HI5721BIP

® CT T ODU ME N E PR PLACE ter at ET en OL RE OBS ENDED upport C om/tsc M S il.c l M rs ECO echnica .inte NO R DataTSheet www ur r IL o act o cont -INTERS 8 1-88 HI5721 March 2003 FN3949.8 10-Bit, 125MSPS, High Speed D/A Converter The HI5721 is a 10-bit, 125MSPS, high speed D/A converter. The converter incorporates a 10-bit, input data register with quadrature data logic capability and current outputs. The HI5721 features low glitch energy and excellent frequency domain specifications. Features • Throughput Rate . . . . . . . . . . . . . . . . . . . . . . . . 125MSPS • Low Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .700mW • Integral Linearity Error . . . . . . . . . . . . . . . . . . . . . 1.5 LSB • Low Glitch Energy . . . . . . . . . . . . . . . . . . . . . . . . .1.5pV•s • TTL/CMOS Compatible Inputs • Improved Hold Time. . . . . . . . . . . . . . . . . . . . . . . . . 0.5ns PKG. NO. E28.6 M28.3 Part Number Information PART NUMBER HI5721BIP HI5721BIB HI5721-EVP HI5721-EVS TEMP. RANGE (oC) -40 to 85 -40 to 85 25 25 PACKAGE 28 Ld PDIP 28 Ld SOIC (W) • Excellent Spurious Free Dynamic Range • Improved Second Source for the AD9721 Applications • Wireless Communications • Direct Digital Frequency Synthesis • Signal Reconstruction • HDTV • Test Equipment • High Resolution Imaging Systems • Arbitrary Waveform Generators Evaluation Board (PDIP) Evaluation Board (SOIC) Pinout HI5721 (PDIP, SOIC) TOP VIEW D9 (MSB) 1 D8 2 D7 3 D6 4 D5 5 D4 6 D3 7 D2 8 D1 9 D0 (LSB) 10 CLOCK 11 NC 12 INVERT 13 VCC 14 28 DGND 27 DVEE 26 CTRL AMP IN 25 REF OUT 24 CTRL AMP OUT 23 REF IN 22 AVEE 21 IOUT 20 IOUT 19 ARTN 18 AGND 17 RSET 16 DVEE 15 DGND 1 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. HI5721 Typical Applications Circuit +5V 0.01µF VCC (14) D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 D9 (MSB) (1) D8 (2) D7 (3) D6 (4) D5 (5) D4 (6) D3 (7) D2 (8) D1 (9) D0 (LSB) (10) CLK (11) 50Ω INVERT (13) DGND (15, 28) DVEE (16, 27) 0.1µF 0.01µF - 5.2V (DVEE) (21) IOUT (17) RSET (19) ARTN (18) AGND (22) AVEE 1960Ω (26) CTRL AMP IN (25) REF OUT (20) IOUT D/A OUT 64Ω 64Ω (24) CTRL AMP OUT -5.2V (AVEE) (23) REF IN 0.1µF HI5721 0.01µF 0.1µF - 5.2V (AVEE) Functional Block Diagram QUADRATURE LOGIC (LSB) D0 D1 D2 D3 D4 D5 D6 D7 D8 (MSB) D9 UPPER 4-BIT DECODER 15 15 227Ω 15 SWITCHED CURRENT CELLS IOUT IOUT INVERT REF IN CLK VOLTAGE REFERENCE + 227Ω DATA BUFFER/ LEVEL SHIFTER 6 LSBs CURRENT CELLS R2R NETWORK SLAVE REGISTER ARTN 25Ω CTRL AMP OUT - AVEE AGND DVEE DGND VCC REF OUT RSET CTRL AMP IN 2 HI5721 Absolute Maximum Ratings Digital Supply Voltage VCC to DGND . . . . . . . . . . . . . . . . . . . +5.5V Negative Digital Supply Voltage DVEE to DGND . . . . . . . . . . -5.5V Negative Analog Supply Voltage AVEE to AGND, ARTN . . . . -5.5V Digital Input Voltages (D9-D0, CLK, INVERT) . . . . . . . VCC to -0.5 V Internal Reference Output Current. . . . . . . . . . . . . . . . . . . . . .500µA Control Amplifier Input Voltage Range. . . . . . . . . . . . AGND to -4.0V Control Amplifier Output Current . . . . . . . . . . . . . . . . . . . . . ±2.5mA Reference Input Voltage Range. . . . . . . . . . . . . . . . . -3.7 V to AVEE Analog Output Current (IOUT) . . . . . . . . . . . . . . . . . . . . . . . . . 30mA Thermal Information Thermal Resistance (Typical, Note 1) PDIP Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SOIC Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Maximum Power Dissipation θJA(oC/W) 55 70 Operating Conditions Temperature Range. . . . . . . . . . . . . . . . . . . . . . . . . . -40oC to 85oC HI5721BIx . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .750mW Maximum Junction Temperature HI5721BIx . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .150oC Maximum Storage Temperature Range . . . . . . . . . -65oC to 150oC Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . .300oC (SOIC - Lead Tips Only) 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 AVEE , DVEE = -4.94 to -5.46V, VCC = +4.75 to +5.25V, CTRL AMP IN = REF OUT, TA = 25oC for All Typical Values HI5721BI TA = -40oC TO 85oC PARAMETER SYSTEM PERFORMANCE Resolution Integral Linearity Error, INL Differential Linearity Error, DNL Offset Error, IOS Full Scale Gain Error, FSE Offset Drift Coefficient Full Scale Output Current, IFS Output Voltage Compliance Range DYNAMIC CHARACTERISTICS Throughput Rate Output Voltage Full Scale Step Settling Time, tSETT FS Output Voltage Small Step Settling Time, tSETT SM Singlet Glitch Area, GE (Peak Glitch) Doublet Glitch Area, (Net Glitch) Output Slew Rate Output Rise Time Output Fall Time (Note 3) (Note 3) TEST CONDITIONS MIN TYP MAX UNITS 10 (Note 4) (“Best Fit” Straight Line) (Note 4) (Note 4) (Notes 2, 4) (Note 3) -1.5 ±0.5 ±0.5 16 2 0.1 -20.48 - ±1.5 ±1.0 75 10 +3.0 Bits LSB LSB µA % µA/oC mA V 125.0 - 4.5 3.5 3.5 1.5 1,000 675 470 - MSPS ns ns pV•s pV•s V/µs ps ps To ±0.5 LSB Error Band RL = 50Ω (Note 3) 100mV Step to ±0.5 LSB Error Band, RL = 50Ω (Note 3) RL = 50Ω (Note 3) RL = 50Ω , DAC Operating in Latched Mode (Note 3) RL = 50Ω , DAC Operating in Latched Mode (Note 3) RL = 50Ω , DAC Operating in Latched Mode (Note 3) - 3 HI5721 Electrical Specifications AVEE , DVEE = -4.94 to -5.46V, VCC = +4.75 to +5.25V, CTRL AMP IN = REF OUT, TA = 25oC for All Typical Values (Continued) HI5721BI TA = -40oC TO 85oC PARAMETER Spurious Free Dynamic Range, SFDR to Nyquist TEST CONDITIONS fCLK = 125 MSPS, fOUT = 2.02MHz, 62.5MHz Span (Notes 3, 5) fCLK = 125 MSPS, fOUT = 25MHz, 62.5MHz Span (Notes 3, 5) fCLK = 100 MSPS, fOUT = 2.02MHz, 50MHz Span (Notes 3, 5) fCLK = 100 MSPS, fOUT = 25MHz, 50MHz Span (Notes 3, 5) Spurious Free Dynamic Range, SFDR Within a Window fCLK = 125 MSPS, fOUT = 2.02MHz, 2MHz Span (Notes 3, 5) fCLK = 125 MSPS, fOUT = 25MHz, 2MHz Span (Notes 3, 5) fCLK = 100 MSPS, fOUT = 2.02MHz, 2MHz Span (Notes 3, 5) fCLK = 100 MSPS, fOUT = 25MHz, 2MHz Span (Notes 3, 5) Signal to Noise Ratio (SNR) to Nyquist (Ignoring the First 5 Harmonics) fCLK = 125 MSPS, fOUT = 2.02MHz, (Notes 3, 5) fCLK = 125 MSPS, fOUT = 25MHz (Notes 3, 5) fCLK = 100 MSPS, fOUT = 2.02MHz, (Notes 3, 5) fCLK = 100 MSPS, fOUT = 25MHz (Notes 3, 5) Signal to Noise Ratio + Distortion (SINAD) to Nyquist fCLK = 125 MSPS, fOUT = 2.02MHz, (Notes 3, 5) fCLK = 125 MSPS, fOUT = 25MHz (Notes 3, 5) fCLK = 100 MSPS, fOUT = 2.02MHz, (Notes 3, 5) fCLK = 100 MSPS, fOUT = 25MHz (Notes 3, 5) Total Harmonic Distortion (THD) to Nyquist fCLK = 125 MSPS, fOUT = 2.02MHz, (Notes 3, 5) fCLK = 125 MSPS, fOUT = 25MHz (Notes 3, 5) fCLK = 100 MSPS, fOUT = 2.02MHz, (Notes 3, 5) fCLK = 100 MSPS, fOUT = 25MHz (Notes 3, 5) Intermodulation Distortion (IMD) to Nyquist fCLK = 125 MSPS, fOUT1 = 800kHz, fOUT2 = 900kHz (Notes 3, 5) fCLK = 100 MSPS, fOUT1 = 800kHz, fOUT2 = 900kHz (Notes 3, 5) MIN TYP -59 -53 -59 -51 -75 -70 -75 -72 54 51.5 54.5 50.3 52.4 49.2 52.7 47.6 -57.8 -53.3 -57.9 -51 57.3 57.2 MAX UNITS dBc dBc dBc dBc dBc dBc dBc dBc dB dB dB dB dB dB dB dB dBc dBc dBc dBc dB dB 4 HI5721 Electrical Specifications AVEE , DVEE = -4.94 to -5.46V, VCC = +4.75 to +5.25V, CTRL AMP IN = REF OUT, TA = 25oC for All Typical Values (Continued) HI5721BI TA = -40oC TO 85oC PARAMETER REFERENCE/CONTROL AMPLIFIER Internal Reference Voltage, REF OUT Internal Reference Voltage Drift Internal Reference Output Current Sink/Source Capability Amplifier Input Impedance Amplifier Large Signal Bandwidth Amplifier Small Signal Bandwidth Reference Input Impedance Reference Input Multiplying Bandwidth DIGITAL INPUTS (D9-D0, CLK, INVERT) Input Logic High Voltage, VIH Input Logic Low Voltage, VIL Input Logic Current, IIH Input Logic Current, IIL Digital Input Capacitance, CIN TIMING CHARACTERISTICS Data Setup Time, tSU Data Hold Time, tHLD Propagation Delay Time, tPD CLK Pulse Width, tPW1 , tPW2 POWER SUPPLY CHARACTERISITICS IDVEE IAVEE VCC Power Dissipation Power Supply Rejection Ratio NOTES: 2. Gain Error measured as the error in the ratio between the full scale output current and the current through RSET (typically 640µA). Ideally the ratio should be 32. 3. Parameter guaranteed by design or characterization and not production tested. 4. All devices are 100% tested at 25oC. 100% productions tested at temperature extremes for military temperature devices, sample tested for industrial temperature devices. 5. Spectral measurements made without external filtering. (Note 4) (Note 4) (Note 4) (Note 4) VCC ±5%, VEE ±5% 100 14 700 50 110 15 25 775 mA mA mA mW µA/V See Figure 3 (Note 3) See Figure 3 (Note 3) See Figure 3 (Note 3) See Figure 3 (Note 3) 2.0 0.5 1.0 4.5 0.85 ns ns ns ns (Note 4) (Note 4) (Note 4) (Note 4) (Note 3) 2.0 3.0 0.8 400 700 V V µA µA pF (Note 4) (Note 3) (Note 3) (Note 3) 4.0VP-P Sine Wave Input, to Slew Rate Limited (Note 3) 1.0VP-P Sine Wave Input, to -3dB Loss (Note 3) (Note 3) RL = 50Ω , 100mV Sine Wave, to -3dB Loss at IOUT (Note 3) -1.15 -50 -1.25 100 10 1 10 4.6 75 -1.35 +500 V µV/oC µA MΩ MHz MHz kΩ MHz TEST CONDITIONS MIN TYP MAX UNITS 5 HI5721 Timing Diagrams CLK 50% V D9-D0 GLITCH AREA = 1/2 (H x W) HEIGHT (H) 1/ LSB ERROR BAND 2 IOUT WIDTH (W) t(ps) tPD tSETT FIGURE 1. FULL SCALE SETTLING TIME DIAGRAM FIGURE 2. PEAK GLITCH AREA (SINGLET) MEASUREMENT METHOD tPW1 tPW2 CLK 50% tSU tHLD D9-D0 tSU tHLD tSU tHLD tPD tSETT IOUT tPD tSETT tPD tSETT FIGURE 3. PROPAGATION DELAY, SETUP TIME, HOLD TIME AND MINIMUM PULSE WIDTH DIAGRAM 6 HI5721 Typical Performance Curves 1.0 +0.5 0.4 0.5 0.2 LSB 200 400 600 800 1023 LSB 0 0 -0.2 -0.5 -0.4 -1.0 0 DATA CODE -0.5 0 200 400 600 800 1023 DATA CODE FIGURE 4. INTEGRAL NON-LINERARITY “BEST FIT” STRAIGHT LINE FIGURE 5. DIFFERENTIAL NON-LINEARITY †ATTEN 20dB RL -10.0dBm -10 -20 -30 -40 -50 dB -60 -70 -80 -90 -100 -110 START 0Hz †RBW 3.0kHz 10dB/ ∆MKR -54.16dB 25.2MHz HI-5721 fCLK = 125 MSPS fOUT = 25 MHZ -10 -20 -30 -40 -50 dB -60 -70 -80 -90 -100 -110 STOP 62.50MHz SWP 53.0s †ATTEN 20dB RL -10.0dBm 10dB/ SFDR = -55.8dBc HI-5721 fCLK = 125 MSPS fOUT = 2 MHz †VBW 1kHz START 0Hz †RBW 3.0kHz †VBW 1.0kHz STOP 62.50MHz SWP 53.0s FIGURE 6. SPURIOUS FREE DYNAMIC RANGE TO NYQUIST 25MHz FUNDAMENTAL 0.0 f1 = 800kHz f2 = 900kHz 800kHz 900kHz dBc FIGURE 7. SPURIOUS FREE DYNAMIC RANGE TO NYQUIST 2MHz FUNDAMENTAL 60 59 58 57 56 55 54 53 52 51 50 49 48 fCLK = 100 MSPS fCLK = 125 MSPS -20 -40 dB -60 -80 -100 -110 0 2 4 FREQUENCY (MHz) 6 2 4 6 8 10 12 14 16 fOUT (MHz) 18 20 22 24 26 FIGURE 8. INTERMODULATION DISTORTION FIGURE 9. SPURIOUS FREE DYNAMIC RANGE (TO NYQUIST) vs OUTPUT FREQUENCY 7 HI5721 Typical Performance Curves 78 77 76 75 74 73 dBc 71 70 69 68 67 66 65 2 4 6 8 10 12 14 16 fOUT (MHz) 18 20 22 24 26 fCLK = 100 MSPS dB 72 fCLK = 125 MSPS (Continued) 58 57 56 55 54 53 52 51 50 49 48 47 2 4 6 8 10 12 14 16 fOUT (MHz) 18 20 22 24 26 fCLK = 100 MSPS fCLK = 125 MSPS FIGURE 10. SPURIOUS FREE DYNAMIC RANGE (±1MHz WINDOW) vs FREQUENCY 56 55 54 53 52 51 dB 50 49 48 47 46 45 44 2 4 6 8 10 12 14 16 fOUT (MHz) 18 20 22 24 26 fCLK = 100 MSPS fCLK = 125 MSPS FIGURE 11. SIGNAL TO NOISE RATIO vs OUTPUT FREQUENCY 58 57 56 55 54 dBc 53 52 51 50 49 48 2 4 6 8 10 12 14 16 fOUT (MHz) 18 20 22 24 26 fCLK = 100 MSPS fCLK = 125 MSPS FIGURE 12. SIGNAL TO NOISE + DISTORTION vs OUTPUT FREQUENCY FIGURE 13. TOTAL HARMONIC DISTORTION vs OUTPUT FREQUENCY -2.5 -2.6 -2.7 -2.8 -2.9 ERROR (%) -3.0 µA -3.1 -3.2 -3.3 -3.4 -3.5 -3.6 -3.7 -3.8 -40 -20 0 20 40 60 80 100 56 54 52 50 48 46 44 42 40 38 36 34 32 30 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 TEMPERATURE (oC) TEMPERATURE (oC) FIGURE 14. GAIN ERROR vs TEMPERATURE FIGURE 15. OFFSET ERROR vs TEMPERATURE 8 HI5721 Typical Performance Curves -1.20 -1.21 -1.22 -1.23 -1.24 -1.25 -1.26 -1.27 -1.28 -1.29 -1.30 -1.31 -1.32 -1.33 -1.34 -1.35 -40 (Continued) 0.80 0.75 0.70 (W) -50µA LOAD 100µA LOAD (V) 0.65 0.60 0.55 0.50 -50 -40 -30 -20 -10 NO LOAD -20 0 20 40 60 80 100 TEMPERATURE (oC) 0 10 20 30 40 50 60 70 80 90 TEMPERATURE (oC) NOTE: Clock Frequency does not alter power dissipation. FIGURE 16. REFERENCE VOLTAGE vs TEMPERATURE FIGURE 17. POWER DISSIPATION vs TEMPERATURE Pin Descriptions PIN NO. 1-10 PIN NAME D0 (LSB) through D9 (MSB) CLK NC INVERT VCC DGND DVEE RSET AGND ARTN IOUT IOUT AVEE REF IN CTRL AMP OUT REF OUT CTRL AMP IN PIN DESCRIPTION Digital Data Bit 0, the Least Significant Bit through Digital Data Bit 9, the Most Significant Bit. 11 12 13 14 15, 28 16, 27 17 18 19 20 21 22 23 24 25 26 Data Clock pin 100kHz to 125 MSPS. No Connect. Data Invert control for bits D0 (LSB) through D8. D9 (MSB) is not affected. Digital Logic Supply +5V. Digital Ground. -5.2V Logic Supply. External resistor to set the full scale output current. IFS = 32 x (CTRL AMP IN/RSET). Typically 1960Ω . Analog Ground supply current return pin. Analog Signal Return for the R/2R ladder. Current Output pin. Complementary Current Output pin. -5.2V Analog Supply. Reference Input pin. Typically connected to CTRL AMP OUT and a 0.1µF capacitor should be connected to AVEE to bypass the reference voltage. Provides a reference for the current switching network. Control Amplifier Output. Used to convert the internal reference or an external signal to the precision reference current. Internal Reference Output. Output of the internal -1.25V (typical) bandgap voltage reference. Control Amplifier Input. High impedance, inverting input of the reference control/buffer amplifier. 9 HI5721 Detailed Description The HI5721 is a 10-bit, current out D/A converter. The DAC can convert at 125 MSPS and runs on +5V and -5.2V supplies. The architecture is an R/2R and segmented switching current cell arrangement to reduce glitch and maintain 10-bit linearity without laser trimming. The HI5721 achieves its low power and high speed performance from an advanced BiCMOS process. The HI5721 consumes 700mW (typical) and has an improved hold time of only 0.5ns (typical). The HI5721 is an excellent converter to be used for communications applications and high performance video systems. To terminate the clock line a shunt terminator to ground is the most effective type at a 125 MSPS clock rate. A typical value for termination can be determined by the equation: RT = ZO , for the termination resistor. For a controlled impedance board with a ZO of 50Ω , the RT = 50Ω . Shunt termination is best used at the receiving end of the transmission line or as close to the HI5721 CLK pin as possible. HI5721 DAC ZO = 50Ω CLK RT = 50Ω Digital Inputs The HI5721 is a TTL/CMOS compatible D/A. The inputs can be inverted using the INVERT pin. When INVERT is LOW (‘0’) the input quadrature logic simply passes the data through unchanged. When INVERT is HIGH (‘1’) bits D0 (LSB) through D8 are inverted. D9 is not inverted and can be considered a sign bit when enabling this quadrature compatible mode. The INVERT function can simplify the requirements for large sine wave lookup tables in a Numerically Controlled Oscillator. The NCO used in a DDS application would only have to store or generate 90 degrees of information and then use the INVERT control to control the sign of the output waveform. FIGURE 18. AC TERMINATION OF THE HI5721 CLOCK LINE Rise and Fall times and propagation delay of the line will be affected by the Shunt Terminator. The terminator can be connected to DGND. Noise Reduction To reduce power supply noise, separate analog and digital power supplies should be used with 0.1µF and 0.01µF ceramic capacitors placed as close to the body of the HI5721 as possible on the analog (AVEE) and digital (DVEE) supplies. The analog and digital ground returns should be connected together back at the device to ensure proper operation on power up. The VCC power pin should be decoupled with a 0.1µF capacitor. Data Buffer/Level Shifters Data inputs D0 (LSB) through D9 (MSB) are internally translated from TTL to ECL. The internal latch and switching current source controls are implemented in ECL technology to maintain high switching speeds and low noise characteristics. Reference The internal reference in the HI5721 is a -1.25V (typical) bandgap voltage reference with a 100µV/oC temperature drift (typical). The internal reference should be buffered by the Control Amplifier to provide adequate drive for the segmented current cells and the R/2R resistor ladder. Reference Out (REF OUT) should be connected to the Control Amplifier Input (CTRL AMP IN). The Control Amplifier Output (CTRL AMP OUT) should be used to drive the Reference Input (REF IN) and a 0.1µF capacitor to analog V- (AVEE). This improves settling time by decoupling switching noise from the analog output of the HI5721. The Full Scale Output Current is controlled by the CTRL AMP IN pin and the set resistor (RSET). The ratio is: IOUT (Full Scale) = (VCTRL AMP IN/RSET) x 32. Decoder/Driver The architecture employs a split R/2R and Segmented Current source arrangement. Bits D0 (LSB) through D5 directly drive a typical R/2R network to create the binary weighted current sources. Bits D6 through D9 (MSB) pass through a “thermometer” encoder that converters the incoming data into 15 individual segmented current source enables. The split architecture helps to improve glitch while maintaining 10-bit linearity without laser trimming. The worst case glitch is more constant across the entire output transfer function. Clocks and Termination The internal 10-bit register is updated on the rising edge of the clock. Since the HI5721 clock rate can run to 125 MSPS, to minimize reflections and clock noise into the part proper termination should be used. In PCB layout clock runs should be kept short and have a minimum of loads. To guarantee consistent results from board to board, controlled impedance PCBs should be used with a characteristic line impedance ZO of 50Ω . Multiplying Capability The HI5721 can operate in two different multiplying configurations. First, using the CTRL AMP IN input pin, a -0.6V to -1.2V signal can be applied with a bandwidth up to 1MHz. To increase the multiplying bandwidth, the 0.1µF capacitor connected from REF IN to AVEE can be reduced. 10 HI5721 HI5721 20 RSET -0.6 TO -1.2V 1MHz (MAX) RT 18 18Ω 17 CTRL AMP OUT REF IN 19 CTRL AMP IN RSET Glitch TABLE 1. INPUT CODING vs CURRENT OUTPUT INPUT CODE (D9-D0) 11 1111 1111 10 0000 0000 00 0000 0000 IOUT (mA) -20.48 -10.24 0 IOUT (mA) 0 -10.24 -20.48 FIGURE 19. LOW FREQUENCY MULTIPLYING CIRCUIT If higher multiplying frequencies are desired, the reference input can be directly driven. The analog signal range is -3.3V to -4.25V. The multiplying signal must be capacitively coupled into REF IN onto a DC bias between -3.3V to -4.25V (-3.8V typically). HI5721 2nF 50Ω 383Ω 17 120Ω AVEE REF IN ≅ -3.8V The output glitch of the HI5721 is measured by summing the area under the switching transients after an update of the DAC. Glitch is caused by the time skew between bits of the incoming digital data. Typically the switching time of digital inputs are asymmetrical meaning that the turn off time is faster than the turn on time (TTL designs). Unequal delay paths through the device can also cause one current source to change before another. To minimize this the Intersil HI5721 employes an internal register, just prior to the current sources, that is updated on the clock edge. Lastly the worst case glitch usually happens at the major transition i.e., 01 1111 1111 to 10 0000 0000. But in the HI5721 the glitch is moved to the 00 0001 1111 to 11 1110 0000 transition. This is achieved by the split R/2R segmented current source architecture. This decreases the amount of current switching at any one time and makes the glitch practically constant over the entire output range. By making the glitch a constant size over the entire output range this effectively integrates this error out of the end application. In measuring the output glitch of the HI5721 the output is terminated into a 64Ω load. The glitch is measured at the major carrys throughout the DAC’s output range. The glitch energy is calculated by measuring the area under the voltage-time curve. Figure 21 shows the area considered as glitch when changing the DAC output. Units are typically specified in picoVolt • seconds (pV • s). FIGURE 20. WIDEBAND MULTIPLYING CIRCUIT Outputs The outputs IOUT and IOUT are complementary current outputs. Current is steered to either IOUT or IOUT in proportion to the digital input code. The sum of the two currents is always equal to the full scale current minus one LSB. The current output can be converted to a voltage by using a load resistor. Both current outputs should have the same load resistor (64Ω typically). By using a 64Ω load on the output, a 50Ω effective output resistance (ROUT) is achieved due to the 227Ω (±15%) parallel resistance seen looking back into the output. This is the nominal value of the R2R ladder of the DAC. The 50Ω output is needed for matching the output with a 50Ω line. The load resistor should be chosen so that the effective output resistance (ROUT) matches the line resistance. The output voltage is: VOUT = IOUT x ROUT . IOUT is defined in the reference section. The compliance range of the output is from -1.5V to 3V, with a 1VP-P voltage swing allowed within this range. However, if it is desired that the output be offset above zero volts, it is necessary that pin 19 (ARTN) be connected to the same voltage as the load resistor, not to exceed 3V. HI5721 (20) IOUT 64Ω 125MHz LOW PASS FILTER SCOPE 50Ω FIGURE 21. GLITCH TEST CIRCUIT 11 HI5721 R2 20K R1 20K U1 248 6 3+ 1 R3 7 HA2705 1K +5V R5 50 -5V PIN 25 (HI5721) R4 240 U2 248 6 3+ 1 7 HFA1100 +5V -5V a (mV) PIN 20 (HI5721) GLITCH ENERGY = (a x t)/2 t (ns) BIPOLAR OUTPUT R6 (±2.0V) 50 FIGURE 22. GLITCH ENERGY FIGURE 24. BIPOLAR OUTPUT CONFIGURATION Applications Voltage Conversion of the Output To convert the output current of the D/A converter to a voltage, an amplifier should be used as shown in Figure 23 below. The DAC needs a 50Ω termination resistor on the IOUT pin to ensure proper settling. The HFA1110 has an internal feedback resistor to compensate for high frequency operation. +5V 2 HI5721 DAC IOUT 20 50Ω 4 6 1 (DDS) applications. Figure 26 shows how to interface an HI5721 to the HSP45102. This high level block diagram is that of a basic PSK modulator. In this example the encoder generates the PSK waveform by driving the Phase Modulation Inputs (P1, P0) of the HSP45102. The P1-0 inputs impart a phase shift to the carrier wave as defined in Table 2. TABLE 2. PHASE MODULATION INPUT CODING P1 0 8 P0 0 1 0 1 PHASE SHIFT (DEGREES) 0 90 270 180 HFA1110 0 1 - + 5 -5.2V 50Ω 1 FIGURE 23. HIGH SPEED CURRENT TO VOLTAGE CONVERSION Bipolar Applications To convert the output to a bipolar ±2.0V output swing the following applications circuit is recommended. The Reference can only provide 100µA of drive, so it must be buffered to create the bipolar offset current needed to generate -2.0V output with all bits ‘off’. The output current must be converted to a voltage and then gained up and offset to produce the proper swing. Care must be taken to compensate for the output voltage swing and error. The 10 MSBs of the HSP45102 drive the 10-bit HI5721 DAC which converts the NCO output into an analog waveform. The output filter connected to the DAC can be tailored to remove unwanted spurs for the desired carrier frequency. The controller is used to load the desired center frequency and control the HSP45102. The HI5721 coupled with the HSP45102 make an inexpensive PSK modulator with Spurious Free operation down to -76dBc. Interfacing to the HSP45106 NCO-16 The HSP45106 is a 16-bit output, Numerically-Controlled Oscillator (NCO). The HSP45106 can be used to generate various modulation schemes for Direct Digital Synthesis (DDS) applications. Figure 25 shows how to interface an HI5721 to the HSP45106. Interfacing to the HSP45102 NCO-12 The HSP45102 is a 12-bit output Numerically Controlled Oscillator (NCO). The HSP45102 can be used to generate various modulation schemes for Direct Digital Synthesis 12 HI5721 U2 33 MSPS CLK BASEBAND BIT STREAM ENCODER K9 C11 B11 C10 A11 F10 F9 F11 H11 G11 G9 J11 G10 D10 CONTROLLER VCC J10 K11 CLK MOD2 MOD1 MOD0 PMSEL DACSTRB# ENPOREG# ENOFREG# ENCFREG# ENPHAC# ENTIREG# INHOFR# INITPAC# INITTAC# TEST PARSER# BINFMT# SIN15 SIN14 SIN13 SIN12 SIN11 SIN10 SIN9 SIN8 SIN7 SIN6 SIN5 SIN4 SIN3 SIN2 SIN1 SIN0 L1 K3 L2 L3 L4 J5 K5 L5 K6 J6 J7 L7 L6 L8 K8 L9 L10 VCC 14 1 2 3 4 5 6 7 8 9 10 U1 DVDD IOUT 20 FILTER R1 64 21 23 24 R1 64 + C2 C1 26 25 R1 1960 ARET 19 1.0µF 0.01µF -5.2V_A -5.2V_A TO RF UP-CONVERT STAGE D9 (MSB) D8 IOUT/ D7 D6 D5 D4 REF IN D3 D2 C AMP OUT D1 D0 (LSB) C AMP IN 11 CLK REF OUT 13 INVERT R4 50 28 DVSS 15 DVSS RSET 17 B8 A8 B6 B7 A7 C7 C6 A6 A5 C5 A4 B4 A3 A2 B3 A1 B10 B9 A10 E11 E9 VCC H10 K2 J2 V CC C15_MSB C4 C13 C12 C11 C10 C9 C8 C7 C6 C5 C4 C3 C2 C1 C0 A2 A1 A0 CS# WR# PACI# OES# OEC# COS15 COS14 COS13 COS12 COS11 COS10 COS9 COS8 COS7 COS6 COS5 COS4 COS3 COS2 COS1 COS0 TICO# C2 B1 C1 D1 E3 E2 E1 F2 F3 G3 G1 G2 H1 H2 J1 K1 B2 -5.2V_D 27 DV EE 16 DVEE HI5721 AVSS 18 AVEE 22 -5.2V_A L1 -5.2V_D 10µH -5.2V_A L2 10µH HSP45106 FIGURE 25. PSK MODULATOR USING THE HI5721 AND THE HSP45106 12-BIT NCO Definition of Specifications Integral Linearity Error, INL, is the measure of the worst case point that deviates from a best fit straight line of data values along the transfer curve. Differential Linearity Error, DNL, is the measure of the step size output deviation from code to code. Ideally the step size should be 1 LSB. A DNL specification of 1 LSB or less guarantees monotonicity. Feedthru is the measure of the undesirable switching noise coupled to the output. Output Voltage Full Scale Settling Time, is the time required from the 50% point on the clock input for a full scale step to settle within an 1/2 LSB error band. 13 Output Voltage Small Scale Settling Time, is the time required from the 50% point on the clock input for a 100mV step to settle within an 1/2 LSB error band. This is used by applications reconstructing highly correlated signals such as sine waves with more than 5 points per cycle. Glitch Area, GE, is the switching transient appearing on the output during a code transition. It is measured as the area under the curve and expressed as a Volt-Time specification. Differential Gain, ∆AV , is the gain error from an ideal sine wave with a normalized amplitude. Differential Phase, ∆Φ , is the phase error from and ideal sine wave. HI5721 TO RF UP-CONVERT STAGE U2 U1 40 MSPS I CLK ENCODER Q 16 19 20 18 17 12 9 CONTROL BUS CONTROLLER 14 13 10 11 SCLK SD SFTEN# MSB/LSB# HSP45102 -5.2V_D R4 50 CLK P1 P0 LOAD# TXFR# ENPHAC# SEL_L/M# OUT11 OUT10 OUT9 OUT8 OUT7 OUT6 OUT5 OUT4 OUT3 OUT2 OUT1 OUT0 6 5 4 3 2 1 28 27 26 25 24 23 VCC 14 1 2 3 4 5 6 7 8 9 10 DVDD IOUT 20 FILTER R1 64 21 23 24 R1 64 + C2 C1 26 25 R1 1960 ARET 19 1.0µF 0.01µF BASEBAND BIT STREAM D9 (MSB) D8 IOUT/ D7 D6 D5 D4 REF IN D3 D2 C AMP OUT D1 D0 (LSB) C AMP IN 11 CLK REF OUT 13 INVERT 28 15 RSET DVSS DVSS -5.2V_A -5.2V_A 17 27 DV EE 16 DVEE HI5721 AVSS 18 AVEE 22 -5.2V_A L1 -5.2V_D 10µH -5.2V_A L2 10µH FIGURE 26. PSK MODULATOR USING THE HI5721 AND THE HSP45102 12-BIT NCO Signal to Noise Ratio, SNR, is the ratio of a fundamental to the noise floor of the analog output. The first 5 harmonics are ignored, and an output filter of 1/2 the clock frequency is used to eliminate alias products. Total Harmonic Distortion, THD, is the ratio of the DAC output fundamental to the RMS sum of the harmonics. The first 5 harmonics are included, and an output filter of 1/2 the clock frequency is used to eliminate alias products. Spurious Free Dynamic Range, SFDR, is the amplitude difference from a fundamental to the largest harmonically or non-harmonically related spur. A sine wave is loaded into the D/A and the output filtered at 1/2 the clock frequency to eliminate noise from clocking alias terms. Intermodulation Distortion, IMD is the measure of the sum and difference products produced when a two tone input is driven into the D/A. The distortion products created will arise at sum and difference frequencies of the two tones. IMD is 20 log (RMS of sum and difference distortion products) IMD = -----------------------------------------------------------------------------------------------------------------------------------------------( RMS amplitude of the fundamental ) 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 14