ESIGNS R NE W D NT O F D E E ND COMME PL A CEM r a t N OT R E DED RE N te E n e M C M rt O NO REC al Suppo il.com/tsc ic n h c e T s r te t our ontacSheet r www.in cData July 2004 ERSIL o T N -I 8 8 1-8 HI5746 FN4129.5 10-Bit, 40MSPS A/D Converter Features The HI5746 is a monolithic, 10-bit, analog-to-digital converter fabricated in a CMOS process. It is designed for high speed applications where wide bandwidth and low power consumption are essential. Its 40MSPS speed is made possible by a fully differential pipelined architecture with an internal sample and hold. • Sampling Rate . . . . . . . . . . . . . . . . . . . . . . . . . . 40MSPS The HI5746 has excellent dynamic performance while consuming only 225mW power at 40MSPS. Data output latches are provided which present valid data to the output bus with a latency of 7 clock cycles. It is pin-for-pin functionally compatible with the HI5702 and the HI5703. For internal voltage reference, please refer to the HI5767 data sheet. TEMP. RANGE (°C) • Low Power at 40MSPS . . . . . . . . . . . . . . . . . . . . 225mW • Wide Full Power Input Bandwidth . . . . . . . . . . . . 250MHz • On-Chip Sample and Hold • Fully Differential or Single-Ended Analog Input • Single Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . +5V • TTL/CMOS Compatible Digital Inputs • CMOS Compatible Digital Outputs. . . . . . . . . . . . 3.0/5.0V • Offset Binary or Two’s Complement Output Format • Pb-free Available Ordering Information PART NUMBER • 8.8 Bits at fIN = 10MHz PACKAGE PKG. DWG. # Applications • Professional Video Digitizing HI5746KCB 0 to 70 28 Ld SOIC (W) M28.3 • Medical Imaging HI5746KCBZ (Note) 0 to 70 28 Ld SOIC (W) (Pb-free) M28.3 • Digital Communication Systems 28 Ld SOIC (W) Tape and Reel (Pb-free) M28.3 HI5746KCBZ-T (Note) • High Speed Data Acquisition HI5746KCA 0 to 70 28 Ld SSOP M28.15 HI5746KCAZ (Note) 0 to 70 28 Ld SSOP (Pb-free) M28.15 HI5746EVAL1 25 Evaluation Board NOTE: Intersil Pb-free products employ special Pb-free material sets; molding compounds/die attach materials and 100% matte tin plate termination finish, which is compatible with both SnPb and Pb-free soldering operations. Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J Std-020B. Pinout HI5746 (SOIC, SSOP) TOP VIEW DVCC1 1 28 D0 DGND1 2 27 D1 DVCC1 3 26 D2 DGND1 4 25 D3 AVCC 5 24 D4 AGND 6 VREF + 7 23 DVCC2 22 CLK VREF - 8 21 DGND2 VIN+ 9 20 D5 VIN- 10 19 D6 VDC 11 18 D7 AGND 12 17 D8 AVCC 13 16 D9 OE 14 1 15 DFS CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 321-724-7143 | Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 1999, 2004. All Rights Reserved All other trademarks mentioned are the property of their respective owners. HI5746 Functional Block Diagram VDC CLOCK BIAS CLK VINVIN+ S/H STAGE 1 DFS 2-BIT FLASH 2-BIT DAC OE + DVCC2 X2 D9 (MSB) D8 D7 D6 DIGITAL DELAY AND DIGITAL ERROR CORRECTION STAGE 8 D5 D4 D3 2-BIT FLASH 2-BIT DAC D2 D1 + D0 (LSB) - X2 DGND2 STAGE 9 2-BIT FLASH AVCC 2 AGND DVCC1 DGND1 VREF + VREF - (OPTIONAL) HI5746 Typical Application Schematic HI5746 2.5V 2.0V (OPTIONAL) VREF+ (7) VREF - (8) (LSB) (28) D0 D0 (27) D1 D1 (26) D2 D2 (25) D3 D3 (24) D4 D4 DGND1 (2) (20) D5 D5 DGND1 (4) (19) D6 D6 DGND2 (21) (18) D7 D7 (17) D8 D8 (MSB) (16) D9 D9 AGND (12) AGND (6) VIN + CLOCK VDC (11) (3) DVCC1 VIN - (10) (23) DVCC2 CLK (22) (13) AVCC DFS (15) (5) AVCC AGND BNC 10F AND 0.1F CAPS ARE PLACED AS CLOSE TO PART AS POSSIBLE (1) DVCC1 VIN + (9) VIN - DGND OE (14) 0.1F + 10F 0.1F + 10F +5V +5V Pin Descriptions PIN NO. NAME Digital Supply (+5.0V). 16 D9 Data Bit 9 Output (MSB). DGND1 Digital Ground. 17 D8 Data Bit 8 Output. 3 DVCC1 Digital Supply (+5.0V). 18 D7 Data Bit 7 Output. 4 DGND1 Digital Ground. 19 D6 Data Bit 6 Output. 5 AVCC Analog Supply (+5.0V). 20 D5 Data Bit 5 Output. 6 AGND Analog Ground. 21 DGND2 7 VREF+ +2.5V Positive Reference Voltage Input. 22 CLK Sample Clock Input. 23 8 VREF - +2.0V Negative Reference Voltage Input (Optional). DVCC2 Digital Output Supply (+3.0V or +5.0V). 24 D4 Data Bit 4 Output. 9 VIN+ Positive Analog Input. 25 D3 Data Bit 3 Output. 10 VIN- Negative Analog Input. 26 D2 Data Bit 2 Output. 11 VDC DC Bias Voltage Output. 27 D1 Data Bit 1 Output. 12 AGND Analog Ground. 28 D0 Data Bit 0 Output (LSB). 13 AVCC Analog Supply (+5.0V). 14 OE Digital Output Enable Control Input. 15 DFS Data Format Select Input. PIN NO. NAME 1 DVCC1 2 DESCRIPTION 3 DESCRIPTION Digital Ground. HI5746 Absolute Maximum Ratings TA = 25oC Thermal Information Supply Voltage, AVCC or DVCC to AGND or DGND . . . . . . . . . . .6V DGND to AGND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.3V Digital I/O Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DGND to DVCC Analog I/O Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . AGND to AVCC Thermal Resistance (Typical, Note 1) JA (oC/W) SOIC Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 SSOP Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 Maximum Junction Temperature . . . . . . . . . . . . . . . . . . . . . . .150oC Maximum Storage Temperature Range . . . . . . . . . . -65oC to 150oC Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . .300oC (SOIC, SSOP - Lead Tips Only) Operating Conditions Temperature Range HI5746KCB (Typ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0oC to 70oC CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. NOTE: 1. JA is measured with the component mounted on an evaluation PC board in free air. Electrical Specifications AVCC = DVCC1 = 5.0V; DVCC2 = 3.0V, VREF+ = 2.5V; VREF - = 2.0V; fS = 40 MSPS at 50% Duty Cycle; CL = 10pF; TA = 25oC; Differential Analog Input; Typical Values are Test Results at 25oC, Unless Otherwise Specified PARAMETER TEST CONDITIONS MIN TYP MAX UNITS 10 - - Bits ACCURACY Resolution Integral Linearity Error, INL fIN = DC - 1.0 2.0 LSB Differential Linearity Error, DNL (Guaranteed No Missing Codes) fIN = DC - 0.5 1.0 LSB Offset Error, VOS fIN = DC -40 12 40 LSB Full Scale Error, FSE fIN = DC - 4 - LSB Minimum Conversion Rate No Missing Codes - 0.5 1 MSPS Maximum Conversion Rate No Missing Codes 40 - - MSPS Effective Number of Bits, ENOB fIN = 10MHz 8.55 8.8 - Bits Signal to Noise and Distortion Ratio, SINAD RMS Signal = -------------------------------------------------------------RMS Noise + Distortion fIN = 10MHz 53.2 54.9 - dB Signal to Noise Ratio, SNR RMS Signal = ------------------------------RMS Noise fIN = 10MHz 53.2 55.4 - dB Total Harmonic Distortion, THD fIN = 10MHz - -64.6 - dBc 2nd Harmonic Distortion fIN = 10MHz - -67.8 - dBc 3rd Harmonic Distortion fIN = 10MHz - -68.3 - dBc Spurious Free Dynamic Range, SFDR fIN = 10MHz - 67.8 - dBc Intermodulation Distortion, IMD f1 = 1MHz, f2 = 1.02MHz - 64 - dBc Differential Gain Error fS = 17.72 MSPS, 6 Step, Mod Ramp - 0.8 - % Differential Phase Error fS = 17.72 MSPS, 6 Step, Mod Ramp - 0.1 - Degree Transient Response (Note 2) - 1 - Cycle Over-Voltage Recovery 0.2V Overdrive (Note 2) - 1 - Cycle DYNAMIC CHARACTERISTICS 4 HI5746 Electrical Specifications AVCC = DVCC1 = 5.0V; DVCC2 = 3.0V, VREF+ = 2.5V; VREF - = 2.0V; fS = 40 MSPS at 50% Duty Cycle; CL = 10pF; TA = 25oC; Differential Analog Input; Typical Values are Test Results at 25oC, Unless Otherwise Specified (Continued) PARAMETER TEST CONDITIONS MIN TYP MAX UNITS Maximum Peak-to-Peak Differential Analog Input Range (VIN+ - VIN-) - 0.5 - V Maximum Peak-to-Peak Single-Ended Analog Input Range - 1.0 - V - 1 - M - 10 - pF ANALOG INPUT (Note 3) Analog Input Resistance, RIN Analog Input Capacitance, CIN Analog Input Bias Current, IB+ or IB- (Note 3) -10 - +10 A Differential Analog Input Bias Current IBDIFF = (IB+ - IB-) (Note 3) - 0.5 - A - 250 - MHz 0.25 - 4.75 V - 2.5K - Positive Reference Current, IREF + - 1.07 - mA Negative Reference Current, IREF - - 21 - A Full Power Input Bandwidth, FPBW Analog Input Common Mode Voltage Range (VIN+ + VIN-)/2 Differential Mode (Note 2) REFERENCE INPUT VREF + to AGND Total Reference Resistance, RL Positive Reference Voltage Input, VREF+ (Note 2) - 2.5 - V Negative Reference Voltage Input, VREF - (Note 2) - 2.0 - V Reference Common Mode Voltage (VREF+ + VREF -)/2 (Note 2) - 2.25 - V DC Bias Voltage Output, VDC - 3.2 - V Maximum Output Current - - 0.4 mA DC BIAS VOLTAGE DIGITAL INPUTS Input Logic High Voltage, VIH CLK, DFS, OE 2.0 - - V Input Logic Low Voltage, VIL CLK, DFS, OE - - 0.8 V Input Logic High Current, IIH CLK, DFS, OE, VIH = 5V -10.0 - +10.0 A Input Logic Low Current, IIL CLK, DFS, OE, VIL = 0V -10.0 - +10.0 A - 7 - pF Input Capacitance, CIN DIGITAL OUTPUTS Output Logic High Voltage, VOH IOH = 100A; DVCC2 = 5V 4.0 - - V Output Logic Low Voltage, VOL IOL = 100A; DVCC2 = 5V - - 0.5 V Output Three-State Leakage Current, IOZ VO = 0/5V; DVCC2 = 5V - 1 10 A Output Logic High Voltage, VOH IOH = 100A; DVCC2 = 3V 2.4 - - V Output Logic Low Voltage, VOL IOL = 100A; DVCC2 = 3V - - 0.5 V 5 HI5746 Electrical Specifications AVCC = DVCC1 = 5.0V; DVCC2 = 3.0V, VREF+ = 2.5V; VREF - = 2.0V; fS = 40 MSPS at 50% Duty Cycle; CL = 10pF; TA = 25oC; Differential Analog Input; Typical Values are Test Results at 25oC, Unless Otherwise Specified (Continued) PARAMETER MIN TYP MAX UNITS - 1 10 A - 10 - pF Aperture Delay, tAP - 5 - ns Aperture Jitter, tAJ - 5 - psRMS Data Output Hold, tH - 7 - ns Data Output Delay, tOD - 8 - ns Data Output Enable Time, tEN - 5 - ns Data Output Enable Time tDIS - 5 - ns Output Three-State Leakage Current, IOZ TEST CONDITIONS VO = 0/5V; DVCC2 = 3V Output Capacitance, COUT TIMING CHARACTERISTICS Data Latency, tLAT For a Valid Sample (Note 2) - - 7 Cycles Power-Up Initialization Data Invalid Time (Note 2) - - 20 Cycles Analog Supply Voltage, AVCC 4.75 5.0 5.25 V Digital Supply Voltage DVCC1 4.75 5.0 5.25 V At 3.0V 2.7 3.0 3.3 V At 5.0V 4.75 5.0 5.25 V POWER SUPPLY CHARACTERISTICS Digital Output Supply Voltage, DVCC2 Total Supply Current, ICC fIN = 10MHz and DFS = “0” - 46 - mA Analog Supply Current, AICC fIN = 10MHz and DFS = “0” - 30 - mA Digital Supply Current, DICC1 fIN = 10MHz and DFS = “0” - 13 - mA Output Supply Current, DICC2 fIN = 10MHz and DFS = “0” - 3 - mA Power Dissipation fIN = 10MHz and DFS = “0” - 225 275 mW Offset Error SensitivityVOS AVCC or DVCC = 5V 5% - 0.4 - LSB Gain Error SensitivityFSE AVCC or DVCC = 5V 5% - 0.8 - LSB NOTES: 2. Parameter guaranteed by design or characterization and not production tested. 3. With the clock low and DC input. All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9001 quality systems. Intersil Corporation’s quality certifications can be viewed at www.intersil.com/design/quality Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries. For information regarding Intersil Corporation and its products, see www.intersil.com 6 HI5746 Timing Waveforms ANALOG INPUT CLOCK INPUT SN - 1 HN - 1 SN HN S N + 1 HN + 1 SN + 2 S N + 5 HN + 5 SN + 6 HN + 6 SN + 7 HN + 7 S N + 8 HN + 8 INPUT S/H 1ST STAGE 2ND STAGE B1, N - 1 B2, N - 2 9TH STAGE DATA OUTPUT B1, N B1, N + 1 B1, N + 4 B1, N + 5 B2, N - 1 B2, N B2, N + 4 B2, N + 5 B2, N + 6 B9, N - 5 B9, N - 4 B9, N B9, N + 1 B9, N + 2 DN - 7 DN - 6 DN - 2 DN - 1 tLAT NOTES: 4. SN : N-th sampling period. 5. HN : N-th holding period. 6. BM, N : M-th stage digital output corresponding to N-th sampled input. 7. DN : Final data output corresponding to N-th sampled input. FIGURE 1. HI5746 INTERNAL CIRCUIT TIMING ANALOG INPUT tAP tAJ CLOCK INPUT 1.5V 1.5V tOD tH DATA OUTPUT 2.4V DATA N - 1 0.5V FIGURE 2. INPUT-TO OUTPUT TIMING 7 B1, N + 6 DATA N DN B1, N + 7 B9, N + 3 DN + 1 HI5746 Typical Performance Curves 9 57 SNR dB ENOB (BITS) 52 SINAD 8 47 7 42 fS = 40 MSPS, TA = 25oC fS = 40 MSPS, TA = 25oC 6 1 10 37 100 1 10 FIGURE 3. EFFECTIVE NUMBER OF BITS (ENOB) vs INPUT FREQUENCY 85 FIGURE 4. SINAD AND SNR vs INPUT FREQUENCY fS = 40 MSPS, TA = 25oC 9 80 8 dBc ENOB (BITS) SFDR 70 -3HD 65 60 -THD 55 50 45 fS = 40 MSPS, fIN = 10MHz, TA = 25oC -2HD 75 7 6 5 1 10 100 4 INPUT FREQUENCY (MHz) 0 -5 -10 FIGURE 5. -2HD, -3HD, -THD AND SFDR vs INPUT FREQUENCY 10 -15 -20 -25 -30 -35 INPUT LEVEL (dBFS) NOTE: SFDR depicted here does not include any harmonic distortion. FIGURE 6. EFFECTIVE NUMBER OF BITS (ENOB) vs ANALOG INPUT LEVEL 9 fS = 40 MSPS, fIN = 10MHz, TA = 25oC fS = 40 MSPS, fIN = 10MHz, TA = 25oC VREF + - VREF - = 0.5V 9.5 8.8 ENOB (BITS) 9 ENOB (BITS) 100 INPUT FREQUENCY (MHz) INPUT FREQUENCY (MHz) 8.5 8 7.5 8.6 8.4 7 6.5 6 30 35 40 45 50 55 60 65 DUTY CYCLE (%, TH /TCLK) FIGURE 7. EFFECTIVE NUMBER OF BITS (ENOB) vs SAMPLE CLOCK DUTY CYCLE 8 70 8.2 2.25 2.3 2.35 2.4 2.45 2.5 2.55 VREF + (V) 2.6 2.65 2.7 2.75 FIGURE 8. EFFECTIVE NUMBER OF BITS (ENOB) vs VREF + HI5746 Typical Performance Curves (Continued) 55 80 SNR -2HD 75 54 SFDR 70 dBc dB SINAD 53 -3HD 65 -THD 52 60 fS = 40 MSPS, fIN = 10MHz fS = 40 MSPS, fIN = 10MHz VREF + - VREF - = 0.5V, TA = 25oC 51 2.25 2.3 2.35 2.4 2.45 2.5 2.55 VREF + (V) 2.6 2.65 2.7 55 2.25 2.75 2.3 2.35 2.4 2.45 2.5 2.55 VREF + (V) 2.6 2.65 2.7 2.75 NOTE: SFDR depicted here does not include any harmonic distortion. FIGURE 9. SINAD AND SNR vs VREF + FIGURE 10. -2HD, -3HD, -THD AND SFDR vs VREF + 8.8 53 fS = 40 MSPS, fIN = 10MHz TA = 25oC fS = 40 MSPS, fIN = 10MHz TA = 25oC 8.6 SNR 52 SINAD dB ENOB (BITS) VREF + - VREF - = 0.5V, TA = 25oC 8.4 8.2 8 2.25 51 50 2.3 2.35 2.4 2.45 2.5 2.55 VREF + (V) 2.6 2.65 2.7 49 2.25 2.75 FIGURE 11. EFFECTIVE NUMBER OF BITS (ENOB) vs VREF + (VREF - NOT DRIVEN) 2.3 2.35 2.4 2.45 2.5 2.55 VREF + (V) 2.6 2.65 2.7 2.75 FIGURE 12. SINAD AND SNR vs VREF + (VREF - NOT DRIVEN) 9.0 80 fIN = 1MHz fS = 40 MSPS, fIN = 10MHz TA = 25oC -2HD 8.8 ENOB (BITS) 75 70 dBc -3HD 65 fIN = 10MHz 8.6 8.4 -THD 60 55 2.25 8.2 SFDR 2.3 2.35 2.4 2.45 2.5 2.55 VREF + (V) fS = 40 MSPS, TA = 25oC DIFFERENTIAL ANALOG INPUT 2.6 2.65 FIGURE 13. -2HD, -3HD, -THD AND SFDR vs VREF + (VREF - NOT DRIVEN) 9 2.7 2.75 8.0 0.25 0.75 1.25 1.75 2.25 2.75 VCM (V) 3.25 3.75 4.25 FIGURE 14. EFFECTIVE NUMBER OF BITS (ENOB) vs ANALOG INPUT COMMON MODE VOLTAGE 4.75 HI5746 Typical Performance Curves (Continued) 50 45.0 44.5 SUPPLY CURRENT (mA) 44.0 43.5 ICC (mA) 1MHz fIN 15MHz, TA = 25oC fS = 40 MSPS, VIN + = VIN - 43.0 42.5 42.0 41.5 ICC (TOTAL) 40 AICC 30 20 DICC1 10 41.0 DICC2 40.5 -40 0 -20 0 20 40 TEMPERATURE (oC) 60 10 80 30 40 fS (MSPS) FIGURE 15. TOTAL SUPPLY CURRENT vs TEMPERATURE FIGURE 16. SUPPLY CURRENT vs SAMPLE CLOCK FREQUENCY 1200 9.5 1000 9.0 IREF + 8.5 800 tOD tOD (ns) IREF (A) 20 600 400 8.0 7.5 7.0 200 6.5 IREF -20 0 20 40 TEMPERATURE (oC) 60 6.0 -40 80 FIGURE 17. REFERENCE CURRENT vs TEMPERATURE DG DG (%) 0.75 0.15 0.70 DP 0.65 0.65 0.2 0.1 0.60 0.55 0.05 0.50 0.45 0.40 -40 -20 0 20 40 TEMPERATURE (oC) 60 80 0 FIGURE 19. DIFFERENTIAL GAIN/PHASE vs TEMPERATURE 10 0.60 DG (%) 0.80 20 40 TEMPERATURE (oC) 60 80 0.3 0.70 fS = 17.72 MSPS DP (DEGREES) 0.85 0 FIGURE 18. DATA OUTPUT DELAY vs TEMPERATURE 0.25 0.90 -20 DP 0.25 DG 0.2 DP 0.15 0.55 DG 0.50 0.45 fS = 17.72 MSPS AVCC/DVCC1 = 5V 5%, TA = 25oC 0.1 0.05 0 0.40 2.75 3.00 3.25 3.50 3.75 4.00 4.25 4.50 4.75 5.00 5.25 DVCC2 (V) FIGURE 20. DIFFERENTIAL GAIN/PHASE vs SUPPLY VOLTAGE DP (DEGREES) 0 -40 HI5746 Typical Performance Curves (Continued) 3.30 9.0 8.8 ENOB (BITS) VDC (V) 3.20 3.10 8.6 8.4 3.00 -40 -20 0 20 40 TEMPERATURE (oC) 60 80 8.2 -40 -20 0 20 40 60 80 TEMPERATURE (oC) FIGURE 21. DC BIAS VOLTAGE (VDC) vs TEMPERATURE FIGURE 22. EFFECTIVE NUMBER OF BITS F(ENOB) vs TEMPERATURE OUTPUT LEVEL (dB) 0 -10 fIN = 10MHz fS = 40 MSPS -20 -30 -40 -50 -60 -70 -80 -90 -100 0 FIGURE 23. 2048 POINT FFT PLOT 512 FREQUENCY BIN 1023 FIGURE 24. 2048 POINT FFT SPECTRAL PLOT Detailed Description Theory of Operation The HI5746 is a 10-bit fully differential sampling pipeline A/D converter with digital error correction logic. Figure 25 depicts the circuit for the front end differential-in-differential-out sampleand-hold (S/H). The switches are controlled by an internal sampling clock which is a non-overlapping two phase signal1 and 2 , derived from the master sampling clock. During the sampling phase, 1 , the input signal is applied to the sampling capacitors, CS . At the same time the holding capacitors, CH , are discharged to analog ground. At the falling edge of 1 the input signal is sampled on the bottom plates of the sampling capacitors. In the next clock phase,2 , the two bottom plates of the sampling capacitors are connected together and the holding capacitors are switched to the op amp output nodes. The charge then redistributes between CS and CH completing one sample-and-hold cycle. The front end sample-and-hold 11 output is a fully-differential, sampled-data representation of the analog input. The circuit not only performs the sample-and-hold function but will also convert a single-ended input to a fullydifferential output for the converter core. During the sampling phase, the VIN pins see only the on-resistance of a switch and CS . The relatively small values of these components result in a typical full power input bandwidth of 250MHz for the converter. HI5746 -+ VOUT+ +- VOUT- structure of the VREF+ and VREF - input pins consists of a resistive voltage divider with one resistor of the divider (nominally 500) connected between VREF+ and VREF - and the other resistor of the divider (nominally 2000) connected between VREF - and analog ground. This allows the user the option of supplying only the +2.5V VREF+ voltage reference with the +2.0V VREF - being generated internally by the voltage division action of the input structure. FIGURE 25. ANALOG INPUT SAMPLE-AND-HOLD The HI5746 is tested with VREF - equal to +2.0V and VREF+ equal to +2.5V yielding a fully differential analog input voltage range of 0.5V. VREF+ and VREF - can differ from the above voltages (see the Typical Performance Curves, Figure 8 through Figure 13). 1 VIN+ 1 1 1 CS 2 VIN- CH CS 1 CH 1 As illustrated in the functional block diagram and the timing diagram in Figure 1, eight identical pipeline subconverter stages, each containing a two-bit flash converter and a two-bit multiplying digital-to-analog converter, follow the S/H circuit with the ninth stage being a two bit flash converter. Each converter stage in the pipeline will be sampling in one phase and amplifying in the other clock phase. Each individual subconverter clock signal is offset by 180 degrees from the previous stage clock signal resulting in alternate stages in the pipeline performing the same operation. The output of each of the eight identical two-bit subconverter stages is a two-bit digital word containing a supplementary bit to be used by the digital error correction logic. The output of each subconverter stage is input to a digital delay line which is controlled by the internal sampling clock. The function of the digital delay line is to time align the digital outputs of the eight identical two-bit subconverter stages with the corresponding output of the ninth stage flash converter before applying the eighteen bit result to the digital error correction logic. The digital error correction logic uses the supplementary bits to correct any error that may exist before generating the final ten bit digital data output of the converter. Because of the pipeline nature of this converter, the digital data representing an analog input sample is output to the digital data bus on the 7th cycle of the clock after the analog sample is taken. This time delay is specified as the data latency. After the data latency time, the digital data representing each succeeding analog sample is output during the following clock cycle. The digital output data is synchronized to the external sampling clock by a double buffered latching technique. The output of the digital error correction circuit is available in two’s complement or offset binary format depending on the state of the Data Format Select (DFS) control input (see Table 1, A/D Code Table). Reference Voltage Inputs, VREF - and VREF+ The HI5746 is designed to accept two external reference voltage sources at the VREF input pins. Typical operation of the converter requires VREF+ to be set at +2.5V and VREF - to be set at 2.0V. However, it should be noted that the input 12 In order to minimize overall converter noise it is recommended that adequate high frequency decoupling be provided at both of the reference voltage input pins, VREF+ and VREF -. Analog Input, Differential Connection The analog input to the HI5746 is a differential input that can be configured in various ways depending on the signal source and the required level of performance. A fully differential connection (Figure 26 and Figure 27) will give the best performance for the converter. VIN+ VIN R HI5746 VDC R -VIN VIN- FIGURE 26. AC COUPLED DIFFERENTIAL INPUT Since the HI5746 is powered by a single +5V analog supply, the analog input is limited to be between ground and +5V. For the differential input connection this implies the analog input common mode voltage can range from 0.25V to 4.75V. The performance of the ADC does not change significantly with the value of the analog input common mode voltage. A DC voltage source, VDC , equal to 3.2V (typical), is made available to the user to help simplify circuit design when using an AC coupled differential input. This low output impedance voltage source is not designed to be a reference but makes an excellent DC bias source and stays well within the analog input common mode voltage range over temperature (see the Typical Performance Curves, Figure 21). For the AC coupled differential input (Figure 26) assume the difference between VREF+, typically 2.5V, and VREF-, typically 2.0V, is 0.5V. Full scale is achieved when the VIN and -VIN input signals are 0.5VP-P, with -VIN being 180 degrees out of phase with VIN . The converter will be HI5746 at positive full scale when the VIN+ input is at VDC + 0.25V and the VIN- input is at VDC - 0.25V (VIN+ VIN- = +0.5V). Conversely, the converter will be at negative fullscale when the VIN+ input is equal to VDC 0.25V and VIN- is at VDC + 0.25V (VIN+ - VIN- = -0.5V). The analog input can be DC coupled (Figure 27) as long as the inputs are within the analog input common mode voltage range (0.25V VDC 4.75V). The single ended analog input can be DC coupled (Figure 27) as long as the input is within the analog input common mode voltage range. VIN VIN+ VDC R C HI5746 VIN VIN+ VDC R C R VDC VIN- FIGURE 27. DC COUPLED DIFFERENTIAL INPUT The resistors, R, in Figure 27 are not absolutely necessary but may be used as load setting resistors. A capacitor, C, connected from VIN+ to VIN- will help filter any high frequency noise on the inputs, also improving performance. Values around 20pF are sufficient and can be used on AC coupled inputs as well. Note, however, that the value of capacitor C chosen must take into account the highest frequency component of the analog input signal. Analog Input, Single-Ended Connection The configuration shown in Figure 28 may be used with a single ended AC coupled input. VIN+ VIN R HI5746 VDC VIN- FIGURE 28. AC COUPLED SINGLE ENDED INPUT Again, assume the difference between VREF+, typically 2.5V, and VREF-, typically 2V, is 0.5V. If VIN is a 1VP-P sinewave, then VIN+ is a 1VP-P sinewave riding on a positive voltage equal to VDC. The converter will be at positive full scale when VIN+ is at VDC + 0.5V (VIN+ - VIN= +0.5V) and will be at negative full scale when VIN+ is equal to VDC - 0.5V (VIN+ - VIN- = -0.5V). Sufficient headroom must be provided such that the input voltage never goes above +5V or below AGND. In this case, VDC could range between 0.5V and 4.5V without a significant change in ADC performance. The simplest way to produce VDC is to use the DC bias source, VDC , output of the HI5746. 13 VIN- HI5746 VDC -VIN VDC FIGURE 29. DC COUPLED SINGLE ENDED INPUT The resistor, R, in Figure 29 is not absolutely necessary but may be used as a load setting resistor. A capacitor, C, connected from VIN+ to VIN- will help filter any high frequency noise on the inputs, also improving performance. Values around 20pF are sufficient and can be used on AC coupled inputs as well. Note, however, that the value of capacitor C chosen must take into account the highest frequency component of the analog input signal. A single ended source may give better overall system performance if it is first converted to differential before driving the HI5746. Digital Output Control and Clock Requirements The HI5746 provides a standard high-speed interface to external TTL logic families. In order to ensure rated performance of the HI5746, the duty cycle of the clock should be held at 50% 5%. It must also have low jitter and operate at standard TTL levels. Performance of the HI5746 will only be guaranteed at conversion rates above 1 MSPS. This ensures proper performance of the internal dynamic circuits. Similarly, when power is first applied to the converter, a maximum of 20 cycles at a sample rate above 1 MSPS will have to be performed before valid data is available. A Data Format Select (DFS) pin is provided which will determine the format of the digital data outputs. When at logic low, the data will be output in offset binary format. When at logic high, the data will be output in two’s complement format. Refer to Table 1 for further information. HI5746 TABLE 1. A/D CODE TABLE OFFSET BINARY OUTPUT CODE (DFS LOW) M S B TWO’S COMPLEMENT OUTPUT CODE (DFS HIGH) L S B M S B L S B DIFFERENTIAL INPUT VOLTAGE (VIN+ - VIN-) D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 +Full Scale (+FS) 1/ LSB 4 0.499756V 1 1 1 1 1 1 1 1 1 1 0 1 1 1 1 1 1 1 1 1 +FS - 11/4 LSB 0.498779V 1 1 1 1 1 1 1 1 1 0 0 1 1 1 1 1 1 1 1 0 +3/4 LSB 732.422V 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -1/4 LSB -244.141V 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 -FS + 13/4 LSB -0.498291V 0 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 1 -Full Scale (-FS) + 3/ LSB 4 -0.499268V 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 CODE CENTER DESCRIPTION NOTES: 8. The voltages listed above represent the ideal center of each output code shown as a function of the reference differential voltage, (VREF + - VREF -) = 0.5V. 9. VREF+ = 2.5V and VREF - = 2V. The output enable pin, OE, when pulled high will three-state the digital outputs to a high impedance state. Set the OE input to logic low for normal operation. OE INPUT DIGITAL DATA OUTPUTS 0 Active 1 High Impedance Supply and Ground Considerations The HI5746 has separate analog and digital supply and ground pins to keep digital noise out of the analog signal path. The digital data outputs also have a separate supply pin, DVCC2 , which can be powered from a 3V or 5V supply. This allows the outputs to interface with 3V logic if so desired. The part should be mounted on a board that provides separate low impedance connections for the analog and digital supplies and grounds. For best performance, the supplies to the HI5746 should be driven by clean, linear regulated supplies. The board should also have good high frequency decoupling capacitors mounted as close as possible to the converter. If the part is powered off a single supply then the analog supply should be isolated with a ferrite bead from the digital supply. Refer to the application note “Using Intersil High Speed A/D Converters” (AN9214) for additional considerations when using high speed converters. 14 Static Performance Definitions Offset Error (VOS) The midscale code transition should occur at a level 1/4 LSB above half-scale. Offset is defined as the deviation of the actual code transition from this point. Full-Scale Error (FSE) The last code transition should occur for an analog input that is 3/4 LSB below positive Full scale (+FS) with the offset error removed. Fullscale error is defined as the deviation of the actual code transition from this point. Differential Linearity Error (DNL) DNL is the worst case deviation of a code width from the ideal value of 1 LSB. Integral Linearity Error (INL) INL is the worst case deviation of a code center from a best fit straight line calculated from the measured data. Power Supply Sensitivity Each of the power supplies are moved plus and minus 5% and the shift in the offset and full scale error (in LSBs) is noted. Dynamic Performance Definitions Fast Fourier Transform (FFT) techniques are used to evaluate the dynamic performance of the HI5746. A low distortion sine wave is applied to the input, it is coherently sampled, and the output is stored in RAM. The data is then transformed into the frequency domain with an FFT and analyzed to evaluate the dynamic performance of the A/D. The sine wave input to the part is -0.5dB down from Fullscale for all these tests. HI5746 SNR and SINAD are quoted in dB. The distortion numbers are quoted in dBc (decibels with respect to carrier) and DO NOT include any correction factors for normalizing to full scale. Full Power Input Bandwidth (FPBW) The effective number of bits (ENOB) is calculated from the SINAD data by: Full power input bandwidth is the analog input frequency at which the amplitude of the digitally reconstructed output has decreased 3dB below the amplitude of the input sine wave. The input sine wave has an amplitude which swings from -FS to +FS. The bandwidth given is measured at the specified sampling frequency. ENOB = (SINAD - 1.76 + VCORR) / 6.02, Video Definitions Effective Number Of Bits (ENOB) where: VCORR = 0.5 dB. VCORR adjusts the SINAD, and hence the ENOB, for the amount the analog input signal is below fullscale. Signal To Noise and Distortion Ratio (SINAD) SINAD is the ratio of the measured RMS signal to RMS sum of all the other spectral components below the Nyquist frequency, fS/2, excluding DC. Signal To Noise Ratio (SNR) SNR is the ratio of the measured RMS signal to RMS noise at a specified input and sampling frequency. The noise is the RMS sum of all of the spectral components below fS/2 excluding the fundamental, the first five harmonics and DC. Differential Gain and Differential Phase are two commonly found video specifications for characterizing the distortion of a chrominance signal as it is offset through the input voltage range of an ADC. Differential Gain (DG) Differential Gain is the peak difference in chrominance amplitude (in percent) relative to the reference burst. Differential Phase (DP) Differential Phase is the peak difference in chrominance phase (in degrees) relative to the reference burst. Timing Definitions Refer to Figure 1 and Figure 2 for these definitions. Total Harmonic Distortion (THD) Aperture Delay (tAP) THD is the ratio of the RMS sum of the first 5 harmonic components to the RMS value of the fundamental input signal. Aperture delay is the time delay between the external sample command (the falling edge of the clock) and the time at which the signal is actually sampled. This delay is due to internal clock path propagation delays. 2nd and 3rd Harmonic Distortion This is the ratio of the RMS value of the applicable harmonic component to the RMS value of the fundamental input signal. Spurious Free Dynamic Range (SFDR) Aperture Jitter (tAJ) Aperture jitter is the RMS variation in the aperture delay due to variation of internal clock path delays. SFDR is the ratio of the fundamental RMS amplitude to the RMS amplitude of the next largest spectral component in the spectrum below fS /2. Data Hold Time (tH) Intermodulation Distortion (IMD) Data Output Delay Time (tOD) Nonlinearities in the signal path will tend to generate intermodulation products when two tones, f1 and f2 , are present at the inputs. The ratio of the measured signal to the distortion terms is calculated. The terms included in the calculation are (f1+f2), (f1-f2), (2f1), (2f2), (2f1+f2), (2f1-f2), (f1+2f2), (f1-2f2). The ADC is tested with each tone 6dB below full scale. Data hold time is the time to where the previous data (N - 1) is no longer valid. Data output delay time is the time to where the new data (N) is valid. Data Latency (tLAT) Transient response is measured by providing a full scale transition to the analog input of the ADC and measuring the number of cycles it takes for the output code to settle within 10-bit accuracy. After the analog sample is taken, the digital data representing an analog input sample is output to the digital data bus on the 7th cycle of the clock after the analog sample is taken. This is due to the pipeline nature of the converter where the analog sample has to ripple through the internal subconverter stages. This delay is specified as the data latency. After the data latency time, the digital data representing each succeeding analog sample is output during the following clock cycle. The digital data lags the analog input sample by 7 sample clock cycles. Over-Voltage Recovery Power-Up Initialization Over-Voltage Recovery is measured by providing a full scale transition to the analog input of the ADC which overdrives the input by 200mV, and measuring the number of cycles it takes for the output code to settle within 10-bit accuracy. This time is defined as the maximum number of clock cycles that are required to initialize the converter at power-up. The requirement arises from the need to initialize the dynamic circuits within the converter. Transient Response 15 HI5746 A/D AMP HI5703 HI5746 HI5767 HFA1100 HFA1105 HFA1106 HFA1135 HFA1145 HFA1245 DSP/P D/A HI5780 HI1171 HI3338 HSP9501 HSP48410 HSP48908 HSP48212 HSP43891 HSP43168 HSP43216 HFA1100: HFA1105: HFA1106: HFA1135: HFA1145: HFA1245: HI5703: HI5746: HI5767: HSP9501: HSP48410: 850MHz Video Op Amp 300MHz Video Op Amp 250MHz Video Op Amp with Bandwidth Limit Control 350MHz Video Op Amp with Output Limiting 300MHz Video Op Amp with Output Disable Dual, 350MHz, Video Op Amp with Output Disable 10-Bit, 40 MSPS, Low Power A/D Converter 10-Bit, 40 MSPS, Very Low Power A/D Converter 10-Bit, 40 MSPS A/D Converter with Voltage Reference Programmable Data Buffer Histogrammer/Accumulating Buffer, 10-Bit Pixel Resolution HSP48908: 2-D Convolver, 3 x 3 Kernal Convolution, 8-Bit HSP48212: HSP43891: HSP43168: HSP43216: HI5780: HI1171: HI3338: HA5020: HA2842: HFA1115: HFA1212: HFA1412: AMP HA5020 HA2842 HFA1115 HFA1212 HFA1412 Digital Video Mixer Digital Filter, 30MHz, 9-Bit Dual FIR Filter, 10-Bit, 33MHz/45MHz Digital Half Band Filter 10-Bit, 80 MSPS, Video D/A Converter 8-Bit, 40 MSPS, Video D/A Converter 8-Bit, 50 MSPS, Video D/A Converter 100MHz Video Op Amp High Output Current, Video Op Amp 225MHz Programmable Gain Video Buffer with Output Limiting 350MHz Dual Programmable Gain Video Buffer 350MHz Quad Programmable Gain Video Buffer In addition, CMOS Logic Families in HC/HCT, AC/ACT, FCT and CD4000 are available. FIGURE 30. 10-BIT VIDEO IMAGING COMPONENTS A/D AMP HI5703 HI5746 HI5767 HFA1100 HFA1110 HFA3101 HFA3102 HFA3600 DSP/P HSP43168 HSP43216 HSP43220 HSP43891 HSP50016 HSP50110 HSP50210 D/A HI5721 HI5780 HI20201 HI20203 AMP HFA1112 HFA1113 HFA1100: 850MHz Op Amp HFA1110: 750MHz Unity Gain Video Buffer HFA3101: Gilbert Cell Transistor Array HFA3102: Dual Long-Tailed Pair Transistor Array HFA3600: Low Noise Amplifier/Mixer HI5703: 10-Bit, 40 MSPS, Low Power A/D Converter HI5746: 10-Bit, 40 MSPS, Very Low Power A/D Converter HI5767: 10-Bit, 40 MSPS A/D Converter with Voltage Reference HSP43168: Dual FIR Filter, 10-Bit, 33MHz/45MHz HSP43216: Digital Half Band Filter HSP43220: Decimating Digital Filter HSP43891: Digital Filter, 30MHz, 9-Bit HSP50016: Digital Down Converter HSP50110: Digital Quadrature Tuner HSP50210: Digital Costas Loop HI5721: 10-Bit, 100 MSPS, Communications D/A Converter HI5780: 10-Bit, 80 MSPS, D/A Converter HI20201: 10-Bit, 160 MSPS, High Speed D/A Converter HI20203: 8-Bit, 160 MSPS, High Speed D/A Converter HFA1112: 850MHz Programmable Gain Video Buffer HFA1113: 850MHz Programmable Gain Video Buffer with Output Limiting In addition, CMOS Logic Families in HC/HCT, AC/ACT, FCT and CD4000 are available. FIGURE 31. 10-BIT COMMUNICATIONS COMPONENTS 16