ADS5481 ADS5482 ADS5483 www.ti.com................................................................................................................................................... SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008 16-Bit, 80/105/135-MSPS Analog-to-Digital Converters FEATURES APPLICATIONS • • • • • • • • • • • 1 23 • 80/105/135-MSPS Sample Rates 16-Bit Resolution SFDR: 95 dBc at 70 MHz and 135 MSPS SNR: 78.6 dBFS at 70 MHz and 135 MSPS Efficient DDR LVDS-Compatible Outputs Internal Dither Available Total Power Dissipation: 2.2 W Power-Down Mode: 70 mW On-Chip High Impedance Analog Buffer QFN-64 PowerPAD™ Package (9 mm × 9 mm Footprint) Industrial Temperature Range: –40°C to +85°C • • • • • • • Wireless Infrastructure (Multi-Carrier GSM, WCDMA, LTE) Test and Measurement Instrumentation Software-Defined Radio Data Acquisition Power Amplifier Linearization Communication Instrumentation Radar Medical Imaging DESCRIPTION The ADS5481/ADS5482/ADS5483 (ADS548x) is a 16-bit family of analog-to-digital converters (ADCs) that operate from both a 5-V supply and 3.3-V supply while providing LVDS-compatible digital outputs. The ADS548x integrated analog input buffer isolates the internal switching of the onboard track and hold (T&H) from disturbing the signal source while providing a high-impedance input. An internal reference generator is also provided to simplify the system design. Designed for highest total ENOB, the ADS548x family has outstanding low noise performance and spurious-free dynamic range. The ADS548x is available in an QFN-64 PowerPAD package. The device is built on Texas Instruments complementary bipolar process (BiCom3) and is specified over the full industrial temperature range (–40°C to +85°C). SFDR vs INPUT FREQUENCY SNR vs INPUT FREQUENCY 100 82 ADS5481 81 ADS5482 80 SNR − dBFS SFDR − dBc 95 ADS5482 90 ADS5481 85 79 78 ADS5483 77 ADS5483 76 80 75 0 20 40 60 80 100 fI − Input Frequency − MHz 120 140 G068 0 20 40 60 80 100 120 140 fI − Input Frequency − MHz G069 1 2 3 Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. PowerPAD is a trademark of Texas Instruments. All other trademarks are the property of their respective owners. PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Copyright © 2008, Texas Instruments Incorporated ADS5481 ADS5482 ADS5483 SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008................................................................................................................................................... www.ti.com This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications. PACKAGE/ORDERING INFORMATION (1) PRODUCT PACKAGE-LEAD PACKAGE DESIGNATOR SPECIFIED TEMPERATURE RANGE PACKAGE MARKING ADS5481 QFN-64 RGC –40°C to +85°C AZ5481 ADS5482 QFN-64 RGC –40°C to +85°C AZ5482 ADS5483 QFN-64 RGC –40°C to +85°C AZ5483 (1) 2 ORDERING NUMBER TRANSPORT MEDIA, QUANTITY ADS5481IRGCT Tape and Reel, 250 ADS5481IRGCR Tape and Reel, 2000 ADS5482IRGCT Tape and Reel, 250 ADS5482IRGCR Tape and Reel, 2000 ADS5483IRGCT Tape and Reel, 250 ADS5483IRGCR Tape and Reel, 2000 For the most current product and ordering information see the Package Option Addendum located at the end of this document, or see the TI website at www.ti.com.. Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 ADS5481 ADS5482 ADS5483 www.ti.com................................................................................................................................................... SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008 ABSOLUTE MAXIMUM RATINGS (1) Over operating free-air temperature range, unless otherwise noted. Supply voltage Analog input to GND ADS5481, ADS5482, ADS5483 UNIT AVDD5 to GND 6 V AVDD3 to GND 5 V DVDD3 to GND 5 V –0.3 to (AVDD5 + 0.3) V –0.3 to (AVDD3 + 0.3) V Valid when AVDD5 is within normal operating range. When AVDD5 is off, analog inputs should be <0.5V. If not, the protection diode between the inputs and AVDD5 will become forward-biased and could be damaged or shorten device lifetime (see Figure 60). Short transient conditions during power on/off are not a concern. Valid when AVDD3 is within normal operating range. When AVDD3 is off, clock inputs should be <0.5V. If not, the protection diode between the Clock input to GND inputs and AVDD3 will become forward-biased and could be damaged or shorten device lifetime (see Figure 67). Short transient conditions during power on/off are not a concern. CLKP to CLKM Digital data output to GND ±2.5 V –0.3 to (DVDD3 + 0.3) V ±1 V –40 to +85 °C +150 °C Digital data output plus-to-minus Operating temperature range Maximum junction temperature Storage temperature range ESD, human-body model (HBM) (1) –65 to +150 °C 2 kV Stresses above these ratings may cause permanent damage. Exposure to absolute maximum conditions for extended periods may degrade device reliability. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those specified is not implied. Kirkendall voidings and current density information for calculation of expected lifetime are available upon request. THERMAL CHARACTERISTICS (1) PARAMETER RθJA (1) TEST CONDITIONS TYP UNIT Soldered thermal pad, no airflow 20 Soldered thermal pad, 150-LFM airflow 16 RθJC thermal resistance from the junction to the package case (top) RθJP thermal resistance from the junction to the thermal pad (bottom) 7 °C/W 0.2 Using 49 thermal vias ( 7 × 7 array). See PowerPAD Package in the Application Information section. Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 Submit Documentation Feedback 3 ADS5481 ADS5482 ADS5483 SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008................................................................................................................................................... www.ti.com RECOMMENDED OPERATING CONDITIONS ADS5481, ADS5482, ADS5483 MIN UNIT TYP MAX SUPPLIES AVDD5 Analog supply voltage 4.75 5 5.25 V AVDD3 Analog supply voltage 3.1 3.3 3.6 V DVDD3 Output driver supply voltage 3 3.3 3.6 V ANALOG INPUT Differential input range VCM 3 Input common mode VPP 3.1 V 5 pF 100 Ω DIGITAL OUTPUT (DRY, DATA) Maximum differential output load (parasitic or intentional) Differential output resistance CLOCK INPUT (CLK) CLK input sample rate (sine wave) 10 Max Rated Clock Clock amplitude, differential sine wave (see Figure 69) 1.5 5 Clock duty cycle (see Figure 74) TA 45 Operating free-air temperature 50 –40 MSPS VPP 55 % +85 °C ELECTRICAL CHARACTERISTICS (ADS5481, ADS5482, ADS5483) Typical values at TA = +25°C: minimum and maximum values over full temperature range TMIN = –40°C to TMAX = +85°C, sampling rate = max rated, 50% clock duty cycle, AVDD5 = 5 V, AVDD3 = 3.3 V, DVDD3 = 3.3 V, –1 dBFS differential input, and 3-VPP differential clock, unless otherwise noted. PARAMETER TEST CONDITIONS ADS5481 MIN TYP ADS5482 MAX MIN TYP ADS5483 MAX MIN TYP MAX UNIT Clock rate 80 105 135 MSPS Resolution 16 16 16 Bits ANALOG INPUTS Differential input range 3 3 3 3.1 3.1 3.1 V Each input to VCM 1000 1000 1000 Ω Each input to GND (including package) 3.5 3.5 3.5 pF 125 125 485 MHz 65 65 65 dB 1.2 1.2 1.2 V Analog input common-mode voltage Self-biased; see VCM specification below Input resistance (dc) Input capacitance Analog input bandwidth (–3dB) CMRR Common-mode rejection ratio Common-mode signal 70 MHz (see Figure 56) VPP INTERNAL REFERENCE VOLTAGE VREF Reference voltage VCM Analog input common-mode voltage reference output With internal voltage reference VCM temperature coefficient 4 Submit Documentation Feedback 3 3.15 3.35 3 3.15 -1 -1 3.35 3 3.15 -1 3.35 V mV/°C Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 ADS5481 ADS5482 ADS5483 www.ti.com................................................................................................................................................... SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008 ELECTRICAL CHARACTERISTICS (ADS5481, ADS5482, ADS5483) (continued) Typical values at TA = +25°C: minimum and maximum values over full temperature range TMIN = –40°C to TMAX = +85°C, sampling rate = max rated, 50% clock duty cycle, AVDD5 = 5 V, AVDD3 = 3.3 V, DVDD3 = 3.3 V, –1 dBFS differential input, and 3-VPP differential clock, unless otherwise noted. PARAMETER TEST CONDITIONS ADS5481 ADS5482 ADS5483 UNIT MIN TYP MAX MIN TYP MAX MIN TYP MAX -0.99 ±0.5 1.0 -0.99 ±0.5 1.0 -0.99 ±0.5 1.0 LSB -10 ±3 +10 -10 ±3 +10 -10 ±3 +10 LSB 15 -15 15 -15 DYNAMIC ACCURACY DNL Differential linearity error No missing codes, fIN = 30 MHz INL Integral linearity error fIN = 30 MHz Offset error -15 Offset temperature coefficient -0.02 Gain error -6 Gain temperature coefficient ±2 -0.02 6 -6 -0.01 ±2 15 -0.02 6 -6 -0.01 ±2 mV mV/°C 6 -0.01 %FS mV/°C POWER SUPPLY IAVDD5 5-V analog IAVDD3 3.3-V analog IDVDD3 3.3-V digital/LVDS Total power dissipation IAVDD5 5-V analog IAVDD3 3.3-V analog IDVDD3 3.3-V digital/LVDS VIN = full-scale, fIN = 30 MHz, fS = Max rated, Normal operation 5-V analog IAVDD3 3.3-V analog IDVDD3 3.3-V digital/LVDS Light sleep mode (PDWNF=H, PDWNS=L) Deep sleep mode (PDWNF=L, PDWNS=H) Slow wakeup time (deep sleep) From PDWNS disabled AVDD5 supply Power-supply rejection ratio, Without 0.1-µF board supply capacitors, with 1-MHz supply noise (see Figure 76) DVDD3 supply 330 317 330 mA 131 150 133 150 mA 60 65 60 65 60 65 mA 2.15 2.35 2.15 2.35 2.2 2.35 98 mA mA 35 35 35 0.07 0.07 680 680 680 W 98 0.07 605 mA 680 mW 13 13 13 mA 2 2 2 mA 0.07 0.07 0.07 70 Fast wakeup time (light sleep) From PDWNF disabled PSRR 316 150 605 Total power dissipation AVDD3 supply 330 131 98 Total power dissipation IAVDD5 316 100 70 100 70 mA 100 mW 600 600 600 µS 6 6 6 mS 60 60 60 dB 80 80 80 dB 95 95 95 dB DYNAMIC AC CHARACTERISTICS SNR Signal-to-noise ratio fIN = 10 MHz 79.5 81 79.5 80.8 77 fIN = 30 MHz 79.4 80.6 79.4 80.7 77 Spurious-free dynamic range 80.1 80.1 78.6 fIN = 100 MHz 79.6 80 78.2 Second-harmonic dBFS 77.8 fIN = 10 MHz 88 98 88 98 87 97 fIN = 30 MHz 88 97 88 98 87 97 fIN = 70 MHz 93 91 95 fIN = 100 MHz 92 90 88 fIN = 130 MHz HD2 79 fIN = 70 MHz fIN = 130 MHz SFDR 79 dBc 85 fIN = 10 MHz 88 108 88 107 87 102 fIN = 30 MHz 88 101 88 105 87 99 fIN = 70 MHz 100 101 95 fIN = 100 MHz 99 100 92 fIN = 130 MHz Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 dBc 85 Submit Documentation Feedback 5 ADS5481 ADS5482 ADS5483 SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008................................................................................................................................................... www.ti.com ELECTRICAL CHARACTERISTICS (ADS5481, ADS5482, ADS5483) (continued) Typical values at TA = +25°C: minimum and maximum values over full temperature range TMIN = –40°C to TMAX = +85°C, sampling rate = max rated, 50% clock duty cycle, AVDD5 = 5 V, AVDD3 = 3.3 V, DVDD3 = 3.3 V, –1 dBFS differential input, and 3-VPP differential clock, unless otherwise noted. PARAMETER HD3 Third-harmonic TEST CONDITIONS ADS5481 MIN TYP fIN = 10 MHz 88 fIN = 30 MHz 88 ADS5482 MAX MIN TYP 103 88 100 88 ADS5483 MAX MIN TYP 96 87 110 98 87 100 fIN = 70 MHz 93 91 96 fIN = 100 MHz 92 90 88 fIN = 130 MHz Worst harmonic/spur (other than HD2 and HD3) Total harmonic distortion 88 98 88 98 87 97 fIN = 30 MHz 88 97 88 98 87 97 fIN = 70 MHz 96 97 98 fIN = 100 MHz 96 94 97 Signal-to-noise and distortion 85 96 85 95 84 97 fIN = 30 MHz 85 94 85 95 84 94 fIN = 70 MHz 93 88 91 fIN = 100 MHz 88 92 86 ENOB Two-tone SFDR Effective number of bits RMS idle-channel noise dBc dBc 83 fIN = 10 MHz 77.8 80 77.8 79.5 75 77.9 fIN = 30 MHz 77.7 79.5 77.7 79.3 75 77.8 fIN = 70 MHz 78.9 78.2 77.4 fIN = 100 MHz 77.8 78 76.6 fIN = 130 MHz IMD dBc 96 fIN = 10 MHz fIN = 130 MHz SINAD UNIT 88 fIN = 10 MHz fIN = 130 MHz THD MAX dBc 76 fIN1 = 29.5 MHz, fIN2 = 30.5 MHz, each at –7 dBFS, worst spur 103 101 100 dBFS fIN1 = 102 MHz, fIN2 = 103 MHz, each at –7 dBFS, worst spur 90 fIN = 10 MHz (from SINAD in dBc) 12.63 13 12.63 12.9 12.16 12.64 fIN = 30 MHz (from SINAD in dBc) 12.61 12.9 12.61 12.88 12.16 12.63 Bits Analog inputs shorted together 1.8 1.8 2.2 LSBrms LVDS DIGITAL OUTPUTS VOD Differential output voltage (±) VOC Common-mode output voltage Assumes a 100Ω differential load on each LVDS pair and LVDS bias = 3.5 mA 247 350 1.125 454 247 1.375 1.125 350 454 247 1.375 1.125 350 454 1.375 mV V DIGITAL INPUTS VIH High level input voltage VIL Low level input voltage IIH High level input current IIL Low level input current 2.0 PDWNF, PDWNS, DITHER Input capacitance 6 2.0 Submit Documentation Feedback -1 2.0 V 0.8 0.8 0.8 V 1 1 1 µA -1 µA -1 2 2 2 pF Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 ADS5481 ADS5482 ADS5483 www.ti.com................................................................................................................................................... SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008 TIMING INFORMATION Sample N N+5 N+3 ta N+1 N+2 N+4 tCLKH N+6 tCLKL CLKM CLK Input CLKP Latency = 4.5 Clock Cycles tDRY DRY_P CLK Output DRY_M tDATA Dx_y_P Output Data E O E O O E O E O E O E E O O Dx_y_M N–5 N–4 N–3 N–2 N–1 N N+1 E = Even Bits = B0, B2, B4, B6, B8, B10, B12, B14 O = Odd Bits = B1, B3, B5, B7, B9, B11, B13, B15 T0158-02 Figure 1. Timing Diagram TIMING CHARACTERISTICS (1) Typical values at TA = +25°C: minimum and maximum values over full temperature range TMIN = –40°C to TMAX = +85°C, sampling rate = max rated, 50% clock duty cycle, AVDD5 = 5 V, AVDD3 = 3.3 V, DVDD3 = 3.3 V, and 3-VPP differential clock, unless otherwise noted. PARAMETER ta TEST CONDITIONS MIN Aperture delay MAX UNIT 200 Aperture jitter, rms Internal jitter of the ADC Latency tCLK Clock period tCLKH Clock pulse duration, high tCLKL Clock pulse duration, low tDRY CLK to DRY delay (2) (2) tDATA CLK to DATA delay tSKEW DATA to DRY skew tRISE DRY/DATA rise time tFALL DRY/DATA fall time (1) (2) TYP CLK = max rated clock for that part number ps 80 fs 4.5 cycles 1e9/CLK 100 ns 0.5e9/CLK 50 ns 0.5e9/CLK 50 ns Zero crossing, 5-pF parasitic to GND tDATA – tDRY, 5-pF parasitic to GND 5-pF parasitic to GND 800 1250 1700 ps 700 1250 1800 ps –600 0 600 ps 500 ps 500 ps Timing parameters are assured by design or characterization, but not production tested. DRY and DATA are updated on the rising edge of CLK input. The latency must be added to tDATA to determine the overall propagation delay. Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 Submit Documentation Feedback 7 ADS5481 ADS5482 ADS5483 SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008................................................................................................................................................... www.ti.com PIN CONFIGURATION D14_15_P D14_15_M D12_13_P D12_13_M D10_11_P D10_11_M D8_9_P D8_9_M DRY_P DRY_M DVDD3 DGND 63 62 61 60 59 58 57 56 55 54 53 52 51 50 D6_7_M DVDD3 64 D6_7_P DGND ADS548x RGC Package (Top View) 49 48 D4_5_P 2 47 D4_5_M AGND 3 46 D2_3_P REF 4 45 D2_3_M NC 5 44 D0_1_P NC 6 43 D0_1_M AGND 7 42 DVDD3 AVDD5 8 41 DGND AVDD5 1 AVDD5 AGND DITHER AVDD5 14 35 PDWNF AVDD3 15 34 PDWNS 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 33 31 32 LVDSB AGND VCM AVDD3 AGND AVDD5 NC 36 AGND 37 13 AVDD3 12 AVDD5 INM AGND NC AVDD3 38 AVDD5 11 AGND INP CLKP NC CLKM AGND AGND NC 39 AVDD3 40 10 AVDD5 9 AGND AVDD3 P0056-08 8 Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 ADS5481 ADS5482 ADS5483 www.ti.com................................................................................................................................................... SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008 Table 1. TERMINAL FUNCTIONS TERMINAL DESCRIPTION NAME NO. AVDD5 1, 2, 8, 14, 18, 24, 27, 30 5V analog supply AVDD3 9, 15, 19, 25, 28, 31 3.3V analog supply AGND 3, 7, 10, 13, 17, 20, 23, 26, 29, Analog ground 32 DVDD3 42, 52, 63 3.3V digital supply DGND 41, 51, 64 Digital ground NC 5, 6, 37-40 No connects - leave floating INP, INM 11, 12 Differential analog inputs (P = plus = true, M = minus = complement) CLKM, CLKP 21, 22 Differential clock inputs (P = plus = true, M = minus = complement) REF 4 Reference voltage input/output (1.2V nominal). To use an external reference and to turn the internal reference off, pull both PDWNF and PDWNS to logic high (DVDD3). VCM 16 Analog input common mode, output (3.1V), for use in applications that require use of the internally generated common-mode. See the applications section for more information on using VCM. LVDSB 33 External bias resistor for LVDS bias current, normally 10kΩ to GND to provide nominal 3.5mA LVDS current PDWNF 35 Light sleep power down, fast wakeup, logic high (DVDD3) = light sleep enabled (bandgap reference remains on) PDWNS 34 Deep sleep power down, slow wakeup, logic high (DVDD3) = deep sleep enabled (bandgap reference is off) DITHER 36 Dither enable, logic high (DVDD3) = dither enabled DRY_P, DRY_M 54, 53 Dataready signal (LVDS clockout) (P = plus = true, M = minus = complement) D14_15_P, D14_15_M 62, 61 DDR LVDS output bits 14 then 15 (15 is MSB) (P = plus = true, M = minus = complement) DE_O_P, DE_O_M 43-50, 55-62 DDR LVDS output bits E (even) then O (odd) (P = plus = true, M = minus = complement) D0_1_P, D0_1_M 44, 43 PowerPAD 65 DDR LVDS output bits 0 then 1 (0 is LSB) (P = plus = true, M = minus = complement) Analog ground (exposed pad on bottom of package) Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 Submit Documentation Feedback 9 ADS5481 ADS5482 ADS5483 SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008................................................................................................................................................... www.ti.com TYPICAL CHARACTERISTICS At TA = +25°C, sampling rate = max rated, 50% clock duty cycle, 3-VPP differential sinusoidal clock, analog input amplitude = –1 dBFS, AVDD5 = 5 V, AVDD3 = 3.3 V, and DVDD3 = 3.3 V, unless otherwise noted. ADS5481 - 80 MSPS Typical Data Plots in this section are with a clock of 80MSPS unless otherwise specified. 0 −10 −20 −30 −40 −50 −60 −70 −80 −90 −100 −110 −120 −130 SFDR = 99 dBc SINAD = 81 dBFS SNR = 81.1 dBFS THD = 96.5 dBc 0 10 20 30 f − Frequency − MHz SFDR = 99 dBc SINAD = 80.8 dBFS SNR = 80.9 dBFS THD = 94.2 dBc 0 10 20 G001 ADS5481 SPECTRAL PERFORMANCE vs FFT for 60 MHz INPUT SIGNAL ADS5481 SPECTRAL PERFORMANCE vs FFT for 100 MHz INPUT SIGNAL SFDR = 102 dBc SINAD = 80.3 dBFS SNR = 80.4 dBFS THD = 97.7 dBc 10 20 30 40 0 −10 −20 −30 −40 −50 −60 −70 −80 −90 −100 −110 −120 −130 SFDR = 94 dBc SINAD = 79.6 dBFS SNR = 79.8 dBFS THD = 92.6 dBc 0 10 20 f − Frequency − MHz G003 Figure 4. Submit Documentation Feedback 40 G002 Figure 3. f − Frequency − MHz 10 30 f − Frequency − MHz Figure 2. 0 −10 −20 −30 −40 −50 −60 −70 −80 −90 −100 −110 −120 −130 0 0 −10 −20 −30 −40 −50 −60 −70 −80 −90 −100 −110 −120 −130 40 Amplitude − dB Amplitude − dB ADS5481 SPECTRAL PERFORMANCE vs FFT for 30 MHz INPUT SIGNAL Amplitude − dB Amplitude − dB ADS5481 SPECTRAL PERFORMANCE vs FFT for 10 MHz INPUT SIGNAL 30 40 G004 Figure 5. Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 ADS5481 ADS5482 ADS5483 www.ti.com................................................................................................................................................... SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008 TYPICAL CHARACTERISTICS (continued) At TA = +25°C, sampling rate = max rated, 50% clock duty cycle, 3-VPP differential sinusoidal clock, analog input amplitude = –1 dBFS, AVDD5 = 5 V, AVDD3 = 3.3 V, and DVDD3 = 3.3 V, unless otherwise noted. 130 SFDR (dBFS, 120 Dither ON) 110 SFDR (dBc, SFDR (dBFS, 100 Dither OFF) Dither OFF) 90 80 70 SNR (dBFS, Dither ON) 60 50 SNR (dBc, Dither ON) 40 30 fS = 80 MSPS fIN = 70 MHz 20 SFDR (dBc, AIN = 0 to −100 dBFS 10 Dither ON) 256k Point FFT 0 −100 −90 −80 −70 −60 −50 −40 −30 −20 −10 0 Input Amplitude − dBFS 100 95 SFDR (dBc, Dither OFF) 90 85 80 75 70 65 fS = 80 MSPS fIN = 70 MHz AIN = 0 to −40 dBFS 256k Point FFT SFDR (dBc, Dither ON) 60 −40 −36 −32 −28 −24 −20 −16 −12 −8 −4 Input Amplitude − dBFS G009 0 G010 Figure 6. Figure 7. ADS5481 TWO-TONE INTERMODULATION DISTORTION (FFT for 29.5 MHz and 30.5 MHz at –7 dBFS) ADS5481 TWO-TONE INTERMODULATION DISTORTION (FFT for 69.5 MHz and 70.5 MHz at –7 dBFS) 0 −10 −20 −30 −40 −50 −60 −70 −80 −90 −100 −110 −120 −130 fIN1 = 29.5 MHz, –7 dBFS fIN2 = 30.5 MHz, –7 dBFS IMD3 = 101 dBFS SFDR = 101 dBFS SNR = 80.9 dBFS Dither Enabled, CLK = 80 MSPS 0 10 Amplitude − dB Amplitude − dB ADS5481 SFDR vs INPUT AMPLITUDE (70 MHz Input Signal) SFDR − dBc AC Performance − dB ADS5481 AC PERFORMANCE vs INPUT AMPLITUDE (70 MHz Input Signal) 20 30 f − Frequency − MHz 40 0 −10 −20 −30 −40 −50 −60 −70 −80 −90 −100 −110 −120 −130 fIN1 = 69.5 MHz, –7 dBFS fIN2 = 70.5 MHz, –7 dBFS IMD3 = 95 dBFS SFDR = 95 dBFS SNR = 80.5 dBFS Dither Enabled, CLK = 80 MSPS 0 10 G011 Figure 8. 20 30 f − Frequency − MHz 40 G012 Figure 9. Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 Submit Documentation Feedback 11 ADS5481 ADS5482 ADS5483 SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008................................................................................................................................................... www.ti.com TYPICAL CHARACTERISTICS (continued) At TA = +25°C, sampling rate = max rated, 50% clock duty cycle, 3-VPP differential sinusoidal clock, analog input amplitude = –1 dBFS, AVDD5 = 5 V, AVDD3 = 3.3 V, and DVDD3 = 3.3 V, unless otherwise noted. ADS5481 TWO-TONE PERFORMANCE vs INPUT AMPLITUDE (f1 = 29.5 MHz and f2 = 30.5 MHz) ADS5481 DIFFERENTIAL NONLINEARITY 1.0 −90 −100 fS = 80 MSPS fIN = 10 MHz, –1 dBFS 0.8 0.6 Dither, Dominant Spur (dBFS) Dither, 2F2−F1 (dBFS) 0.4 DNL − LSB Performance − dBFS No Dither, Dominant Spur (dBFS) −110 −120 0.2 0.0 −0.2 −0.4 −130 −0.6 −0.8 −140 −90 Dither, 2F1−F2 (dBFS) −80 −70 −60 −50 −40 −30 −20 −10 Input Amplitude − dBFS −1.0 0 0 32768 49152 65536 Code G013 G014 Figure 10. Figure 11. ADS5481 INTEGRAL NONLINEARITY ADS5481 SFDR vs AVDD5 OVER TEMPERATURE 100 4 fS = 80 MSPS fIN = 10 MHz, –1 dBFS 3 TA = 85°C TA = 100°C 95 SFDR − dBc 2 INL − LSB 16384 1 0 −1 90 TA = −20°C TA = 55°C TA = 25°C TA = −40°C TA = 10°C −2 85 TA = 0°C fS = 80 MSPS fIN = 30 MHz −3 −4 0 16384 32768 49152 Code 65536 G015 80 4.7 4.8 4.9 Figure 12. 12 Submit Documentation Feedback 5.0 5.1 AVDD5 − Supply Voltage − V 5.2 5.3 G016 Figure 13. Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 ADS5481 ADS5482 ADS5483 www.ti.com................................................................................................................................................... SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008 TYPICAL CHARACTERISTICS (continued) At TA = +25°C, sampling rate = max rated, 50% clock duty cycle, 3-VPP differential sinusoidal clock, analog input amplitude = –1 dBFS, AVDD5 = 5 V, AVDD3 = 3.3 V, and DVDD3 = 3.3 V, unless otherwise noted. ADS5481 SNR vs AVDD5 OVER TEMPERATURE ADS5481 SFDR vs AVDD3 OVER TEMPERATURE 82 100 TA = −40°C TA = 85°C 81 95 TA = −20°C TA = 100°C TA = 85°C 78 TA = 0°C 77 TA = 55°C 4.9 5.0 5.1 5.2 AVDD5 − Supply Voltage − V TA = 0°C fS = 80 MSPS fIN = 30 MHz 80 2.9 5.3 3.2 3.3 3.4 3.5 3.6 3.7 G018 Figure 15. ADS5481 SNR vs AVDD3 OVER TEMPERATURE ADS5481 SFDR vs DVDD3 OVER TEMPERATURE 100 TA = −40°C TA = 85°C TA = 100°C TA = 55°C 95 TA = −20°C SFDR − dBc SNR − dBFS 3.1 G017 80 TA = 100°C TA = 85°C 78 TA = 0°C TA = 10°C TA = −20°C fS = 80 MSPS fIN = 30 MHz TA = 10°C 3.1 TA = 25°C TA = −40°C 85 TA = 25°C 3.0 90 TA = 0°C TA = 55°C 77 75 2.9 3.0 AVDD3 − Supply Voltage − V 81 76 TA = −20°C Figure 14. 82 79 TA = 10°C TA = −40°C fS = 80 MSPS fIN = 30 MHz TA = 10°C 4.8 TA = 25°C 90 85 TA = 25°C 76 75 4.7 SFDR − dBc SNR − dBFS 80 79 TA = 100°C TA = 55°C 3.2 3.3 3.4 3.5 AVDD3 − Supply Voltage − V 3.6 fS = 80 MSPS fIN = 30 MHz 3.7 G019 80 2.9 3.0 3.1 3.2 3.3 3.4 3.5 3.6 DVDD3 − Supply Voltage − V Figure 16. Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 3.7 G020 Figure 17. Submit Documentation Feedback 13 ADS5481 ADS5482 ADS5483 SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008................................................................................................................................................... www.ti.com TYPICAL CHARACTERISTICS (continued) At TA = +25°C, sampling rate = max rated, 50% clock duty cycle, 3-VPP differential sinusoidal clock, analog input amplitude = –1 dBFS, AVDD5 = 5 V, AVDD3 = 3.3 V, and DVDD3 = 3.3 V, unless otherwise noted. ADS5481 SNR vs DVDD3 OVER TEMPERATURE 82 TA = 0°C 81 SNR − dBFS 80 79 78 TA = −20°C TA = 100°C TA = 85°C TA = −40°C TA = 55°C 77 TA = 25°C 76 75 2.9 fS = 80 MSPS fIN = 30 MHz TA = 10°C 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 DVDD3 − Supply Voltage − V G021 Figure 18. 14 Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 ADS5481 ADS5482 ADS5483 www.ti.com................................................................................................................................................... SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008 TYPICAL CHARACTERISTICS (continued) At TA = +25°C, sampling rate = max rated, 50% clock duty cycle, 3-VPP differential sinusoidal clock, analog input amplitude = –1 dBFS, AVDD5 = 5 V, AVDD3 = 3.3 V, and DVDD3 = 3.3 V, unless otherwise noted. ADS5482 - 105 MSPS Typical Data Plots in this section are with a clock of 105MSPS unless otherwise specified. 0 −10 −20 −30 −40 −50 −60 −70 −80 −90 −100 −110 −120 −130 ADS5482 SPECTRAL PERFORMANCE vs FFT for 30 MHz INPUT SIGNAL SFDR = 101 dBc SINAD = 80.8 dBFS SNR = 80.8 dBFS THD = 100.4 dBc Amplitude − dB Amplitude − dB ADS5482 SPECTRAL PERFORMANCE vs FFT for 10 MHz INPUT SIGNAL 0 10 20 30 40 50 10 20 30 40 G005 G006 Figure 19. Figure 20. ADS5482 SPECTRAL PERFORMANCE vs FFT for 70 MHz INPUT SIGNAL ADS5482 SPECTRAL PERFORMANCE vs FFT for 90 MHz INPUT SIGNAL 10 20 30 40 f − Frequency − MHz 50 50 f − Frequency − MHz SFDR = 97 dBc SINAD = 79.4 dBFS SNR = 79.5 dBFS THD = 93.8 dBc 0 SFDR = 100 dBc SINAD = 80.2 dBFS SNR = 80.3 dBFS THD = 96.6 dBc 0 Amplitude − dB Amplitude − dB f − Frequency − MHz 0 −10 −20 −30 −40 −50 −60 −70 −80 −90 −100 −110 −120 −130 0 −10 −20 −30 −40 −50 −60 −70 −80 −90 −100 −110 −120 −130 0 −10 −20 −30 −40 −50 −60 −70 −80 −90 −100 −110 −120 −130 SFDR = 90 dBc SINAD = 78.8 dBFS SNR = 79.3 dBFS THD = 88.1 dBc 0 10 G007 Figure 21. Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 20 30 40 f − Frequency − MHz 50 G008 Figure 22. Submit Documentation Feedback 15 ADS5481 ADS5482 ADS5483 SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008................................................................................................................................................... www.ti.com TYPICAL CHARACTERISTICS (continued) At TA = +25°C, sampling rate = max rated, 50% clock duty cycle, 3-VPP differential sinusoidal clock, analog input amplitude = –1 dBFS, AVDD5 = 5 V, AVDD3 = 3.3 V, and DVDD3 = 3.3 V, unless otherwise noted. ADS5482 SFDR vs INPUT AMPLITUDE (70 MHz Input Signal) 130 SFDR (dBFS, 120 Dither ON) 110 SFDR (dBFS, 100 Dither OFF) 90 80 SFDR (dBc, 70 SNR (dBFS, Dither OFF) Dither ON) 60 SFDR (dBc, 50 Dither ON) 40 30 fS = 105 MSPS fIN = 70 MHz 20 SNR (dBc, AIN = 0 to −100 dBFS 10 Dither ON) 256k Point FFT 0 −100 −90 −80 −70 −60 −50 −40 −30 −20 −10 0 95 SFDR (dBc, Dither ON) 90 SFDR (dBc, Dither OFF) 85 80 75 70 fS = 105 MSPS fIN = 70 MHz AIN = 0 to −40 dBFS 256k Point FFT 65 60 −40 −36 −32 −28 −24 −20 −16 −12 −4 0 G022 G023 Figure 23. Figure 24. ADS5482 TWO-TONE INTERMODULATION DISTORTION (FFT for 29.5 MHz and 30.5 MHz at –7 dBFS) ADS5482 TWO-TONE INTERMODULATION DISTORTION (FFT for 69.5 MHz and 70.5 MHz at –7 dBFS) 0 −10 −20 −30 −40 −50 −60 −70 −80 −90 −100 −110 −120 −130 fIN1 = 29.5 MHz, –7 dBFS fIN2 = 30.5 MHz, –7 dBFS IMD3 = 101 dBFS SFDR = 101 dBFS SNR = 80.6 dBFS Dither Enabled, CLK = 105 MSPS 0 10 20 30 40 f − Frequency − MHz 50 0 −10 −20 −30 −40 −50 −60 −70 −80 −90 −100 −110 −120 −130 fIN1 = 69.5 MHz, –7 dBFS fIN2 = 70.5 MHz, –7 dBFS IMD3 = 102 dBFS SFDR = 100 dBFS SNR = 80.1 dBFS Dither Enabled, CLK = 105 MSPS 0 10 20 Submit Documentation Feedback 30 f − Frequency − MHz G024 Figure 25. 16 −8 Input Amplitude − dBFS Amplitude − dB Amplitude − dB Input Amplitude − dBFS 100 SFDR − dBc AC Performance − dB ADS5482 AC PERFORMANCE vs INPUT AMPLITUDE (70 MHz Input Signal) 40 50 G025 Figure 26. Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 ADS5481 ADS5482 ADS5483 www.ti.com................................................................................................................................................... SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008 TYPICAL CHARACTERISTICS (continued) At TA = +25°C, sampling rate = max rated, 50% clock duty cycle, 3-VPP differential sinusoidal clock, analog input amplitude = –1 dBFS, AVDD5 = 5 V, AVDD3 = 3.3 V, and DVDD3 = 3.3 V, unless otherwise noted. ADS5482 TWO-TONE PERFORMANCE vs INPUT AMPLITUDE (f1 = 69.5 MHz and f2 =70.5 MHz) ADS5482 DIFFERENTIAL NONLINEARITY 1.0 −80 Dither, 2F1−F2 (dBFS) No Dither, Dominant Spur (dBFS) 0.6 Dither, Dominant Spur (dBFS) −100 0.4 Dither, 2F2−F1 (dBFS) DNL − LSB Performance − dBFS −90 fS = 105 MSPS fIN = 10 MHz, –1 dBFS 0.8 −110 −120 0.2 0.0 −0.2 −0.4 −0.6 −130 −0.8 −140 −90 −1.0 −80 −70 −60 −50 −40 −30 −20 −10 Input Amplitude − dBFS 0 0 32768 49152 Code G026 65536 G027 Figure 27. Figure 28. ADS5482 INTEGRAL NONLINEARITY ADS5482 SFDR vs AVDD5 OVER TEMPERATURE 100 4 fS = 105 MSPS fIN = 10 MHz, –1 dBFS 3 TA = 100°C 95 SFDR − dBc 2 INL − LSB 16384 1 0 −1 TA = −40°C TA = −20°C TA = 55°C TA = 85°C 90 TA = 0°C TA = 25°C TA = 10°C −2 85 fS = 105 MSPS fIN = 30 MHz −3 −4 0 16384 32768 49152 Code 65536 G028 80 4.7 4.8 4.9 5.0 5.1 5.2 AVDD5 − Supply Voltage − V Figure 29. Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 5.3 G029 Figure 30. Submit Documentation Feedback 17 ADS5481 ADS5482 ADS5483 SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008................................................................................................................................................... www.ti.com TYPICAL CHARACTERISTICS (continued) At TA = +25°C, sampling rate = max rated, 50% clock duty cycle, 3-VPP differential sinusoidal clock, analog input amplitude = –1 dBFS, AVDD5 = 5 V, AVDD3 = 3.3 V, and DVDD3 = 3.3 V, unless otherwise noted. ADS5482 SNR vs AVDD5 OVER TEMPERATURE ADS5482 SFDR vs AVDD3 OVER TEMPERATURE 82 100 TA = −20°C TA = −40°C 81 95 SFDR − dBc SNR − dBFS 80 79 78 TA = 55°C TA = 0°C 77 TA = 85°C TA = 25°C 76 75 4.7 TA = 100°C TA = 10°C 4.8 4.9 5.1 5.2 80 2.9 5.3 3.1 3.2 3.4 3.5 G030 3.6 3.7 G031 Figure 32. ADS5482 SNR vs AVDD3 OVER TEMPERATURE ADS5482 SFDR vs DVDD3 OVER TEMPERATURE 100 TA = −40°C TA = −20°C 95 SFDR − dBc 79 78 TA = 55°C TA = 25°C TA = 0°C TA = 85°C 3.1 TA = 85°C 90 TA = −40°C TA = 0°C TA = 55°C TA = −20°C TA = 25°C 85 TA = 10°C fS = 105 MSPS fIN = 30 MHz TA = 10°C 3.0 TA = 100°C TA = 100°C 3.2 3.3 3.4 3.5 AVDD3 − Supply Voltage − V 3.6 fS = 105 MSPS fIN = 30 MHz 3.7 G032 80 2.9 3.0 3.1 3.2 Submit Documentation Feedback 3.3 3.4 3.5 DVDD3 − Supply Voltage − V Figure 33. 18 3.3 AVDD3 − Supply Voltage − V 80 SNR − dBFS 3.0 fS = 105 MSPS fIN = 30 MHz Figure 31. 81 75 2.9 TA = −40°C TA = 25°C TA = 10°C 82 76 TA = 0°C TA = 55°C fS = 105 MSPS fIN = 30 MHz 5.0 TA = −20°C TA = 85°C 90 85 AVDD5 − Supply Voltage − V 77 TA = 100°C 3.6 3.7 G033 Figure 34. Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 ADS5481 ADS5482 ADS5483 www.ti.com................................................................................................................................................... SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008 TYPICAL CHARACTERISTICS (continued) At TA = +25°C, sampling rate = max rated, 50% clock duty cycle, 3-VPP differential sinusoidal clock, analog input amplitude = –1 dBFS, AVDD5 = 5 V, AVDD3 = 3.3 V, and DVDD3 = 3.3 V, unless otherwise noted. ADS5482 SNR vs DVDD3 OVER TEMPERATURE 82 81 TA = −20°C TA = −40°C SNR − dBFS 80 79 78 77 TA = 85°C TA = 0°C TA = 55°C TA = 100°C TA = 25°C 76 fS = 105 MSPS fIN = 30 MHz TA = 10°C 75 2.9 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 DVDD3 − Supply Voltage − V G034 Figure 35. ADS5482/5481 SNR vs INPUT FREQUENCY AND SAMPLING FREQUENCY 105 100 78 80 fS - Sampling Frequency - MSPS 90 79 80 80 70 78 79 60 50 80 79 40 30 73 70 78 79 75 78 20 10 10 75 78 73 75 20 40 80 60 100 68 70 140 120 160 170 fIN - Input Frequency - MHz 64 68 66 70 72 74 SNR - dBFS 76 78 80 M0048-06 Figure 36. Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 Submit Documentation Feedback 19 ADS5481 ADS5482 ADS5483 SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008................................................................................................................................................... www.ti.com TYPICAL CHARACTERISTICS (continued) At TA = +25°C, sampling rate = max rated, 50% clock duty cycle, 3-VPP differential sinusoidal clock, analog input amplitude = –1 dBFS, AVDD5 = 5 V, AVDD3 = 3.3 V, and DVDD3 = 3.3 V, unless otherwise noted. ADS5482/5481 SFDR vs INPUT FREQUENCY AND SAMPLING FREQUENCY 105 100 75 85 95 fS - Sampling Frequency - MSPS 90 90 95 80 80 70 95 75 85 60 90 95 50 40 90 90 80 30 20 73 85 85 10 10 75 70 70 65 85 20 40 80 60 80 100 140 120 160 170 fIN - Input Frequency - MHz 60 65 70 75 80 85 SFDR - dBc 90 95 M0049-06 Figure 37. 20 Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 ADS5481 ADS5482 ADS5483 www.ti.com................................................................................................................................................... SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008 TYPICAL CHARACTERISTICS (continued) At TA = +25°C, sampling rate = max rated, 50% clock duty cycle, 3-VPP differential sinusoidal clock, analog input amplitude = –1 dBFS, AVDD5 = 5 V, AVDD3 = 3.3 V, and DVDD3 = 3.3 V, unless otherwise noted. ADS5483 - 135 MSPS Typical Data Plots in this section are with a clock of 135MSPS unless otherwise specified. 0 −10 −20 −30 −40 −50 −60 −70 −80 −90 −100 −110 −120 −130 0.0 SFDR = 97 dBc SINAD = 78.9 dBFS SNR = 78.9 dBFS THD = 94.6 dBc 13.5 27.0 40.5 54.0 67.5 0 −10 −20 −30 −40 −50 −60 −70 −80 −90 −100 −110 −120 −130 0.0 SFDR = 97 dBc SINAD = 78.8 dBFS SNR = 78.9 dBFS THD = 94.6 dBc 13.5 27.0 40.5 54.0 f − Frequency − MHz G037 Figure 39. ADS5483 SPECTRAL PERFORMANCE FFT FOR 70 MHz INPUT SIGNAL ADS5483 SPECTRAL PERFORMANCE FFT FOR 100 MHz INPUT SIGNAL SFDR = 95 dBc SINAD = 78.3 dBFS SNR = 78.5 dBFS THD = 91 dBc 13.5 27.0 40.5 f − Frequency − MHz 54.0 67.5 0 −10 −20 −30 −40 −50 −60 −70 −80 −90 −100 −110 −120 −130 0.0 67.5 G038 Figure 38. Amplitude − dB Amplitude − dB f − Frequency − MHz 0 −10 −20 −30 −40 −50 −60 −70 −80 −90 −100 −110 −120 −130 0.0 ADS5483 SPECTRAL PERFORMANCE FFT FOR 30 MHz INPUT SIGNAL Amplitude − dB Amplitude − dB ADS5483 SPECTRAL PERFORMANCE FFT FOR 10 MHz INPUT SIGNAL SFDR = 88 dBc SINAD = 77.7 dBFS SNR = 78.1 dBFS THD = 86.6 dBc 13.5 G039 Figure 40. Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 27.0 40.5 54.0 f − Frequency − MHz 67.5 G040 Figure 41. Submit Documentation Feedback 21 ADS5481 ADS5482 ADS5483 SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008................................................................................................................................................... www.ti.com TYPICAL CHARACTERISTICS (continued) At TA = +25°C, sampling rate = max rated, 50% clock duty cycle, 3-VPP differential sinusoidal clock, analog input amplitude = –1 dBFS, AVDD5 = 5 V, AVDD3 = 3.3 V, and DVDD3 = 3.3 V, unless otherwise noted. NORMALIZED GAIN RESPONSE vs INPUT FREQUENCY 0 −10 −20 −30 −40 −50 −60 −70 −80 −90 −100 −110 −120 −130 0.0 3 fIN1 = 39.5 MHz, –10 dBFS fIN2 = 40.5 MHz, –10 dBFS IMD3 = 103 dBFS SFDR = 100 dBFS SNR = 79 dBFS ADS5483 0 Normalized Gain − dB Amplitude − dB ADS5483 TWO-TONE INTERMODULATION DISTORTION (FFT for 39.5 MHz and 40.5 MHz at –10 dBFS) −3 −6 ADS5481 −9 −12 ADS5482 −15 −18 −21 13.5 27.0 40.5 54.0 f − Frequency − MHz −24 10M 67.5 100M G041 Figure 42. ADS5483 DIFFERENTIAL NONLINEARITY ADS5483 INTEGRAL NONLINEARITY 4 fS = 135 MSPS fIN = 10 MHz, –1 dBFS 0.8 fS = 135 MSPS fIN = 10 MHz, –1 dBFS 3 0.6 2 INL − LSB 0.4 DNL − LSB G042 Figure 43. 1.0 0.2 0.0 −0.2 −0.4 1 0 −1 −2 −0.6 −3 −0.8 −1.0 −4 0 16384 32768 49152 Code 65536 0 16384 Submit Documentation Feedback 32768 Code G043 Figure 44. 22 1G f − Frequency − Hz 49152 65536 G044 Figure 45. Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 ADS5481 ADS5482 ADS5483 www.ti.com................................................................................................................................................... SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008 TYPICAL CHARACTERISTICS (continued) At TA = +25°C, sampling rate = max rated, 50% clock duty cycle, 3-VPP differential sinusoidal clock, analog input amplitude = –1 dBFS, AVDD5 = 5 V, AVDD3 = 3.3 V, and DVDD3 = 3.3 V, unless otherwise noted. ADS5483 AC PERFORMANCE vs INPUT AMPLITUDE (30 MHz Input Signal) NOISE HISTOGRAM WITH INPUTS SHORTED 35 25 ADS5481/5482 ADS5483 AC Performance − dB Percentage − % 30 fs = 80 MSPS for ADS5481 fs = 105 MSPS for ADS5482 fs = 135 MSPS for ADS5483 Analog Inputs Shorted to VCM 20 15 10 5 32701 32702 32699 32700 32697 32698 32695 32696 32693 32694 32691 32692 32689 32690 AC Performance − dB Input Amplitude − dBFS G046 G045 Output Code Figure 46. Figure 47. ADS5483 AC PERFORMANCE vs INPUT AMPLITUDE (100 MHz Input Signal) ADS5483 TWO-TONE PERFORMANCE vs INPUT AMPLITUDE (f1 = 39.5 MHz and f2 = 40.5 MHz) 180 SFDR (dBFS, SNR (dBFS, SFDR (dBc, SFDR (dBFS, 160 Dither OFF) Dither OFF) Dither ON) Dither ON) 140 120 100 80 60 40 SNR (dBc, 20 Dither ON) 0 SNR (dBFS, f = 135 MSPS −20 S Dither ON) fIN = 100 MHz −40 AIN = −0.6 to −100 dBFS SFDR (dBc, SNR (dBc, −60 Dither OFF) Dither OFF) 512k Point FFT −80 −100 −90 −80 −70 −60 −50 −40 −30 −20 −10 0 Input Amplitude − dBFS −80 No Dither, Dominant Spur (dBFS) −90 Performance − dBFS 32687 32688 0 180 SFDR (dBFS, SNR (dBFS, SFDR (dBc, SFDR (dBFS, 160 Dither OFF) Dither OFF) Dither ON) Dither ON) 140 120 100 80 60 40 SNR (dBc, 20 Dither ON) 0 SNR (dBFS, f = 135 MSPS −20 S Dither ON) fIN = 30 MHz −40 AIN = −0.8 to −100 dBFS SFDR (dBc, SNR (dBc, −60 Dither OFF) Dither OFF) 512k Point FFT −80 −100 −90 −80 −70 −60 −50 −40 −30 −20 −10 0 Dither, Dominant Spur (dBFS) −100 −110 −120 −130 Dither, 2F1−F2 (dBFS) −140 Dither, 2F2−F1 (dBFS) −150 −90 −80 −70 G065 Figure 48. Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 −60 −50 −40 −30 −20 −10 Input Amplitude − dBFS 0 G047 Figure 49. Submit Documentation Feedback 23 ADS5481 ADS5482 ADS5483 SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008................................................................................................................................................... www.ti.com TYPICAL CHARACTERISTICS (continued) At TA = +25°C, sampling rate = max rated, 50% clock duty cycle, 3-VPP differential sinusoidal clock, analog input amplitude = –1 dBFS, AVDD5 = 5 V, AVDD3 = 3.3 V, and DVDD3 = 3.3 V, unless otherwise noted. ADS5483 SFDR vs AVDD5 OVER TEMPERATURE ADS5483 SNR vs AVDD5 OVER TEMPERATURE 100 80 fS = 135 MSPS fIN = 70 MHz TA = 100°C TA = 85°C TA = −40°C 79 SNR − dBFS SFDR − dBc 95 90 TA = 0°C 85 TA = −40°C TA = 55°C 4.8 4.9 TA = 0°C TA = 55°C TA = 25°C TA = 100°C TA = 85°C fS = 135 MSPS fIN = 70 MHz 5.0 5.1 5.2 75 4.7 5.3 4.8 4.9 5.0 5.1 G048 Figure 51. ADS5483 SFDR vs AVDD3 OVER TEMPERATURE ADS5483 SNR vs AVDD3 OVER TEMPERATURE 80 79 SNR − dBFS 90 TA = −20°C 78 77 TA = 25°C TA = 0°C TA = 55°C TA = 25°C TA = 55°C TA = −40°C TA = 0°C TA = 85°C 76 fS = 135 MSPS fIN = 70 MHz 3.0 3.1 3.2 3.3 TA = −20°C TA = −40°C TA = 100°C TA = 85°C 95 3.4 3.5 AVDD3 − Supply Voltage − V 3.6 3.7 G050 75 2.9 3.0 3.1 Submit Documentation Feedback TA = 100°C 3.2 3.3 3.4 3.5 AVDD3 − Supply Voltage − V Figure 52. 24 5.3 G049 Figure 50. fS = 135 MSPS fIN = 70 MHz 80 2.9 5.2 AVDD5 − Supply Voltage − V 100 SFDR − dBc 77 76 AVDD5 − Supply Voltage − V 85 78 TA = 25°C TA = −20°C 80 4.7 TA = −20°C 3.6 3.7 G051 Figure 53. Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 ADS5481 ADS5482 ADS5483 www.ti.com................................................................................................................................................... SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008 TYPICAL CHARACTERISTICS (continued) At TA = +25°C, sampling rate = max rated, 50% clock duty cycle, 3-VPP differential sinusoidal clock, analog input amplitude = –1 dBFS, AVDD5 = 5 V, AVDD3 = 3.3 V, and DVDD3 = 3.3 V, unless otherwise noted. ADS5483 SFDR vs DVDD3 OVER TEMPERATURE ADS5483 SNR vs DVDD3 OVER TEMPERATURE 100 80 fS = 135 MSPS fIN = 70 MHz TA = 100°C TA = 85°C SNR − dBFS SFDR − dBc TA = −40°C TA = 25°C TA = 85°C 79 95 90 TA = −40°C 85 TA = −20°C TA = 0°C 77 TA = 55°C TA = 0°C TA = −20°C 78 TA = 55°C TA = 100°C TA = 25°C 76 fS = 135 MSPS fIN = 70 MHz 80 2.9 3.0 3.1 3.2 3.3 3.4 3.5 3.6 DVDD3 − Supply Voltage − V 75 2.9 3.7 3.0 3.1 3.2 G052 Figure 54. 3.5 3.6 3.7 G053 ADC WAKEUP TIME 0 90 −10 80 −20 70 SNR − dBFS CMRR − dB 3.4 Figure 55. CMRR vs COMMON-MODE INPUT FREQUENCY −30 −40 −50 PDWNF 60 PDWNS 50 40 30 −60 fS = 135 MSPS fIN = 10 MHz PDWNF and PDWNS Tested Independently PDWNx Disabled at 0 ms PDWNx Enabled at ≈ 8 ms 20 −70 −80 0.1 3.3 DVDD3 − Supply Voltage − V 10 0 1 10 100 fIN − Input Frequency − Hz 1k 0 1 2 3 4 5 6 7 8 9 t − time − ms G054 Figure 56. Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 10 G066 Figure 57. Submit Documentation Feedback 25 ADS5481 ADS5482 ADS5483 SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008................................................................................................................................................... www.ti.com TYPICAL CHARACTERISTICS (continued) At TA = +25°C, sampling rate = max rated, 50% clock duty cycle, 3-VPP differential sinusoidal clock, analog input amplitude = –1 dBFS, AVDD5 = 5 V, AVDD3 = 3.3 V, and DVDD3 = 3.3 V, unless otherwise noted. ADS5483 SNR vs INPUT FREQUENCY AND SAMPLING FREQUENCY 135 130 78.5 76 fS - Sampling Frequency - MSPS 120 110 78 75 77 74 79 100 90 78.5 79 78 76 77 74 75 80 70 60 78.5 78 50 40 10 50 72 150 100 73 74 75 76 77 200 250 300 fIN - Input Frequency - MHz 70 71 72 73 74 75 76 77 78 79 80 SNR - dBFS M0048-02 Figure 58. ADS5483 SFDR vs INPUT FREQUENCY AND SAMPLING FREQUENCY 135 130 fS - Sampling Frequency - MSPS 120 75 80 95 70 85 90 65 110 100 70 75 90 95 85 90 80 65 80 70 60 40 10 85 95 50 70 80 75 90 50 150 100 65 200 250 300 fIN - Input Frequency - MHz 60 65 70 75 80 85 SFDR - dBc 90 95 M0049-02 Figure 59. 26 Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 ADS5481 ADS5482 ADS5483 www.ti.com................................................................................................................................................... SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008 APPLICATIONS INFORMATION Theory of Operation The ADS5481/ADS5482/ADS5483 (ADS548x) is a 16-bit, 80-135MSPS family of monolithic pipeline ADCs. The bipolar analog core operates from 5-V and 3.3-V supplies, while the output uses a 3.3-V supply to provide LVDS-compatible outputs. Prior to the track-and-hold, the analog input signal passes through a high-performance bipolar buffer. The buffer presents a high and consistent impedance to the analog inputs. The buffer isolates the board circuitry external to the ADC from the sampling glitches caused by the track-and-hold in the ADC. The conversion process is initiated by the falling edge of the external input clock. At that instant, the differential input signal is captured by the input track-and-hold, and the input sample is converted sequentially by a series of lower resolution stages, with the outputs combined in a digital correction logic block. Both the rising and the falling clock edges are used to propagate the sample through the pipeline every half clock cycle. This process results in a data latency of 4.5 clock cycles, after which the output data are available as a 16-bit parallel word, coded in offset binary format. Input Configuration The analog input for the ADS548x consists of an analog pseudo-differential buffer followed by a bipolar transistor T&H. The analog buffer isolates the source driving the input of the ADC from any internal switching and presents a high impedance that is easy to drive at high input frequencies, compared to an ADC without a buffered input. The input common-mode is set internally through a 1000-Ω resistor connected from 3.1 V to each of the inputs. This configuration results in a differential input impedance of 2 kΩ at 0 Hz. ADS548x Bipolar Transistor Buffer AVDD5 ~ 2 nH Bond Wire 10 W INP ~ 200 fF Bond Pad ~ 200 fF Package Analog Inputs 3 pF 1000 W AGND 1000 W ~ 2 nH Bond Wire Track and Hold, VCM AVDD5 st 1 Pipeline Stage 3 pF AGND INM ~ 200 fF Bond Pad ~ 200 fF Package 10 W AGND Bipolar Transistor Buffer S0293-02 Figure 60. Analog Input Circuit For a full-scale differential input, each of the differential lines of the input signal (pins 11 and 12) swings symmetrically between (3.1 V + 0.75 V) and (3.1 V – 0.75 V). This range means that each input has a maximum signal swing of 1.5 VPP for a total differential input signal swing of 3 VPP. Operation below 3 VPP is allowable, with the characteristics of performance versus input amplitude demonstrated in Figure 6 through Figure 10. For instance, for performance at 2 VPP rather than 3 VPP, refer to the SNR and SFDR at –3.5 dBFS (0 dBFS = 3 VPP). The maximum swing is determined by the internal reference voltage generator, eliminating the need for any external circuitry for this purpose. The primary degradation visible if the max amplitude is kept to 2 VPP is ~3 dBc of SNR compared to using 3 VPP, while SFDR will be the same or even improved. The smaller input signal will also likely help any components in the signal chain prior to the ADC to be more linear and provide better distortion. Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 Submit Documentation Feedback 27 ADS5481 ADS5482 ADS5483 SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008................................................................................................................................................... www.ti.com The ADS548x performs optimally when the analog inputs are driven differentially. The circuit in Figure 61 shows one possible configuration using an RF transformer with termination either on the primary or on the secondary of the transformer. If voltage gain is required, a step-up transformer can be used. R0 50 W Z0 50 W INP R 200 W AC Signal Source ADS548x INM n = 2:1 S0176-04 Figure 61. Converting a Single-Ended Input to a Differential Signal Using an RF Transformer Dither The ADS548x family of devices contain a dither option that is enabled via the DITHEREN pin. Dither is a technique applied to convert small static errors in the converter to dynamic errors, which will look similar to white noise in the output. In virtually all cases tested, the harmonic performance is equal or better when dither is enabled versus disabled. It improves the harmonics that are a function of the static errors. The dither is very low level and will only be indicated in the output waveform as wideband noise that may slightly degrade the SNR (<0.5dB). It is recommended that it be enabled, but users should allow the capability to disable it in the event they suspect it may be degrading their specific application, or to compare the results during their evaluation. Figure 6 through Figure 10 show the minor differences of dither ON/OFF when carefully studied. External Voltage Reference For systems that require the analog signal gain to be adjusted or calibrated, this can be performed by using an external reference. The dependency on the signal amplitude to the value of the external reference voltage is characterized typically by Figure 62 (VREF = 1.2 V is normalized to 0 dB as this is the internal reference voltage). As can be seen in the linear fit, this equates to approximately ~1 dB of signal adjustment per 100 mV of reference adjustment. The range of allowable variation depends on the analog input amplitude that is applied to the inputs and the desired spectral performance, as can be seen in the performance versus external reference graphs in Figure 63 and Figure 64. For dc-coupled applications that use the VCM pin of the ADS548x as the common mode of the signal in the analog signal gain path prior to the ADC inputs, Figure 66 indicates very little change in VCM output as VREF is externally adjusted. The VCM output is buffered with a 2kΩ series output resistor. The method for disabling the internal reference for use with an external reference is described in Table 4 . 28 Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 ADS5481 ADS5482 ADS5483 www.ti.com................................................................................................................................................... SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008 100 fS = 135 MSPS fIN = 30 MHz AIN = < −1 dBFS Normalized to 1.2 VREF 8 6 AIN = −2 dBFS 95 SFDR − dBc Normalized Gain Adjustment − dB 10 Linear Fit: y = −9.8x + 11.8 4 2 AIN = −1 dBFS 90 AIN = −10 dBFS 85 AIN = −4 dBFS AIN = −6 dBFS 80 0 fS = 135 MSPS fIN = 30 MHz Dither Enabled Signal Amplitude Relative to Adjusted Fullscale AIN = −3 dBFS −2 75 −4 0.5 70 0.5 AIN = −7 dBFS 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 Applied External VREF − V G057 76 1.0 1.1 1.2 1.3 1.4 G058 fS = 135 MSPS fIN = 30 MHz Signal Adjusted to −1 dBFS AIN = −1 dBFS 2.2 AIN = −6 dBFS P − Power − W SNR − dBc 0.9 2.3 AIN = −3 dBFS AIN = −2 dBFS AIN = −4 dBFS 78 AIN = −7 dBFS 70 68 66 64 62 60 0.5 0.8 Figure 63. SFDR versus External VREF and AIN 80 72 0.7 Applied External VREF − V Figure 62. Signal Gain Adjustment versus External Reference (VREF) 74 0.6 AIN = −10 dBFS 0.6 0.7 0.8 0.9 fS = 135 MSPS fIN = 30 MHz Dither Enabled Signal Amplitude Relative to Adjusted Fullscale 1.0 1.1 1.2 1.3 2.1 2.0 1.9 1.8 1.7 0.5 1.4 Applied External VREF − V 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 Applied External VREF − V G059 Figure 64. SNR versus External VREF and AIN 1.4 G060 Figure 65. Total Power Consumption versus External VREF 3.20 VCM Pin Output Voltage − V 3.19 3.18 3.17 3.16 3.15 3.14 3.13 3.12 3.11 3.10 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 Applied External VREF − V 1.4 G061 Figure 66. VCM Pin Output versus External VREF Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 Submit Documentation Feedback 29 ADS5481 ADS5482 ADS5483 SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008................................................................................................................................................... www.ti.com Clock Inputs The ADS548x equivalent clock input circuit is shown in Figure 67. The clock inputs can be driven with either a differential clock signal or a single-ended clock input, but differential is highly recommended. The characterization of the ADS548x is typically performed with a 3-VPP differential clock, but the ADC performs well with a differential clock amplitude down to ~1 VPP, as shown in Figure 69 and Figure 70 . The clock amplitude becomes more of a factor in performance as the analog input frequency increases. When single-ended clocking is a necessity, it is best to connect CLKM to ground with a 0.01-µF capacitor, while CLKP is ac-coupled with a 0.01-µF capacitor to the clock source, as shown in Figure 68. Figure 67. Clock Input Circuit Square Wave or Sine Wave CLKP 0.01 mF ADS548x CLKM 0.01 mF S0168-08 Figure 68. Single-Ended Clock 30 Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 ADS5481 ADS5482 ADS5483 www.ti.com................................................................................................................................................... SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008 SFDR vs CLOCK AMPLITUDE SNR vs CLOCK AMPLITUDE 80 100 fIN = 9.97 MHz 78 76 90 fIN = 69.59 MHz SNR − dBFS SFDR − dBc 95 fIN = 30.13 MHz 85 fIN = 100.33 MHz 80 72 fIN = 69.59 MHz 70 fIN = 30.13 MHz 68 66 64 75 62 fS = 135 MSPS 70 0.0 fIN = 100.33 MHz fIN = 9.97 MHz 74 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 Clock Amplitude − VPP 4.5 5.0 fS = 135 MSPS 60 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 Clock Amplitude − VPP G055 Figure 69. 5.0 G056 Figure 70. For jitter-sensitive applications, the use of a differential clock has some advantages at the system level. The differential clock allows for common-mode noise rejection at the printed circuit board (PCB) level. With a differential clock, the signal-to-noise ratio of the ADC is better for jitter-sensitive, high-frequency applications because the board level clock jitter is superior. The sampling process will be more sensitive to jitter using high analog input frequencies or slow clock frequencies. Large clock amplitude levels are recommended when possible to reduce the indecision (jitter) in the ADC clock input buffer. Whenever possible, the ideal combination is a differential clock with large signal swing (~1-3Vpp). Figure 71 demonstrates a recommended method for converting a single-ended clock source into a differential clock; it is similar to the configuration found on the evaluation board and was used for much of the characterization. See also Clocking High Speed Data Converters (SLYT075) for more details. 0.1 mF Clock Source CLKP ADS548x CLKM S0194-03 Figure 71. Differential Clock The common-mode voltage of the clock inputs is set internally to ~2 V using internal 0.5-kΩ resistors. It is recommended to use ac coupling, but if this scheme is not possible, the ADS548x features good tolerance to clock common-mode variation (as shown in Figure 72 and Figure 73). The internal ADC core uses both edges of the clock for the conversion process. Ideally, a 50% duty-cycle clock signal should be provided. Performance degradation as a result of duty cycle can be seen in Figure 74. Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 Submit Documentation Feedback 31 ADS5481 ADS5482 ADS5483 SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008................................................................................................................................................... www.ti.com 100 81 79 77 10 MHz 80 SNR − dBFS SFDR − dBc 90 30 MHz 70 MHz 70 100 MHz 60 75 70 MHz 10 MHz 73 100 MHz 71 30 MHz 69 231 MHz 67 50 0.5 1.0 1.5 2.0 2.5 3.0 3.5 Clock Common Mode Voltage − V 231 MHz 65 0.5 1.0 1.5 2.0 2.5 3.0 3.5 Clock Common Mode Voltage − V G062 Figure 72. SFDR versus Clock Common Mode G063 Figure 73. SNR versus Clock Common Mode 100 fS = 135 MSPS AIN = −1 dBFS Clock Input = 3 Vpp 10 MHz SFDR − dBc 90 70 MHz 80 30 MHz 70 231 MHz 60 100 MHz 50 0 10 20 30 40 50 60 70 80 90 100 Clock Duty Cycle − % G064 Figure 74. SFDR vs Clock Duty Cycle The ADS5483 is capable of achieving 78.2 dBFS SNR at 100 MHz of analog input frequency. In order to achieve the SNR at 100 MHz the clock source rms jitter (at the ADC clock input pins) must be at most 205 fsec in order for the total rms jitter to be 220 fsec due to internal ADC aperture jitter of ~80 fsec. A summary of maximum recommended rms clock jitter as a function of analog input frequency for the ADS5483 is provided in Table 2. The equations used to create the table are presented and can be used to estimate required clock jitter for virtually any pipeline ADC. Table 2. Recommended Approximate RMS Clock Jitter for ADS5483 ANALOG INPUT FREQUENCY (MHz) MEASURED SNR (dBc) TOTAL JITTER (fsec rms) MAXIMUM CLOCK JITTER (fsec rms) 32 1 78.2 19581 19581 10 78 2004 2002 70 77.8 300 289 100 77.2 220 205 130 76 177 158 170 75.8 152 129 230 75.1 122 92 300 73.2 116 84 Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 ADS5481 ADS5482 ADS5483 www.ti.com................................................................................................................................................... SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008 Equation 1 and Equation 2 are used to estimate the required clock source jitter. SNR (dBc) = -20 ´ LOG10 (2 ´ p ´ fIN ´ jTOTAL) (1) jTOTAL = (jADC2 + jCLOCK2)1/2 (2) where: jTOTAL = the rms summation of the clock and ADC aperture jitter; jADC = the ADC internal aperture jitter which is located in the data sheet; jCLOCK = the rms jitter of the clock at the clock input pins to the ADC; and fIN = the analog input frequency. Notice that the SNR is a strong function of the analog input frequency, not the clock frequency. The slope of the clock source edges can have a mild impact on SNR as well and is not taken into account for these estimates. For this reason, maximizing clock source amplitudes at the ADC clock inputs is recommended, though not required (faster slope is desirable for jitter-related SNR). For more information on clocking high-speed ADCs, see Application Note SLWA034, Implementing a CDC7005 Low Jitter Clock Solution For High-Speed, High-IF ADC Devices, on the Texas Instruments web site. Recommended clock distribution chips (CDCs) are the TI CDCE72010 and CDCM7005. Depending on the jitter requirements, a band pass filter (BPF) is sometimes required between the CDC and the ADC. If the insertion loss of the BPF causes the clock amplitude to be too low for the ADC, or the clock source amplitude is too low to begin with, an inexpensive amplifier can be placed between the CDC and the BPF, as its harmonics and wide-band noise will be reduced by the BPF. Figure 75 represents a scenario where an LVCMOS single-ended clock output is used from a TI CDCE72010 with the clock signal path optimized for maximum amplitude and minimum jitter. The jitter of this setup is difficult to estimate and requires a careful phase noise analysis of the clock path. The BPF (and possibly a low-cost amplifier because of insertion loss in the BPF) can improve the jitter between the CDC and ADC when the jitter provided by the CDC is still not adequate. The total jitter at the CDCE72010 output depends largely on the phase noise of the VCXO/VCO selected, as well as from the CDCE72010 itself. Board Master Reference Clock (High or Low Jitter) 10 MHz AMP and/or BPF Optional REF LVCMOS 100 MHz AMP BPF XFMR 400 MHz (To Transmit DAC) CLKP CLKM ADC TI ADS548x 100 MHz (To DSP) LVPECL or LVCMOS Low Jitter Oscillator 100 MHz (To FPGA) 400 MHz VCO/ VCXO CDC (Clock Distribution Chip) Ex: TI CDCE72010 To Other B0268-01 Consult the CDCE72010 data sheet for proper schematic and specifications regarding allowable input and output frequency and amplitude ranges. Figure 75. Optimum Jitter Clock Circuit Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 Submit Documentation Feedback 33 ADS5481 ADS5482 ADS5483 SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008................................................................................................................................................... www.ti.com Digital Outputs The ADC provides eight LVDS-compatible, offset binary, DDR data outputs (2 bits per LVDS output driver) and a data-ready LVDS signal (DRY). It is recommended to use the DRY signal to capture the output data of the ADS548x (use as a Clock Output). DRY is source-synchronous to the DATA outputs and operates at the same frequency, creating a full-rate DDR interface that updates data on both the rising and falling edges of DRY. It is recommended that the capacitive loading on the digital outputs be minimized. Higher capacitance shortens the data-valid timing window. The values given for timing (see Figure 1) were obtained with a 5-pF parasitic board capacitance to ground on each LVDS line. When setting the time relationship between DRY and DATA at the receiving device, it is generally recommended that setup time be maximized, but this partially depends on the setup and hold times of the device receiving the digital data. Since DRY and DATA are coincident, it will likely be necessary to delay either DRY such that DATA setup time is maximized. The LVDS outputs all require an external 100-Ω load between each output pair in order to meet the expected LVDS voltage levels. For long trace lengths, it may be necessary to place a 100-Ω load on each digital output as close to the ADS548x as possible and another 100-Ω differential load at the end of the LVDS transmission line to terminate the transmission line and avoid signal reflections. The effective load in this case reduces the LVDS voltage levels by half. The current of all LVDS drivers is set externally with a resistor connected between the LVDSB (LVDS Bias) pin and ground. Normal LVDS current is 3.5mA per LVDS pair, set with a 10kΩ external resistor. For systems with excessive load capacitance on the LVDS lines, reducing the resistor value in order to increase the LVDS Bias current is allowed to create a stronger LVDS drive capability. For systems with short traces and minimal loading, increasing the resistor in order to decrease the LVDS current is allowable in order to save power. Table 3 provides a sampling of LVDSB resistor values should deviation from the recommended LVDS output current of 3.5mA be considered. It is not recommended to exceed the range listed in the table. If the LVDS bias current is adjusted, the differential load resistance should also be adjusted to maintain voltage levels within the specification for the LVDS outputs. The signal integrity of the LVDS lines on the board layout should be scrutinized to ensure proper LVDS signal integrity exists. Table 3. Setting the LVDS Current Drive 34 LVDSB RESISTOR TO GND, Ω LVDS NOMINAL CURRENT, mA 6k 5.6 8k 4.3 10k (value for normal recommended operation) 3.5 12k 2.8 14k 2.3 16k 2.0 18k 1.7 20k 1.5 Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 ADS5481 ADS5482 ADS5483 www.ti.com................................................................................................................................................... SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008 Power Supplies and Sleep Modes The ADS548x uses three power supplies. For the analog portion of the design, a 5-V and 3.3-V supply (AVDD5 and AVDD3) are used, while the digital portion uses a 3.3-V supply (DVDD3). The use of low-noise power supplies with adequate decoupling is recommended. Linear supplies are preferred to switched supplies; switched supplies generate more noise that can be coupled to the ADS548x. However, the PSRR value and plot shown in Figure 76 were obtained without bulk supply decoupling capacitors. When bulk (0.1 µF) decoupling capacitors are used near the supply pins, the board-level PSRR is much higher than the stated value for the ADC. The user may be able to supply power to the device with a less-than-ideal supply and still achieve very good performance. It is not possible to make a single recommendation for every type of supply and level of decoupling for all systems. If the noise characteristics of the available supplies are understood, a study of the PSRR data for the ADS548x may provide the user with enough information to select noisy supplies if the performance is still acceptable within the frequency range of interest. The power consumption of the ADS548x does not change substantially over clock rate or input frequency. 0 PSRR − dB −20 −40 AVDD3V −60 AVDD5V −80 −100 DVDD3V −120 0.1 1 10 100 1k fIN − Input Frequency − MHz G067 Figure 76. PSRR versus Supply Injected Frequency Two separate sleep modes are offered. They are differentiated by the amount of power consumed and the time it takes for the ADC to wakeup from sleep. The light sleep mode consumes 605mW and can be used when wakeup of less than 600us is required. Deep sleep consumes 70mW and requires 6ms to wakeup. See the wakeup characteristic at Figure 57. For directions on enabling these modes, see Table 4. The input clock can be in either state when the power down modes are enabled. The device can enter power-down mode whether using internal or external reference. However, the wakeup time from light sleep enabled to external reference mode is dependent on the external reference voltage and is not necessarily 0.6 ms, but should be noticeably faster than deep sleep wakeup. No specific power sequences are required. Table 4. Power Down and Reference Modes MODE PDWNF PIN PDWNS PIN POWER CONSUMPTION WAKEUP TIME On ADC ON - Internal reference Low Low 2.2 W ADC ON - External reference High High 2.2 W On Light sleep High Low 605 mW when enabled 0.6 ms Deep sleep Low High 70 mW when enabled 6 ms Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 Submit Documentation Feedback 35 ADS5481 ADS5482 ADS5483 SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008................................................................................................................................................... www.ti.com Layout Information The evaluation board represents a good model of how to lay out the printed circuit board (PCB) to obtain the maximum performance from the ADS548x. Follow general design rules, such as the use of multilayer boards, a single ground plane for ADC ground connections, and local decoupling ceramic chip capacitors. The analog input traces should be isolated from any external source of interference or noise, including the digital outputs as well as the clock traces. The clock signal traces should also be isolated from other signals, especially in applications such as high IF sampling where low jitter is required. Besides performance-oriented rules, care must be taken when considering the heat dissipation of the device. The thermal heatsink included on the bottom of the package should be soldered to the board as described in the PowerPad Package section. See the ADS548x EVM User Guide on the TI web site for the evaluation board schematic. PowerPAD Package The PowerPAD package is a thermally-enhanced, standard-size IC package designed to eliminate the use of bulky heatsink and slugs traditionally used in thermal packages. This package can be easily mounted using standard PCB assembly techniques, and can be removed and replaced using standard repair procedures. The PowerPAD package is designed so that the leadframe die pad (or thermal pad) is exposed on the bottom of the IC. This pad design provides an extremely low thermal resistance path between the die and the exterior of the package. The thermal pad on the bottom of the IC can then be soldered directly to the PCB, using the PCB as a heatsink. Assembly Process 1. Prepare the PCB top-side etch pattern including etch for the leads as well as the thermal pad as illustrated in the Mechanical Data section (at the end of this data sheet). 2. Place a 6-by-6 array of thermal vias in the thermal pad area. These holes should be 13 mils (0.013 in or 0.3302 mm) in diameter. The small size prevents wicking of the solder through the holes. 3. It is recommended to place a small number of 25 mil (0.025 in or 0.635 mm) diameter holes under the package, but outside the thermal pad area, to provide an additional heat path. 4. Connect all holes (both those inside and outside the thermal pad area) to an internal copper plane (such as a ground plane). 5. Do not use the typical web or spoke via-connection pattern when connecting the thermal vias to the ground plane. The spoke pattern increases the thermal resistance to the ground plane. 6. The top-side solder mask should leave exposed the terminals of the package and the thermal pad area. 7. Cover the entire bottom side of the PowerPAD vias to prevent solder wicking. 8. Apply solder paste to the exposed thermal pad area and all of the package terminals. For more detailed information regarding the PowerPAD package and its thermal properties, see either the PowerPAD Made Easy application brief (SLMA004) or the PowerPAD Thermally Enhanced Package application report (SLMA002), both available for download at www.ti.com. 36 Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 ADS5481 ADS5482 ADS5483 www.ti.com................................................................................................................................................... SLAS565A – JUNE 2008 – REVISED NOVEMBER 2008 DEFINITION OF SPECIFICATIONS Analog Bandwidth The analog input frequency at which the power of the fundamental is reduced by 3 dB with respect to the low-frequency value. The injected frequency level is translated into dBFS, the spur in the output FFT is measured in dBFS, and the difference is the PSRR in dB. The measurement calibrates out the benefit of the board supply decoupling capacitors. Aperture Uncertainty (Jitter) The sample-to-sample variation in aperture delay. Signal-to-Noise Ratio (SNR) SNR is the ratio of the power of the fundamental (PS) to the noise floor power (PN), excluding the power at dc and in the first five harmonics. P SNR + 10log 10 S PN Clock Pulse Duration/Duty Cycle The duty cycle of a clock signal is the ratio of the time the clock signal remains at a logic high (clock pulse duration) to the period of the clock signal, expressed as a percentage. SNR is either given in units of dBc (dB to carrier) when the absolute power of the fundamental is used as the reference, or dBFS (dB to full-scale) when the power of the fundamental is extrapolated to the converter full-scale range. Differential Nonlinearity (DNL) An ideal ADC exhibits code transitions at analog input values spaced exactly 1 LSB apart. DNL is the deviation of any single step from this ideal value, measured in units of LSB. Signal-to-Noise and Distortion (SINAD) SINAD is the ratio of the power of the fundamental (PS) to the power of all the other spectral components including noise (PN) and distortion (PD), but excluding dc. PS SINAD + 10log 10 PN ) PD Aperture Delay The delay in time between the rising edge of the input sampling clock and the actual time at which the sampling occurs. Common-Mode Rejection Ratio (CMRR) CMRR measures the ability to reject signals that are presented to both analog inputs simultaneously. The injected common-mode frequency level is translated into dBFS, the spur in the output FFT is measured in dBFS, and the difference is the CMRR in dB. Effective Number of Bits (ENOB) ENOB is a measure in units of bits of converter performance as compared to the theoretical limit based on quantization noise: ENOB = (SINAD – 1.76)/6.02 Gain Error Gain error is the deviation of the ADC actual input full-scale range from its ideal value, given as a percentage of the ideal input full-scale range. Integral Nonlinearity (INL) INL is the deviation of the ADC transfer function from a best-fit line determined by a least-squares curve fit of that transfer function. The INL at each analog input value is the difference between the actual transfer function and this best-fit line, measured in units of LSB. Offset Error Offset error is the deviation of output code from mid-code when both inputs are tied to common-mode. Power-Supply Rejection Ratio (PSRR) PSRR is a measure of the ability to reject frequencies present on the power supply. (4) (5) SINAD is either given in units of dBc (dB to carrier) when the absolute power of the fundamental is used as the reference, or dBFS (dB to full-scale) when the power of the fundamental is extrapolated to the converter full-scale range. Temperature Drift Temperature drift (with respect to gain error and offset error) specifies the change from the value at the nominal temperature to the value at TMIN or TMAX. It is computed as the maximum variation the parameters over the whole temperature range divided by TMIN – TMAX. Total Harmonic Distortion (THD) THD is the ratio of the power of the fundamental (PS) to the power of the first five harmonics (PD). P THD + 10log 10 S PD (6) THD is typically given in units of dBc (dB to carrier). Two-Tone Intermodulation Distortion (IMD3) IMD3 is the ratio of the power of the fundamental (at frequencies f1, f2) to the power of the worst spectral component at either frequency 2f1 – f2 or 2f2 – f1). IMD3 is given in units of either dBc (dB to carrier) when the absolute power of the fundamental is used as the reference, or dBFS (dB to full-scale) when the power of the fundamental is extrapolated to the converter full-scale range. Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): ADS5481 ADS5482 ADS5483 Submit Documentation Feedback 37 PACKAGE OPTION ADDENDUM www.ti.com 15-Dec-2008 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Drawing Pins Package Eco Plan (2) Qty ADS5481IRGCR ACTIVE VQFN RGC 64 2000 TBD Call TI Call TI ADS5481IRGCT ACTIVE VQFN RGC 64 250 TBD Call TI Call TI ADS5482IRGCR ACTIVE VQFN RGC 64 2000 TBD Call TI Call TI ADS5482IRGCT ACTIVE VQFN RGC 64 250 TBD Call TI Call TI ADS5483IRGCR ACTIVE VQFN RGC 64 2000 TBD Call TI Call TI ADS5483IRGCRG4 ACTIVE VQFN RGC 64 2000 TBD Call TI Call TI ADS5483IRGCT ACTIVE VQFN RGC 64 250 TBD Call TI Call TI ADS5483IRGCTG4 ACTIVE VQFN RGC 64 250 TBD Call TI Call TI Lead/Ball Finish MSL Peak Temp (3) (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. TBD: The Pb-Free/Green conversion plan has not been defined. Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes. Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above. Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material) (3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. 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