AD5724R

Complete, Quad, 12-/14-/16-Bit, Serial Input, Unipolar/Bipolar Voltage Output DACs Preliminary Technical Data FEATURES Complete, quad, 12-/14-/16-bit D/A converter Operates from single/dual supplies Software programmable output range +5 V, +10 V, +10.8 V, ±5 V, ±10 V, ±10.8 V INL error: ±16 LSB maximum, DNL error: ±1 LSB maximum Total unadjusted error (TUE): 0.1% FSR maximum Settling time: 10 µs maximum Integrated reference: 5 ppm/°C typ. Integrated reference buffers Output control during power-up/brownout Simultaneous updating via LDAC Asynchronous CLR to zero-/mid-scale DSP/microcontroller-compatible serial interface 24-lead TSSOP Operating temperature range: −40°C to +85°C iCMOS™ process technology1 AD5724R/AD5734R/AD5754R GENERAL DESCRIPTION The AD5724R/AD5734R/AD5754R are quad, 12-/14-/16-bit serial input, voltage output, digital-to-analog converters. They operate from single supply voltages of +4.5 V up to +16.5 V or dual supply voltages from ±4.5 V up to ±16.5 V. Nominal fullscale output range is software-selectable from the options of +5 V, +10 V, +10.8 V, ±5 V, ±10 V, or ±10.8 V. Integrated output amplifiers, reference buffers, and proprietary power-up/powerdown control circuitry are also provided. The parts offer guaranteed monotonicity, integral nonlinearity (INL) of ±16 LSB maximum, low noise, 10 µs maximum settling time, and an on-chip +2.5 V reference. The AD5724R/AD5734R/AD5754R use a serial interface that operates at clock rates up to 30 MHz and are compatible with DSP and microcontroller interface standards. Double buffering allows the simultaneous updating of all DACs. The input coding is user-selectable twos complement or offset binary for a bipolar output (depending on the state of pin BIN/2sComp), and straight binary for a unipolar output. The asynchronous clear function clears all DAC registers to a user-selectable zero-scale or mid-scale output. The parts are available in a 24-lead TSSOP and offer guaranteed specifications over the −40°C to +85°C industrial temperature range. Table 1. Pin Compatible Devices Part Number AD5724/AD5734/AD5754 AD5722/AD5732/AD5752 Description AD5724R/AD5734R/AD5754R without internal reference. Complete, dual, 12-/14-/16-bit, serial input, unipolar/bipolar, voltage output DAC. AD5722/AD5732/AD5752 with internal reference. APPLICATIONS Industrial automation Closed-loop servo control, process control Automotive test and measurement Programmable logic controllers AD5722R/AD5732R/AD5752R 1 For analog systems designers within industrial/instrumentation equipment OEMs who need high performance ICs at higher-voltage levels, iCMOS is a technology platform that enables the development of analog ICs capable of 30 V and operating at ±15 V supplies while allowing dramatic reductions in power consumption and package size, and increased AC and DC performance. Rev. PrC Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 www.analog.com Fax: 781.461.3113 ©2007 Analog Devices, Inc. All rights reserved. AD5724R/AD5734R/AD5754R TABLE OF CONTENTS Features .............................................................................................. 1 Applications....................................................................................... 1 General Description ......................................................................... 1 Revision History ............................................................................... 2 Functional Block Diagram .............................................................. 3 Specifications..................................................................................... 4 Dual Supply Specifications.......................................................... 4 Single Supply Specifications........................................................ 6 AC Performance Characteristics ................................................ 7 Timing Characteristics ................................................................ 8 Absolute Maximum Ratings.......................................................... 11 ESD Caution................................................................................ 11 Pin Configuration and Function Descriptions........................... 12 Typical Performance Characteristics ........................................... 13 Terminology .................................................................................... 19 Theory of Operation ...................................................................... 21 Architecture................................................................................. 21 Serial Interface ............................................................................ 21 Load DAC (LDAC)..................................................................... 23 Preliminary Technical Data Asynchronous Clear (CLR)....................................................... 23 Configuring the AD5724R/AD5734R/AD5754R .................. 23 Transfer Function....................................................................... 23 Input Register.............................................................................. 27 Data Register............................................................................... 27 Output Range Select Register ................................................... 28 Control Register ......................................................................... 28 Power Control Register ............................................................. 29 Features ............................................................................................ 30 Analog Output Control ............................................................. 30 Overcurrent Protection ............................................................. 30 Thermal Shutdown .................................................................... 30 Internal Reference ...................................................................... 30 Applications Information .............................................................. 31 Layout Guidelines....................................................................... 31 Galvanically Isolated Interface ................................................. 31 Microprocessor Interfacing....................................................... 31 Outline Dimensions ....................................................................... 32 Ordering Guide .......................................................................... 32 REVISION HISTORY PrC – Preliminary Revision, November 16, 2007 Rev. PrC | Page 2 of 32 Preliminary Technical Data FUNCTIONAL BLOCK DIAGRAM AVSS AVDD AD5724R/AD5734R/AD5754R REFIN/REFOUT DVCC AD5754R 16 2.5V REFERENCE 16 REFERENCE BUFFERS SDIN SCLK SYNC SDO INPUT SHIFT REGISTER AND CONTROL LOGIC INPUT REGISTER A DAC REGISTER A DAC A VOUTA INPUT REGISTER B DAC REGISTER B 16 DAC B VOUTB CLR BIN/2sCOMP INPUT REGISTER C DAC REGISTER C 16 DAC C VOUTC INPUT REGISTER D DAC REGISTER D 16 DAC D VOUTD GND LDAC DAC_GND (2) SIG_GND (2) Figure 1. Rev. PrC | Page 3 of 32 06465-001 AD5724R/AD5734R/AD5754R SPECIFICATIONS DUAL SUPPLY SPECIFICATIONS Preliminary Technical Data AVDD = 4.5 V1 to 16.5 V, AVSS = −4.5 V1 to −16.5 V, GND = 0 V, REFIN= +2.5 V external, DVCC = 2.7 V to 5.5 V, RLOAD = 2 kΩ, CLOAD = 200 pF; all specifications TMIN to TMAX, ±10 V range unless otherwise noted. Table 2. Parameter ACCURACY Bipolar Output Resolution AD5754R AD5734R AD5724R Total Unadjusted Error (TUE) Relative Accuracy (INL) B Grade Differential Nonlinearity (DNL) Bipolar Zero Error Bipolar Zero TC2 Zero-Scale Error Zero-Scale TC2 Gain Error Gain TC2 DC Crosstalk2 Unipolar Output Resolution AD5754R AD5734R AD5724R Total Unadjusted Error (TUE) Relative Accuracy (INL) B Grade Differential Nonlinearity (DNL) Zero-Scale Error Zero-Scale TC2 Offset Error Gain Error Gain TC2 DC Crosstalk2 REFERENCE INPUT/OUTPUT Reference Input2 Reference Input Voltage DC Input Impedance Input Current Reference Range Reference Output Output Voltage Reference TC Output Noise (0.1 Hz to 10 Hz)2 Noise Spectral Density2 Output Voltage Drift vs. Time2 Value Unit Test Conditions/Comments Outputs unloaded 16 14 12 0.1 ±16 ±1 ±5 ±8 ±1 ±8 ±0.05 ±8 0.6 Bits Bits Bits % FSR max LSB max LSB max mV max ppm FSR/°C max mV max ppm FSR/°C max % FSR max ppm FSR/°C max LSB max Over temperature, supplies, and time @ 16-bit resolution Guaranteed monotonic (@ 16-bit resolution) @ 25°C, error at other temperatures obtained using Bipolar Zero TC @ 25°C, error at other temperatures obtained using Zero Scale TC @ 25°C, error at other temperatures obtained using Gain TC @ 16-bit resolution 16 14 12 0.1 ±16 ±1 +10 ±4 ±10 ±0.05 ±4 0.6 Bits Bits Bits % FSR max LSB max LSB max mV max ppm FSR/°C max mV max % FSR max ppm FSR/°C max LSB max Over temperature, supplies, and time @ 16-bit resolution Guaranteed monotonic (@ 16 bit-resolution) @ 25°C, error at other temperatures obtained using Zero-Scale TC @ 25°C, error at other temperatures obtained using Gain TC @ 16-bit resolution 2.5 1 ±10 2 to 3 2.498 to 2.502 ±5 ±10 18 75 ±40 ±50 V nom MΩ min µA max V min to V max V min to V max ppm/°C typ ppm/°C max µV p-p typ nV/√Hz typ ppm/500 hr typ ppm/1000 hr typ ±1% for specified performance Typically 100 MΩ Typically ±30 nA @ 25°C @ 10 kHz Rev. PrC | Page 4 of 32 Preliminary Technical Data Parameter OUTPUT CHARACTERISTICS2 Output Voltage Range Headroom Output Voltage TC Output Voltage Drift vs. Time Value ±10.8 ±12 0.9 0.5 ±8 ±12 ±15 Short-Circuit Current Load Capacitive Load Stability DC Output Impedance DIGITAL INPUTS2 VIH, Input High Voltage VIL, Input Low Voltage Input Current Pin Capacitance DIGITAL OUTPUTS (SDO) 2 VOL, Output Low Voltage VOH, Output High Voltage VOL, Output Low Voltage VOH, Output High Voltage High Impedance Leakage Current High Impedance Output Capacitance POWER REQUIREMENTS AVDD AVSS DVCC Power Supply Sensitivity2 ∆VOUT/∆ΑVDD AIDD AISS DICC Power Dissipation Power-Down Currents AIDD AISS DICC 1 2 AD5724R/AD5734R/AD5754R Unit V min to V max V min to V max V max V typ ppm FSR/°C max ppm FSR/500 hr typ ppm FSR/1000 hr typ mA typ kΩ min pF max Ω typ V min V max µA max pF typ V max V min V max V min µA max pF typ Test Conditions/Comments AVDD/AVSS = ±11.7 V min , REFIN = +2.5 V AVDD/AVSS = ±12.9 V min, REFIN = +3 V 20 2 4000 0.5 2 0.8 ±1 5 0.4 DVCC − 1 0.4 DVCC − 0.5 ±1 5 For specified performance DVCC = 2.7 V to 5.5 V, JEDEC compliant Per pin Per pin DVCC = 5 V ± 10%, sinking 200 µA DVCC = 5 V ± 10%, sourcing 200 µA DVCC = 2.7 V to 3.6 V, sinking 200 µA DVCC = 2.7 V to 3.6 V, sourcing 200 µA 4.5 to 16.5 -4.5 to -16.5 2.7 to 5.5 −75 2 1.5 1 TBD 80 TBD TBD V min to V max V min to V max V min to V max dB typ mA/channel max mA/channel max µA max mW typ µA typ µA typ µA typ 200mV sine wave superimposed on AVSS/AVDD @ 50/60 Hz Outputs unloaded Outputs unloaded VIH = DVCC, VIL = GND, 0.5 µA typ ±12 V operation, outputs unloaded All DAC channels and internal reference powered-down For specified performance minimum headroom requirement is 0.9V Guaranteed by characterization. Not production tested. Rev. PrC | Page 5 of 32 AD5724R/AD5734R/AD5754R SINGLE SUPPLY SPECIFICATIONS Preliminary Technical Data AVDD = 4.5 V1 to 16.5 V, AVSS = 0 V, GND = 0 V, REFIN= 2.5 V external, DVCC = 2.7 V to 5.5 V, RLOAD = 2 kΩ, CLOAD = 200 pF; all specifications TMIN to TMAX, 10 V range unless otherwise noted. Table 3. Parameter ACCURACY Resolution AD5754R AD5734R AD5724R Total Unadjusted Error (TUE) Relative Accuracy (INL) B Grade Differential Nonlinearity (DNL) Zero-Scale Error Zero-Scale TC2 Offset Error Gain Error Gain TC2 DC Crosstalk2 REFERENCE INPUT/OUTPUT Reference Input2 Reference Input Voltage DC Input Impedance Input Current Reference Range Reference Output Output Voltage Reference TC Output Noise (0.1 Hz to 10 Hz)2 Noise Spectral Density2 Output Drift vs. Time2 OUTPUT CHARACTERISTICS2 Output Voltage Range Headroom Output Voltage TC Output Voltage Drift vs. Time Short Circuit Current Load Capacitive Load Stability DC Output Impedance DIGITAL INPUTS2 VIH, Input High Voltage VIL, Input Low Voltage Input Current Pin Capacitance DIGITAL OUTPUTS (SDO)2 VOL, Output Low Voltage Value Unit Test Conditions/Comments Outputs unloaded 16 14 12 0.1 ±16 ±1 +10 ±4 ±10 ±0.02 ±8 0.6 Bits Bits Bits % FSR max LSB max LSB max mV max ppm FSR/°C max mV max % FSR max ppm FSR/°C max LSB max Across temperature and supplies @ 16-bit resolution Guaranteed monotonic (@ 16-bit resolution) @ 25°C, error at other temperatures obtained using Zero-Scale TC @ 25°C, error at other temperatures obtained using Gain TC @ 16-bit resolution 2.5 1 ±10 2 to 3 2.498 to 2.502 ±5 18 75 ±40 ±50 10.8 12 0.9 0.5 ±8 ±12 ±15 20 2 4000 0.5 2 0.8 ±1 5 0.4 V nom MΩ min µA max V min to max V min to V max ppm/°C max µV p-p typ nV/√Hz typ ppm/500 hr typ ppm/1000 hr typ V max V max V max V typ ppm FSR/°C max ppm/500 hr typ ppm/1000 hr typ mA typ KΩ min pF max Ω typ V min V max µA max pF max V max Rev. PrC | Page 6 of 32 ±1% for specified performance Typically 100 MΩ Typically ±30 nA @ 25°C @ 10 kHz AVDD = 11.7 V min, REFIN = 2.5 V AVDD = 12.9 V min, REFIN = 3.75 V For specified performance DVCC = 2.7 V to 5.5 V, JEDEC compliant Per pin Per pin DVCC = 5 V ± 10%, sinking 200 µA Preliminary Technical Data Parameter VOH, Output High Voltage VOL, Output Low Voltage VOH, Output High Voltage High Impedance Leakage Current High Impedance Output Capacitance POWER REQUIREMENTS AVDD DVCC Power Supply Sensitivity2 ∆VOUT/∆ΑVDD AIDD DICC Power Dissipation Power-down currents AIDD DICC 1 2 AD5724R/AD5734R/AD5754R Unit V min V max V min µA max pF typ Test Conditions/Comments DVCC = 5 V ± 10%, sourcing 200 µA DVCC = 2.7 V to 3.6 V, sinking 200 µA DVCC = 2.7 V to 3.6 V, sourcing 200 µA Value DVCC − 1 0.4 DVCC − 0.5 ±1 5 4.5 to 16.5 2.7 to 5.5 −75 2.75 1 TBD 80 TBD V min to V max V min to V max dB typ mA/channel max µA max mW typ µA typ µA typ 200mV sine wave superimposed on AVDD @ 50/60 Hz Outputs unloaded VIH = DVCC, VIL = GND, 0.5 µA typ 12 V operation, outputs unloaded All DAC channels and internal reference powered-down For specified performance minimum headroom requirement is 0.9V Guaranteed by characterization. Not production tested. AC PERFORMANCE CHARACTERISTICS AVDD = 4.51 V to 16.5 V, AVSS = −4.51 V to −16.5 V / 0V, GND = 0 V, REFIN= 2.5 V external, DVCC = 2.7 V to 5.5 V, RLOAD = 2 kΩ, CLOAD = 200 pF; all specifications TMIN to TMAX, ±10 V range unless otherwise noted. Table 4. Parameter2 DYNAMIC PERFORMANCE Output Voltage Settling Time B Grade 8 10 5 4.5 35 25 10 10 0.1 0.05 80 1 120 Unit µs typ µs max µs typ V/µs typ nV-sec typ mV typ nV-sec typ nV-sec typ nV-sec typ LSB p-p typ µV rms typ kHz typ nV/√Hz typ Test Conditions/Comments Full-scale step (20 V) to ±0.03 % FSR 512 LSB step settling (@ 16 bits) Slew Rate Digital-to-Analog Glitch Energy Glitch Impulse Peak Amplitude Digital Crosstalk DAC-to-DAC Crosstalk Digital Feedthrough Output Noise (0.1 Hz to 10 Hz Bandwidth) Output Noise (100 kHz Bandwidth) 1/f Corner Frequency Output Noise Spectral Density 1 2 @ 16 bit resolution Measured at 10 kHz For specified performance headroom requirement is 0.9V Guaranteed by design and characterization, not production tested. Rev. PrC | Page 7 of 32 AD5724R/AD5734R/AD5754R TIMING CHARACTERISTICS Preliminary Technical Data AVDD = 4.5 V to 16.5 V, AVSS = −4.5 V to −16.5 V / 0V, GND = 0 V, REFIN = 2.5 V external, DVCC = 2.7 V to 5.5 V, RLOAD = 2 kΩ, CLOAD = 200 pF; all specifications TMIN to TMAX, unless otherwise noted. Table 5. Parameter1, 2, 3 t1 t2 t3 t4 t5 t6 t7 t8 t9 t10 t11 t12 t13 t14 t15 t16 t174 t184 t19 1 2 Limit at TMIN, TMAX 33 13 13 13 13 100 5 0 20 20 20 1.5 10 1.5 20 2.5 13 40 200 Unit ns min ns min ns min ns min ns min ns min ns min ns min ns min ns min ns min µs max µs max µs max ns min µs max ns min ns max ns min Description SCLK cycle time SCLK high time SCLK low time SYNC falling edge to SCLK falling edge setup time SCLK falling edge to SYNC rising edge Minimum SYNC high time (write mode) Data setup time Data hold time LDAC falling edge to SYNC falling edge SYNC rising edge to LDAC falling edge LDAC pulse width low LDAC falling edge to DAC output response time DAC output settling time SYNC rising edge to output response time (LDAC = 0) CLR pulse width low CLR pulse activation time SYNC rising edge to SCLK falling edge SCLK rising edge to SDO valid (CL SDO5 = 15 pF) Minimum SYNC high time (readback/daisy-chain mode) Guaranteed by characterization. Not production tested. All input signals are specified with tR = tF = 5 ns (10% to 90% of DVCC) and timed from a voltage level of 1.2 V. 3 See Figure 2, Figure 3, and Figure 4. 4 Daisy-chain and Readback mode. 5 CL SDO = Capacitive load on SDO output. Rev. PrC | Page 8 of 32 Preliminary Technical Data t1 SCLK 1 2 24 AD5724R/AD5734R/AD5754R t6 t4 SYNC t3 t2 t5 t7 SDIN DB23 t8 DB0 t9 LDAC t10 t11 t13 t12 VOUTX t13 VOUTX t14 CLR t15 t16 VOUTX Figure 2. Serial Interface Timing Diagram t1 SCLK 24 48 t19 t4 SYNC t3 t2 t5 t17 t7 SDIN DB23 t8 DB0 DB23 DB0 INPUT WORD FOR DAC N t18 DB23 INPUT WORD FOR DAC N-1 DB0 SDO UNDEFINED LDAC INPUT WORD FOR DAC N t10 t11 Figure 3. Daisy Chain Timing Diagram Rev. PrC | Page 9 of 32 AD5724R/AD5734R/AD5754R SCLK 1 24 Preliminary Technical Data 1 24 t19 SYNC SDIN DB23 DB0 DB23 DB0 INPUT WORD SPECIFIES REGISTER TO BE READ NOP CONDITION SDO DB23 DB0 DB23 DB0 06465-004 UNDEFINED SELECTED REGISTER DATA CLOCKED OUT Figure 4. Readback Timing Diagram Rev. PrC | Page 10 of 32 Preliminary Technical Data ABSOLUTE MAXIMUM RATINGS TA = 25°C unless otherwise noted. Transient currents of up to 100 mA do not cause SCR latch-up. Table 6. Parameter AVDD to GND AVSS to GND DVCC to GND Digital Inputs to GND Digital Outputs to GND REFIN/REFOUT to GND VOUTA, VOUTB, VOUTC, VOUTD to GND DAC_GND to GND SIG_GND to GND Operating Temperature Range, TA Industrial Storage Temperature Range Junction Temperature, TJ max 24-Lead TSSOP Package θJA Thermal Impedance Power Dissipation Lead Temperature Soldering Rating −0.3 V to +17 V +0.3 V to −17 V −0.3 V to +7 V −0.3 V to DVCC + 0.3 V or 7 V (whichever is less) −0.3 V to DVCC + 0.3 V or 7V (whichever is less) −0.3 V to +17 V AVSS to AVDD -0.3V to +0.3V -0.3V to +0.3V −40°C to +85°C −65°C to +150°C 105°C 90°C/W (TJ max – TA)/ θJA JEDEC Industry Standard J-STD-020 AD5724R/AD5734R/AD5754R Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ESD CAUTION Rev. PrC | Page 11 of 32 Preliminary Technical Data PIN CONFIGURATION AND FUNCTION DESCRIPTIONS AVSS NC VOUTA VOUTB BIN/2sCOMP NC SYNC SCLK SDIN 1 2 3 4 5 6 7 8 9 24 AVDD 23 VOUTC AD5724R/AD5734R/AD5754R AD5724R/ AD5734R/ AD5754R 22 VOUTD 21 SIG_GND 20 SIG_GND TOP VIEW (Not to Scale) 19 DAC_GND 18 DAC_GND 17 REFIN/REFOUT 16 SDO 15 GND 14 DVCC 13 NC 06465-005 LDAC 10 CLR 11 NC 12 NC = NO CONNECT Figure 5.Pin Configuration Table 7. Pin Function Descriptions Pin No. 1 2, 6, 12, 13 3 4 5 Mnemonic AVSS NC VOUTA VOUTB BIN/2sCOMP Description Negative Analog Supply Pin. Voltage ranges from –4.5 V to –16.5 V. This pin can be connected to 0 V if output ranges are unipolar. Do not connect to these pins. Analog Output Voltage of DAC A. The output amplifier is capable of directly driving a 2 kΩ, 4000 pF load. Analog Output Voltage of DAC B. The output amplifier is capable of directly driving a 2 kΩ, 4000 pF load. Determines the DAC coding for a bipolar output range. This pin should be hardwired to either DVCC or GND. When hardwired to DVCC, input coding is offset binary. When hardwired to GND, input coding is twos complement. (For unipolar output ranges, coding is always straight binary). Active Low Input. This is the frame synchronization signal for the serial interface. While SYNC is low, data is transferred on the falling edge of SCLK. Serial Clock Input. Data is clocked into the shift register on the falling edge of SCLK. This operates at clock speeds up to 30 MHz. Serial Data Input. Data must be valid on the falling edge of SCLK. Load DAC, Logic Input. This is used to update the DAC registers and consequently, the analog output. When tied permanently low, the addressed DAC register is updated on the rising edge of SYNC. If LDAC is held high during the write cycle, the DAC input register is updated, but the output update is held off until the falling edge of LDAC. In this mode, all analog outputs can be updated simultaneously on the falling edge of LDAC. The LDAC pin should not be left unconnected. Active Low Input. Asserting this pin sets the DAC registers to zero-scale code or mid-scale code (user-selectable). Digital Supply Pin. Voltage ranges from 2.7 V to 5.5 V. Ground Reference Pin. Serial Data Output. Used to clock data from the serial register in daisy-chain or readback mode. Data is clocked out on the rising edge of SCLK and is valid on the falling edge of SCLK. External Reference Voltage Input and Internal Reference Voltage Output. Reference input range is 2 V to 3 V. REFIN = 2.5 V for specified performance. REFOUT = 2.5 V ± 2 mV @ 25°C. Ground reference pins for the four digital-to-analog converters. Ground reference pins for the four output amplifiers. Analog Output Voltage of DAC D. The output amplifier is capable of directly driving a 2 kΩ, 4000 pF load. Analog Output Voltage of DAC C. The output amplifier is capable of directly driving a 2 kΩ, 4000 pF load. Positive Analog Supply Pin. Voltage ranges from 4.5 V to 16.5 V. Negative Analog Supply connection. Voltage ranges from –4.5 V to –16.5 V. This paddle can be connected to 0 V if output ranges are unipolar. 7 8 9 10 SYNC SCLK SDIN LDAC 11 14 15 16 17 18, 19 20, 21 22 23 24 Exposed Paddle 1 CLR1 DVCC GND SDO REFIN/REFOUT DAC_GND SIG_GND VOUTD VOUTC AVDD AVSS Internal pull-up device on this logic input. Therefore, it can be left floating and defaults to a logic high. Rev. PrC | Page 12 of 32 Preliminary Technical Data TYPICAL PERFORMANCE CHARACTERISTICS AD5724R/AD5734R/AD5754R Figure 6. AD5754R Integral Nonlinearity Error vs. Code (Four Traces) Figure 9. AD5754R Differential Nonlinearity Error vs. Code (Four Traces) Figure 7. AD5734R Integral Nonlinearity Error vs. Code (Four Traces) Figure 10. AD5734R Differential Nonlinearity Error vs. Code (Four Traces) Figure 8. AD5724R Integral Nonlinearity Error vs. Code (Four Traces) Figure 11. AD5724R Differential Nonlinearity Error vs. Code (Four Traces) Rev. PrC | Page 13 of 32 AD5724R/AD5734R/AD5754R Preliminary Technical Data Figure 12. AD5754R Integral Nonlinearity Error vs. Temperature (Four Traces) Figure 15.AD5754R Differential Nonlinearity Error vs. Supply Voltage (Four Traces) Figure 13. AD5754R Differential Nonlinearity Error vs. Temperature (Four Traces) Figure 16. AD5754R Integral Nonlinearity Error vs. Reference Voltage (Four Traces) Figure 14. AD5754R Integral Nonlinearity Error vs. Supply Voltage (Four Traces) Figure 17. AD5754R Differential Nonlinearity vs. Reference Voltage (Four Traces) Rev. PrC | Page 14 of 32 Preliminary Technical Data AD5724R/AD5734R/AD5754R Figure 18. AD5754R Total Unadjusted Error vs. Reference Voltage (Four Traces) Figure 21. AIDD vs. AVDD Figure 19. AD5754R Total Unadjusted Error vs. Supply Voltage (Four Traces) Figure 22. Zero-Scale Error vs. Temperature (Four Traces) Figure 20. AIDD/AISS vs. AVDD/AVSS Figure 23. Bipolar Zero Error vs. Temperature (Two Traces) Rev. PrC | Page 15 of 32 AD5724R/AD5734R/AD5754R Preliminary Technical Data Figure 24. Gain Error vs. Temperature (Four Traces) Figure 27. Full-Scale Settling Time, ±10 V Range (Two Traces)+ve & -ve Figure 25. DICC vs. Logic Input Voltage Increasing and Decreasing Figure 28. Full-Scale Settling Time, ±5 V Range (Two Traces) Figure 26. Output Amplifier Source and Sink Capability (Four Traces) Figure 29. Full-Scale Settling Time, +10 V Range (Two Traces) Rev. PrC | Page 16 of 32 Preliminary Technical Data AD5724R/AD5734R/AD5754R Figure 30. Full-Scale Settling Time, +5 V Range (Two Traces) Figure 33. Peak-to-Peak Noise, 100 kHz Bandwidth, (Four Traces) Figure 31. Digital-to-Analog Glitch Energy (Four Traces) Figure 34. VOUT vs. AVDD/AVSS on Power Up (Two Traces) (single and dual) Figure 32. Peak-to-Peak Noise, 0.1 Hz to 10 Hz Bandwidth (Four Traces) Figure 35. REFOUT Turn-On Transient Rev. PrC | Page 17 of 32 AD5724R/AD5734R/AD5754R Preliminary Technical Data Figure 36. REFOUT Output Noise (100 kHz Bandwidth) Figure 39. REFOUT Load Transient (Two Traces) Figure 37. REFOUT Output Noise (0.1 Hz to 10 Hz Bandwidth) Figure 40. REFOUT Histogram of Thermal Hysteresis Figure 41. REFOUT Voltage vs. Load Current Figure 38. REFOUT Line Transient (Two Traces) Rev. PrC | Page 18 of 32 Preliminary Technical Data TERMINOLOGY Relative Accuracy or Integral Nonlinearity (INL) For the DAC, relative accuracy, or integral nonlinearity, is a measure of the maximum deviation in LSBs from a straight line passing through the endpoints of the DAC transfer function. A typical INL vs. code plot can be seen in Figure 6. Differential Nonlinearity (DNL) Differential nonlinearity is the difference between the measured change and the ideal 1 LSB change between any two adjacent codes. A specified differential nonlinearity of ±1 LSB maximum ensures monotonicity. This DAC is guaranteed monotonic by design. A typical DNL vs. code plot can be seen in Figure 9. Monotonicity A DAC is monotonic if the output either increases or remains constant for increasing digital input code. The AD5724R/ AD5734R/AD5754R are monotonic over their full operating temperature range. Bipolar Zero Error Bipolar zero error is the deviation of the analog output from the ideal half-scale output of 0 V when the DAC register is loaded with 0x8000 (straight binary coding) or 0x0000 (twos complement coding). A plot of bipolar zero error vs. temperature can be seen in Figure 23. Bipolar Zero TC Bipolar Zero TC is a measure of the change in the bipolar zero error with a change in temperature. It is expressed in ppm FSR/°C. Zero-Scale Error/Negative Full-Scale Error Zero-scale error is the error in the DAC output voltage when 0x0000 (straight binary coding) or 0x8000 (twos complement coding) is loaded to the DAC register. Ideally, the output voltage should be negative full-scale − 1 LSB. A plot of zero-scale error vs. temperature can be seen in Figure 22. Zero-Scale TC This is a measure of the change in zero-scale error with a change in temperature. Zero-Scale TC is expressed in ppm FSR/°C. Output Voltage Settling Time Output voltage settling time is the amount of time it takes for the output to settle to a specified level for a full-scale input change. A plot of settling time can be seen in Figure 27. AD5724R/AD5734R/AD5754R Slew Rate The slew rate of a device is a limitation in the rate of change of the output voltage. The output slewing speed of a voltage output D/A converter is usually limited by the slew rate of the amplifier used at its output. Slew rate is measured from 10% to 90% of the output signal and is given in V/µs. Gain Error This is a measure of the span error of the DAC. It is the deviation in slope of the DAC transfer characteristic from ideal expressed in % FSR. A plot of gain error vs. temperature can be seen in Figure 24. Gain TC This is a measure of the change in gain error with changes in temperature. Gain TC is expressed in ppm FSR/°C. Total Unadjusted Error (TUE) Total unadjusted error is a measure of the output error taking all the various errors into account, namely INL error, offset error, gain error, and output drift over supplies, temperature, and time. TUE is expressed in % FSR. Digital-to-Analog Glitch Impulse Digital-to-analog glitch impulse is the impulse injected into the analog output when the input code in the DAC register changes state, but the output voltage remains constant. It is normally specified as the area of the glitch in nV-sec and is measured when the digital input code is changed by 1 LSB at the major carry transition (0x7FFF to 0x8000). See Figure 31. Glitch Impulse Peak Amplitude Glitch impulse peak amplitude is the peak amplitude of the impulse injected into the analog output when the input code in the DAC register changes state. It is specified as the amplitude of the glitch in mV and is measured when the digital input code is changed by 1 LSB at the major carry transition (0x7FFF to 0x8000). See Figure 31. Digital Feedthrough Digital feedthrough is a measure of the impulse injected into the analog output of the DAC from the digital inputs of the DAC, but is measured when the DAC output is not updated. It is specified in nV-sec and measured with a full-scale code change on the data bus. Power Supply Sensitivity Power supply sensitivity indicates how the output of the DAC is affected by changes in the power supply voltage, it is measured by superimposing a 50/60Hz, 200mVpk-pk sine wave on the supply voltages and measuring the proportion of the sine wave that transfers to the outputs. Rev. PrC | Page 19 of 32 AD5724R/AD5734R/AD5754R DC Crosstalk This is the dc change in the output level of one DAC in response to a change in the output of another DAC. It is measured with a full-scale output change on one DAC while monitoring another DAC. It is expressed in LSBs. Digital Crosstalk Digital crosstalk is a measure of the impulse injected into the analog output of one DAC from the digital inputs of another DAC, but is measured when the DAC output is not updated. It is specified in nV-sec and measured with a full-scale code change on the data bus. Preliminary Technical Data DAC-to-DAC Crosstalk DAC-to-DAC crosstalk is the glitch impulse transferred to the output of one DAC due to a digital code change and subsequent output change of another DAC. This includes both digital and analog crosstalk. It is measured by loading one of the DACs with a full-scale code change (all 0s to all 1s and vice versa) with LDAC low and monitoring the output of another DAC. The energy of the glitch is expressed in nV-sec. Voltage Reference TC Reference TC is a measure of the change in the reference output voltage with a change in temperature. It is expressed in ppm/°C. Rev. PrC | Page 20 of 32 AD5724R/AD5734R/AD5754R THEORY OF OPERATION The AD5724R/AD5734R/AD5754R are quad, 12-/14-/16-bit, serial input, unipolar/bipolar, voltage output DACs. They operate from single supply voltages of +4.5 V to +16.5 V or dual supply voltages of ±4.5 V to ±16.5 V. In addition, the parts have software-selectable output ranges of +5 V, +10 V, +10.8 V, ±5 V, ±10 V, and ±10.8 V. Data is written to the AD5724R/AD5734R/AD5754R in a 24-bit word format via a 3-wire serial interface. The devices also offer an SDO pin to facilitate daisy chaining or readback. The AD5724R/AD5734R/AD5754R incorporate a power-on reset circuit to ensure that the DAC registers power up loaded with 0x0000. When powered on, the outputs are clamped to 0 V via a low impedance path. The parts also feature on-chip reference and reference buffers. Preliminary Technical Data REFIN R R R TO OUTPUT AMPLIFIER R ARCHITECTURE The DAC architecture consists of a string DAC followed by an output amplifier. Figure 42 shows a block diagram of the DAC architecture. The reference input is buffered before being applied to the DAC. REFIN R Figure 43. Resistor String Structure Output Amplifiers The output amplifiers are capable of generating both unipolar and bipolar output voltages. They are capable of driving a load of 2 kΩ in parallel with 4000 pF to GND. The source and sink capabilities of the output amplifiers can be seen in Figure 26. The slew rate is 4.5 V/µs with a full-scale settling time of 10 µs. REF (+) DAC REGISTER RESISTOR STRING REF (–) VOUTX CONFIGURABLE OUTPUT AMPLIFIER 04645-006 Reference Buffers The AD5724R/AD5734R/AD5754R can operate with either an external or internal reference. The reference input has an input range of 2 V to 3 V with 2.5 V for specified performance. This input voltage is then buffered before it is applied to the DAC cores. GND OUTPUT RANGE CONTROL Figure 42. DAC Architecture Block Diagram The resistor string structure is shown in Figure 43. It is a string of resistors, each of value R. The code loaded to the DAC register determines the node on the string where the voltage is to be tapped off and fed into the output amplifier. The voltage is tapped off by closing one of the switches connecting the string to the amplifier. Because it is a string of resistors, it is guaranteed monotonic. SERIAL INTERFACE The AD5724R/AD5734R/AD5754R are controlled over a versatile 3-wire serial interface that operates at clock rates up to 30 MHz. It is compatible with SPI®, QSPI™, MICROWIRE™, and DSP standards. Input Shift Register The input shift register is 24 bits wide. Data is loaded into the device MSB first as a 24-bit word under the control of a serial clock input, SCLK. The input register consists of a read/write bit, three register select bits, three DAC address bits, and 16 data bits. The timing diagram for this operation is shown in Figure 2. Rev. PrC | Page 21 of 32 06465-007 AD5724R/AD5734R/AD5754R Standalone Operation The serial interface works with both a continuous and noncontinuous serial clock. A continuous SCLK source can only be used if SYNC is held low for the correct number of clock cycles. In gated clock mode, a burst clock containing the exact number of clock cycles must be used, and SYNC must be taken high after the final clock to latch the data. The first falling edge of SYNC starts the write cycle. Exactly 24 falling clock edges must be applied to SCLK before SYNC is brought high again. If SYNC is brought high before the 24th falling SCLK edge, the data written is invalid. If more than 24 falling SCLK edges are applied before SYNC is brought high, the input data is also invalid. The input register addressed is updated on the rising edge of SYNC. For another serial transfer to take place, SYNC must be brought low again. After the end of the serial data transfer, data is automatically transferred from the input shift register to the addressed register. When the data has been transferred into the chosen register of the addressed DAC, all DAC registers and outputs can be updated by taking LDAC low while SYNC is high. 68HC11* MOSI SCK PC7 PC6 MISO Preliminary Technical Data Daisy-Chain Operation For systems that contain several devices, the SDO pin can be used to daisy chain several devices together. Daisy-chain mode can be useful in system diagnostics and in reducing the number of serial interface lines. The first falling edge of SYNC starts the write cycle. SCLK is continuously applied to the input shift register when SYNC is low. If more than 24 clock pulses are applied, the data ripples out of the shift register and appears on the SDO line. This data is clocked out on the rising edge of SCLK and is valid on the falling edge. By connecting the SDO of the first device to the SDIN input of the next device in the chain, a multidevice interface is constructed. Each device in the system requires 24 clock pulses. Therefore, the total number of clock cycles must equal 24 × N, where N is the total number of AD5724R/AD5734R/AD5754R devices in the chain. When the serial transfer to all devices is complete, SYNC is taken high. This latches the input data in each device in the daisy chain and prevents any further data from being clocked into the input shift register. The serial clock can be a continuous or a gated clock. A continuous SCLK source can only be used if SYNC is held low for the correct number of clock cycles. In gated clock mode, a burst clock containing the exact number of clock cycles must be used, and SYNC must be taken high after the final clock to latch the data. AD5724R/ AD5734R/ AD5754R* SDIN SCLK SYNC LDAC SDO Readback Operation Readback mode is invoked by setting the R/W bit = 1 in the serial input register write. (If the SDO output is disabled via the SDO DISABLE bit in the control register, it is automatically enabled for the duration of the read operation after which it is disabled again) With R/W = 1, Bit A2 to Bit A0 in association with Bit REG2 to Bit REG0 select the register to be read. The remaining data bits in the write sequence are don’t care bits. During the next SPI write, the data appearing on the SDO output contains the data from the previously addressed register. For a read of a single register, the NOP command can be used in clocking out the data from the selected register on SDO. The readback diagram in Figure 4 shows the readback sequence. For example, to read back the data register of Channel A, the following sequence should be implemented: 1. Write 0x800000 to the AD5724R/AD5734R/AD5754R input register. This configures the part for read mode with the data register of Channel A selected. Note that all the data bits, DB15 to DB0, are don’t care bits. Follow this with a second write, a NOP condition, 0x180000. During this write, the data from the register is clocked out on the SDO line. SDIN AD5724R/ AD5734R/ AD5754R* SCLK SYNC LDAC SDO SDIN SCLK AD5724R/ AD5734R/ AD5754R* SYNC LDAC SDO 04645-008 2. *ADDITIONAL PINS OMITTED FOR CLARITY. Figure 44. Daisy Chaining the AD5724R/AD5734R/AD5754R Rev. PrC | Page 22 of 32 Preliminary Technical Data LOAD DAC (LDAC) After data has been transferred into the input register of the DACs, there are two ways to update the DAC registers and DAC outputs. Depending on the status of both SYNC and LDAC, one of two update modes is selected, individual DAC updating or simultaneous updating of all DACs. OUTPUT AMPLIFIER VREFIN 12-/14-/16-BIT DAC VOUT AD5724R/AD5734R/AD5754R CONFIGURING THE AD5724R/AD5734R/AD5754R When the power supplies are applied to the AD5724R/ AD5734R/AD5754R, the power-on reset circuit ensures that all registers default to 0. This places all channels and the internal reference in power-down mode. The first communication to the AD5724R/AD5734R/AD5754R should be to set the required output range on all channels (default range is the 5 V unipolar range) by writing to the range select register. The user should then write to the power-control register to power-on the required channels and the internal reference, if required. If an external reference source is being used, the internal reference must remain in power-down mode. To program an output value on a channel, that channel must first be powered up; any writes to a channel while it is in power down mode are ignored. The AD5724R/AD5734R/AD5754R operate with a wide power supply range. It is important that the power supply applied to the parts provides adequate headroom to support the chosen output ranges. LDAC DAC REGISTER INPUT REGISTER SDO 06465-009 SCLK SYNC SDIN INTERFACE LOGIC Figure 45. Simplified Diagram of Input Loading Circuitry for One DAC TRANSFER FUNCTION Table 9 to Table 17 show the relationships of the ideal input code to output voltage for the AD5754R, AD5734R, and AD5724R, respectively, for all output voltage ranges. For unipolar output ranges, the data coding is straight binary. For bipolar output ranges, the data coding is user-selectable via the BIN/2sCOMP pin and can be either offset binary or twos complement. For a unipolar output range, the output voltage expression is given by Individual DAC Updating In this mode, LDAC is held low while data is being clocked into the input shift register. The addressed DAC output is updated on the rising edge of SYNC. Simultaneous Updating of All DACs In this mode, LDAC is held high while data is being clocked into the input shift register. All DAC outputs are asynchronously updated by taking LDAC low after SYNC has been taken high. The update now occurs on the falling edge of LDAC. D VOUT = VREFIN × Gain ⎡ N ⎤ ⎢2 ⎥ ⎣⎦ For a bipolar output range, the output voltage expression is given by Gain × VREFIN D VOUT = VREFIN × Gain ⎡ N ⎤ − ⎢⎦ 2 ⎣2 ⎥ where: D is the decimal equivalent of the code loaded to the DAC. N is the bit resolution of the DAC. VREFIN is the reference voltage applied at the REFIN pin. Gain is an internal gain the value of which depends on the output range selected by the user as shown in Table 8. Table 8. Output Range (V) +5 +10 +10.8 ±5 ±10 ±10.8 Gain Value 2 4 4.32 4 8 8.64 ASYNCHRONOUS CLEAR (CLR) CLR is an active low clear that allows the outputs to be cleared to either zero-scale code or mid-scale code. The clear code value is user-selectable via the CLR SELECT bit of the control register (see the Control Register section). It is necessary to maintain CLR low for a minimum amount of time to complete the operation (see Figure 2). When the CLR signal is returned high, the output remains at the cleared value until a new value is programmed. The outputs cannot be updated with a new value while the CLR pin is low. A clear operation can also be performed via the clear command in the control register. Rev. PrC | Page 23 of 32 AD5724R/AD5734R/AD5754R Ideal Output Voltage to Input Code Relationship—AD5754R Table 9. Bipolar Output, Offset Binary Coding Digital Input MSB 1111 1111 – 1000 1000 0111 – 0000 0000 1111 1111 – 0000 0000 1111 – 0000 0000 1111 1111 – 0000 0000 1111 – 0000 0000 LSB 1111 1110 – 0001 0000 1111 – 0001 0000 ±5 V Output Range +2 REFIN(32767/32768) +2 REFIN(32766/32768) – +2 REFIN(1/32768) 0V −2 REFIN(1/32768) – −2 REFIN(32766/32768) −2 REFIN(32767/32768 Preliminary Technical Data Analog Output ±10 V Output Range +4 REFIN(32767/32768) +4 REFIN(32766/32768) – +4 REFIN(1/32768) 0V −4 REFIN(1/32768) – −4 REFIN(32766/32768) −4 REFIN(32767/32768) ±10.8 V Output Range +4.32 REFIN(32767/32768) +4.32 REFIN(32766/32768) – +4.32 REFIN(1/32768) 0V −4.32 REFIN(32766/32768) – −4.32 REFIN(32766/32768) −4.32 REFIN(32767/32768) Table 10. Bipolar Output, Twos Complement Coding Digital Input MSB 0111 0111 – 0000 0000 1111 – 1000 1000 1111 1111 – 0000 0000 1111 – 0000 0000 1111 1111 – 0000 0000 1111 – 0000 0000 LSB 1111 1110 – 0001 0000 1111 – 0001 0000 ±5 V Output Range +2 REFIN(32767/32768) +2 REFIN(32766/32768) – +2 REFIN(1/32768) 0V −2 REFIN(1/32768) – −2 REFIN(32766/32768) −2 REFIN(32767/32768) Analog Output ±10 V Output Range +4 REFIN(32767/32768) +4 REFIN(32766/32768) – +4 REFIN(1/32768) 0V −4 REFIN(1/32768) – −4 REFIN(32766/32768) −4 REFIN(32767/32768) ±10.8 V Output Range +4.32 REFIN(32767/32768) +4.32 REFIN(32766/32768) – +4.32 REFIN(1/32768) 0V −4.32 REFIN(1/32768) – −4.32 REFIN(32766/32768) −4.32 REFIN(32767/32768) Table 11. Unipolar Output, Straight Binary Coding Digital Input MSB 1111 1111 – 1000 1000 0111 – 0000 0000 1111 1111 – 0000 0000 1111 – 0000 0000 1111 1111 – 0000 0000 1111 – 0000 0000 LSB 1111 1110 – 0001 0000 1111 – 0001 0000 +5 V Output Range +2 REFIN(65535/65536) +2 REFIN(65534/65536) – +2 REFIN(32769/65536) +2 REFIN(32768/65536) +2 REFIN(32767/65536) – +2 REFIN(1/65536) 0V Analog Input +10 V Output Range +4 REFIN(65535/65536) +4 REFIN(65534/65536) – +4 REFIN(32769/65536) +4 REFIN(32768/65536) +4 REFIN(32767/65536) – +4 REFIN(1/65536) 0V +10.8 V Output Range +4.32 REFIN(65535/65536) +4.32 REFIN(65534/65536) – +4.32 REFIN(32769/65536) +4.32 REFIN(32768/65536) +4.32 REFIN(32767/65536) – +4.32 REFIN(1/65536) 0V Rev. PrC | Page 24 of 32 Preliminary Technical Data Ideal Output Voltage to Input Code Relationship—AD5734R Table 12. Bipolar Output, Offset Binary Coding Digital Input MSB 11 11 – 10 10 01 – 00 00 1111 1111 – 0000 0000 1111 – 0000 0000 1111 1111 – 0000 0000 1111 – 0000 0000 LSB 1111 1110 – 0001 0000 1111 – 0001 0000 ±5 V Output Range +2 REFIN(8191/8192) +2 REFIN(8190/8192) – +2 REFIN(1/8192) 0V −2 REFIN(1/8192) – −2 REFIN(8190/8192) −2 REFIN(8191/8191) AD5724R/AD5734R/AD5754R Analog Output ±10 V Output Range +4 REFIN(8191/8192) +4 REFIN(8190/8192) – +4 REFIN(1/8192) 0V −4 REFIN(1/8192) – −4 REFIN(8190/8192) −4 REFIN(8191/8192) ±10.8 V Output Range +4.32 REFIN(8191/8192) +4.32 REFIN(8190/8192) – +4 REFIN(1/8192) 0V −4.32 REFIN(1/8192) – −4.32 REFIN(8190/8192) −4.32 REFIN(8191/8192) Table 13. Bipolar Output, Twos Complement Coding Digital Input MSB 01 01 – 00 00 11 – 10 10 1111 1111 – 0000 0000 1111 – 0000 0000 1111 1111 – 0000 0000 1111 – 0000 0000 LSB 1111 1110 – 0001 0000 1111 – 0001 0000 ±5 V Output Range +2 REFIN(8191/8192) +2 REFIN(8190/8192) – +2 REFIN(1/8192) 0V −2 REFIN(1/8192) – −2 REFIN(8190/8192) −2 REFIN(8191/8192) Analog Output ±10 V Output Range +4 REFIN(8191/8192) +4 REFIN(8190/8192) – +4 REFIN(1/8192) 0V −4 REFIN(1/8192) – −4 REFIN(8190/8192) −4 REFIN(8191/8192) ±10.8 V Output Range +4.32 REFIN(8191/8192) +4.32 REFIN(8190/8192) – +4 REFIN(1/8192) 0V −4.32 REFIN(1/8192) – −4.32 REFIN(8190/8192) −4.32 REFIN(8191/8192) Table 14. Unipolar Output, Straight Binary Coding Digital Input MSB 11 11 – 10 10 01 – 00 00 1111 1111 – 0000 0000 1111 – 0000 0000 1111 1111 – 0000 0000 1111 – 0000 0000 LSB 1111 1110 – 0001 0000 1111 – 0001 0000 ±5 V Output Range +2 REFIN(16383/16384) +2 REFIN(16382/16384) – +2 REFIN(8193/16384) +2 REFIN(8192/16384) +2 REFIN(8191/16384) – +2 REFIN(1/16384) 0V Analog Output ±10 V Output Range +4 REFIN(16383/16384) +4 REFIN(16382/16384) – +4 REFIN(8193/16384) +4 REFIN(8192/16384) +4 REFIN(8191/16384) – +4 REFIN(1/16384) 0V ±10.8 V Output Range +4.32 REFIN(16383/16384) +4.32 REFIN(16382/16384) – +4.32 REFIN(8193/16384) +4.32 REFIN(8192/16384) +4.32 REFIN(8191/16384) – +4.32 REFIN(1/16384) 0V Rev. PrC | Page 25 of 32 AD5724R/AD5734R/AD5754R Ideal Output Voltage to Input Code Relationship—AD5724R Table 15. Bipolar Output, Offset Binary Coding Digital Input MSB 1111 1111 – 1000 1000 0111 – 0000 0000 1111 1111 – 0000 0000 1111 – 0000 0000 LSB 1111 1110 – 0001 0000 1111 – 0001 0000 ±5 V Output Range +2 REFIN(2047/2048) +2 REFIN(2046/2048) – +2 REFIN(1/2048) 0V −2 REFIN(1/2048) – −2 REFIN(2046/2048) −2 REFIN(2047/2047) Preliminary Technical Data Analog Output ±10 V Output Range +4 REFIN(2047/2048) +4 REFIN(2046/2048) – +4 REFIN(1/2048) 0V −4 REFIN(1/2048) – −4 REFIN(2046/2048) −4 REFIN(2047/2048) ±10.8 V Output Range +4.32 REFIN(2047/2048) +4.32 REFIN(2046/2048) – +4 REFIN(1/2048) 0V −4.32 REFIN(1/2048) – −4.32 REFIN(2046/2048) −4.32 REFIN(2047/2048) Table 16. Bipolar Output, Twos Complement Coding MSB 0111 0111 – 0000 0000 1111 – 1000 1000 Digital Output LSB 1111 1111 1111 1110 – – 0000 0001 0000 0000 1111 1111 – – 0000 0001 0000 0000 ±5 V Output Range +2 REFIN(2047/2048) +2 REFIN(2046/2048) – +2 REFIN(1/2048) 0V −2 REFIN(1/2048) – −2 REFIN(2046/2048) −2 REFIN(2047/2048) Analog Output ±10 V Output Range +4 REFIN(2047/2048) +4 REFIN(2046/2048) – +4 REFIN(1/2048) 0V −4 REFIN(1/2048) – −4 REFIN(2046/2048) −4 REFIN(2047/2048) ±10.8 V Output Range +4.32 REFIN(2047/2048) +4.32 REFIN(2046/2048) – +4 REFIN(1/2048) 0V −4.32 REFIN(1/2048) – −4.32 REFIN(2046/2048) −4.32 REFIN(2047/2048) Table 17. Unipolar Output, Straight Binary Coding Digital Input MSB 1111 1111 – 1000 1000 0111 – 0000 0000 1111 1111 – 0000 0000 1111 – 0000 0000 LSB 1111 1110 – 0001 0000 1111 – 0001 0000 +5 V Output Range +2 REFIN(4095/4096) +2 REFIN(4094/4096) – +2 REFIN(2049/4096) +2 REFIN(2048/4096) +2 REFIN(2047/4096) – +2 REFIN(1/4096) 0V Analog Output +10 V Output Range +4 REFIN(4095/4096) +4 REFIN(4094/4096) – +4 REFIN(2049/4096) +4 REFIN(2048/4096) +4 REFIN(2047/4096) – +4 REFIN(1/4096) 0V +10.8 V Output Range +4.32 REFIN(4095/4096) +4.32 REFIN(4094/4096) – +4.32 REFIN(2049/4096) +4.32 REFIN(2048/4096) +4.32 REFIN(2047/4096) – 4.32 REFIN(1/4096) 0V Rev. PrC | Page 26 of 32 Preliminary Technical Data INPUT REGISTER AD5724R/AD5734R/AD5754R The input register is 24 bits wide and consists of a read/write bit, a reserved bit, three register select bits, three DAC address bits, and 12/14-/16 data bits. The register data is clocked in MSB first on the SDIN pin. Table 18 shows the register format while Table 19 describes the function of each bit in the register. All registers are read/write registers. Table 18. Input Register Format MSB DB23 R/W DB22 0 DB21 REG2 DB20 REG1 DB19 REG0 DB18 A2 DB17 A1 DB16 A0 LSB DB15 to DB0 DATA Table 19. Input Register Bit Functions Bit Mnemonic R/W REG2, REG1, REG0 Description Indicates a read from or a write to the addressed register. Used in association with the address bits to determine if a write operation is to the data register, output range select register, power control register or control register. REG2 REG1 REG0 Function 0 0 0 Data Register 0 0 1 Output Range Select Register 0 1 0 Power Control Register 0 1 1 Control Register These bits are used to decode the DAC channels. A2 A1 A0 Channel Address 0 0 0 DAC A 0 0 1 DAC B 0 1 0 DAC C 0 1 1 DAC D 1 0 0 All Four DACs Data bits. A2, A1, A0 DB15 to DB0 DATA REGISTER The data register is addressed by setting the three REG bits to 000. The DAC address bits select the DAC channel where the data transfer is to take place (see Table 19). The data bits are in positions DB15 to DB0 for the AD5754R (see Table 20), DB15 to DB2 for the AD5734R (see Table 21), and DB15 to DB4 for the AD5724R (see Table 22). Table 20. Programming the AD5754R Data Register MSB REG2 0 REG1 0 REG0 0 A2 A1 DAC Address A0 LSB DB15 to DB0 16-Bit DAC Data Table 21. Programming the AD5734R Data Register MSB REG2 0 LSB REG1 0 REG0 0 A2 A1 DAC Address A0 DB15 to DB2 14-Bit DAC Data DB1 X DB0 X Table 22. Programming the AD5724R Data Register MSB REG2 0 LSB REG1 0 REG0 0 A2 A1 A0 DAC Address DB15 to DB4 12-Bit DAC Data DB3 X DB2 X DB1 X DB0 X Rev. PrC | Page 27 of 32 AD5724R/AD5734R/AD5754R OUTPUT RANGE SELECT REGISTER Preliminary Technical Data The output range select register is addressed by setting the three REG bits to 001. The DAC address bits select the DAC channel, while, the range bits (R2, R1, R0) select the required output range (see Table 23 and Table 24). Table 23. Programming the Required Output Range MSB REG2 0 LSB REG1 0 REG0 1 A2 A1 A0 DAC Address DB15 to DB3 Don’t Care DB2 R2 DB1 R1 DB0 R0 Table 24. Output Range Options R2 0 0 0 0 1 1 R1 0 0 1 1 0 0 R0 0 1 0 1 0 1 Output Range (V) +5 +10 +10.8 ±5 ±10 ±10.8 CONTROL REGISTER The control register is addressed by setting the three REG bits to 011. The value written to the address and data bits determines the control function selected. The control register options are shown in Table 25 and Table 26. Table 25. Control Register Format MSB REG2 0 REG2 0 REG2 0 REG2 0 REG1 1 REG1 1 REG1 1 REG1 1 REG0 1 REG0 1 REG0 1 REG0 1 A2 0 A2 0 A2 1 A2 1 A1 0 A1 0 A1 0 A1 0 A0 0 A0 1 A0 0 A0 1 DB15 to DB4 DB3 DB2 DB1 NOP, Data = Don’t Care DB2 CLAMP ENABLE DB1 CLR SELECT LSB DB0 DB15 to DB4 Don’t Care DB15 to DB4 DB3 TSD ENABLE DB3 DB0 SDO DISABLE DB0 DB2 DB1 CLEAR, Data = Don’t Care DB2 DB1 LOAD, Data = Don’t Care DB15 to DB4 DB3 DB0 Table 26. Control Register Functions Option NOP CLEAR LOAD SDO DISABLE CLR SELECT CLAMP ENABLE Description No operation instruction used in readback operations. Addressing this function sets the DAC registers to the clear code and updates the outputs. Addressing this function updates the DAC registers and consequently, the DAC outputs. Set by the user to disable the SDO output. Cleared by the user to enable the SDO output (default). See Table 27 for a description of the CLR SELECT operation. Set by the user to enable the current limit clamp (default). The channel does not power down on detection of overcurrent; the current is clamped at 20 mA. Cleared by the user to disable the current-limit clamp. The channel powers down on detection of overcurrent. Set by the user to enable the thermal shutdown feature. Cleared by the user to disable the thermal shutdown feature (default). TSD ENABLE Table 27. CLR Select Options CLR SELECT Setting 0 1 Unipolar Output Range 0V Mid-Scale Output CLR Value Bipolar Output Range 0V Negative Full-Scale Rev. PrC | Page 28 of 32 Preliminary Technical Data POWER CONTROL REGISTER AD5724R/AD5734R/AD5754R The power control register is addressed by setting the three REG bits to 010. This register allows the user to control and determine the power and thermal status of the AD5724R/AD5734R/AD5754R. The power control register options are shown in Table 28 and Table 29. Table 28. Power Control Register Format MSB REG2 0 REG1 1 REG0 0 A2 0 A1 0 A0 0 DB15 to DB11 Don’t Care DB10 OCD DB9 OCC DB8 OCB DB7 OCA DB6 0 DB5 TSD DB4 PUREF DB3 P UD DB2 P UC DB1 P UB LSB DB0 P UA Table 29. Power Control Register Functions Option PUA Description DAC A Power-Up. When set, this bit places DAC A in normal operating mode. When cleared, this bit places DAC A in power-down mode (default). If the CLAMP ENABLE bit of the control register is cleared, DACA will power down automatically on detection of an over-current, PUA will be cleared to reflect this. DAC B Power-Up. When set, this bit places DAC B in normal operating mode. When cleared, this bit places DAC B in power-down mode (default). If the CLAMP ENABLE bit of the control register is cleared, DACB will power down automatically on detection of an over-current, PUB will be cleared to reflect this. DAC C Power-Up. When set, this bit places DAC C in normal operating mode. When cleared, this bit places DAC C in power-down mode (default). If the CLAMP ENABLE bit of the control register is cleared, DACC will power down automatically on detection of an over-current, PUC will be cleared to reflect this. DAC D Power-Up. When set, this bit places DAC D in normal operating mode. When cleared, this bit places DAC D in power-down mode (default). If the CLAMP ENABLE bit of the control register is cleared, DACD will power down automatically on detection of an over-current, PUD will be cleared to reflect this. Reference Power-Up. When set, this bit places the internal reference in normal operating mode. When cleared, this bit places the internal reference in power-down mode (default). Thermal Shutdown Alert. Read-Only Bit. In the event of an over-temperature situation, this bit is set. DAC A Overcurrent Alert. Read-Only Bit. In the event of an overcurrent situation on DAC A, this bit is set. DAC B Overcurrent Alert. Read-Only Bit. In the event of an overcurrent situation on DAC B, this bit is set. DAC C Overcurrent Alert. Read-Only Bit. In the event of an overcurrent situation on DAC C, this bit is set. DAC D Overcurrent Alert. Read-Only Bit. In the event of an overcurrent situation on DAC D, this bit is set. PUB PUC PUD PUREF TSD OCA OCB OCC OCD Rev. PrC | Page 29 of 32 AD5724R/AD5734R/AD5754R FEATURES ANALOG OUTPUT CONTROL In many industrial process control applications, it is vital that the output voltage be controlled during power-up. When the supply voltages change during power-up, the VOUT pins are clamped to 0 V via a low impedance path (approxiamately 4kΩ). To prevent the output amplifiers from being shorted to 0 V during this time, Transmission Gate G1 is also opened (see Figure 46). These conditions are maintained until the power supplies have stabilized and a valid word is written to a DAC register. At this time, G2 opens and G1 closes. VOLTAGE MONITOR AND CONTROL G1 VOUTA G2 06465-010 Preliminary Technical Data Constant Current Clamp (CLAMP ENABLE = 1) If a short circuit occurs, in this configuration the current is clamped at 20 mA. This event is signaled to the user by the setting of the appropriate overcurrent (OCX) bit in the power control register. Upon removal of the short-circuit fault, the OCX bit is cleared. Automatic Channel Power-Down (CLAMP ENABLE = 0) If a short circuit occurs, in this configuration the shorted channel powers down and its output is clamped to ground via a resistance of approx. 4kΩ, also at this time the output of the amplifier is disconnected from the output pin. The short-circuit event is signaled to the user via the overcurrent (OCX) bits, while the power-up (PUX ) bits indicate which channels have powered down. After the fault is rectified, the channels can be powered up again by setting the PUX bits. THERMAL SHUTDOWN The AD5724R/AD5734R/AD5754R incorporate a thermal shutdown feature that automatically shuts down the device if the core temperature exceeds approximately 150°C. The thermal shutdown feature is disabled by default and can be enabled via the TSD ENABLE bit of the control register. In the event of a thermal shutdown, the TSD bit of the power control register is set. Figure 46. Analog Output Control Circuitry POWER-DOWN MODE Each DAC channel of the AD5724R/AD5734R/AD5754R can be individually powered-down. By default all channels are in power-down mode. The power status is controlled by the POWER CONTROL register, see Table 28 and Table 29 for details. When a channel is in power-down mode its output pin is clamped to ground through a resistance of approx. 4kΩ and the output of the amplifier is disconnected from the output pin. INTERNAL REFERENCE The on-chip voltage reference is powered down by default. If an external voltage reference source is to be used, the internal reference must remain powered down at all times. If the internal reference is to be used as the reference source, it must be powered up via the PUREF bit of the power control register. The internal reference voltage is accessible at the REFIN/REFOUT pin for use as a reference source for other devices within the system. If the internal reference is to be used external to the AD5724R/AD5734R/AD5754R, it must first be buffered. OVERCURRENT PROTECTION Each DAC channel of the AD5724R/AD5734R/AD5754R incorporates individual overcurrent protection. The user has two options for the configuration of the overcurrent protection, constant current clamp, or automatic channel power-down. The configuration of the overcurrent protection is selected via the CLAMP ENABLE bit in the control register. Rev. PrC | Page 30 of 32 Preliminary Technical Data APPLICATIONS INFORMATION +5V / ±5V OPERATION When operating from a single +5V supply or a dual ±5V supply an output range of +5V or ±5V is not achievable as sufficient headroom for the output amplifier is not available. In this situation a reduced reference voltage can be used, for instance a 2V reference will produce an output range of +4V or ±4V, the 1V of headroom is more than enough for full operation. A standard value voltage reference of 2.048V can be used to produce output ranges of +4.096V and ±4.096V. Refer to the Typical Performance Characteristics plots for performance data at a range of voltage reference values. AD5724R/AD5734R/AD5754R GALVANICALLY ISOLATED INTERFACE In many process control applications, it is necessary to provide an isolation barrier between the controller and the unit being controlled to protect and isolate the controlling circuitry from any hazardous common-mode voltages that may occur. The iCoupler® family of products from Analog Devices provides voltage isolation in excess of 2.5 kV. The serial loading structure of the AD5724R/AD5734R/AD5754R make them ideal for isolated interfaces because the number of interface lines is kept to a minimum. Figure 47 shows a 4-channel isolated interface to the AD5724R/AD5734R/AD5754R using an ADuM1400. For further information, visit http://www.analog.com/icouplers. MICROCONTROLLER SERIAL CLOCK OUT SERIAL DATA OUT SYNC OUT CONTROL OUT V IA LAYOUT GUIDELINES In any circuit where accuracy is important, careful consideration of the power supply and ground return layout helps to ensure the rated performance. The printed circuit board on which the AD5724R/AD5734R/AD5754R are mounted should be designed so that the analog and digital sections are separated and confined to certain areas of the board. If the AD5724R/AD5734R/AD5754R are in a system where multiple devices require an AGND-to-DGND connection, the connection should be made at one point only. The star ground point should be established as close as possible to the device. The AD5724R/AD5734R/AD5754R should have an ample supply bypassing of a 10 µF capacitor in parallel with 0.1 µF capacitor on each supply located as close to the package as possible, ideally right up against the device. The 10 µF capacitors are the tantalum bead type. The 0.1 µF capacitor should have low effective series resistance (ESR) and low effective series inductance (ESI) such as the common ceramic types, which provide a low impedance path to ground at high frequencies to handle transient currents due to internal logic switching. The power supply lines of the AD5724R/AD5734R/AD5754R should use as large a trace as possible to provide low impedance paths and reduce the effects of glitches on the power supply line. Fast switching signals such as clocks should be shielded with digital ground to avoid radiating noise to other parts of the board and should never be run near the reference inputs. A ground line routed between the SDIN and SCLK lines helps reduce crosstalk between them (this is not required on a multilayer board that has a separate ground plane, but separating the lines does help). It is essential to minimize noise on the REFIN line because it couples through to the DAC output. Avoid crossover of digital and analog signals. Traces on opposite sides of the board should run at right angles to each other. This reduces the effects of feed through the board. A microstrip technique is by far the best, but not always possible with a double-sided board. In this technique, the component side of the board is dedicated to ground plane, while signal traces are placed on the solder side. ADuM1400* ENCODE ENCODE ENCODE ENCODE DECODE DECODE DECODE DECODE V OA V OB V OC V OD TO SCLK TO SDIN TO SYNC TO LDAC 06465-011 V IB V IC V ID *ADDITIONAL PINS OMITTED FOR CLARITY. Figure 47. Isolated Interface MICROPROCESSOR INTERFACING Microprocessor interfacing to the AD5724R/AD5734R/AD5754R is via a serial bus that uses standard protocol compatible with microcontrollers and DSP processors. The communications channel is a 3-wire (minimum) interface consisting of a clock signal, a data signal, and a synchronization signal. The AD5724R/AD5734R/AD5754R require a 24-bit data-word with data valid on the falling edge of SCLK. For all interfaces, the DAC output update can be initiated automatically when all the data is clocked in, or it can be performed under the control of LDAC. The contents of the registers can be read using the readback function. AD5724R/AD5734R/AD5754R to Blackfin® DSP interface Figure 48 shows how the AD5724R/AD5734R/AD5754R can be interfaced to Analog Devices Blackfin DSP. The Blackfin has an integrated SPI port that can be connected directly to the SPI pins of the AD5724R/AD5734R/AD5754R and the programmable I/O pins that can be used to set the state of a digital input such as the LDAC pin. SPISELx SCK MOSI SYNC SCLK SDIN ADSP-BF531 AD5724R/ AD5734R/ AD5754R LDAC 06465-012 PF10 Figure 48. AD5724R/AD5734R/AD5754R to Blackfin Interface Rev. PrC | Page 31 of 32 AD5724R/AD5734R/AD5754R OUTLINE DIMENSIONS 7.90 7.80 7.70 5.02 5.00 4.95 Preliminary Technical Data 24 13 4.50 4.40 4.30 6.40 BSC 1 12 EXPOSED PAD (Pins Up) 3.25 3.20 3.15 TOP VIEW 1.20 MAX 1.05 1.00 0.80 0.65 BSC 0.30 0.19 BOTTOM VIEW 8° 0° 0.20 0.09 0.75 0.60 0.45 COMPLIANT TO JEDEC STANDARDS MO-153-ADT Figure 49. 24-Lead Thin Shrink Small Outline Package, Exposed Pad [TSSOP_EP] (RE-24) Dimensions shown in millimeters ORDERING GUIDE Model AD5724RBREZ1 AD5724RBREZ-REEL71 AD5734RBREZ1 AD5734RBREZ-REEL71 AD5754RBREZ1 AD5754RBREZ-REEL71 1 Resolution 12 12 14 14 16 16 Temperature Range −40°C to 85°C −40°C to 85°C −40°C to 85°C −40°C to 85°C −40°C to 85°C −40°C to 85°C INL ±1 LSB ±1 LSB ±4 LSB ±4 LSB ±16 LSB ±16 LSB Package Description 24-Lead TSSOP_EP 24-Lead TSSOP_EP 24-Lead TSSOP_EP 24-Lead TSSOP_EP 24-Lead TSSOP_EP 24-Lead TSSOP_EP Package Option RE-24 RE-24 RE-24 RE-24 RE-24 RE-24 Z = Pb-free part. ©2007 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. PR06465-0-11/07(PrC) Rev. PrC | Page 32 of 32 050806-A SEATING PLANE 0.10 COPLANARITY 0.15 0.05