REV. BInformation furnished by Analog Devices is believed to be accurate andreliable. However, no responsibility is assumed by Analog Devices for itsuse, nor for any infringements of patents or other rights of third partieswhich may result from its use. No license is granted by implication orotherwise under any patent or patent rights of Analog Devices.a10-Bit 20 MSPS 160 mWCMOS A/D ConverterAD876FEATURESCMOS 10-Bit 20 MSPS Sampling A/D ConverterPin-Compatible 8-Bit OptionPower Dissipation: 160 mW+5 V Single Supply OperationDifferential Nonlinearity: 0.5 LSBGuaranteed No Missing CodesPower Down (Standby) ModeThree-State OutputsDigital I/Os Compatible with +5 V or +3.3 V LogicAdjustable Reference InputSmall Size: 28-Lead SOIC, 28-Lead SSOP, or 48-LeadThin Quad Flatpack (TQFP)PRODUCT DESCRIPTIONThe AD876 is a CMOS, 160 mW, 10-bit, 20 MSPS analog-to-digital converter (ADC). The AD876 has an on-chip inputsample-and-hold amplifier. By implementing a multistage pipe-lined architecture with output error correction logic, the AD876offers accurate performance and guarantees no missing codesover the full operating temperature range. Force and sense con-nections to the reference inputs minimize external voltage drops.The AD876 can be placed into a standby mode of operationreducing the power below 50 mW. The AD876’s digital I/Ointerfaces to either +5 V or +3.3 V logic. Digital output pinscan be placed in a high impedance state; the format of the out-put is straight binary coding.The AD876’s speed, resolution and single-supply operationideally suit a variety of applications in video, multimedia, imag-ing, high speed data acquisition and communications. TheAD876’s low power and single-supply operation satisfy require-ments for high speed portable applications. Its speed and reso-lution ideally suit charge coupled device (CCD) input systemssuch as color scanners, digital copiers, electronic still camerasand camcorders.The AD876 comes in a space saving 28-lead SOIC and 48-leadthin quad flatpack (TQFP) and is specified over the commercial(0°C to +70°C) temperature range.PRODUCT HIGHLIGHTSLow PowerThe AD876 at 160 mW consumes a fraction of the power ofpresently available 8- or 10-bit, video speed converters. Power-down mode and single-supply operation further enhance itsdesirability in low power, battery operated applications suchas electronic still cameras, camcorders and communicationsystems.Very Small PackageThe AD876 comes in a 28-lead SOIC, 28-lead SSOP, and 48-lead surface mount, thin quad flat package. The TQFP packageis ideal for very tight, low headroom designs.Digital I/O FunctionalityThe AD876 offers three-state output control.Pin Compatible Upgrade PathThe AD876 offers the option of laying out designs for eightbits and migrating to 10-bit resolution if prototype resultswarrant.FUNCTIONAL BLOCK DIAGRAMA/DD/AA/DD/A A/D D/AA/DCORRECTION LOGICAINREFTFREFTSREFBSREFBFSTBYTHREE-STATE(MSB)D9D0(LSB)DRVDDDVDDAVDDCLKDRVSSDVSSAVSSCMLAD876SHA SHA SHAGAIN SHA GAINGAINOUTPUT BUFFERSOne Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.Tel: 781/329-4700 World Wide Web Site: http://www.analog.comFax: 781/326-8703 © Analog Devices, Inc., 1998AD876–SPECIFICATIONSREV. B–2–AD876JR-8 AD876Parameter Min Typ Max Min Typ Max UnitsRESOLUTION 8 10 BitsDC ACCURACYIntegral Nonlinearity (INL) ±0.3 ±1.0 ±1.0 LSBDifferential Nonlinearity (DNL) ±0.1 ±0.75 ±0.5 ±1 LSBNo Missing Codes GUARANTEED GUARANTEEDOffset Error 0.1 0.4 % FSRGain Error 0.1 0.2 % FSRANALOG INPUTInput Range 2 2 V p-pInput Capacitance 5.0 5.0 pFREFERENCE INPUTReference Top Voltage 3.5 4.0 4.5 3.5 4.0 4.5 VReference Bottom Voltage 1.6 2.0 2.5 1.6 2.0 2.5 VReference Input Resistance 250 250 ΩReference Input Current 8.0 8.0 mAReference Top Offset 35 35 mVReference Bottom Offset 35 35 mVDYNAMIC PERFORMANCEEffective Number of BitsfIN = 1 MHz 7.8 9.0 BitsfIN = 3.58 MHz 7.4 7.8 8.2 9.0 BitsfIN = 10 MHz 7.5 8.2 BitsSignal-to-Noise and Distortion (S/N+D) RatiofIN = 1 MHz 49 56 dBfIN = 3.58 MHz 46 49 51 56 dBfIN = 10 MHz 47 51 dBTotal Harmonic Distortion (THD)fIN =1 MHz –62 –62 dBfIN = 3.58 MHz –62 –56 –62 –56 dBfIN =10 MHz –60 –60 dBSpurious Free Dynamic Range2–65 –65 dBFull Power Bandwidth 150 150 MHzDifferential Phase 0.5 0.5 DegreeDifferential Gain 1 1 %POWER SUPPLIESOperating VoltageAVDD1+4.5 +5.25 +4.5 +5.25 VoltsDVDD1+4.5 +5.25 +4.5 +5.25 VoltsDRVDD+3.0 +5.25 +3.0 +5.25 VoltsOperating CurrentIAVDD20 25 20 25 mAIDVDD12 16 12 16 mAIDRVDD0.1 1 0.1 1 mAPOWER CONSUMPTION 160 190 160 190 mWTEMPERATURE RANGESpecified 0 +70 0 +70 °CNOTES1AVDD and DVDD must be within 0.5 V of each other to maintain specified performance levels.23.58 MHz Input Frequency.Specifications subject to change without notice. See Definition of Specifications for additional information.(TMIN to TMAX with AVDD = +5.0 V, DVDD = +5.0 V, DRVDD = +3.3 V, VREFB = +4.0 V, VREFB =+2.0 V, fCLOCK = 20 MSPS, unless otherwise noted)AD876REV. B–3–DIGITAL SPECIFICATIONS AD876Parameter Symbol DRVDDMin Typ Max UnitsLOGIC INPUTHigh Level Input Voltage VIH3.0 2.4 V5.0 4.0 V5.25 4.2 VLow Level Input Voltage VIL3.0 0.6 V5.0 1.0 V5.25 1.05 VHigh Level Input Current IIH5.0 –10 +10 µALow Level Input Current IIL5.0 –50 +50 µALow Level Input Current (CLK Only) IIL5.0 –10 +10 µAInput Capacitance CIN5pFLOGIC OUTPUTSHigh Level Output Voltage VOH(IOH = 50 µA) 3.0 2.4 V5.0 3.8 V(IOH = 0.5 mA) 5.0 2.4 VLow Level Output Voltage VOL(IOL = 50 µA) 3.6 0.7 V5.25 1.05 V(IOL = 0.6 mA) 5.25 0.4 VOutput Capacitance COUT5pFOutput Leakage Current IOZ–10 10 µASpecifications subject to change without notice.TIMING SPECIFICATIONSSymbol Min Typ Max UnitsMaximum Conversion Rate120 MHzClock Period tC50 nsClock High tCH23 25 nsClock Low tCL23 25 nsOutput Delay tOD10 20 nsPipeline Delay (Latency) 3.5 Clock CyclesAperture Delay Time 4 nsAperture Jitter 22 psNOTE1Conversion rate is operational down to 10 kHz without degradation in specified performance.OUT DATA N-4 DATA N-3 DATA N-2 DATA N-1 DATA NSAMPLE N SAMPLE N+1 SAMPLE N+2AINCLK tCL tCH tC tODFigure 1. Timing Diagram(TMIN to TMAX with AVDD = +5.0 V, DVDD = +5.0 V, DRVDD = +3.3 V, VREFT = +4.0 V, VREFB = +2.0 V,fCLOCK = 20 MSPS, CL = 20 pF unless otherwise noted)REV. B–4–AD876SOIC TQFPSymbol Pin No. Pin No. Type Name and FunctionD0 (LSB) 3 1 DO Least Significant Bit.D1–D4 4–7 2–5 DO Data Bits 1 through 4.D5–D8 8–11 8–11 Data Bits 5 through 8.D9 (MSB) 12 12 DO Most