® HI5905 CT T O D U C E M EN t R P E A ra T L e ent O LE R EP OBS ENDED upport C om/tsc M il.c lS C OM nica w.inters E h R c Data Sheet e NO ur T L o r w w I act o cont -INTERS 8 8 8 1- March 2003 FN4259.4 14-Bit, 5MSPS A/D Converter Features The HI5905 is a monolithic, 14-bit, 5MSPS Analog-toDigital Converter fabricated in an advanced BiCMOS process. It is designed for high speed, high resolution applications where wide bandwidth, low power consumption and excellent SINAD performance are essential. With a 100MHz full power input bandwidth and high frequency accuracy, the converter is ideal for many types of communication systems employing digital IF architectures. • Sampling Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5MSPS The HI5905 is designed in a fully differential pipelined architecture with a front end differential-in-differential-out sample-and-hold amplifier (S/H). The HI5905 has excellent dynamic performance while consuming 350mW power at 5MSPS. • Internal Voltage Reference • Low Power at 5MSPS . . . . . . . . . . . . . . . . . . . . . .350mW • Internal Sample and Hold • Fully Differential Architecture • Full Power Input Bandwidth . . . . . . . . . . . . . . . . . 100MHz • SINAD at 1MHz . . . . . . . . . . . . . . . . . . . . . . . . . . . >70dB • Low Data Latency • TTL Compatible Clock Input • CMOS Compatible Digital Data Outputs Applications Data output latches are provided which present valid data to the output bus with a low data latency of 4 clock cycles. • Digital Communication Systems • Undersampling Digital IF Part Number Information PART NUMBER HI5905IN HI5905EVAL2 TEMP. RANGE (oC) -40 to 85 25 • Asymmetric Digital Subscriber Line (ADSL) 44 Ld MQFP • Document Scanners PKG. NO. PACKAGE • Reference Literature - AN9214, Using Intersil High Speed A/D Converters - AN9785, Using the Intersil HI5905 EVAL2 Evaluation Board Q44.10x10 Low Frequency Eval Platform Pinout NC NC NC D2 D1 D0 NC CLK DVCC1 44 43 42 41 40 39 38 37 36 35 34 33 2 32 1 D3 D4 DGND1 3 31 D5 NC 4 30 D6 AVCC 5 29 D7 AGND 6 28 NC NC 7 27 DVCC2 NC NC D10 11 23 12 13 14 15 16 17 18 19 20 21 22 D11 D9 VDC D12 24 D13 10 NC D8 VIN- AVCC DGND2 25 AGND 26 9 VRIN 8 VROUT NC VIN+ NC 1 DGND1 NC NC DVCC1 HI5905 (MQFP) TOP VIEW 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. 2003. All Rights Reserved All other trademarks mentioned are the property of their respective owners. HI5905 Functional Block Diagram VDC VINVIN+ BIAS CLOCK CLK VROUT VRIN REF S/H STAGE 1 DVCC2 4-BIT FLASH 4-BIT DAC + D13 (MSB) ∑ - D12 X8 D11 DIGITAL DELAY AND DIGITAL ERROR CORRECTION STAGE 4 4-BIT FLASH 4-BIT DAC + ∑ D10 D9 D8 D7 D6 D5 D4 D3 - D2 X8 D1 D0 (LSB) STAGE 5 4-BIT FLASH AVCC AGND DGND2 DVCC1 DGND1 Typical Application Schematic (LSB) D0 (38) D1 (37) D2 (36) VRIN (14) D3 (33) AGND (6) D4 (32) AGND (15) D5 (31) DGND1 (3) D6 (30) DGND1 (42) D7 (29) DGND2 (26) D8 (25) VIN+ (9) D9 (24) D10 (21) VDC (11) D11 (20) VIN- (10) D12 (19) (MSB) D13 (18) VROUT (13) VIN+ VIN- D0 D1 D2 D3 D4 D5 D6 D7 D8 D9 D10 D11 D12 DGND D13 DVCC1 (41) AVCC (5) DVCC1 (43) +5V + 10µF AVCC (16)DVCC2 (27) 0.1µF 0.1µF HI5905 2 BNC 10µF AND 0.1µF CAPS ARE PLACED AS CLOSE TO PART AS POSSIBLE CLK (40) CLOCK AGND + 10µF +5V HI5905 Absolute Maximum Ratings Thermal Information Supply Voltage, AVCC or DVCC to AGND or DGND . . . . . . . . . +6.0V DGND to AGND. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.3V Digital I/O Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .DGND to DVCC Analog I/O Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AGND to AVCC Thermal Resistance (Typical, Note 1) θJA (oC/W) MQFP Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Maximum Junction Temperature (Plastic Package) . . . . . . . .150oC Maximum Storage Temperature Range . . . . . . . . . -65oC to 150oC Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . .300oC (MQFP - Lead Tips Only) Operating Conditions Temperature Range (HI5905IN) . . . . . . . . . . . . . . . . -40oC to 85oC 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. θJA is measured with the component mounted on an evaluation PC board in free air. Electrical Specifications AVCC = DVCC1 = DVCC2 = +5.0V, fS = 5MSPS at 50% Duty Cycle, VRIN = VROUT , CL = 15pF, TA = 25oC, Differential Analog Input, Unless Otherwise Specified PARAMETER TEST CONDITIONS MIN TYP MAX UNITS 14 - - Bits ACCURACY Resolution Integral Linearity Error, INL Sinewave Histogram - ± 2.5 - LSB Differential Linearity Error, DNL (Guaranteed No Missing Codes) Sinewave Histogram -1 ±0.5 +1.5 LSB Offset Error, VOS fIN = DC - - 120 LSB Full Scale Error, FSE fIN = DC - - 164 LSB Minimum Conversion Rate No Missing Codes (Note 2) - - 0.5 MSPS Maximum Conversion Rate No Missing Codes 5 - - MSPS Effective Number of Bits, ENOB fIN = 1MHz 11.2 11.7 - Bits Signal to Noise and Distortion Ratio, SINAD fIN = 1MHz 69 72.2 - dB fIN = 1MHz 71 74.6 - dB Total Harmonic Distortion, THD fIN = 1MHz -73 75.7 - dBc 2nd Harmonic Distortion fIN = 1MHz - -95 3rd Harmonic Distortion fIN = 1MHz - -77 - dBc Spurious Free Dynamic Range, SFDR fIN = 1MHz 80 - - dBc Intermodulation Distortion, IMD f1 = 1MHz, f2 = 1.02MHz - 74 - dBc - 1 - Cycle - 2 - Cycle Maximum Peak-to-Peak Differential Analog Input Range (VIN+ - VIN-) - ±2.0 - V Maximum Peak-to-Peak Single-Ended Analog Input Range - 4.0 - V 1 - - MΩ DYNAMIC CHARACTERISTICS RMS Signal = -------------------------------------------------------------RMS Noise + Distortion Signal to Noise Ratio, SNR RMS Signal = ------------------------------RMS Noise Transient Response Over-Voltage Recovery 0.2V Overdrive dBc ANALOG INPUT Analog Input Resistance, RIN (Notes 1, 2) Analog Input Capacitance, CIN (Note 2) - 10 16 pF Analog Input Bias Current, IB+ or IB- (Note 3) -50 - +50 µA - ±0.5 - µA Differential Analog Input Bias Current IB DIFF = (IB+ - IB-) 3 HI5905 Electrical Specifications AVCC = DVCC1 = DVCC2 = +5.0V, fS = 5MSPS at 50% Duty Cycle, VRIN = VROUT , CL = 15pF, TA = 25oC, Differential Analog Input, Unless Otherwise Specified (Continued) PARAMETER TEST CONDITIONS MIN TYP MAX UNITS - 100 - MHz 1 2.3 4 V 3.95 4.0 4.05 V Reference Output Current - - 0.75 mA Reference Temperature Coefficient - 125 - ppm/oC Reference Voltage Input, VRIN - 4.0 - V Total Reference Resistance, RL - 5.6 - kΩ Reference Current - 715 - µA DC Bias Voltage Output, VDC - 2.3 - V Max Output Current (Not To Exceed) - - 1 mA Input Logic High Voltage, VIH 2.0 - - V Input Logic Low Voltage, VIL - - 0.8 V Full Power Input Bandwidth (FPBW) Analog Input Common Mode Voltage Range (VIN+ + VIN-)/2 Differential Mode (Note 2) INTERNAL VOLTAGE REFERENCE Reference Output Voltage, VROUT REFERENCE VOLTAGE INPUT DC BIAS VOLTAGE DIGITAL INPUTS (CLK) Input Logic High Current, IIH VCLK = 5V -10.0 - +10.0 µA Input Logic Low Current, IIL VCLK = 0V -10.0 - +10.0 µA - 10 - pF Input Capacitance, CIN DIGITAL OUTPUTS (D0-D13) Output Logic High Voltage, VOH IOH = 100µA 3.5 - - V Output Logic Low Voltage, VOL IOL = 100µA - - 1.5 V - 5 - pF Aperture Delay, tAP - 7 - ns Aperture Jitter, tAJ - 1 - ps (RMS) Output Capacitance, COUT TIMING CHARACTERISTICS Data Output Delay, tOD - 50 60 ns Data Output Hold, t H (Note 2) 5 8 - ns Data Latency, tLAT For a Valid Sample (Note 2) - - 4 Cycles Clock Pulse Width (Low) 5MSPS Clock (Note 2) 95 100 105 ns Clock Pulse Width (High) 5MSPS Clock (Note 2) 95 100 105 ns POWER SUPPLY CHARACTERISTICS Total Supply Current, ICC VIN+ = VIN- = VDC - 70 80 mA Analog Supply Current, AICC VIN+ = VIN- = VDC - 50 - mA Digital Supply Current, DICC1 VIN+ = VIN- = VDC - 14 - mA Output Supply Current, DICC2 VIN+ = VIN- = VDC - 6 - mA Power Dissipation VIN+ = VIN- = VDC - 350 400 mW Offset Error PSRR, ∆VOS AVCC or DVCC = 5V ± 5% - 2 - LSB Gain Error PSRR, ∆FSE AVCC or DVCC = 5V ± 5% - 45 - LSB NOTES: 2. Parameter guaranteed by design or characterization and not production tested. 3. With the clock off (clock low, hold mode). 4 HI5905 Timing Waveforms ANALOG INPUT CLOCK INPUT SN - 1 HN - 1 SN HN S N + 1 HN + 1 SN + 2 HN + 2 S N + 3 HN + 3 S N + 4 HN + 4 B1, N + 2 B1, N + 3 SN + 5 H N + 5 SN + 6 HN + 6 INPUT S/H 1ST STAGE 2ND STAGE B1 , N - 1 B2 , N - 2 3RD STAGE 4TH STAGE B1, N B2 , N - 1 B3 , N - 2 B4 , N - 3 5TH STAGE DATA OUTPUT B1, N + 1 B2 , N B3 , N - 1 B4 , N - 2 B2 , N + 1 B3 , N B4 , N - 1 B5 , N - 3 B5 , N - 2 DN - 4 DN - 3 B2 , N + 2 B3 , N + 1 B4 , N B5 , N - 1 DN - 2 B2 , N + 3 B3 , N + 2 B4 , N + 1 B5 , N DN B1, N + 5 B2 , N + 4 B3 , N + 3 B4 , N + 2 B5 , N + 1 DN - 1 B1, N + 4 B3 , N + 4 B4 , N + 3 B5 , N + 2 B5 , N + 3 DN + 1 DN + 2 tLAT NOTES: 6. BM , N : M-th stage digital output corresponding to N-th sampled input. 4. SN : N-th sampling period. 5. HN: N-th holding period. 7. DN : Final data output corresponding to N-th sampled input. FIGURE 1. INTERNAL CIRCUIT TIMING ANALOG INPUT tAP tAJ CLOCK INPUT 1.5V 1.5V tOD tH 3.5V DATA OUTPUT DATA N-1 DATA N 1.5V FIGURE 2. INPUT-TO-OUTPUT TIMING 5 HI5905 Typical Performance Curves 74 12 fIN = 1MHz TA = 25oC 74 73 11.75 72 fIN = 1MHz TA = 25oC 11.25 11 68 10.75 SNR (dB) 71 SINAD (dB) ENOB (BITS) 11.5 70 69 68 65 10.5 71 67 10.25 10 0 1 2 3 4 5 6 7 8 66 62 0 1 2 3 fS (MSPS) 4 5 6 7 8 fS (MSPS) FIGURE 3. EFFECTIVE NUMBER OF BITS (ENOB) AND SINAD vs SAMPLE CLOCK FREQUENCY FIGURE 4. SNR vs SAMPLE CLOCK FREQUENCY 88 90 86 fIN = 1MHz TA = 25oC 88 84 86 SFDR (dBc) 80 78 76 -THD -3HD 74 84 82 80 72 78 70 68 76 0 1 2 3 4 5 6 7 8 0 1 2 3 fS (MSPS) 5 6 7 FIGURE 6. SFDR vs SAMPLE CLOCK FREQUENCY 80 fIN = 1MHz TA = 25oC 70 ICC 60 AICC 50 40 30 DICC1 + DICC2 20 10 0 1 2 3 4 5 6 7 8 fS (MSPS) FIGURE 7. SUPPLY CURRENT vs SAMPLE CLOCK FREQUENCY 6 4 fS (MSPS) FIGURE 5. -2HD, -3HD AND -THD vs SAMPLE CLOCK FREQUENCY SUPPLY CURRENT (mA) dBc -2HD fIN = 1MHz TA = 25oC 82 8 HI5905 Detailed Description Pin Descriptions PIN # NAME 1 NC No Connection DESCRIPTION 2 NC No Connection 3 DGND1 Digital Ground 4 NC No Connection 5 AVCC Analog Supply (5.0V) 6 AGND Analog Ground 7 NC No Connection 8 NC No Connection 9 VIN+ Positive Analog Input 10 VIN- Negative Analog Input 11 VDC DC Bias Voltage Output 12 NC No Connection 13 VROUT Reference Voltage Output 14 VRIN Reference Voltage Input 15 AGND Analog Ground 16 AVCC Analog Supply (5.0V) 17 NC No Connection 18 D13 Data Bit 11 Output (MSB) 19 D12 Data Bit 11 Output 20 D11 Data Bit 11 Output 21 D10 Data Bit 10 Output 22 NC No Connection 23 NC No Connection 24 D9 Data Bit 9 Output 25 D8 Data Bit 8 Output 26 DGND2 Digital Ground 27 DVCC2 Digital Supply (5.0V) 28 NC No Connection 29 D7 Data Bit 7 Output 30 D6 Data Bit 6 Output 31 D5 Data Bit 5 Output 32 D4 Data Bit 4 Output 33 D3 Data Bit 3 Output 34 NC No Connection 35 NC No Connection 36 D2 Data Bit 2 Output 37 D1 Data Bit 1 Output 38 D0 Data Bit 0 Output (LSB) 39 NC No Connection 40 CLK Input Clock 41 DVCC1 Digital Supply (5.0V) 42 DGND1 Digital Ground 43 DVCC1 Digital Supply (5.0V) 44 NC No Connection 7 Theory of Operation The HI5905 is a 14-bit fully differential sampling pipeline A/D converter with digital error correction. Figure 8 depicts the circuit for the front end differential-in-differential-out sampleand-hold (S/H). The switches are controlled by an internal clock which is a non-overlapping two phase signal, φ1 and φ2 , derived from the master clock. During the sampling phase, φ1 , 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 φ1 the input signal is sampled on the bottom plates of the sampling capacitors. In the next clock phase, φ2 , the two bottom plates of the sampling capacitors are connected together and the holding capacitors are switched to the opamp output nodes. The charge then redistributes between CS and CH completing one sample-and-hold cycle. The output is a fully-differential, sampled-data representation of the analog input. The circuit not only performs the sampleand-hold function but will also convert a single-ended input to a fully-differential 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 100MHz for the converter. φ1 VIN + φ1 φ1 φ1 CS φ2 VIN - CH -+ VOUT + +- VOUT - CS φ1 CH φ1 FIGURE 8. ANALOG INPUT SAMPLE-AND-HOLD As illustrated in the functional block diagram and the timing diagram in Figure 1, four identical pipeline subconverter stages, each containing a four-bit flash converter, a four-bit digital-toanalog converter and an amplifier with a voltage gain of 8, follow the S/H circuit with the fifth stage being only a 4-bit flash converter. Each converter stage in the pipeline will be sampling in one phase and amplifying in the other clock phase. Each individual sub-converter clock signal is offset by 180 degrees from the previous stage clock signal, with the result that alternate stages in the pipeline will perform the same operation. The output of each of the four-bit subconverter stages is a four-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 four identical four-bit subconverter stages with the corresponding output of the fifth stage flash converter before applying the HI5905 twenty 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 fourteen 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 4th 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 with a latch. The digital output data is available in two’s complement binary format (see Table 1, A/D Code Table). Internal Reference Generator, VROUT and VRIN The HI5905 has an internal reference generator, therefore, no external reference voltage is required. VROUT must be connected to VRIN when using the internal reference voltage. The HI5905 can be used with an external reference. The converter requires only one external reference voltage connected to the VRIN pin with VROUT left open. The HI5905 is tested with VROUT , equal to 4.0V, connected to VRIN . Internal to the converter, two reference voltages of 1.3V and 3.3V are generated for a fully differential input signal range of ±2V. In order to minimize overall converter noise, it is recommended that adequate high frequency decoupling be provided at the reference voltage input pin, VRIN . A 2.3V DC bias voltage source, VDC , half way between the top and bottom internal reference voltages, is made available to the user to help simplify circuit design when using a differential input. This low output impedance voltage source is not designed to be a reference but makes an excellent bias source and stays within the analog input common mode voltage range over temperature. The difference between the converter’s two internal voltage references is 2V. For the AC coupled differential input, (Figure 9), if VIN is a 2VP-P sinewave with -VIN being 180 degrees out of phase with VIN, then VIN+ is a 2VP-P sinewave riding on a DC bias voltage equal to VDC and VIN- is a 2VP-P sinewave riding on a DC bias voltage equal to VDC . Consequently, the converter will be at positive full scale, resulting in a digital data output code with D13 (MSB) equal to a logic “0” and D0-D12 equal to logic “1” (see Table 1, A/D Code Table), when the VIN+ input is at VDC+1V and the VIN- input is at VDC-1V (VIN+ - VIN- = 2V). Conversely, the ADC will be at negative full scale, resulting in a digital data output code with D13 (MSB) equal to a logic “1” and D0-D12 equal to logic “0” (see Table 1, A/D Code Table), when the VIN+ input is equal to VDC - 1V and VIN- is at VDC + 1V (VIN+ - VIN- = -2V). From this, the converter is seen to have a peak-to-peak differential analog input voltage range of ±2V. The analog input can be DC coupled (Figure 10) as long as the inputs are within the analog input common mode voltage range (1.0V ≤ VDC ≤ 4.0V). VIN VIN+ VDC R Analog Input, Differential Connection Since the HI5905 is powered off a single +5V supply, the analog input must be biased so it lies within the analog input common mode voltage range of 1.0V to 4.0V. The performance of the ADC does not change significantly with the value of the analog input common mode voltage. VIN+ HI5905 VDC -VIN VIN- FIGURE 9. AC COUPLED DIFFERENTIAL INPUT 8 HI5905 VDC The analog input to the HI5905 can be configured in various ways depending on the signal source and the required level of performance. A fully differential connection (Figure 9) will give the best performance for the converter. VIN C -VIN VDC R VIN- FIGURE 10. DC COUPLED DIFFERENTIAL INPUT The resistors, R, in Figure 10 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. HI5905 TABLE 1. A/D CODE TABLE CODE CENTER DESCRIPTION DIFFERENTIAL INPUT VOLTAGE † (USING INTERNAL REFERENCE) TWO’S COMPLEMENT BINARY OUTPUT CODE MSB LSB D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 +Full Scale (+FS) - 1/4 LSB +1.99994V 0 1 1 1 1 1 1 1 1 1 1 1 1 1 +FS - 1 1/4 LSB 1.99969V 0 1 1 1 1 1 1 1 1 1 1 1 1 0 + 3/4 LSB 183.105µV 0 0 0 0 0 0 0 0 0 0 0 0 0 0 - 1/4 LSB -61.035µV 1 1 1 1 1 1 1 1 1 1 1 1 1 1 -FS + 1 3/4 LSB -1.99957V 1 0 0 0 0 0 0 0 0 0 0 0 0 1 -Full Scale (-FS) + 3/4 LSB -1.99982V 1 0 0 0 0 0 0 0 0 0 0 0 0 0 † The voltages listed above represent the ideal center of each two’s complement binary output code shown. Analog Input, Single-Ended Connection The configuration shown in Figure 11 may be used with a single ended AC coupled input. Sufficient headroom must be provided such that the input voltage never goes above +5V or below AGND . VIN VIN+ VDC R HI5905 C VDC VIN - VIN+ VIN HI5905 VDC VIN- FIGURE 11. AC COUPLED SINGLE ENDED INPUT Again, the difference between the two internal voltage references is 2V. If VIN is a 4VP-P sinewave, then VIN+ is a 4VP- P sinewave riding on a positive voltage equal to VDC. The converter will be at positive full scale when VIN+ is at VDC + 2V (VIN+ - VIN- = 2V) and will be at negative full scale when VIN+ is equal to VDC - 2V (VIN+ - VIN- = -2V). In this case, VDC could range between 2V and 3V without a significant change in ADC performance. The simplest way to produce VDC is to use the VDC bias voltage output of the HI5905. The single ended analog input can be DC coupled (Figure 12) as long as the input is within the analog input common mode voltage range. FIGURE 12. DC COUPLED SINGLE ENDED INPUT The resistor, R, in Figure 12 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 will give better overall system performance if it is first converted to differential before driving the HI5905. Digital I/O and Clock Requirements The HI5905 provides a standard high-speed interface to external TTL/CMOS logic families. The digital CMOS clock input has TTL level thresholds. The low input bias current allows the HI5905 to be driven by CMOS logic. The digital CMOS outputs have a separate +5.0V digital supply input pin. In order to ensure rated performance of the HI5905, 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 HI5905 will only be guaranteed at conversion rates above 0.5MSPS. This ensures proper performance of the internal dynamic circuits. 9 HI5905 Supply and Ground Considerations Signal-to-Noise Ratio (SNR) The HI5905 has separate analog and digital supply and ground pins to keep digital noise out of the analog signal path. 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 HI5905 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 and ground pins should be isolated by ferrite beads from the digital supply and ground pins. SNR is 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 except the fundamental and the first five harmonics. Refer to the Application Note AN9214, “Using Intersil High Speed A/D Converters” for additional considerations when using high speed converters. ENOB = ( SINAD + V CORR -1.76 )/6.02 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) Signal-to-Noise + Distortion Ratio (SINAD) SINAD is the measured RMS signal to RMS sum of all other spectral components below the Nyquist frequency, fS/2, excluding DC. Effective Number Of Bits (ENOB) The effective number of bits (ENOB) is calculated from the SINAD data by: where: VCORR = 0.5dB (Typical) VCORR adjusts the ENOB for the amount the input is below fullscale. Total Harmonic Distortion (THD) THD is the ratio of the RMS sum of the first 5 harmonic components to the RMS value of the fundamental input signal. The last code transition should occur for an analog input that is 3/4 LSB below positive full-scale with the offset error removed. Full-scale error is defined as the deviation of the actual code transition from this point. 2nd and 3rd Harmonic Distortion Differential Linearity Error (DNL) Spurious Free Dynamic Range (SFDR) DNL is the worst case deviation of a code width from the ideal value of 1 LSB. SFDR is the ratio of the fundamental RMS amplitude to the RMS amplitude of the next largest spur or spectral component (excluding the first 5 harmonic components) in the spectrum below fS/2. 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 Rejection Ratio (PSRR) Each of the power supplies are moved plus and minus 5% and the shift in the offset and gain error (in LSBs) is noted. Dynamic Performance Definitions Fast Fourier Transform (FFT) techniques are used to evaluate the dynamic performance of the HI5905. 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 full-scale for all these tests. 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. 10 This is the ratio of the RMS value of the applicable harmonic component to the RMS value of the fundamental input signal. Intermodulation Distortion (IMD) 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. Transient Response Transient response is measured by providing a fullscale transition to the analog input of the ADC and measuring the number of cycles it takes for the output code to settle within 14-bit accuracy. Over-Voltage Recovery Over-voltage Recovery is measured by providing a fullscale 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 14-bit accuracy. HI5905 Full Power Input Bandwidth (FPBW) Data Hold Time (tH) 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 sinewave. The input sinewave has an amplitude which swings from -fS to +fS . The bandwidth given is measured at the specified sampling frequency. Data hold time is the time to where the previous data (N - 1) is still valid. Data Output Delay Time (tOD) Data output delay time is the time to where the new data (N) is valid. Data Latency (tLAT) Timing Definitions Refer to Figure 1, Internal Circuit Timing, and Figure 2, Input-To-Output Timing, for these definitions. Aperture Delay (tAP) 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. After the analog sample is taken, the digital data is output on the bus at the third cycle of the clock. This is due to the pipeline nature of the converter where the data has to ripple through the stages. This delay is specified as the data latency. After the data latency time, the data representing each succeeding sample is output at the following clock pulse. The digital data lags the analog input sample by 4 clock cycles. Aperture Jitter (tAJ) Aperture Jitter is the RMS variation in the aperture delay due to variation of internal clock path delays. All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 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 11