product Highlights ........................................................................... 1 Encode Input ............................................................................... 17 Revision History ............................................................................... 2 Encode Voltage Level Definition.............................................. 17 Specifications..................................................................................... 3 Analog Input ............................................................................... 18 DC Specifications ......................................................................... 3 SFDR Optimization.................................................................... 18 AC Specifications.......................................................................... 4 Digital Outputs ........................................................................... 18 Switching Specifications .............................................................. 5 Voltage Reference ....................................................................... 18 Timing Diagram ........................................................................... 5 Timing ......................................................................................... 18 Absolute Maximum Ratings............................................................ 6 Applications Information .............................................................. 19 Explanation of Test Levels ........................................................... 6 Layout Information .................................................................... 19 Thermal Characteristics .............................................................. 6 Replacing the AD9432 with the AD9433 ................................ 19 ESD Caution .................................................................................. 6 Outline Dimensions ....................................................................... 20 Pin Configuration and Function Descriptions ............................. 7 Ordering Guide .......................................................................... 20 REVISION HISTORY 6/09—Rev. 0 to Rev. A Updated Format .................................................................. Universal Reorganized Layout ............................................................ Universal Added TQFP_EP Package ................................................. Universal Deleted LQFP_ED Package ............................................... Universal Changes to Thermal Characteristics Section ................................ 6 Changes to Pin Configuration and Function Descriptions Section ................................................................................................ 7 Deleted Evaluation Board Section ................................................ 16 Updated Outline Dimensions ....................................................... 20 Changes to Ordering Guide .......................................................... 20 10/01—Revision 0: Initial Version Rev. A | Page 2 of 20 AD9433 SPECIFICATIONS DC SPECIFICATIONS VDD = 3.3 V, VCC = 5 V; internal reference; differential encode input, unless otherwise noted. Table 1. Parameter RESOLUTION ACCURACY No Missing Codes Offset Error Gain Error 1 Differential Nonlinearity (DNL) 2 Integral Nonlinearity (INL)2 THERMAL DRIFT Offset Error Gain Error1 Reference REFERENCE Internal Reference Voltage (VREFOUT) Output Current (VREFOUT) Input Current (VREFIN) ANALOG INPUTS (AIN, AIN) Input Voltage Range Common-Mode Voltage Input Resistance Input Capacitance Analog Bandwidth, Full Power POWER SUPPLY VCC VDD Power Dissipation 3 IVCC3 IVDD3 Power Supply Rejection Ratio (PSRR) ENCODE INPUTS Internal Common-Mode Bias Differential Input (ENCODE, ENCODE) Input Voltage Range Input Common-Mode Range Input Resistance Input Capacitance DIGITAL INPUTS Input High Voltage Input Low Voltage Input High Current (VIN = 5 V) Input Low Current (VIN = 0 V) Temp Test Level Min 105 MSPS Typ Max 12 Full Full 25°C 25°C Full 25°C Full VI VI I I VI I VI −5 −7 −0.75 −1 −1.0 −1.3 Full Full Full V V V Full I Full Full V IV 100 Full Full Full Full Full V V VI V V 2.0 4.0 3 4 750 Full Full Full Full Full 25°C IV IV VI VI VI I Full Full V V Full Full Full 25°C IV IV VI V −0.5 2.0 Full Full Full Full I I V V 2.0 Guaranteed 0 +5 ±1 +3 ±0.25 +0.75 +1 ±0.5 +1.0 +1.3 Min −5 −7 −0.75 −1 −1.0 −1.3 −50 −125 ±80 2.4 2.5 125 MSPS Typ 12 Guaranteed 0 +5 ±1 +3 ±0.3 +0.75 +1 ±0.5 +1.0 +1.3 −50 −125 ±80 2.6 2.4 2.5 4.75 2.7 5.0 1275 255 12.5 ±3 4 2 5.25 3.3 1425 285 14 4.75 2.7 2.0 4.0 3 4 750 5.0 1350 270 16 ±3 3.75 500 −0.5 2.0 6 3 V 50 μA μA 4 5.25 3.3 1500 300 18 6 3 2.0 50 50 Rev. A | Page 3 of 20 0.8 50 50 V p-p V kΩ pF MHz V V mW mA mA mV/V V mV VCC + 0.05 4.25 0.8 mV % FS LSB LSB LSB LSB 2.6 3.75 500 VCC + 0.05 4.25 Unit Bits ppm/°C ppm/°C ppm/°C 100 50 2 Max V V kΩ pF V V μA μA AD9433 Parameter DIGITAL OUTPUTS Logic 1 Voltage Logic 0 Voltage Output Coding 1 2 3 Temp Test Level Full Full VI VI 105 MSPS Typ Max Min 125 MSPS Typ Min Max VDD − 0.05 VDD − 0.05 0.05 Twos complement or offset binary 0.05 Twos complement or offset binary Unit V V Gain error and gain temperature coefficients are based on the ADC only (with a fixed 2.5 V external reference and a 2 V p-p differential analog input). SFDR mode disabled (SFDR MODE = GND) for DNL and INL specifications. Power dissipation measured with rated encode and a dc analog input (outputs static, IVDD = 0). IVCC and IVDD measured with 10.3 MHz analog input @ −0.5 dBFS. AC SPECIFICATIONS VDD = 3.3 V, VCC = 5 V; differential encode input, unless otherwise noted. Table 2. Parameter DYNAMIC PERFORMANCE 1 Signal-to-Noise Ratio (SNR) (Without Harmonics) fIN = 10.3 MHz fIN = 49 MHz fIN = 70 MHz fIN = 150 MHz fIN = 250 MHz Signal-to-Noise and Distortion (SINAD) Ratio (with Harmonics) fIN = 10.3 MHz fIN = 49 MHz fIN = 70 MHz fIN = 150 MHz fIN = 250 MHz Effective Number of Bits (ENOB) fIN = 10.3 MHz fIN = 49 MHz fIN = 70 MHz fIN = 150 MHz fIN = 250 MHz Second-Order and Third-Order Harmonic Distortion fIN = 10.3 MHz fIN = 49 MHz fIN = 70 MHz fIN = 150 MHz fIN = 250 MHz Worst Other Harmonic or Spur (Excluding Second-Order and Third-Order Harmonics) fIN = 10.3 MHz fIN = 49 MHz fIN = 70 MHz fIN = 150 MHz fIN = 250 MHz Two-Tone Intermodulation Distortion (IMD3) fIN1 = 49.3 MHz; fIN2 = 50.3 MHz fIN1 = 150 MHz; fIN2 = 151 MHz 1 Temp Test Level 25°C 25°C 25°C 25°C 25°C I I V V V 66.5 65.5 68.0 67.5 67.0 65.4 63.7 66.0 64.0 67.7 66.0 65.4 62.0 60.0 dB dB dB dB dB 25°C 25°C 25°C 25°C 25°C I I V V V 66.0 64.0 68.0 67.5 66.9 64.0 61.2 65.0 63.5 67.0 65.5 64.5 61.5 57.7 dB dB dB dB dB 25°C 25°C 25°C 25°C 25°C I I V V V 10.9 10.7 10.6 10.0 9.4 Bits Bits Bits Bits Bits 25°C 25°C 25°C 25°C 25°C I I V V V −78 −73 −85 −80 −83 −72 −67 −76 −72 −85 −76 −78 −67 −65 dBc dBc dBc dBc dBc 25°C 25°C 25°C 25°C 25°C I I V V V −88 −82 −92 −89 −87 −87 −85 −84 −82 −90 −87 −85 −84 −76 dBc dBc dBc dBc dBc 25°C 25°C V V −90 −76 dBc dBc Min 105 MSPS Typ Max Min 11.1 11.0 10.9 10.4 9.9 −92 −80 125 MSPS Typ Max Unit SNR/harmonics based on an analog input voltage of −0.5 dBFS referenced to a 2 V full-scale input range. Harmonics are specified with the SFDR mode enabled (SFDR MODE = 5 V). SNR/SINAD specified with the SFDR mode disabled (SFDR MODE = ground). Rev. A | Page 4 of 20 AD9433 SWITCHING SPECIFICATIONS VDD = 3.3 V, VCC = 5 V; differential encode input, unless otherwise noted. Table 3. Parameter Encode Rate Encode Pulse Width High (tEH) Encode Pulse Width Low (tEL) Aperture Delay (tA) Aperture Uncertainty (Jitter) 1 Output Valid Time (tV) 2 Output Propagation Delay (tPD)2 Output Rise Time (tR)2 Output Fall Time (tF)2 Out-of-Range Recovery Time Transient Response Time Latency 1 2 Test Level IV IV IV V V VI VI V V V V IV Temp Full Full Full 25°C 25°C Full Full Full Full 25°C 25°C Full Min 10 2.9 2.9 105 MSPS Typ Max 105 2.5 2.1 0.25 4.0 4.0 2.1 1.9 2 2 10 Min 10 2.4 2.4 2.5 5.5 125 MSPS Typ Max 125 2.1 0.25 4.0 4.0 2.1 1.9 2 2 10 Unit MSPS ns ns ns ps rms ns ns ns ns ns ns Cycles 5.5 Aperture uncertainty includes contribution of the AD9433, crystal clock reference, and encode drive circuit. tV and tPD are measured from the transition points of the ENCODE input to the 50%/50% levels of the digital output swing. The digital output load during testing is not to exceed an ac load of 10 pF or a dc current of 50 μA. Rise and fall times are measured from 10% to 90%. TIMING DIAGRAM SAMPLE N – 1 SAMPLE N SAMPLE N + 9 SAMPLE N + 10 AIN tA SAMPLE N + 1 tEH tEL SAMPLE N + 8 1/fS ENCODE ENCODE D11 TO D0 DATA N – 11 DATA N – 10 DATA N–9 DATA N–2 DATA N – 1 Figure 2. Timing Diagram Rev. A | Page 5 of 20 tV DATA N DATA N + 1 01977-003 tPD AD9433 ABSOLUTE MAXIMUM RATINGS THERMAL CHARACTERISTICS Table 4. Parameter VDD VCC Analog Inputs Digital Inputs Digital Output Current Operating Temperature Range (TA) Storage Temperature Range Maximum Junction Temperature (TJ) Table 5 lists AD9433 thermal characteristics for simulated typical performance in a 4-layer JEDEC board, horizontal orientation. Rating −0.5 V to +6.0 V −0.5 V to +6.0 V −0.5 V to VCC + 0.5 V −0.5 V to VDD + 0.5 V 20 mA −40°C to +85°C −65°C to +125°C 150°C Table 5. Thermal Resistance Package Type 52-Lead TQFP_EP (SV-52-2)1 No Airflow 1.0 m/s Airflow 1 Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; 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. θJA θJMA θJC 2 19.3 16 Bottom of package (exposed pad soldered to ground plane). ESD CAUTION EXPLANATION OF TEST LEVELS I II 100% production tested. 100% production tested at 25°C and sample tested at specified temperatures. III Sample tested only. IV Parameter is guaranteed by design and characterization testing. V Parameter is a typical value only. VI 100% production tested at 25°C; guaranteed by design and characterization testing for industrial temperature range. Rev. A | Page 6 of 20 Unit °C/W °C/W °C/W AD9433 GND DFS SFDR MODE GND VCC VREFIN VREFOUT VCC GND AIN AIN GND VCC PIN CONFIGURATION AND FUNCTION DESCRIPTIONS 52 51 50 49 48 47 46 45 44 43 42 41 40 39 GND 38 GND 3 37 VCC GND 4 36 VCC VCC 5 GND VCC 6 AD9433 35 34 GND ENCODE 7 TOP VIEW (Not to Scale) 33 GND ENCODE 8 32 VDD GND 9 31 DGND VCC 10 30 D0 (LSB) GND 11 29 D1 DGND 12 28 D2 VDD 13 27 D3 GND 1 VCC 2 GND PIN 1 NOTES 1. THE EXPOSED PADDLE ON THE UNDERSIDE OF THE PACKAGE MUST BE SOLDERED TO THE GROUND PLANE. SOLDERING THE EXPOSED PADDLE TO THE PCB INCREASES THE RELIABILITY OF THE SOLDER JOINTS, MAXIMIZING THE THERMAL CAPABILITY OF THE PACKAGE. 01977-002 D4 D5 DGND VDD VDD DGND D6 D7 D8 D9 D10 OR D11 (MSB) 14 15 16 17 18 19 20 21 22 23 24 25 26 Figure 3. Pin Configuration Table 6. Pin Function Descriptions Pin No. 1, 3, 4, 9, 11, 33, 34, 35, 38, 39, 40, 43, 48, 51 2, 5, 6, 10, 36, 37, 44, 47, 52 7 8 12, 21, 24, 31 13, 22, 23, 32 14 15 to 20, 25 to 30 41 42 45 46 49 50 Mnemonic GND Description Analog Ground. VCC Analog Supply (5 V). ENCODE ENCODE DGND VDD OR D11 to D6, D5 to D0 DFS SFDR MODE Encode Clock for ADC, Complementary. Encode Clock for ADC, True. ADC samples on rising edge of ENCODE. Digital Output Ground. Digital Output Power Supply (3 V). Out-of-Range Output. Digital Output. Data Format Select. Logic low = twos complement, logic high = offset binary; floats low. CMOS Control Pin. This pin enables SFDR mode, a proprietary circuit that can improve the SFDR performance of the AD9433. SFDR mode is useful in applications where the dynamic range of the system is limited by discrete spurious frequency content caused by nonlinearities in the ADC transfer function. Set this pin to 0 for normal operation; floats low. Reference Input for ADC (2.5 V Typical). Bypass with 0.1 μF capacitor to ground. Internal Reference Output (2.5 V Typical). Analog Input, True. Analog Input, Complementary. The exposed paddle on the underside of the package must be soldered to the ground plane. Soldering the exposed paddle to the PCB increases the reliability of the solder joints, maximizing the thermal capability of the package. VREFIN VREFOUT AIN AIN Exposed Pad (EP) Rev. A | Page 7 of 20 AD9433 TYPICAL PERFORMANCE CHARACTERISTICS 0 –95 SNR = 67.5dB SFDR = 85dBFS –10 –90 –20 WORST OTHER –85 –40 HARMONICS (dBc) AMPLITUDE (dBFS) –30 –50 –60 –70 –80 –90 –100 –80 THIRD HARMONIC –75 SECOND HARMONIC –70 –65 0 13.1 26.3 FREQUENCY (MHz) 39.4 52.5 –60 01977-009 Figure 4. FFT: fS = 105 MSPS, fIN = 49.3 MHz, Differential AIN @ −0.5 dBFS, SFDR Mode Enabled SNR = 68dB SFDR = 80dBFS –20 250 68 11.1 67 10.9 10.8 –80 –90 –110 13.1 26.3 FREQUENCY (MHz) 39.4 52.5 Figure 5. FFT: fS = 105 MSPS, fIN = 49.3 MHz, Differential AIN @ −0.5 dBFS, SFDR Mode Disabled SINAD 63 10.3 62 10.1 61 9.9 60 01977-010 0 10.4 64 0 50 100 150 AIN (MHz) 200 250 ENOB (Bits) –70 10.6 65 9.8 300 01977-013 –60 –100 Figure 8. SNR/SINAD and ENOB vs. AIN Frequency, Differential AIN @ −0.5 dBFS, fS = 105 MSPS, SFDR Mode Disabled 0 100 SNR = 67.7dB SFDR = 76dBFS –10 95 –20 –30 THIRD HARMONIC (dBc) 90 –40 SNR/SINAD (dB) AMPLITUDE (dBFS) 200 SNR –50 –50 –60 –70 –80 –90 85 80 SECOND HARMONIC (dBc) 75 SNR 70 –100 65 –110 SINAD 0 15.6 31.2 FREQUENCY (MHz) 46.8 62.5 60 10 01977-011 –120 100 150 AIN (MHz) 66 –40 SNR/SINAD (dB) AMPLITUDE (dBFS) –30 –120 50 Figure 7. Harmonics (Second, Third, Worst Other) vs. AIN Frequency, AIN @ −0.5 dBFS, fS = 105 MSPS, SFDR Mode Enabled 0 –10 0 Figure 6. FFT: fS = 125 MSPS, fIN = 49.3 MHz, Differential AIN @ −0.5 dBFS, SFDR Mode Enabled Rev. A | Page 8 of 20 30 50 70 90 ENCODE (MSPS) 110 130 01977-014 –120 01977-012 –110 Figure 9. SNR/SINAD and Harmonic Distortion vs. Encode Frequency, Differential AIN @ −0.5 dBFS AD9433 IMD3 = 92dBFS –20 AMPLITUDE (dBFS) –30 69 11.3 67 10.9 65 SNR/SINAD (dB) –40 –50 –60 –70 –80 –90 –100 10.6 SNR SINAD 63 ENOB (Bits) 0 –10 10.3 61 9.9 59 9.6 57 9.3 –110 15.0 22.5 30.0 37.5 FREQUENCY (MHz) 45.0 52.5 Figure 10. FFT: fS = 105 MSPS, fIN = 49.3 MHz and 50.3 MHz, Differential AIN @ −7 dBFS for Each Tone, SFDR Mode Enabled 90 SFDR (dBc) SNR/SFDR (dB) DYNAMIC PERFORMANCE (dB) 90 SNR (dBFS) 70 60 SFDR (dBFS) 40 30 20 90dBFS REFERENCE 80.3 AIN (MHz) 170.3 250.3 –80 –70 –60 –50 –40 –30 AIN LEVEL (dBFS) THIRD HARMONIC 80 SECOND HARMONIC 70 SNR 60 50 40 30 20 10 –20 –10 0 0 3.5 01977-016 10 0 –90 49.3 100 100 50 10.3 Figure 13. SNR/SINAD and ENOB vs. AIN Frequency, Differential AIN @ −0.5 dBFS, fS = 125 MSPS, SFDR Mode Enabled 110 80 8.9 55 01977-018 7.5 Figure 11. SNR and SFDR vs. AIN Level, fS = 105 MSPS, fIN = 49.3 MHz, Differential AIN, SFDR Mode Enabled 3.6 3.7 3.8 3.9 4.0 4.1 4.2 4.3 AIN COMMON-MODE VOLTAGE (V) 4.4 4.5 01977-019 0 01977-015 –120 Figure 14. Dynamic Performance vs. AIN Common-Mode Voltage, Differential AIN @ −0.5 dBFS, fIN = 49.3 MHz, fS = 105 MSPS 110 69 68 100 66 90 –40°C SNR (dB) THIRD-ORDER IMD (dB) 67 80 65 64 +25°C 63 70 62 60 +85°C –80 –70 –60 –50 –40 –30 AIN LEVEL (dBFS) –20 –10 0 60 01977-017 50 –90 Figure 12. Third-Order IMD vs. AIN Level, fS = 105 MSPS, fIN = 49.3 MHz and 50.3 MHz, Differential AIN, SFDR Mode Enabled Rev. A | Page 9 of 20 10.3 49.3 80.3 AIN (MHz) 170.3 250.3 01977-020 61 Figure 15. SNR vs. AIN Frequency over Temperature, fS = 105 MSPS, Differential AIN, SFDR Mode Disabled AD9433 –95 300 18 280 15 WORST OTHER (dBc) THIRD HARMONIC (dBc) 12 ICC (mA) 260 –80 SECOND HARMONIC (dBc) –75 ICC (mA) 9 240 6 220 IDD (mA) 10 20 30 40 50 60 DUTY CYCLE HIGH (%) 70 80 90 180 0 25 0.50 0.50 0.25 0.25 INL (LSB) 0.75 0 –0.25 –0.25 –0.50 –0.50 0 512 1024 1536 2048 2560 OUTPUT CODE 3072 3584 4096 –0.75 01977-022 Figure 17. Integral Nonlinearity vs. Output Code with SFDR Mode Disabled 0 512 1024 1536 2048 2560 OUTPUT CODE 3072 3584 4096 Figure 20. Integral Nonlinearity vs. Output Code with SFDR Mode Enabled 0.5 0 0.4 –10 –20 0.3 –30 AMPLITUDE (dBFS) 0.2 0.1 0 –0.1 –0.2 –40 –50 –60 –70 –80 –90 –0.3 –100 –110 –0.5 –120 0 512 1024 1536 2048 2560 OUTPUT CODE 3072 3584 Figure 18. Differential Nonlinearity vs. Output Code 4096 01977-023 –0.4 0 7.68 15.36 FREQUENCY (MHz) 23.04 30.72 01977-026 INL (LSB) 0.75 –0.75 0 125 100 Figure 19. IDD and ICC vs. Encode Rate, fIN = 10.3 MHz, Differential AIN @ −0.5 dBFS Figure 16. Dynamic Performance vs. Encode Duty Cycle, fS = 105 MSPS, fIN = 49.3 MHz, Differential AIN @ −0.5 dBFS, SFDR Mode Enabled 0 50 75 ENCODE FREQUENCY (MHz) 01977-025 0 3 200 01977-024 SNR (dB) –70 –65 DNL (LSB) IDD (mA) –85 01977-021 DYNAMIC PERFORMANCE (dB) –90 Figure 21. FFT: fS = 61.44 MSPS, fIN = 46.08 MHz, Four WCDMA Carriers, Differential AIN, SFDR Mode Enabled Rev. A | Page 10 of 20 AD9433 0 0 SNR = 66.8dB SFDR = 83dBFS –20 –20 –30 –30 AMPLITUDE (dBFS) –50 –60 –70 –80 –40 –50 –60 –70 –80 –90 –90 –100 –100 –110 –110 0 7.5 15.0 22.5 30.0 37.5 FREQUENCY (MHz) 45.0 52.5 –120 Figure 22. FFT: fS = 105 MSPS, fIN = 70.3 MHz, Differential AIN @ −0.5 dBFS, SFDR Mode Enabled 15.0 22.5 30.0 37.5 FREQUENCY (MHz) 45.0 100 SFDR (dBFS) 90 –30 SNR (dBFS) 80 SNR/SFDR (dB) –40 –50 –60 –70 –80 70 60 SFDR (dBc) 50 40 80dBFS REFERENCE LINE –100 20 fS = 105MSPS fIN = 70.3MHz –110 10 DIFFERENTIAL AIN SFDR ENABLED 7.5 15.0 22.5 30.0 37.5 FREQUENCY (MHz) 45.0 52.5 0 –90 01977-030 0 Figure 23. FFT: fS = 105 MSPS, fIN = 70.3 MHz, Differential AIN @ −0.5 dBFS, SFDR Mode Disabled –80 –70 –60 –50 –40 –30 AIN LEVEL (dBFS) –20 –10 0 01977-031 30 –90 –120 52.5 110 SNR = 67dB SFDR = 80dBFS –20 AMPLITUDE (dBFS) 7.5 Figure 25. FFT: fS = 105 MSPS, fIN = 69.3 MHz and 70.3 MHz, Differential AIN @ −7 dBFS for Each Tone, SFDR Mode Enabled 0 –10 Figure 26. SNR and SFDR vs. AIN Level, fS = 105 MSPS, fIN = 70.3 MHz, Differential AIN, SFDR Mode Enabled 0 –110 SNR = 65.5dB SFDR = 78dBFS –10 –20 –100 THIRD-ORDER IMD (dBFS) –30 AMPLITUDE (dBFS) 0 01977-029 –40 –120 IMD3 = 85dBc –10 01977-027 AMPLITUDE (dBFS) –10 –40 –50 –60 –70 –80 –90 –100 –90 –80 –70 –60 0 6.2 12.5 18.7 25.0 31.2 37.5 43.7 FREQUENCY (MHz) 50.0 56.2 62.5 –50 –90 01977-028 –120 Figure 24. FFT: fS = 125 MSPS, fIN = 70.3 MHz, Differential AIN @ −0.5 dBFS, SFDR Mode Enabled –80 –70 –60 –50 –40 –30 AIN LEVEL (dBFS) –20 –10 0 01977-032 –110 Figure 27. Third-Order IMD vs. AIN Level, fS = 105 MSPS, fIN = 70.3 MHz and 69.3 MHz, Differential AIN, SFDR Mode Enabled Rev. A | Page 11 of 20 AD9433 0 0 –30 AMPLITUDE (dBFS) –20 –30 –40 –50 –60 –70 –80 –60 –70 –80 –90 –100 –110 –110 0 7.5 15.0 22.5 30.0 37.5 FREQUENCY (MHz) 45.0 52.5 –120 12.5 18.7 25.0 31.2 37.5 43.7 FREQUENCY (MHz) 50.0 56.2 62.5 –30 –40 –50 –60 –70 –80 –40 –50 –60 –70 –80 –90 –90 –100 –100 –110 –110 15.0 22.5 30.0 37.5 FREQUENCY (MHz) 45.0 52.5 –120 01977-034 7.5 Figure 29. FFT: fS = 105 MSPS, fIN = 250.3 MHz, Differential AIN @ −0.5 dBFS, SFDR Mode Enabled 0 6.2 12.5 18.7 25.0 31.2 37.5 43.7 FREQUENCY (MHz) 50.0 56.2 62.5 01977-037 AMPLITUDE (dBFS) –20 0 SNR = 54.6dB SFDR = 58dBFS –10 –30 Figure 32. FFT: fS = 125 MSPS, fIN = 350.3 MHz, Differential AIN @ −0.5 dBFS, SFDR Mode Enabled –110 0 SNR = 55.3dB SFDR = 61dBFS –10 –100 –20 –90 THIRD-ORDER IMD (dBFS) –30 –40 –50 –60 –70 –80 –90 –80 –70 –60 –50 –40 –30 –20 –100 7.5 15.0 22.5 30.0 37.5 FREQUENCY (MHz) 45.0 52.5 0 –90 01977-035 0 Figure 30. FFT: fS = 105 MSPS, fIN = 350.3 MHz, Differential AIN @ −0.5 dBFS, SFDR Mode Enabled –80 –70 –60 –50 –40 –30 AIN LEVEL (dBFS) –20 –10 0 01977-038 –10 –110 –120 6.25 0 SNR = 61.2dB SFDR = 67dBFS –20 –120 0 Figure 31. FFT: fS = 125 MSPS, fIN = 150.3 MHz, Differential AIN @ −0.5 dBFS, SFDR Mode Enabled 0 –10 AMPLITUDE (dBFS) –50 –100 Figure 28. FFT: fS = 105 MSPS, fIN = 150.3 MHz, Differential AIN @ −0.5 dBFS, SFDR Mode Enabled AMPLITUDE (dBFS) –40 –90 01977-033 AMPLITUDE (dBFS) –20 –120 SNR = 62dB SFDR = 70dBFS –10 01977-036 SNR = 64dB SFDR = 78dBFS –10 Figure 33. Third-Order IMD vs. AIN Level, fS = 105 MSPS, fIN = 150.3 MHz and 151.3 MHz, Differential AIN, SFDR Mode Enabled Rev. A | Page 12 of 20 0 –10 –20 –20 –30 –30 –40 –50 –60 –70 –80 –40 –50 –60 –70 –80 –90 –90 –100 –100 –110 –110 –120 0 9.6 19.2 FREQUENCY (MHz) 28.8 38.4 –120 Figure 34. FFT: fS = 76.8 MSPS, fIN = 59.6 MHz, Two WCDMA Carriers, Differential AIN, SFDR Mode Enabled 0 11.52 23.04 FREQUENCY (MHz) 34.56 46.08 01977-040 AMPLITUDE (dBFS) 0 –10 01977-039 AMPLITUDE (dBFS) AD9433 Figure 35. FFT: fS = 92.16 MSPS, fIN = 70.3 MHz, WCDMA @ 70.0 MHz, SFDR Mode Enabled Rev. A | Page 13 of 20 AD9433 TERMINOLOGY Analog Bandwidth 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 the 50% point of the rising edge of the ENCODE command and the instant at which the analog input is sampled. Aperture Uncertainty (Jitter) The sample-to-sample variation in aperture delay. Differential Analog Input Resistance, Differential Analog Input Capacitance, and Differential Analog Input Impedance The real and complex impedances measured at each analog input port. The resistance is measured statically and the capacitance and differential input impedances are measured with a network analyzer. Differential Analog Input Voltage Range The peak-to-peak differential voltage that must be applied to the converter to generate a full-scale response. Peak differential voltage is computed by observing the voltage on a single pin and subtracting the voltage from the other pin, which is 180° out of phase. Peak-to-peak differential voltage is computed by rotating the input phase 180° and taking the peak measurement again. The difference is then computed between both peak measurements. Differential Nonlinearity (DNL) The deviation of any code width from an ideal 1 LSB step. Effective Number of Bits (ENOB) The effective number of bits (ENOB) is calculated from the measured SNR based on the following equation: Gain Error The difference between the measured and the ideal full-scale input voltage range of the ADC. Harmonic Distortion The ratio of the rms signal amplitude fundamental frequency to the rms signal amplitude of a single harmonic component (second, third, and so on); reported in dBc. Integral Nonlinearity (INL) The deviation of the transfer function from a reference line measured in fractions of 1 LSB using a “best straight line” determined by a least square curve fit. Maximum Conversion Rate The maximum encode rate at which parametric testing is performed. Minimum Conversion Rate The encode rate at which the SNR of the lowest analog signal frequency drops by no more than 3 dB below the guaranteed limit. Noise (for Any Range within the ADC) Noise can be calculated using the following equation: − SNRdBc − Signal dBFS ⎛ FS VNOISE = Z × 0.001 × 10 ⎜⎜ dBm 10 ⎝ ⎞ ⎟⎟ ⎠ where: Z is the input impedance. FS is the full scale of the device for the frequency in question. SNR is the value for the particular input level. Signal is the signal level within the ADC reported in dB below full scale. This value includes both thermal and quantization noise. ⎛ Full − Scale Amplitude ⎞ ⎟ SNR MEASURED − 1.76 dB + 20 log ⎜ ⎜ Input Amplitude ⎟ ⎝ ⎠ ENOB = 6.02 Output Propagation Delay The delay between a differential crossing of ENCODE and ENCODE and the time when all output data bits are within valid logic levels. Encode Pulse Width/Duty Cycle Pulse width high is the minimum amount of time that the encode pulse should be left in the Logic 1 state to achieve the rated performance. Pulse width low is the minimum amount of time that the encode pulse should be left in the Logic 0 state. At a given clock rate, these specifications define an acceptable encode duty cycle. Power Supply Rejection Ratio (PSRR) The ratio of a change in input offset voltage to a change in power supply voltage. Full-Scale Input Power Expressed in dBm. Computed using the following equation: Signal-to-Noise Ratio (SNR) The ratio of the rms signal amplitude (set at 1 dB below full scale) to the rms value of the sum of all other spectral components, excluding the first five harmonics and dc. PowerFullScale ⎛ ⎜ V 2 FullScale rms = 10 log ⎜ Z ⎜ ⎜ 0.001 ⎝ ⎞ ⎟ ⎟ ⎟ ⎟ ⎠ Signal-to-Noise and Distortion (SINAD) The ratio of the rms signal amplitude (set at 1 dB below full scale) to the rms value of the sum of all other spectral components, including harmonics but excluding dc. Rev. A | Page 14 of 20 AD9433 Spurious-Free Dynamic Range (SFDR) The ratio of the rms signal amplitude to the rms value of the peak spurious spectral component. The peak spurious component may or may not be a harmonic. May be reported in dBc (degrades as signal level is lowered) or in dBFS (always related back to converter full scale). Two-Tone SFDR The ratio of the rms value of either input tone (f1, f2) to the rms value of the peak spurious component. The peak spurious component may or may not be an IMD product. May be reported in dBc (degrades as signal level is lowered) or in dBFS (always related back to converter full scale). Two-Tone Intermodulation Distortion Rejection The ratio of the rms value of either input tone (f1, f2) to the rms value of the worst third-order intermodulation product; reported in dBc. Products are located at 2f1 − f2 and 2f2 − f1. Worst Other Spur The ratio of the rms signal amplitude to the rms value of the worst spurious component (excluding the second-order and third-order harmonic); reported in dBc. Rev. A | Page 15 of 20 AD9433 EQUIVALENT CIRCUITS VCC VCC VREFIN 01977-008 01977-006 VREFOUT Figure 39. Voltage Reference Output Circuit Figure 36. Voltage Reference Input Circuit VCC VCC 3.75kΩ 3.75kΩ 8kΩ AIN AIN 8kΩ ENCODE ENCODE 15kΩ 01977-005 15kΩ 24kΩ 01977-007 24kΩ Figure 37. Analog Input Circuit Figure 40. Encode Input Circuit VDD 01977-004 Dx Figure 38. Digital Output Circuit Rev. A | Page 16 of 20 AD9433 THEORY OF OPERATION The AD9433 is a 12-bit pipeline converter that uses a switchedcapacitor architecture. Optimized for high speed, this converter provides flat dynamic performance up to and beyond the Nyquist limit. DNL transitional errors are calibrated at final test to a typical accuracy of 0.25 LSB or less. ENCODE The ENCODE and ENCODE inputs are internally biased to 3.75 V (nominal) and support either differential or singleended signals. For best dynamic performance, a differential signal is recommended. Good performance is obtained using an MC10EL16 translator in the circuit to directly drive the encode inputs (see Figure 41). 0.1µF CLOCK SOURCE 100Ω 01977-042 AD9433 T1-4T ENCODE ENCODE HMS2812 DIODES Figure 43. Transformer-Coupled Encode Circuit ENCODE VOLTAGE LEVEL DEFINITION The voltage level definitions for driving ENCODE and ENCODE in single-ended and differential mode are shown in Figure 44. ENCODE VIHD VID VICM, VECM ENCODE 01977-041 ENCODE ENCODE Figure 41. Using PECL to Drive the ENCODE Inputs VILD VIHS VICM, VECM Often, the cleanest clock source is a crystal oscillator producing a pure, single-ended sine wave. In this configuration, or with any roughly symmetrical, single-ended clock source, the signal can be ac-coupled to the encode input. To minimize jitter, the signal amplitude should be maximized within the input range described in Table 7. The 12 kΩ resistors to ground at each of the inputs, in parallel with the internal bias resistors, set the common-mode voltage to approximately 2.5 V, allowing the maximum swing at the input. The ENCODE input should be bypassed with a capacitor to ground to reduce noise. This ensures that the internal bias voltage is centered on the encode signal. For best dynamic performance, impedances at ENCODE and ENCODE should match. ENCODE VILS 01977-044 510Ω 12kΩ Figure 43 shows another preferred method for clocking the AD9433. The clock source (low jitter) is converted from singleended to differential using an RF transformer. The back-to-back Schottky diodes across the transformer secondary limit clock excursions into the AD9433 to approximately 0.8 V p-p differential. This helps to prevent the large voltage swings of the clock from feeding through to other portions of the AD9433 and limits the noise presented to the encode inputs. A crystal clock oscillator can also be used to drive the RF transformer if an appropriate limiting resistor (typically 100 Ω) is placed in series with the primary. AD9433 510Ω 25Ω Figure 42. Single-Ended Sine Source Encode Circuit ENCODE PECL GATE ENCODE 50Ω 01977-043 The AD9433 has an internal clock duty cycle stabilization circuit that locks to the rising edge of ENCODE (falling edge of ENCODE if driven differentially) and optimizes timing internally. This allows for a wide range of input duty cycles at the input without degrading performance. Jitter in the rising edge of the input is still of paramount concern and is not reduced by the internal stabilization circuit. This circuit is always on and cannot be disabled by the user. 12kΩ 0.1µF 50Ω SINE SOURCE ENCODE INPUT Any high speed ADC is extremely sensitive to the quality of the sampling clock provided by the user. A track-and-hold circuit is essentially a mixer, and any noise, distortion, or timing jitter on the clock is combined with the desired signal at the ADC output. For this reason, considerable care has been taken in the design of the encode input of the AD9433, and the user is advised to give commensurate thought to the clock source. AD9433 0.1µF 0.1µF Figure 44. Differential and Single-Ended Input Levels Table 7. Encode Inputs Input Differential Signal Amplitude (VID) Input Voltage Range (VIHD, VILD, VIHS, VILS) Internal Common-Mode Bias (VICM) External Common-Mode Bias (VECM) Rev. A | Page 17 of 20 Min 200 mV Nominal 750 mV Max 5.5 V VCC + 0.5 V −0.5 V 3.75 V 2.0 V 4.25 V AD9433 ANALOG INPUT The analog input to the AD9433 is a differential buffer. The input buffer is self-biased by an on-chip resistor divider that sets the dc common-mode voltage to a nominal 4 V (see the Equivalent Circuits section). Rated performance is achieved by driving the input differentially. The minimum input offset voltage is obtained when driving from a source with a low differential source impedance, such as a transformer in ac applications (see Figure 45). Capacitive coupling at the inputs increases the input offset voltage by as much as 50 mV. 25Ω 0.1µF AIN 25Ω 01977-045 AIN 1:1 Table 8. Offset Binary Output Coding (DFS = 1, VREF = 2.5 V) Figure 45. Transformer-Coupled Analog Input Circuit In the highest frequency applications, two transformers connected in series may be necessary to minimize even-order harmonic distortion. The first transformer isolates and converts the signal to a differential signal, but the grounded input on the primary side degrades amplitude balance on the secondary winding. Capacitive coupling between the windings causes this imbalance. Because one input to the first transformer is grounded, there is little or no capacitive coupling, resulting in an amplitude mismatch at the output of the first transformer. A second transformer improves the amplitude balance, and thus improves the harmonic distortion. A wideband transformer, such as the ADT1-1WT from Mini-Circuits®, is recommended for these applications, because the bandwidth through the two transformers is reduced by √2. AD9433 AIN 25Ω 25Ω 1:1 1:1 AIN Code 4095 … 2048 2047 … 0 AIN − AIN (V) +1.000 … 0 −0.00049 … −1.000 Digital Output 1111 1111 1111 … 1000 0000 0000 0111 1111 1111 … 0000 0000 0000 Table 9. Twos Complement Output Coding (DFS = 0, VREF = 2.5 V) Code +2047 … 0 −1 … −2048 AIN − AIN (V) +1.000 … 0 −0.00049 … −1.000 Digital Output 0111 1111 1111 … 0000 0000 0000 1111 1111 1111 … 1000 0000 0000 VOLTAGE REFERENCE 0.1µF 01977-046 50Ω ANALOG SIGNAL SOURCE DIGITAL OUTPUTS The digital outputs are 3 V (2.7 V to 3.3 V) TTL-/CMOScompatible for lower power consumption. The output data format is selectable through the data format select (DFS) CMOS input. DFS = 1 selects offset binary; DFS = 0 selects twos complement coding (see Table 8 and Table 9). AD9433 50Ω ANALOG SIGNAL SOURCE Enabling this circuit gives the circuit a dynamic transfer function, meaning that the voltage threshold between two adjacent output codes can change from clock cycle to clock cycle. While improving spurious frequency content, this dynamic aspect of the transfer function may be inappropriate for some time domain applications of the converter. Connecting the SFDR MODE pin to ground disables this function. The improvement in the linearity of the converter and its effect on spurious free dynamic range is shown in Figure 4 and Figure 5 and in Figure 22 and Figure 23. Figure 46. Driving the Analog Input with Two Transformers for Improved Even-Order Harmonics Driving the ADC single-ended degrades performance, particularly even-order harmonics. For best dynamic performance, impedances at AIN and AIN should match. Special care was taken in the design of the analog input section of the AD9433 to prevent damage and corruption of data when the input is overdriven. SFDR OPTIMIZATION When set to Logic 1, the SFDR MODE pin enables a proprietary circuit that can improve the spurious-free dynamic range (SFDR) performance of the AD9433. This pin is useful in applications where the dynamic range of the system is limited by discrete spurious frequency content caused by nonlinearities in the ADC transfer function. A stable and accurate 2.5 V voltage reference is built into the AD9433 (VREFOUT). In normal operation, the internal reference is used by strapping Pin 45 to Pin 46 and placing a 0.1 μF decoupling capacitor at VREFIN. The input range can be adjusted by varying the reference voltage applied to the AD9433. No appreciable degradation in performance occurs when the reference is adjusted ±5%. The full-scale range of the ADC tracks reference voltage changes linearly. TIMING The AD9433 provides latched data outputs, with 10 pipeline delays. Data outputs are available one propagation delay (tPD) after the rising edge of the encode command (see Figure 2). The length of the output data lines and the loads placed on them should be minimized to reduce transients within the AD9433; these transients can detract from the dynamic performance of the converter. The minimum guaranteed conversion rate of the AD9433 is 10 MSPS. At internal clock rates below 10 MSPS, dynamic performance may degrade. Rev. A | Page 18 of 20 AD9433 APPLICATIONS INFORMATION LAYOUT INFORMATION REPLACING THE AD9432 WITH THE AD9433 A multilayer board is recommended to achieve best results. It is highly recommended that high quality, ceramic chip capacitors be used to decouple each supply pin to ground directly at the device. The AD9433 is pin-compatible with the AD9432, although there are two control pins on the AD9433 that are do not connect (DNC) and supply (VCC) connections on the AD9432 (see Table 10). The pinout of the AD9433 facilitates ease of use in the implementation of high frequency, high resolution design practices. All of the digital outputs and their supply and ground pin connections are segregated on one side of the package, with the inputs on the opposite side for isolation purposes. Table 10. AD9432/AD9433 Pin Differences Care should be taken when routing the digital output traces. To prevent coupling through the digital outputs into the analog portion of the AD9433 (VCC, AIN, and VREF), minimal capacitive loading should be placed on these outputs. Pin 41 42 AD9433 DFS SFDR MODE Using the AD9433 in an AD9432 pin assignment configures the AD9433 as follows: • • It is recommended that a fanout of only one gate be used for all AD9433 digital outputs. The layout of the encode circuit is equally critical and should be treated as an analog input. Any noise received on this circuitry results in corruption in the digitization process and lower overall performance. The encode clock must be isolated from the digital outputs and the analog inputs. AD9432 DNC VCC The SFDR improvement circuit is enabled. The DFS pin floats low, selecting twos complement coding for the digital outputs. (Twos complement coding is the only output coding available on the AD9432.) Table 11 summarizes the differences between the AD9432 and AD9433 analog and encode input common-mode voltages. These inputs can be ac-coupled so that the devices can be used interchangeably. Table 11. AD9432/AD9433 Analog and Encode Input Common-Mode Voltages Input Pins ENCODE/ENCODE AIN/AIN Rev. A | Page 19 of 20 Common-Mode Voltage AD9432 AD9433 1.6 V 3.75 V 3.0 V 4.0 V AD9433 OUTLINE DIMENSIONS 1.20 MAX 12.00 BSC SQ 52 10.00 BSC SQ TOP VIEW 0° MIN 0.15 0.05 1 PIN 1 (PINS DOWN) 1.05 1.00 0.95 39 39 SEATING PLANE 52 40 40 1 0.20 0.09 7° 3.5° 0° 0.08 MAX COPLANARITY 7.30 BSC SQ EXPOSED PAD BOTTOM VIEW 13 27 14 26 VIEW A (PINS UP) 27 26 0.65 BSC LEAD PITCH 13 14 0.38 0.32 0.22 VIEW A ROTATED 90° CCW COMPLIANT TO JEDEC STANDARDS MS-026-ACC FOR PROPER CONNECTION OF THE EXPOSED PAD, REFER TO THE PIN CONFIGURATION AND FUNCTION DESCRIPTIONS SECTION OF THIS DATA SHEET. 072508-A 0.75 0.60 0.45 Figure 47. 52-Lead Thin Quad Flat Package, Exposed Pad [TQFP_EP] (SV-52-2) Dimensions shown in millimeters ORDERING GUIDE Model AD9433BSVZ-105 1 AD9433BSVZ-1251 1 Temperature Range −40°C to +85°C −40°C to +85°C Package Description 52-Lead Thin Quad Flat Package, Exposed Pad [TQFP_EP] 52-Lead Thin Quad Flat Package, Exposed Pad [TQFP_EP] Z = RoHS Compliant Part. ©2001–2009 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D01977-0-6/09(A) Rev. A | Page 20 of 20 Package Option SV-52-2 SV-52-2