19-6243; Rev 0; 3/12 EVALUATION KIT AVAILABLE MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface General Description The MAX5723/MAX5724/MAX5725 8-channel, low-power, 8-/10-/12-bit, voltage-output digital-to-analog converters (DACs) include output buffers and an internal 3ppm/°C reference that is selectable to be 2.048V, 2.500V, or 4.096V. The MAX5723/MAX5724/MAX5725 accept a wide supply voltage range of 2.7V to 5.5V with extremely low power (6mW) consumption to accommodate most low-voltage applications. A precision external reference input allows rail-to-rail operation and presents a 100kI (typ) load to an external reference. The MAX5723/MAX5724/MAX5725 have a fast 50MHz, 4-wire SPI/QSPI™/MICROWIRE®/DSP-compatible serial interface that operates at clock rates up to 50MHz. The DAC output is buffered and has a low supply current of less than 250FA per channel and a low offset error of Q0.5mV (typ). On power-up, the MAX5723/MAX5724/ MAX5725 reset the DAC outputs to zero or midscale based on the status of M/Z logic input, providing flexibility for a variety of control applications. The internal reference is initially powered down to allow use of an external reference. The MAX5723/MAX5724/MAX5725 allow simultaneous output updates using software LOAD commands or the hardware load DAC logic input (LDAC). The MAX5723/MAX5724/MAX5725 feature a programmable watchdog function which can be enabled to monitor the I/O interface for activity and integrity. A clear logic input (CLR) allows the contents of the CODE and the DAC registers to be cleared asynchronously and simultaneously sets the DAC outputs to the programmable default value. The MAX5723/MAX5724/MAX5725 are available in a 20-pin TSSOP and an ultra-small, 20-bump WLP package and are specified over the -40NC to +125NC temperature range. Applications Programmable Voltage and Current Sources Gain and Offset Adjustment Automatic Tuning and Optical Control Power Amplifier Control and Biasing Process Control and Servo Loops Portable Instrumentation QSPI is a trademark of Motorola, Inc. MICROWIRE is a registered trademark of National Semiconductor Corporation. Benefits and Features SEight High-Accuracy DAC Channels 12-Bit Accuracy Without Adjustment ±1 LSB INL Buffered Voltage Output Guaranteed Monotonic Over All Operating Conditions Independent Mode Settings for Each DAC SThree Precision Selectable Internal References 2.048V, 2.500V, or 4.096V SInternal Output Buffer Rail-to-Rail Operation with External Reference 4.5µs Settling Time Outputs Directly Drive 2kI Loads SSmall 6.5mm x 4.4mm 20-Pin TSSOP or UltraSmall 2.5mm x 2.3mm 20-Bump WLP Package SWide 2.7V to 5.5V Supply Range SSeparate 1.8V to 5.5V VDDIO Power-Supply Input SFast 50MHz 4-Wire SPI/QSPI/MICROWIRE/DSPCompatible Serial Interface SProgrammable Interface Watchdog Timer SPin-Selectable Power-On-Reset to Zero-Scale or Midscale DAC Output SLDAC and CLR For Asynchronous DAC Control SThree Selectable Power-Down Output Impedances 1kI, 100kI, or High Impedance Functional Diagram VDDIO VDD REF MAX5723 MAX5724 MAX5725 INTERNAL REFERENCE/ EXTERNAL BUFFER CSB SCLK DIN DOUT 1 OF 8 DAC CHANNELS CODE REGISTER SPI SERIAL INTERFACE DAC LATCH 8 -/10-/12-BIT DAC OUT0 BUFFER OUT1 CLR OUT2 LDAC CODE IRQ CLEAR/ RESET LOAD (GATE/ CLEAR/ RESET) OUT3 OUT4 100kI WATCHDOG TIMER DAC CONTROL LOGIC POWER-DOWN 1kI OUT5 OUT6 OUT7 M/Z POR GND Ordering Information appears at end of data sheet. For related parts and recommended products to use with this part, refer to: www.maxim-ic.com/MAX5723.related ���������������������������������������������������������������� Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface ABSOLUTE MAXIMUM RATINGS VDD, VDDIO to GND.................................................-0.3V to +6V OUT_, REF to GND.....0.3V to the lower of (VDD + 0.3V) and +6V SCLK, CSB, IRQ, M/Z, LDAC, CLR to GND............-0.3V to +6V DIN, DOUT to GND......................................-0.3V to the lower of (VDDIO + 0.3V) and +6V Continuous Power Dissipation (TA = +70NC) TSSOP (derate at 13.6mW/NC above 70NC)...............1084mW WLP (derate at 21.3mW/NC above 70NC)...................1700mW Maximum Continuous Current into Any Pin..................... Q50mA Operating Temperature..................................... -40NC to +125NC Storage Temperature........................................ -65NC to +150NC Lead Temperature (TSSOP only)(soldering, 10s)............+300NC Soldering Temperature (reflow)..................................... +260NC Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. PACKAGE THERMAL CHARACTERISTICS (Note 1) TSSOP Junction-to-Ambient Thermal Resistance (θJA) .......73.8NC/W Junction-to-Case Thermal Resistance (θJC) ...............20NC/W WLP Junction-to-Ambient Thermal Resistance (θJA) (Note 2)....................................................................47NC/W Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a fourlayer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial. Note 2:Visit www.maxim-ic.com/app-notes/index.mvp/id/1891 for information about the thermal performance of WLP packaging. ELECTRICAL CHARACTERISTICS (VDD = 2.7V to 5.5V, VDDIO = 1.8V to 5.5V, VGND = 0V, CL = 200pF, RL = 2kI, TA = -40NC to +125NC, unless otherwise noted. Typical values are at TA = +25NC.) (Note 3) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DC PERFORMANCE (Note 4) Resolution and Monotonicity Integral Nonlinearity (Note 5) Differential Nonlinearity (Note 5) Offset Error (Note 6) MAX5723 8 MAX5724 10 MAX5725 12 MAX5723 -0.25 Q0.05 +0.25 MAX5724 -0.5 Q0.2 +0.5 MAX5725 -1 Q0.5 +1 MAX5723 -0.25 Q0.05 +0.25 MAX5724 -0.5 Q0.1 +0.5 MAX5725 -1 Q0.2 +1 OE -5 Q0.5 +5 GE -1.0 Q0.1 N INL DNL Offset Error Drift Bits Q10 Gain Error (Note 6) Gain Temperature Coefficient With respect to VREF Q3.0 LSB LSB mV FV/NC +1.0 %FS ppm of FS/NC ���������������������������������������������������������������� Maxim Integrated Products 2 MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface ELECTRICAL CHARACTERISTICS (continued) (VDD = 2.7V to 5.5V, VDDIO = 1.8V to 5.5V, VGND = 0V, CL = 200pF, RL = 2kI, TA = -40NC to +125NC, unless otherwise noted. Typical values are at TA = +25NC.) (Note 3) PARAMETER SYMBOL CONDITIONS Zero-Scale Error Full-Scale Error With respect to VREF MIN TYP MAX UNITS 0 +10 mV -0.5 +0.5 %FS DAC OUTPUT CHARACTERISTICS Output Voltage Range (Note 7) Load Regulation No load 0 VDD 2kI load to GND 0 VDD 0.2 2kI load to VDD 0.2 VDD VOUT = VFS/2 DC Output Impedance VOUT = VFS/2 Maximum Capacitive Load Handling CL Resistive Load Handling RL Short-Circuit Output Current 300 VDD = 5V Q10%, |IOUT| P 10mA 300 VDD = 3V Q10%, |IOUT| P 5mA 0.3 VDD = 5V Q10%, |IOUT| P 10mA 0.3 FV/mA I 500 2 VDD = 5.5V DC Power-Supply Rejection VDD = 3V Q10%, |IOUT| P 5mA V pF kI Sourcing (output shorted to GND) 30 Sinking (output shorted to VDD) 50 mA VDD = 3V Q10% or 5V Q10% 100 FV/V Positive and negative 1.0 V/Fs ¼ scale to ¾ scale, to P 1 LSB, MAX5723 2.2 ¼ scale to ¾ scale, to P 1 LSB, MAX5724 2.6 ¼ scale to ¾ scale, to P 1 LSB, MAX5725 4.5 DYNAMIC PERFORMANCE Voltage-Output Slew Rate Voltage-Output Settling Time SR DAC Glitch Impulse Major code transition (code x7FF to x800) Channel-to-Channel Feedthrough (Note 8) Internal reference 3.3 External reference 4.07 Midscale code, all digital inputs from 0V to VDDIO 0.2 nV*s Startup calibration time (Note 9) 200 Fs From power-down 50 Fs Digital Feedthrough Power-Up Time 2 Fs nV*s nV*s ���������������������������������������������������������������� Maxim Integrated Products 3 MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface ELECTRICAL CHARACTERISTICS (continued) (VDD = 2.7V to 5.5V, VDDIO = 1.8V to 5.5V, VGND = 0V, CL = 200pF, RL = 2kI, TA = -40NC to +125NC, unless otherwise noted. Typical values are at TA = +25NC.) (Note 3) PARAMETER SYMBOL CONDITIONS External reference Output Voltage-Noise Density (DAC Output at Midscale) 82 112 f = 10kHz 102 2.5V internal reference f = 1kHz 125 f = 10kHz 110 4.096V internal reference f = 1kHz 160 f = 10kHz 145 f = 0.1Hz to 10Hz 12 2.048V internal reference 2.5V internal reference f = 0.1Hz to 10kHz 76 f = 0.1Hz to 300kHz 385 f = 0.1Hz to 10Hz 14 f = 0.1Hz to 10kHz 91 f = 0.1Hz to 300kHz 450 f = 0.1Hz to 10Hz 15 f = 0.1Hz to 10kHz 99 f = 0.1Hz to 300kHz 470 f = 0.1Hz to 10Hz 16 f = 0.1Hz to 10kHz 124 f = 0.1Hz to 300kHz 490 f = 1kHz 114 f = 10kHz 99 2.048V internal reference f = 1kHz 175 f = 10kHz 153 2.5V internal reference f = 1kHz 200 f = 10kHz 174 4.096V internal reference f = 1kHz 295 f = 10kHz 255 f = 0.1Hz to 10Hz 13 f = 0.1Hz to 10kHz 94 f = 0.1Hz to 300kHz 540 External reference 2.048V internal reference 2.5V internal reference 4.096V internal reference MAX UNITS 90 f = 1kHz External reference Integrated Output Noise (DAC Output at Full Scale) TYP f = 10kHz 4.096V internal reference Output Voltage-Noise Density (DAC Output at Full Scale) MIN 2.048V internal reference External reference Integrated Output Noise (DAC Output at Midscale) f = 1kHz f = 0.1Hz to 10Hz 19 f = 0.1Hz to 10kHz 143 f = 0.1Hz to 300kHz 685 f = 0.1Hz to 10Hz 21 f = 0.1Hz to 10kHz 159 f = 0.1Hz to 300kHz 705 f = 0.1Hz to 10Hz 26 f = 0.1Hz to 10kHz 213 f = 0.1Hz to 300kHz 750 nV/√Hz FVP-P nV/√Hz FVP-P ���������������������������������������������������������������� Maxim Integrated Products 4 MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface ELECTRICAL CHARACTERISTICS (continued) (VDD = 2.7V to 5.5V, VDDIO = 1.8V to 5.5V, VGND = 0V, CL = 200pF, RL = 2kI, TA = -40NC to +125NC, unless otherwise noted. Typical values are at TA = +25NC.) (Note 3) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS VDD V REFERENCE INPUT Reference Input Range VREF Reference Input Current IREF Reference Input Impedance RREF 1.24 VREF = VDD = 5.5V 55 74 75 100 VREF = 2.048V, TA = +25NC 2.043 2.048 2.053 VREF = 2.5V, TA = +25NC 2.494 2.5 2.506 VREF = 4.096V, TA = +25NC 4.086 4.096 4.106 FA kI REFERENCE OUTPUT Reference Output Voltage VREF Reference Temperature Coefficient (Note 10) MAX5725A Q3 Q10 MAX5723/MAX5724/MAX5725B Q10 Q25 Reference Drive Capacity External load Reference Capacitive Load Handling Reference Load Regulation ISOURCE = 0 to 500FA Reference Line Regulation V ppm/NC 25 kI 200 pF 2 mV/mA 0.05 mV/V POWER REQUIREMENTS Supply Voltage VDD I/O Supply Voltage VREF = 4.096V 4.5 5.5 All other options 2.7 5.5 VDDIO 1.8 Internal reference Supply Current (Note 11) IDD External reference Power-Down Mode Supply Current Digital Supply Current IPD IDDIO 5.5 VREF = 2.048V 1.6 2 VREF = 2.5V 1.7 2.1 VREF = 4.096V 2.0 2.5 VREF = 3V 1.6 2.0 1.9 2.5 VREF = 5V All DACs off, internal reference ON 140 All DACs off, internal reference OFF, TA = -40NC to +85NC 0.7 2 All DACs off, internal reference OFF, TA = +125NC 2 4 Static logic inputs, all outputs unloaded V V mA FA 1 FA Q1 FA DIGITAL INPUT CHARACTERISTICS (SCLK, DIN, CSB, LDAC, CLR, M/Z) Input Leakage Current IIN VIN = 0V or VDDIO, all inputs except M/Z (Note 11) Q0.1 VIN = 0V or VDD, for M/Z (Note 11) ���������������������������������������������������������������� Maxim Integrated Products 5 MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface ELECTRICAL CHARACTERISTICS (continued) (VDD = 2.7V to 5.5V, VDDIO = 1.8V to 5.5V, VGND = 0V, CL = 200pF, RL = 2kI, TA = -40NC to +125NC, unless otherwise noted. Typical values are at TA = +25NC.) (Note 3) PARAMETER Input High Voltage SYMBOL VIH CONDITIONS (All inputs except M/Z) 2.2V < VDDIO < 5.5V 1.8V < VDDIO < 2.2V 0.8 x VDDIO 2.7V < VDD < 5.5V (for M/Z) Input Low Voltage VIL (All inputs except M/Z) MIN 0.7 x VDDIO TYP CIN Hysteresis Voltage VH UNITS V V 0.7 x VDD 2.2V < VDDIO < 5.5V 0.3 x VDDIO 1.8V < VDDIO < 2.2V 0.2 x VDDIO 0.3 x VDD 2.7V < VDD < 5.5V (for M/Z) Input Capacitance (Note 10) MAX 10 0.15 V V pF V DIGITAL OUTPUT (IRQ) Output Low Voltage VOL Output Inactive Leakage IOFF Output Inactive Capacitance (Note 10) COFF ISINK = 3mA Q0.1 0.2 V Q1 FA 10 pF DIGITAL OUTPUT (DOUT) Output High Voltage VDDIO > 2.5V, ISOURCE = 3mA VDDIO - 0.2 VDDIO > 1.8V, ISOURCE = 2mA VDDIO - 0.2 VOH V VDDIO > 2.5V, ISINK = 3mA 0.2 VDDIO > 1.8V, ISINK = 2mA 0.2 Output Low Voltage VOL Output Short-Circuit Current IOSS Output Three-State Leakage IOZ ±0.1 Output Three-State Capacitance COZ 10 ISINK, ISOURCE ±100 V mA ±1 µA pF WATCHDOG TIMER CHARACTERISTICS Watchdog Timer Period tWDOSC VDD = 3V, TA = +25°C Watchdog Timer Period Supply Drift VDD = 2.7V to 5.5V, TA = +25°C Watchdog Timer Period Temperature Drift VDD = 3V 0.95 1 1.05 ms 0.6 %/V 0.0375 %/°C ���������������������������������������������������������������� Maxim Integrated Products 6 MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface ELECTRICAL CHARACTERISTICS (continued) (VDD = 2.7V to 5.5V, VDDIO = 1.8V to 5.5V, VGND = 0V, CL = 200pF, RL = 2kI, TA = -40NC to +125NC, unless otherwise noted. Typical values are at TA = +25NC.) (Note 3) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS SPI TIMING CHARACTERISTICS 2.7V < VDDIO < 5.5V fSCLK SCLK Frequency 1.8V < VDDIO < 2.7V tSCLK SCLK Period Write mode 0 50 Read mode, strobing on 1 SCLK 0 25 Read mode, strobing on ½ SCLK 0 12.5 Write mode 0 33 Read mode, strobing on 1 SCLK 0 20 Read mode, strobing on ½ SCLK 0 10 2.7V < VDDIO < 5.5V, write mode 20 1.8V < VDDIO < 2.7V, write mode 30 MHz ns SCLK Pulse Width High tCH 8 ns SCLK Pulse Width Low tCL 8 ns 2.7V < VDDIO < 5.5V 8 1.8V < VDDIO < 2.7V 12 CSB Fall to SCLK Fall Setup Time tCSS0 To first SCLK falling edge CSB Fall to SCLK Fall Hold Time tCSH0 Applies to inactive SCLK falling edge preceding the first SCLK falling edge 0 ns CSB Rise to SCLK Fall Hold Time tCSH1 Applies to the 24th SCLK falling edge 0 ns 12 ns 100 ns CSB Rise to SCLK Fall tCSA SCLK Fall to CSB Fall tCSF CSB Pulse Width High Applies to the 24th SCLK falling edge, aborted sequence Applies to 24th SCLK falling edge ns tCSPW 20 ns DIN to SCLK Fall Setup Time tDS 5 ns DIN to SCLK Fall Hold Time tDH 4.5 ns 20 ns 20 ns 20 ns 20 ns CLR Pulse Width Low tCLPW CLR Rise to CSB Fall tCSC LDAC Pulse Width Low Required for command to be executed tLDPW LDAC Fall to SCLK Fall Hold tLDH Applies to 24th SCLK falling edge SCLK Fall to DOUT Transition tDOT DPHA = 0, CLOAD = 20pF 2.7V < VDDIO < 5.5V 35 1.8V < VDDIO < 2.7V 40 SCLK Rise to DOUT Transition tDOT DPHA = 1, CLOAD = 20pF 2.7V < VDDIO < 5.5V 35 1.8V < VDDIO < 2.7V 40 ns ns ���������������������������������������������������������������� Maxim Integrated Products 7 MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface ELECTRICAL CHARACTERISTICS (continued) (VDD = 2.7V to 5.5V, VDDIO = 1.8V to 5.5V, VGND = 0V, CL = 200pF, RL = 2kI, TA = -40NC to +125NC, unless otherwise noted. Typical values are at TA = +25NC.) (Note 3) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS SCLK Fall to DOUT Hold tDOH DPHA = 0, CLOAD = 0pF 2 ns SCLK Rise to DOUT Hold tDOH DPHA = 1, CLOAD = 0pF 2 ns CSB Fall to DOUT Fall tDOE Enable time, CLOAD = 20pF tDOZ CSB Rise to DOUT Hi-Z Disable time 20 2.7V < VDDIO < 5.5V 20 1.8V < VDDIO < 2.7V 40 ns ns Note 3: Limits are 100% production tested at TA = +25NC and/or TA = +125NC. Limits over the operating temperature range and relevant supply voltage range are guaranteed by design and characterization. Typical values are at TA = +25NC and are not guaranteed. Note 4: DC performance is tested without load, VREF = VDD. Note 5: Linearity is tested with unloaded outputs to within 20mV of GND and VDD. Note 6: Gain and offset calculated from measurements made with VREF = VDD at codes 30 and 4065 for MAX5725, codes 8 and 1016 for MAX5724, and codes 2 and 254 for MAX5723. Note 7: Subject to zero- and full-scale error limits and VREF settings. Note 8: Measured with all other DAC outputs at midscale with one channel transitioning 0 to full scale. Note 9: On power-up, the device initiates an internal 200µs (typ) calibration sequence. All commands issued during this time will be ignored. Note 10:Guaranteed by design. Note 11:All channels active at VFS, unloaded. Static logic inputs with VIL = VGND and VIH = VDDIO for all inputs. DIN23 DIN DIN22 DIN21 DIN20 1 tCSH0 2 3 tCSS0 4 tCH DIN18 DIN17 DIN16 DIN15 DIN14 7 8 9 10 DIN1 DIN0 DIN23’ tSCLK tDH tDS SCLK DIN19 5 6 23 24 tCSA tCL 1 tCSH1 CSB tCSPW DOUT (DPHA = x) DO15 tDOE DOUT (DPHA = x) CLR Z tCLPW DO1 tDOT DO15 DO14 tCSF tDOH tDOT Z DO0 tDOH DO1 Z tDOZ Z DO0 tCSC tLDH tLDPW LDAC Figure 1. SPI Serial Interface Timing Diagram ���������������������������������������������������������������� Maxim Integrated Products 8 MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface Typical Operating Characteristics (MAX5725, 12-bit performance, TA = +25°C, unless otherwise noted.) INL vs. CODE VDD = VREF = 5V NO LOAD 0.8 0.6 1.0 MAX5723 toc02 0.6 0.4 0.2 0.2 0.2 -0.2 DNL (LSB) 0.4 INL (LSB) 0.4 0 0 -0.2 0 -0.2 -0.4 -0.4 -0.4 -0.6 -0.6 -0.6 -0.8 -0.8 -0.8 -1.0 -1.0 -1.0 512 1024 1536 2048 2560 3072 3584 4096 0 CODE (LSB) 512 1024 1536 2048 2560 3072 3584 4096 CODE (LSB) MAX5723 toc04 VDD = VREF = 5V NO LOAD 0.6 INL AND DNL vs. SUPPLY VOLTAGE 1.0 0.6 ERROR (LSB) DNL (LSB) 0 -0.2 0 -0.2 -0.4 -0.6 -0.6 -0.8 -0.8 -1.0 512 1024 1536 2048 2560 3072 3584 4096 3.1 3.5 3.9 4.3 4.7 5.1 SUPPLY VOLTAGE (V) INL AND DNL vs. TEMPERATURE OFFSET AND ZERO-SCALE ERROR vs. SUPPLY VOLTAGE 1.0 MAX5723 toc06 VDD = VREF = 3V 0.6 -0.2 -0.4 MIN INL MIN DNL -0.8 5.5 ZERO-SCALE ERROR 0.4 MAX DNL 0 VREF = 2.5V (EXTERNAL) NO LOAD 0.8 MAX INL 0.2 -0.6 2.7 CODE (LSB) ERROR (mV) 0.4 MIN DNL MIN INL -1.0 0 0.6 MAX DNL 0.2 -0.4 0.8 MAX INL 0.4 0.2 1.0 VDD = VREF 0.8 0.4 MAX5723 toc05 DNL vs. CODE 0.8 512 1024 1536 2048 2560 3072 3584 4096 0 CODE (LSB) 1.0 ERROR (LSB) 0 VDD = VREF = 3V NO LOAD 0.8 MAX5723 toc07 0.6 INL (LSB) MAX5723 toc01 VDD = VREF = 3V NO LOAD 0.8 DNL vs. CODE 1.0 MAX5723 toc03 INL vs. CODE 1.0 0.2 0 -0.2 OFFSET ERROR -0.4 -0.6 -0.8 -1.0 -40 -25 -10 5 20 35 50 65 80 95 110 125 TEMPERATURE (°C) -1.0 2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5 SUPPLY VOLTAGE (V) ���������������������������������������������������������������� Maxim Integrated Products 9 MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface Typical Operating Characteristics (continued) (MAX5725, 12-bit performance, TA = +25°C, unless otherwise noted.) OFFSET AND ZERO-SCALE ERROR vs. TEMPERATURE 0.6 0.016 0.012 GAIN ERROR 0.008 0.4 OFFSET ERROR (VDD = 5V) 0.2 ERROR (%fs) 0 -0.2 OFFSET ERROR (VDD = 3V) -0.4 0.004 0 -0.004 FULL-SCALE ERROR -0.008 -0.6 -0.012 -0.8 -0.016 VREF = 2.5V (EXTERNAL) NO LOAD -0.020 -1.0 2.7 -40 -25 -10 5 20 35 50 65 80 95 110 125 3.1 FULL-SCALE ERROR AND GAIN ERROR vs. TEMPERATURE ERROR (%fsr) GAIN ERROR (VDD = 5V) 0 FULL-SCALE ERROR GAIN ERROR (VDD = 3V) -0.05 5.1 5.5 VREF (INTERNAL) = 4.096V, VDD = 5V 1.4 VREF (INTERNAL) = 2.5V, VDD = 5V VREF (INTERNAL) = 2.048V, VDD = 5V VREF (EXTERNAL) = VDD = 3V -40 -25 -10 5 20 35 50 65 80 95 110 125 TEMPERATURE (°C) SUPPLY CURRENT vs. SUPPLY VOLTAGE POWER-DOWN MODE SUPPLY CURRENT vs. SUPPLY VOLTAGE VREF (INTERNAL) = 4.096V 1.8 VREF (INTERNAL) = 2.5V 1.6 1.4 1.2 VREF (INTERNAL) = 2.048V 0.6 VREF = 2.5V (EXTERNAL) VDD = VDDIO VDAC_ = FULL SCALE ALL DACS ENABLED NO LOAD 0.4 0.2 0 2.7 3.1 3.5 3.9 4.3 4.7 SUPPLY VOLTAGE (V) 5.1 5.5 2.0 POWER-DOWN SUPPLY CURRENT (µA) MAX5723 toc12 TEMPERATURE (°C) 2.0 SUPPLY CURRENT (mA) 4.7 VREF (EXTERNAL) = VDD = 5V 1.6 1.0 -40 -25 -10 5 20 35 50 65 80 95 110 125 0.8 VDD = VDDIO VDAC_ = FULL SCALE ALL DACS ENABLED NO LOAD 1.2 -0.10 1.0 4.3 MAX5723 toc11 1.8 SUPPLY CURRENT (mA) VREF = 2.5V (EXTERNAL) NO LOAD 0.05 3.9 SUPPLY CURRENT vs. TEMPERATURE 2.0 MAX5723 toc10 0.10 3.5 SUPPLY VOLTAGE (V) TEMPERATURE (°C) 1.6 MAX5723 toc13 ERROR (mV) MAX5723 toc09 VREF = 2.5V (EXTERNAL) NO LOAD ZERO-SCALE ERROR 0.8 0.020 MAX5723 toc08 1.0 FULL-SCALE ERROR AND GAIN ERROR vs. SUPPLY VOLTAGE VDD = VDDIO VREF = 2.5V (EXTERNAL) POWER-DOWN MODE WITH HI-Z NO LOAD TA = +125°C 1.2 0.8 TA = +85°C TA = +25°C TA = -40°C 0.4 0 2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5 SUPPLY VOLTAGE (V) ���������������������������������������������������������������� Maxim Integrated Products 10 MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface Typical Operating Characteristics (continued) (MAX5725, 12-bit performance, TA = +25°C, unless otherwise noted.) IVDD vs. CODE SUPPLY CURRENT (mA) 1.6 VDD = VREF = 5V 1.2 VDD = 5V, VREF = 2.048V 0.8 VDD = 5V, VREF = 2.5V VDD = VREF = 3V 0.4 VDD = VREF NO LOAD 50 REFERENCE CURRENT (µA) VDD = 5V, VREF = 4.096V MAX5723 toc15 IREF (EXTERNAL) vs. CODE 60 MAX5723 toc14 2.0 40 VREF = 5V 30 VREF = 3V 20 10 NO LOAD 0 0 512 1024 1536 2048 2560 3072 3584 4096 0 0 512 1024 1536 2048 2560 3072 3584 4096 CODE (LSB) CODE (LSB) SETTLING TO ±1 LSB (VDD = VREF = 5V, RL = 2kI, CL = 200pF) SETTLING TO ±1 LSB (VDD = VREF = 5V, RL = 2kI, CL = 200pF) MAX5723 toc17 MAX5723 toc16 VOUT 0.5V/div 3/4 SCALE TO 1/4 SCALE 1/4 SCALE TO 3/4 SCALE 4.3µs ZOOMED VOUT 1 LSB/div ZOOMED VOUT 1 LSB/div 3.75µs VOUT 0.5V/div TRIGGER PULSE 5V/div TRIGGER PULSE 5V/div MAJOR CODE TRANSITION GLITCH ENERGY (VDD = VREF = 5V, RL = 2kI, CL = 200pF) MAJOR CODE TRANSITION GLITCH ENERGY (VDD = VREF = 5V, RL = 2kI, CL = 200pF) 1 LSB CHANGE (MIDCODE TRANSITION 0x800 TO 0x7FF) GLITCH IMPULSE = 2nV*s 1 LSB CHANGE (MIDCODE TRANSITION 0x7FF TO 0x800) GLITCH IMPULSE = 2nV*s ZOOMED VOUT 1.25mV/div ZOOMED VOUT 1.25mV/div TRIGGER PULSE 5V/div TRIGGER PULSE 5V/div 2µs/div MAX5723 toc19 4µs/div MAX5723 toc18 4µs/div 2µs/div ���������������������������������������������������������������� Maxim Integrated Products 11 MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface Typical Operating Characteristics (continued) (MAX5725, 12-bit performance, TA = +25°C, unless otherwise noted.) VOUT vs. TIME TRANSIENT EXITING POWER-DOWN POWER-ON RESET TO 0V MAX5723 toc21 MAX5723 toc20 VSCLK 5V/div 0V 24TH EDGE DAC OUTPUT 500mV/div VDD = VREF = 5V 10kI LOAD TO VDD VDD 2V/div 0V VOUT 2V/div 0V VDD = 5V, VREF = 2.5V EXTERNAL 0V 10µs/div 20µs/div CHANNEL-TO-CHANNEL FEEDTHROUGH (VDD = VREF = 5V, TA = +25NC, NO LOAD) CHANNEL-TO-CHANNEL FEEDTHROUGH (VDD = 5V, VREF = 4.096V, TA = +25NC, NO LOAD) MAX5723 toc23 MAX5723 toc22 TRANSITIONING DAC: 0 TO FULL SCALE STATIC DAC: MIDSCALE ANALOG CROSSTALK = 2.6nV*s VDAC4 0.585 LSB/div NO LOAD TRANSITIONING DAC: 0 TO FULL SCALE STATIC DAC: MIDSCALE ANALOG CROSSTALK = 3.3nV*s VDAC0 5V/div NO LOAD VDAC4 0.585 LSB/div NO LOAD VDAC0 5V/div NO LOAD 4µs/div 4µs/div CHANNEL-TO-CHANNEL FEEDTHROUGH (VDD = VREF = 5V, TA = +25NC, RL = 2kI, CL = 200pF) CHANNEL-TO-CHANNEL FEEDTHROUGH (VDD = 5V, VREF = 4.096V (INTERNAL), TA = +25NC, RL = 2kI, CL = 200pF) MAX5723 toc24 MAX5723 toc25 TRANSITIONING DAC: 0 TO FULL SCALE STATIC DAC: MIDSCALE ANALOG CROSSTALK = 4.07nV*s TRANSITIONING DAC: 0 TO FULL SCALE STATIC DAC: MIDSCALE ANALOG CROSSTALK = 3.3nV*S VDAC4 0.585 LSB/div NO LOAD VDAC4 0.585 LSB/div NO LOAD VDAC0 5V/div LOADED VDAC0 5V/div LOADED 4µs/div 4µs/div ���������������������������������������������������������������� Maxim Integrated Products 12 MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface Typical Operating Characteristics (continued) (MAX5725, 12-bit performance, TA = +25°C, unless otherwise noted.) DIGITAL FEEDTHROUGH (VDD = VREF = 5V, RL = 10kI) OUTPUT LOAD REGULATION MAX5723 toc26 VREF = 4.096V (INTERNAL) DIGITAL CROSSTALK = 0.2nV*S MAX5723 toc27 10 VDD = VREF 8 6 VDD = 5V DVOUT (mV) 4 2.5mV/div 2 0 VDD = 3V -2 -4 -6 -8 -10 -30 -20 -10 20ns/div 0 10 20 30 40 50 60 IOUT (mA) HEADROOM AT RAILS vs. OUTPUT CURRENT OUTPUT CURRENT LIMITING VDD = VREF 5.00 300 4.50 VDD = 5V, SOURCING 4.00 3.50 200 0 -100 3.00 VOUT (V) VDD = 5V 100 2.50 VDD = 3V, SOURCING 2.00 VDD = 3V -200 1.50 -300 1.00 -400 0.50 VDD = 3V AND 5V SINKING VDD = VREF DAC = FULL SCALE 0 -500 -30 -20 -10 0 0 10 20 30 40 50 60 70 1 2 3 4 5 6 7 8 9 10 IOUT (mA) IOUT (mA) NOISE-VOLTAGE DENSITY vs. FREQUENCY (DAC AT MIDSCALE) MAX5723 toc30 350 NOISE-VOLTAGE DENSITY (nV/√Hz) DVOUT (mV) MAX5723 toc29 400 MAX5723 toc28 500 VDD = 5V, VREF = 4.096V INTERNAL 300 VDD = 5V, VREF = 2.5V INTERNAL 250 200 VDD = 5V, VREF = 2.048V INTERNAL 150 100 50 VDD = 5V, VREF = 3.5V (EXTERNAL) 0 100 1k 10k 100k FREQUENCY (Hz) ���������������������������������������������������������������� Maxim Integrated Products 13 MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface Typical Operating Characteristics (continued) (MAX5725, 12-bit performance, TA = +25°C, unless otherwise noted.) 0.1Hz TO 10Hz OUTPUT NOISE, EXTERNAL REFERENCE (VDD = 5V, VREF = 4.5V) 0.1Hz TO 10Hz OUTPUT NOISE, INTERNAL REFERENCE (VDD = 5V, VREF = 2.048V) MAX5723 toc31 MAX5723 toc32 MIDSCALE UNLOADED VP-P = 12µV MIDSCALE UNLOADED VP-P = 13µV 2µV/div 4s/div 2µV/div 4s/div 0.1Hz TO 10Hz OUTPUT NOISE, INTERNAL REFERENCE (VDD = 5V, VREF = 2.5V) 0.1Hz TO 10Hz OUTPUT NOISE, INTERNAL REFERENCE (VDD = 5V, VREF = 4.096V) MAX5723 toc33 MAX5723 toc34 MIDSCALE UNLOADED VP-P = 16µV MIDSCALE UNLOADED VP-P = 15µV 2µV/div 4s/div 2µV/div 4s/div ���������������������������������������������������������������� Maxim Integrated Products 14 MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface Typical Operating Characteristics (continued) (MAX5725, 12-bit performance, TA = +25°C, unless otherwise noted.) VREF DRIFT vs. TEMPERATURE MAX5723 toc35 VDD = 5V INTERNAL REFERENCE -0.2 20 DVREF (mV) 15 -0.4 -0.6 10 VREF = 2.048V, 2.5V, AND 4.096V -0.8 5 -1.0 0 0 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 TEMPERATURE DRIFT (ppm /°C) WATCHDOG TIMER PERIOD HISTOGRAM 2500 2000 1500 1000 VDDIO = 3V 12 10 8 6 4 2 500 0 1 2 3 4 5 INPUT LOGIC VOLTAGE (V) FREQUENCY (Hz) WATCHDOG TIMER FREQUENCY vs. TEMPERATURE WATCHDOG TIMER FREQUENCY vs. SUPPLY VOLTAGE 1000 995 990 985 980 1010 WATCHDOG TIMER FREQUENCY (Hz) MAX5723 toc39 1005 VDD = 3V 1000 990 MAX5723 toc40 0 988 VDDIO = 1.8V 0 WATCHDOG TIMER FREQUENCY (Hz) MAX5723 toc38 VDDIO = 5V 14 PERCENT OF POPULATION (%) SUPPLY CURRENT (µA) VDD = 3V SCLK, CSB, DIN, CLR, AND LDAC SWEPT FROM 0V TO VDDIO AND VDDIO TO 0V 3000 MAX5723 toc37 SUPPLY CURRENT vs. SUPPLY VOLTAGE 3500 50 100 150 200 250 300 350 400 450 500 REFERENCE OUTPUT CURRENT (µA) 990 992 994 996 998 1000 1002 1004 1006 1008 1010 1012 1014 PERCENT OF POPULATION (%) VDD = 2.7V VREF = 2.5V (INTERNAL) BOX METHOD 25 0 MAX5723 toc36 REFERENCE LOAD REGULATION 30 980 970 960 950 940 930 920 975 2.7 3.1 3.5 3.9 4.3 4.7 SUPPLY VOLTAGE (V) 5.1 5.5 910 -40 -25 -10 5 20 35 50 65 80 95 110 125 TEMPERATURE (°C) ���������������������������������������������������������������� Maxim Integrated Products 15 MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface Pin Configurations TOP VIEW TOP VIEW REF 1 + 20 M/Z DAC0 2 19 GND DAC1 3 18 LDAC DAC2 4 17 CLR DAC3 5 DAC4 6 MAX5723 MAX5724 MAX5725 16 IRQ 15 CSB DAC5 7 14 SCLK DAC6 8 13 DIN DAC7 9 12 DOUT VDD 10 11 VDDIO MAX5723/MAX5724/MAX5725 1 2 3 4 5 + DAC6 DAC7 VDDIO DOUT DIN DAC5 DAC4 VDD CSB SCLK DAC2 DAC3 M/Z CLR IRQ DAC1 DAC0 REF GND LDAC A B C D WLP TSSOP Pin Description PIN NAME FUNCTION TSSOP WLP 1 D3 REF Reference Voltage Input/Output 2 D2 DAC0 DAC Channel 0 Voltage Output 3 D1 DAC1 DAC Channel 1 Voltage Output 4 C1 DAC2 DAC Channel 2 Voltage Output 5 C2 DAC3 DAC Channel 3 Voltage Output 6 B2 DAC4 DAC Channel 4 Voltage Output 7 B1 DAC5 DAC Channel 5 Voltage Output 8 A1 DAC6 DAC Channel 6 Voltage Output 9 A2 DAC7 DAC Channel 7 Voltage Output 10 B3 VDD Analog Supply Voltage 11 A3 VDDIO Digital Supply Voltage 12 A4 DOUT SPI Serial Data Output 13 A5 DIN SPI Serial Data Input 14 B5 SCLK SPI Serial Clock Input 15 B4 CSB SPI Chip-Select Input 16 C5 IRQ 17 C4 CLR Active-Low Open Drain Interrupt Output. IRQ low indicates watchdog timeout. Active-Low Asynchronous DAC Clear Input 18 D5 19 D4 LDAC GND 20 C3 M/Z Active-Low Asynchronous DAC Load Input Ground DAC Output Reset Selection. Connect M/Z to GND for zero-scale and connect M/Z to VDD for midscale. ��������������������������������������������������������������� Maxim Integrated Products 16 MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface Detailed Description The MAX5723/MAX5724/MAX5725 are 8-channel, lowpower, 8-/10-/12-bit buffered voltage-output DACs. The 2.7V to 5.5V wide supply voltage range and low-power consumption accommodates most low-power and lowvoltage applications. The devices present a 100kI load to the external reference. The internal output buffers allow rail-to-rail operation. An internal voltage reference is available with software-selectable options of 2.048V, 2.500V, or 4.096V. The devices feature a fast 4-wire SPI/QSPI/MICROWIRE/DSP-compatible serial interface to save board space and reduce the complexity in isolated applications interface. The MAX5723/MAX5724/ MAX5725 include a serial-in/parallel-out shift register, internal CODE and DAC registers, a power-on-reset (POR) circuit to initialize the DAC outputs to zero scale (M/Z = 0) or midscale (M/Z = 1), and control logic. CLR is available to asynchronously clear the DAC outputs to a user-programmable default value, independent of the serial interface. LDAC is available to simultaneously update selected DACs on one or more devices. The MAX5723/MAX5724/MAX5725 also feature userconfigurable interface watchdog, with status indicated by the IRQ output. DAC Outputs (OUT_) The MAX5723/MAX5724/MAX5725 include internal buffers on all DAC outputs, which provide improved load regulation for the DAC outputs. The output buffers slew at 1V/Fs (typ) and drive resistive loads are as low as 2kI in parallel with as much as 500pF of capacitance. The analog supply voltage (VDD) determines the maximum output voltage range of the devices since it powers the output buffers. Under no-load conditions, the output buffers drive from GND to VDD, subject to offset and gain errors. With a 2kω load to GND, the output buffers drive from GND to within 200mV of VDD. With a 2kω load to VDD, the output buffers drive to within 200mV of GND and VDD. The DAC ideal output voltage is defined by: VOUT = VREF × D 2N where D = code loaded into the DAC register, VREF = reference voltage, N = resolution. Internal Register Structure The user interface is separated from the DAC logic to minimize digital feedthrough. Within the serial interface is an input shift register, the contents of which can be routed to control registers, individual, or multiple DACs as determined by the user command. Within each DAC channel there is a CODE register followed by a DAC latch register (see the Detailed Functional Diagram). The contents of the CODE register hold pending DAC output settings which can later be loaded into the DAC registers. The CODE register can be updated using both CODE and CODE_LOAD user commands. The contents of the DAC register hold the current DAC output settings. The DAC register can be updated directly from the serial interface using the CODE_LOAD commands or can upload the current contents of the CODE register using LOAD commands or the LDAC logic input. The contents of both CODE and DAC registers are maintained during power-down states, so that when the DACs are powered on, they return to their previously stored output settings. Any CODE or LOAD commands issued during power-down states continue to update the register contents. Once the device is powered up, each DAC channel can be independently programmed with a desired RETURN value using the RETURN command. This becomes the value the CODE and DAC registers will use in the event of any watchdog, clear or gate activity, as selected by the DEFAULT command. Hardware CLR operations and SW_CLEAR commands return the contents of all CODE and DAC registers to their user-selected defaults. SW_RESET commands will reset CODE and DAC register contents to their M/Z selected initial codes. A SW_GATE state can be used to momentarily hold selected DAC outputs in their DEFAULT positions. The contents of CODE and DAC registers can be manipulated by watchdog timer activity, enabling a variety of safety features. Internal Reference The MAX5723/MAX5724/MAX5725 include an internal precision voltage reference that is software selectable to be 2.048V, 2.500V, or 4.096V. When an internal reference is selected, that voltage is available on the REF output for other external circuitry (see the Typical Operating Circuits) and can drive loads down to 25kI. ��������������������������������������������������������������� Maxim Integrated Products 17 MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface External Reference The external reference input has a typical input impedance of 100kI and accepts an input voltage from +1.24V to VDD. Apply an external voltage between REF and GND to use an external reference. The MAX5723/MAX5724/MAX5725 power up and reset to external reference mode. Visit www.maxim-ic.com/products/references for a list of available external voltage-reference devices. M/Z Input The MAX5723/MAX5724/MAX5725 feature a pin-selectable DAC reset state using the M/Z input. Upon a poweron reset, all CODE and DAC data registers are reset to zero scale (M/Z = GND) or midscale (M/Z = VDD). M/Z is referenced to VDD (not VDDIO). In addition, M/Z must be valid at the time the device is powered up—connect M/Z directly to VDD or GND. Load DAC (LDAC) Input The MAX5723/MAX5724/MAX5725 feature an active-low asynchronous LDAC logic input that allows DAC outputs to update simultaneously. Connect LDAC to VDDIO or keep LDAC high during normal operation when the device is controlled only through the serial interface. Drive LDAC low to update the DAC outputs with data from the CODE registers. Holding LDAC low causes the DAC registers to become transparent and CODE data is passed through to the DAC registers immediately updating the DAC outputs. A software CONFIG command can be used to configure the LDAC operation of each DAC independently. Clear (CLR) Input The MAX5723/MAX5724/MAX5725 feature an asynchronous active-low CLR logic input that simultaneously sets all selected DAC outputs to their programmable DEFAULT states. Driving CLR low clears the contents of both the CODE and DAC registers and also ignores any on-going I2C command which modifies registers associated with a DAC configured to accept clear operations. To allow a new I2C command, drive CLR high, satisfying the tCSC timing requirement. A software CONFIG com- mand can be used to configure the clear operation of each DAC independently. Watchdog Feature The MAX5723/MAX5724/MAX5725 feature an interface watchdog timer with programmable timeout duration. This monitors the I/O interface for activity and integrity. If the watchdog is enabled, the host processor must write a valid command to the device within the timeout period to prevent a timeout. If the watchdog is allowed to timeout, selected DAC outputs are returned to the programmable DEFAULT state, protecting the system against control faults. By default, all watchdog features are disabled; users wishing to activate any watchdog feature must configure the device accordingly. Individual DAC channels can be configured using the CONFIG command to accept the watchdog alarm and to gate, clear, or hold their outputs in response to an alarm. A watchdog refresh event and watchdog behavior upon timeout is defined by a programmable safety level using the WDOG_CONFIG command. IRQ Output The MAX5723/MAX5724/MAX5725 feature an active-low open-drain interrupt output indicating to the host when a watchdog timeout has occurred. Interface Power Supply (VDDIO) The MAX5723/MAX5724/MAX5725 feature a separate supply input (VDDIO) for the digital interface (1.8V to 5.5V). Connect VDDIO to the I/O supply of the host processor. SPI Serial Interface The MAX5723/MAX5724/MAX5725 4-wire serial interface is compatible with MICROWIRE, SPI, QSPI, and DSPs. The interface provides three inputs, SCLK, CSB, and DIN. The chip-select input (CSB, active-low) frames the data loaded through the serial data input (DIN). Following a CSB input high-to-low transition, the data is shifted in synchronously and latched into the input register on each falling edge of the serial clock input (SCLK). Each serial operation word is 24-bits long. The DAC data is left justified as shown in Table 1. The serial Table 1. Format DAC Data Bit Positions PART B15 B14 B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 B0 MAX5723 D7 D6 D5 D4 D3 D2 D1 D0 X X X X X X X X MAX5724 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 X X X X X X MAX5725 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 X X X X ��������������������������������������������������������������� Maxim Integrated Products 18 MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface input register transfers its contents to the destination registers after loading 24 bits of data on the 24th SCLK falling edge. To initiate a new SPI operation, drive CSB high and then low to begin the next operation sequence, being sure to meet all relevant timing requirements. During CSB high periods, SCLK is ignored, allowing communication to other devices on the same bus. SPI operations consisting of more than 24 SCLK cycles are executed on the 24th SCLK falling edge, using the first three bytes of data available. SPI operations consisting of less than 24 SCLK cycles will not be executed. The content of the SPI operation consists of a command byte followed by a two-byte data word. The DOUT phase for all SPI_READ commands is determined by the readback command used, allowing the selection of the SCLK DOUT update edge best suited to the digital I/O implementation, maximizing data transfer speed and/or timing margin. Guaranteed non-zero DOUT hold times allow the microprocessor to strobe DOUT on the same edge as the MAX5723/MAX5724/MAX5725 updates for fastest SPI read mode transfers. For example, if DPHA = 0 is used, the MAX5723/MAX5724/MAX5725 update DOUT in response to SCLK falling edges 8-23, while a microprocessor (µP) with low data hold time requirements can strobe in the DOUT data on SCLK falling edges 9-24. The device supports readback speeds of up to 25MHz for a microprocessor with 5ns data input setup requirements and allowing 35ns for tDOT at VDDIO > 2.7V. Variable DOUT phase also supports microprocessors with longer data input hold time requirements. For example, if DPHA = 1 is used, the MAX5723/MAX5724/ MAX5725 updates DOUT in response to SCLK rising edges 9-24 while the microprocessor can strobe in the DOUT data on SCLK falling edges 9-24. The device supports readback speeds up to 12.5MHz for a µP with 5ns data input setup requirements and allowing 35ns for tDOT (assuming 50% duty cycle SCLK). For improved readback speed while monitoring device status, the SPI_READ_STATUS command repeats the device status information for multiple bits, allowing polling of the device at maximum interface speeds (up to 50MHz when the readback strobe is placed away from DOUT transition edges). This transfer speed cannot be achieved for other forms of readback using the SPI_READ_DATA command, where more DOUT bus transitions occur. +5V RPU = 5kI µC CSB1 CSB SCLK SCLK MOSI DIN MISO DOUT IRQ IRQ CSB2 CSB MAX5723 MAX5724 MAX5725 SCLK DIN DOUT IRQ CSB3 CSB SCLK DIN Figure 2. Typical SPI Application Circuit Figure 1 shows the timing diagram for the complete 4-wire serial interface transmission. The DAC code settings (D) for the MAX5723/MAX5724/MAX5725 are accepted in an offset binary format (see Table 1). Otherwise, the expected data format for each command is listed in Table 2. SPI User-Command Register Map This section lists the user-accessible commands and registers for the MAX5723/MAX5724/MAX5725. Table 2 provides detailed information about the Command Registers. ��������������������������������������������������������������� Maxim Integrated Products 19 0 0 0 0 WD_RESET SW_CLEAR SW_RESET CONFIG 1 0 0 0 0 0 0 0 0 0 0 WD_REFRESH SET CLR SW_GATE_ SW_GATE_ 0 REF 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 X 0 1 1 0 0 0 0 1=ON 10 = 2.0V DAC 0 0 0 1 1 0 0 0 1 0 1 0 1 0 11 = 4.1V 00 = EXT 01 = 2.5V 0= REF Mode X Power REF X 0 0 0 0 0 0 X 1 1 1 1 1 1 X 1 1 1 1 1 1 X 0 0 0 0 0 0 X 1 1 1 1 1 1 X 0 0 0 0 0 0 X 0 0 0 0 0 0 X 1 1 1 1 1 1 X TIMEOUT SELECTION[11:4] DAC7 X B8 DAC6 1 B9 DAC5 0 B10 DAC4 0 B11 DAC3 0 B13 B12 DAC2 WDOG B14 DAC1 CONFIGURATION AND SOFTWARE COMMANDS B16 B15 B5 TIMEOUT B6 B4 0 0 0 0 0 0 0 0 0 0 0 0 11: HOLD 10: CLR 01: GATE 00: DIS Config. WDOG X X Level 0 0 0 0 0 0 0 X 0 0 X 0 0 0 X X 11: Max 10: High 01: Med 00: Low 0 0 0 0 0 0 X B1 Safety B2 1 1 1 1 1 1 X B3 1 1 1 1 1 1 X SELECTION[3:0] B7 GATE_ENB B23 B22 B21 B20 B19 B18 B17 LDAC_ENB COMMAND DAC0 WD_MASK CLEAR_ENB Table 2. SPI Commands Summary X 0 0 0 0 0 0 X X B0 are not impacted) corresponding DACn bit DACs with a 0 in the DACn bit are updated, 1 in the corresponding DACs selected with a and CLEAR operations. Watchdog, GATE, LOAD, Configures selected DAC values) to their power-on reset control registers returned (all CODE, DAC, and Executes a software reset DEFAULT values) registers cleared to their clear (all CODE and DAC Executes a software timer refreshes the watchdog out alarm status and Reset the watchdog time timer Refreshes the watchdog Initiates a GATE condition GATE condition always powered Removes any existing 1 = Internal reference is DAC is powered only powered if at least one 0 = Internal reference is Power (B18): operating mode. REF Sets the reference settings and safety levels Updates watchdog DESCRIPTION MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface ��������������������������������������������������������������� Maxim Integrated Products 20 0 DEFAULT 1 LOADn CODE_ALL LOADn CODEn_ LOAD_ALL 1 1 1 1 CODEn CODEn_ 0 RETURNn DAC COMMANDS 0 POWER 1 0 0 0 0 1 1 1 0 1 1 0 0 1 1 0 0 1 0 1 0 1 0 0 0 0 0 0 0 0 0 DAC Selection DAC Selection DAC Selection DAC Selection DAC Selection 0 0 0 0 0 B9 B8 X X X X X CODE REGISTER DATA[3:0] CODE REGISTER DATA[11:4] CODE REGISTER DATA[3:0] CODE REGISTER X DATA[3:0] X DATA[11:4] CODE REGISTER DATA[11:4] CODE REGISTER X DATA[3:0] DATA[11:4] X CODE REGISTER CODE REGISTER X DATA[3:0] DATA[11:4] 101+: No Effect 100: RETURN 011: FULL 010: MID 001: ZERO 000: MZ Default Values: X X X X X X X X X X X X X X X X X X X X X X X X are not impacted) 11 = PD registers Writes data to all CODE register(s) updating selected DAC CODE register(s) while data to the selected registers Simultaneously writes updating all DAC CODE register(s) while data to the selected Simultaneously writes register(s) to the selected DAC selected CODE registers Transfers data from the register(s) selected CODE Writes data to the register(s) selected RETURN Writes data to the impacted) DACn bit are not a 0 in the corresponding are updated, DACs with corresponding DACn bit selected with a 1 in the RETURN codes. (DACs mode programmable DACs in RETURN selected DACs. Note, code settings for Sets the DEFAULT corresponding DACn bit 100kI Hi-Z DACs with a 0 in the 10 = PD DACn bit are updated, 1 in the corresponding PD1kI (DACs selected with a DESCRIPTION 01 = X B0 of the selected DACs X B1 Normal X B2 Sets the Power Mode X B3 00 = X B4 Mode X B5 RETURN REGISTER X B6 Power B7 RETURN REGISTER X DAC7 DAC7 B10 DAC6 DAC6 B11 DAC5 DAC5 B13 B12 DAC4 DAC4 B14 DAC3 DAC3 B16 B15 DAC2 DAC2 B17 DAC1 DAC1 B23 B22 B21 B20 B19 B18 DAC0 DAC0 COMMAND Table 2. SPI Commands Summary (continued) MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface ��������������������������������������������������������������� Maxim Integrated Products 21 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 0 0 1 1 0 1 1 0 0 0 0 0 1 1 0 1 0 1 1 0 1 0 X X X X X X X DAC Selection 0 0 0 B17 X X X X X X X 1 0 1 X X X X X X X INC X B16 B15 X X X X X X X X B6 X B5 X B4 00 = DAC X X X X X X X 11 = WDT 10 = RET X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X DATA[3:0] X RETURN REGISTER CODE REGISTER X B7 DATA[11:4] X X B8 RETURN REGISTER X X B9 DATA[3:0] X B10 DATA[11:4] 01 = CODE X X B11 CODE REGISTER X B13 B12 DATA SEL [1:0] X B14 Reserved Commands: Any commands not specifically listed above are reserved for Maxim internal use only. No Operation 1 1 0 0 0 0 1 0 0 0 B23 B22 B21 B20 B19 B18 NO OPERATION COMMANDS DATA SPI_READ STATUS SPI_READ REQUEST SPI_DATA_ RETURN_ALL LOAD_ALL CODE_ALL LOAD_ALL COMMAND Table 2. SPI Commands Summary (continued) X X X X X X X X X X X B3 X X X X X X X X X X X B2 X X X X X X X X X X X B1 X X X X X X X X X X X B0 DESCRIPTION safety level is set to low. the watchdog timer if device, but will refresh have no effect on the These commands will requested data DPHA = 1 Readback requested data DPHA = 0 Readback status DPHA = 1 Readback status DPHA = 0 Readback read back the data content to be DATA SEL[1:0] indicates operation each SPI_READ _DATA to the next DAC after selection is incremented INC indicates if the DAC readback. Setup data request for RETURN registers Writes data to all all DAC registers registers while updating data to the all CODE Simultaneously writes register data with current CODE Updates all DAC latches MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface ��������������������������������������������������������������� Maxim Integrated Products 22 MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface RETURNn Command The RETURN command (B[23:20] = 0111) sets the programmable default RETURN value. This value is used for all future watchdog, clear, and gate operations when RET is selected for the DAC using the DEFAULT command. Issuing this command with DAC_ADDRESS set to all DACs will program the value for all RETURN registers and is equivalent to RETURN_ALL. Note: This command is inaccessible when a watchdog timeout has occurred if the watchdog timer is configured for safety level = high or max. CODEn Command The CODEn command (B[23:20] = 1000) updates the CODE register contents for the selected DAC(s). Changes to the CODE register content based on this command will not affect DAC outputs directly unless the LDAC input is in a low state or the DAC latch has been configured as transparent using the CONFIG command. Issuing this command with DAC_ADDRESS set to all DACs will program the value for all CODE registers and is equivalent to CODE_ALL. LOADn Command The LOADn command (B[23:20] = 1001) updates the DAC register content for the selected DAC(s) by uploading the current contents of the selected CODE register(s) into the selected DAC register(s). Channels for which CODE content has not been modified since the last LOAD or LDAC operation will not be updated to reduce digital crosstalk. Issuing this command with DAC_ADDRESS set to all DACs will update the contents of all DAC registers and is equivalent to LOAD_ALL. CODEn_LOADn Command The CODEn_LOADn command (B[23:20] = 1011) updates the CODE register contents for the selected DAC(s) as well as the DAC register content of the selected DAC(s). Channels for which CODE content has not been modified since the last LOAD or LDAC operation will not be updated to reduce digital crosstalk. Issuing this command with DAC_ADDRESS set to all DACs is equivalent to the CODE_ALL_LOAD_ALL command. CODEn_LOAD_ALL Command The CODEn_LOAD_ALL command (B[23:20] = 1010) updates the CODE register contents for the selected DAC(s) as well as the DAC register content of all DACs. Channels for which CODE content has not been modified since the last LOAD or LDAC operation will not be updated to reduce digital crosstalk. Issuing this command with DAC_ADDRESS set to all DACs will update the CODE Table 3. DAC Selection B19 B18 B17 B16 DAC SELECTED 0 0 0 0 DAC0 0 0 0 1 DAC1 0 0 1 0 DAC2 0 0 1 1 DAC3 0 1 0 0 DAC4 0 1 0 1 DAC5 0 1 1 0 DAC6 0 1 1 1 DAC7 1 X X X ALL DACs and DAC register contents of all DACs and is equivalent to CODE_ALL_LOAD_ALL. Note this command by definition will modify at least one CODE register; to avoid this use the LOAD command with DAC_ADDRESS set to all DACs or the LOAD_ALL command. CODE_ALL Command The CODE_ALL command (B[23:16] = 1100_0000) updates the CODE register contents for all DACs. LOAD_ALL Command The LOAD_ALL command (B[23:16] = 1100_0001) updates the DAC register content for all DACs by uploading the current contents of the CODE registers to the DAC registers. CODE_ALL_LOAD_ALL Command The CODE_ALL_LOAD_ALL command (B[23:16] = 1100_0010) updates the CODE register contents for all DACs as well as the DAC register content of all DACs. RETURN_ALL Command The RETURN_ALL command (B[23:16] = 1100_0011) updates the RETURN register contents for all DACs. NO_OP Commands Command All unused commands in the space (B[23:16] = 1100_01XX or 1100_1XXX) have no effect on the device, but will refresh the watchdog timer (if active) with the safety level set to low. ��������������������������������������������������������������� Maxim Integrated Products 23 MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface WDOG Command The WDOG command (B[23:20] = 0001) updates the watchdog timeout settings and safety levels for the device. Timeout thresholds are selected in 1ms increments (1ms to 4095ms are available). The WD_MASK bit can be used to mask the IRQ operation in response to the watchdog status, if WD_MASK = 1, watchdog alarms will not assert IRQ . The watchdog alarm status (WD bit) can be polled using the available SPI status readback commands regardless of WD_MASK settings. A write to this register will not reset a previously triggered watchdog alarm (use the WD_RESET command for this purpose). The watchdog timer refresh and timeout behavior is defined by the programmable safety level below. any register. LDAC and CLR inputs still function after a watchdog timeout event. Medium (01): A WD_REFRESH command must be executed in order to refresh the watchdog timer. Other commands as well as LDAC or CLR activity do not refresh the watchdog timer. A triggered watchdog alarm does not prevent writes to any register. LDAC and CLR inputs still function after a watchdog timeout event. Available safety levels (WL[1:0]): High (10): A WD_REFRESH command must be executed to refresh the watchdog timer. Other commands as well as LDAC or CLR activity do not refresh the watchdog timer. A triggered watchdog alarm prevents execution of all POWER, REF, CONFIG, DEFAULT, and RETURN commands. LDAC and CLR inputs still function after a watchdog timeout event. Low (00): Watchdog timer will refresh with the execution of any valid user mode command or no-op. Any successful slave address acknowledge qualifies to restart the watchdog timer (run to the ninth SCL edge), regardless of the command which follows. Issuing hardware CLR or LDAC falling edge will also refresh the watchdog timer. A triggered watchdog alarm does not prevent writes to Max (11): A WD_REFRESH command must be executed to refresh the watchdog timer. Other commands, as well as LDAC or CLR activity, do not refresh the watchdog timer. A triggered watchdog alarm prevents execution of all POWER, REF, CONFIG, DEFAULT, and RETURN commands. LDAC and CLR are gated and do not function after a watchdog timeout event. Table 4. WDOG Command Format 0 0 1 X WDOG Command X X X C11 C10 C9 Don’t Care C8 C7 C6 C5 B8 B7 B6 B5 B4 C4 C3 C2 C1 C0 WDM WL1 WL0 Timeout Selection Default Value → 0 0 Command Byte 0 0 0 0 Timeout Selection 0 0 0 0 0 Data High Byte 0 B3 B2 B1 WDOG Safety Level: 00: Low 01: Med 10: High 11: Max 0 0 0 B0 X Don’t Care 0 WD_MASK B23 B22 B21 B20 B19 B18 B17 B16 B15 B14 B13 B12 B11 B10 B9 X Data Low Byte Table 5. Watchdog Safety Level Protection WATCHDOG ANY COMMAND SAFETY REFRESHES LEVEL WDT CLR/LDAC REFRESHES WDT SW_RESET PLUS WD_RFRS REFRESHES WDT ALL REGISTERS ACCESSIBLE AFTER WDT TIMEOUT* CLR/LDAC AFFECT DAC REGISTERS AFTER WDT TIMEOUT* 00 (Low) X X X X X 01 (Med) — — X X X 10 (High) — — X — X 11 (Max) — — X — — *Unless otherwise affected by Watchdog HOLD or CLR configurations as set by the CONFIG command. See the CONFIG register definition for details. ��������������������������������������������������������������� Maxim Integrated Products 24 MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface REF Command The REF command (B[23:20] = 0010) updates the global reference setting used for all DAC channels. If an internal reference mode is selected, bit RF2 (B18) defines the reference power mode. If RF2 is set to zero (default), the reference will be powered down any time all DAC channels are powered down (i.e. the device is in STANDBY mode). If RF2 is set to one, the reference will remain powered even if all DAC channels are powered down, allowing continued operation of external circuitry (note in this mode the low current shutdown state is not available). This command is inaccessible when a watchdog timeout has occurred and the watchdog timer is configured with a safety level of high or max. SW_GATE_CLR Command The SW_GATE_CLR command (B[23:0] = 0011_0000_ 1001_0110_0011_0000) will remove any existing GATE condition initiated by a previous SW_GATE_SET comand. SW_GATE_SET Command The SW_GATE_SET command (B[23:0] = 0011_0001_ 1001_0110_0011_0000) will initiate a GATE condition. Any DACs configured with GTB = 0 (see the CONFIG Command section) will have their outputs held at the selected DEFAULT value until the GATE condition is later removed by a subsequent SW_GATE_CLR command. While in gate mode, the CODE and DAC registers con- tinue to function normally and are not reset (unless reset by a watchdog timeout). WD_REFRESH Command The WD_REFRESH command (B[23:0] = 0011_0010_ 1001_0110_0011_0000) will refresh the watchdog timer. This is the only command which will refresh the watchdog timer if the device is configured with a safety level of medium, high, or max. Use this command to prevent the watchdog timer from timing out. WD_RESET Command A WD_RESET command (B[23:0] = 0011_0011_ 1001_0110_0011_0000) will reset the watchdog interrupt (timeout) status and refresh the watchdog timer. Use this command to reset the IRQ timeout condition after the watchdog timer has timed out. Any DACs impacted by an existing timeout condition will return to normal operation. SW_CLEAR Command A software clear command (B[23:0] = 0011_0100_ 001_0110_0011_0000) will clear the contents of the CODE and DAC registers to the DEFAULT state for all channels configured with CLB = 0 (see CONFIG command). SW_RESET Command A software reset command (B[23:0] = 0011_0101_ 1001_0110_0011_0000) will reset all CODE, DAC, and configuration registers to their defaults (including POWER, DEFAULT, CONFIG, WDOG, and REF registers), simulating a power-on reset. 0 1 0 REF Command Default Value → B18 B17 B16 0 RF2 RF1 RF0 0 = DAC Controlled 1 = Always ON B23 B22 B21 B20 B19 0 Reserved Table 6. REF Command Format 0 Command Byte B15 B14 B13 B12 B11 B10 B9 X X X REF Mode: 00: EXT 01: 2.5V 10: 2.0V 11: 4.0V 0 0 X X X X B8 X B7 B6 B5 B4 B3 B2 B1 B0 X X X Don’t Care X X X X X Data High Byte X X X X X X X X Don’t Care X X X X X X X X Data Low Byte ��������������������������������������������������������������� Maxim Integrated Products 25 MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface POWER Command The POWER command (B[23:20] = 0100) updates the power mode settings of the selected DACs. DACs that are not selected do not update their power settings in response to the command. The new power setting is determined by bits PD[1:0] (B[7:6]) while the affected DAC(s) are selected using B[15:8]). If all DACs are powered down and the RF2 bit is not set, the device enters a STANDBY mode (all analog circuitry is disabled). This command is inaccessible when a watchdog timeout has occurred and the watchdog timer is configured with a safety level of high or max. Available power modes (PD[1:0]): Normal (00): DAC channel is active (default). PD 1kω (01): Power down with 1kω termination to GND. PD 100kω (10): Power down with 100kω termination to GND. PD Hi-Z (11): Power down with high-impedance output. Table 7. POWER Command Format B23 B22 B21 B20 B19 B18 B17 B16 B15 B14 B13 B12 B11 B10 B9 0 1 0 0 0 POWER Command 0 0 0 7 6 Reserved Default Value → 5 4 3 2 1 B8 0 1 1 Command Byte 1 1 Data High Byte CONFIG Command The CONFIG command (B[23:16] = 0101) updates the watchdog, gate, load, and clear mode settings of the selected DACs. DACs which are not selected do not update their settings in response to the command. The new mode settings to be written are determined by bits B[7:3] while the affected DAC(s) are selected by B[15:8]. This command is inaccessible when a watchdog timeout has occurred and the watchdog timer is configured with a safety level of high or max. Watchdog Configuration: WDOG Config settings are written by WC[1:0] (B[7:6]): DISABLE (WC = 00): Watchdog timeout does not affect the operation of the selected DAC. GATE (WC = 01): DAC code is gated to DEFAULT value in response to watchdog timeouts. Unless otherwise prohibited by the watchdog safety level, LDAC, CLR, 1 B6 PD1 PD0 B5 B4 B3 X X Power Mode: 00 = Normal 01 = 1kW 10 = 100kW 11 = Hi-Z Multiple DAC Selection 1 B7 1 1 0 0 X B2 B1 B0 X X X X X Don’t Care X X X X Data Low Byte and write operations to the CODE and DAC registers are accepted but will not be reflected on the DAC output until the watchdog timeout status is reset. CLR (WC = 10): CODE and DAC register contents are cleared to DEFAULT value in response to watchdog timeouts. All writes to CODE and DAC registers are ignored and LDAC or CLR input activity has no effect until the watchdog timeout status is reset, regardless of watchdog safety level. HOLD (WC = 11): DAC code is held at its previously programmed value in response to watchdog timeout. All writes to DAC and CODE registers are ignored and LDAC or CLR input activity has no effect until the watchdog timeout status is reset, regardless of watchdog safety level. Note: For the watchdog to timeout and have an impact, the function must first be enabled and configured using the WDOG command. ��������������������������������������������������������������� Maxim Integrated Products 26 MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface LDB = 1: DAC latch is transparent, the CODE register content controls the DAC output directly. Gate Configuration: The DAC GATE setting is written by GTB (B5); GATE operation is as follows: Clear Configuration: GTB = 0: Enables software gating function (default), DAC outputs are gated to their DEFAULT settings as long as the device remains in GATE mode (set by SW_GATE_ SET and removed by SW_GATE_CLR). CLEAR_ENB setting is written by CLB (B3); CLEAR_ENB operation is as follows: CLB = 0: Clear input and command functions impact the DAC (default), clearing CODE and DAC registers to their DEFAULT value. GTB = 1: Disable software gating function, DAC outputs are not impacted by GATE mode. CLB = 1: Clear input and command functions have no effect on the DAC. Load Configuration: The LDAC_ENB setting is written by LDB (B4); LDAC_ENB operation is as follows: LDB = 0: DAC latch is operational, enabling LDAC and LOAD functions (default). Table 8. CONFIG Command Format 0 1 0 CONFIG Command 0 0 0 7 6 Reserved Default Value → Command Byte 5 4 3 2 1 B8 0 1 1 1 1 1 Data High Byte B6 WDOG Config: 00: DISABLE 01: GATE 10: CLR 11: HOLD Multiple DAC Selection 1 B7 1 1 B5 B4 B3 WC1 WC0 GTB LDB CLB 0 0 B2 B1 B0 X X X CLEAR_ENB 1 LDAC_ENB 0 GATE_ENB B23 B22 B21 B20 B19 B18 B17 B16 B15 B14 B13 B12 B11 B10 B9 Don’t Care 0 0 0 X X X Data Low Byte ��������������������������������������������������������������� Maxim Integrated Products 27 MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface DEFAULT Command The DEFAULT command (B[23:20] = 0110) selects the default value for selected DACs. DACs which are not selected do not update their default settings in response to the command. These default values are used for all future watchdog, clear, and gate operations. The new default setting is determined by bits DF[2:0] (B[7:5]) while the affected DAC(s) are selected using B[15:8]. This command is inaccessible when a watchdog timeout has occurred and the watchdog timer is configured with a safety level of high or max. Note the selected default values do not apply to resets initiated by SW_RESET commands or supply cycling, both of which return all DACs to the values determined by the M/Z input and reset this register to M/Z mode. Available default values (DF[2:0]): M/Z (000): DAC channel defaults to value as selected by the M/Z input (default). ZERO (001): DAC channel defaults to zero scale. MID (010): DAC channel defaults to midscale. FULL (011): DAC channel defaults to full scale. RETURN (100): DAC channel defaults to the value programmed by the RETURN command. No Effect (101, 110, 111): DAC channel default behavior is unchanged. Table 9. DEFAULT Command Format B23 B22 B21 B20 B19 B18 B17 B16 B15 B14 B13 B12 B11 B10 B9 0 1 1 0 0 DEFAULT Command 0 0 0 7 6 Reserved Default Value → Command Byte 5 4 3 2 1 B8 0 1 1 1 1 Data High Byte 1 B6 B5 B4 B3 B2 B1 B0 X X X X X Default Values: 000: M/Z 001: ZERO 010: MID 011: FULL 100: RETURN 101+: No Effect Multiple DAC Selection 1 B7 DF2 DF1 DF0 1 1 0 0 0 Don’t Care X X X X X Data Low Byte ��������������������������������������������������������������� Maxim Integrated Products 28 MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface SPI_DATA_REQUEST Command The SPI_DATA_REQUEST command (B[23:20] = 1101) sets up the data request for future SPI_READ_DATA operations. SPI_READ_DATA is used to fetch the current settings of the internal CODE, DAC, or RETURN registers for each channel or the watchdog configuration (WDOG) settings or the device. The DAC address provided tells the part which channel location data is to be read back by the next SPI_READ_DATA command (see Table 3). Setting the DAC address greater than the number of available DACS will read back channel 0 content. 0 = Fix the address pointer (all further readbacks continue at the current address). 1 = Increment the address pointer (further readbacks continue at the next address, with rollover, default). The SEL[1:0] bits tells the part what type of data is requested: DAC (00): DAC register data (current DAC latch data, not subject to gating status, default). CODE (01): CODE register data. RET (10): RETURN register data. The INC bit tells the device how the next readback will update the DAC address pointer: WDT (11): WDOG register data (DAC selection does not apply). Table 10. SPI_DATA_REQUEST Command Format B23 B22 B21 B20 B19 B18 B17 B16 B15 B14 B13 B12 B11 B10 B9 1 0 1 DAC SELECTION SPI_DATA_REQUEST Default Value → DAC Selection 0 0 0 INC SEL[1:0] Increment 1 0 1 X Data Selection 00: DAC 01: CODE 10: RET 11: WDT 0 0 Command Byte X X X B8 B7 B6 B5 B4 B3 B2 B1 B0 X X X X X X X X X X X X Don’t Care X X X X Don’t Care X X X X Data High Byte SPI_READ_STATUS Command The SPI_READ_STATUS command (B[23:18] = 111000 for DPHA = 0, B[23:18] = 111001 for DPHA = 1) reads back the watchdog timer and CLR pin status (intentionally repeated to allow maximum interface speeds) through DOUT. X X Data Low Byte WD_STAT indicates a watchdog timeout condition. It reads 0 during normal operation, 1 during a timeout. WD_STAT is not masked by the WD_MASK bit in the WDOG_CONFIG command. CLR_STAT indicates the line level of the CLR pin. ‘0’ indicates the CLR input is or was asserted (grounded) during the current SPI operation. ‘1’ indicates the CLR input is not currently asserted (VDDIO level). DIN[18] selects the DOUT Phase (DPHA) to be used (see the SPI Serial Interface Timing Diagram in Figure 1 for details). Table 11. SPI_READ_STATUS Command Format B23 B22 B21 B20 B19 B18 B17 B16 B15 B14 B13 B12 B11 B10 B9 1 1 1 0 0 0 X X X SPI_READ_STATUS (DPHA = 0) 1 1 1 0 0 1 X X X X X X X B8 B7 B6 B5 B4 B3 B2 B1 B0 X X X X X X X X X DOUT = WD_STAT (Repeated) X X X X X X X X DOUT = CLR_STAT (Repeated) X X X X X X X X SPI_READ_STATUS (DPHA = 1) DOUT = WD_STAT (Repeated) DOUT = CLR_STAT (Repeated) Command Byte Data High Byte Data Low Byte X ��������������������������������������������������������������� Maxim Integrated Products 29 MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface SPI_READ_DATA Command The SPI_READ_DATA command (B[23:18] = 111010 for DPHA = 0, B[23:18] = 111011 for DPHA = 1) reads back the data requested using the SPI_DATA_REQUEST command through DOUT. readback speed capabilities based on the DPHA selection). The SPI_READ_DATA command provides register and address data as defined by the SPI_DATA_REQUEST configuration SEL bits. SPI_READ_DATA also increments the channel address pointer if configured to do so by the SPI_DATA_REQUEST INC bit, the address readback is the address corresponding to the data returned. DIN[18] selects the DOUT phase (DPHA) to be used (see Figure 1 for details, and the SPI Timing Characteristics in the Electrical Characteristics for a complete listing of Table 12. SPI_READ_DATA Command Format B23 B22 B21 B20 B19 B18 B17 B16 B15 B14 B13 B12 B11 B10 B9 1 1 1 0 1 0 X X X X SPI_READ_DATA (DPHA = 0, SEL = 00) X X X X X B8 B7 B6 B5 B4 B3 B2 B1 B0 X X X X X X X X X DOUT = DAC[11:4] DOUT = DAC[3:0] ADDRESS[3:0] SPI_READ_DATA (DPHA = 0, SEL = 01) DOUT = CODE[11:4] DOUT = CODE[3:0] ADDRESS[3:0] SPI_READ_DATA (DPHA = 0, SEL = 10) DOUT = RETURN[11:4] DOUT = RET[3:0] ADDRESS[3:0] SPI_READ_DATA (DPHA = 0, SEL = 11) 1 1 1 0 1 1 X X SPI_READ_DATA (DPHA = 1, SEL = 00) DOUT = WDOG[15:8] X X X X X X DOUT = WDOG[7:1] X X X X X X X X 0 X DOUT = DAC[11:4] DOUT = DAC[3:0] ADDRESS[3:0] SPI_READ_DATA (DPHA = 1, SEL = 01) DOUT = CODE[11:4] DOUT = CODE[3:0] ADDRESS[3:0] SPI_READ_DATA (DPHA = 1, SEL = 10) DOUT = RETURN[11:4] DOUT = RET[3:0] ADDRESS[3:0] SPI_READ_DATA (DPHA = 1, SEL = 11) DOUT = WDOG[15:8] Command Byte Data High Byte DOUT = WDOG[7:1] X 0 Data Low Byte ��������������������������������������������������������������� Maxim Integrated Products 30 MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface Applications Information Offset Error Power-On Reset (POR) Offset error indicates how well the actual transfer function matches the ideal transfer function at a single point. Typically, the point at which the offset error is specified is at or near the zero-scale point of the transfer function. Power Supplies and Bypassing Considerations Gain error is the difference between the ideal and the actual full-scale output voltage on the transfer curve, after nullifying the offset error. This error alters the slope of the transfer function and corresponds to the same percentage error in each step. Layout Considerations Zero-scale error is the difference between the DAC output voltage when set to code zero and ground. This includes offset and other die level nonidealities. When power is applied to VDD and VDDIO, the DAC output is set to zero scale. To optimize DAC linearity, wait until the supplies have settled and the internal setup and calibration sequence completes (200Fs, typ). Bypass VDD and VDDIO with high-quality ceramic capacitors to a low-impedance ground as close as possible to the device. Minimize lead lengths to reduce lead inductance. Connect the GND to the analog ground plane. Digital and AC transient signals on GND can create noise at the output. Connect GND to form the star ground for the DAC system. Refer remote DAC loads to this system ground for the best possible performance. Use proper grounding techniques, such as a multilayer board with a low-inductance ground plane, or star connect all ground return paths back to the MAX5723/MAX5724/MAX5725 GND. Carefully layout the traces between channels to reduce AC cross-coupling. Do not use wire-wrapped boards and sockets. Use shielding to minimize noise immunity. Do not run analog and digital signals parallel to one another, especially clock signals. Avoid routing digital lines underneath the MAX5723/MAX5724/MAX5725 package. Definitions Integral Nonlinearity (INL) INL is the deviation of the measured transfer function from a straight line drawn between two codes once offset and gain errors have been nullified. Differential Nonlinearity (DNL) DNL is the difference between an actual step height and the ideal value of 1 LSB. If the magnitude of the DNL P 1 LSB, the DAC guarantees no missing codes and is monotonic. If the magnitude of the DNL R 1 LSB, the DAC output may still be monotonic. Gain Error Zero-Scale Error Full-Scale Error Full-scale error is the difference between the DAC output voltage when set to full scale and the reference voltage. This includes offset, gain error, and other die level nonidealities. Settling Time The settling time is the amount of time required from the start of a transition, until the DAC output settles to the new output value within the converter’s specified accuracy. Digital Feedthrough Digital feedthrough is the amount of noise that appears on the DAC output when the DAC digital control lines are toggled. Digital-to-Analog Glitch Impulse A major carry transition occurs at the midscale point where the MSB changes from low to high and all other bits change from high to low, or where the MSB changes from high to low and all other bits change from low to high. The duration of the magnitude of the switching glitch during a major carry transition is referred to as the digital-to-analog glitch impulse. Although all bits change, larger steps may lead to larger glitch energy. The digital-to-analog power-up glitch is the duration of the magnitude of the switching glitch that occurs as the device exits power-down mode. ��������������������������������������������������������������� Maxim Integrated Products 31 MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface Detailed Functional Diagram VDD REF RIN 100kI INTERNAL/EXTERNAL REFERENCE (USER OPTION) CODE REGISTER 0 DAC LATCH 0 8-/10-/12-BIT DAC0 OUT0 BUFFER 0 VDDIO CODE CLEAR / RESET GATE/ CLEAR / RESET LOAD CHANNEL 0 DAC CONTROL LOGIC CONTROL LOGIC CSB 100kI 1kI POWER-DOWN DAC CHANNEL 0 DAC CHANNEL 1 OUT1 DAC CHANNEL 2 OUT2 DAC CHANNEL 3 OUT3 DAC CHANNEL 4 OUT4 DAC CHANNEL 5 OUT5 DAC CHANNEL 6 OUT6 SCLK DIN DOUT SPI SERIAL INTERFACE CLR LDAC IRQ WATCHDOG TIMER M/Z POR CODE REGISTER 7 CODE MAX5723 MAX5724 MAX5725 CLEAR / RESET DAC LATCH 7 LOAD CHANNEL 7 DAC CONTROL LOGIC 8-/10-/12-BIT DAC7 OUT7 BUFFER 7 GATE/ CLEAR / RESET 100kI 1kI POWER-DOWN DAC CHANNEL 7 GND ��������������������������������������������������������������� Maxim Integrated Products 32 MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface Typical Operating Circuits 100nF 4.7µF RPU = 5kI VDDIO VDD LDAC OUT DAC CSB 100nF SCLK DIN µC DOUT MAX5723 MAX5724 MAX5725 R1 REF R2 CLR R1 = R2 IRQ M/Z GND NOTE: BIPOLAR OPERATING CIRCUIT, ONE CHANNEL SHOWN 100nF 4.7µF RPU = 5kI VDDIO VDD LDAC CSB 100nF DAC OUT SCLK µC DIN DOUT MAX5723 MAX5724 MAX5725 REF CLR IRQ M/Z GND NOTE: UNIPOLAR OPERATING CIRCUIT, ONE CHANNEL SHOWN ��������������������������������������������������������������� Maxim Integrated Products 33 MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface Ordering Information PART TEMP RANGE PIN-PACKAGE RESOLUTION (BIT) MAX5723AUP+* -40°C to +125°C 20 TSSOP 8 MAX5724AUP+* -40°C to +125°C 20 TSSOP 10 MAX5725AAUP+ -40°C to +125°C 20 TSSOP 12 MAX5725AWP+T* -40°C to +125°C 20 WLP 12 MAX5725BAUP+* -40°C to +125°C 20 TSSOP 12 Note: All devices are specified over the -40°C to +125°C temperature range. +Denotes a lead(Pb)–free/RoHS-compliant package. *Future product—Contact factory for availability. T = Tape and reel. Chip Information PROCESS: BiCMOS Package Information For the latest package outline information and land patterns (footprints), go to www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO. 20 TSSOP U20+1 21-0066 90-0116 20 WLP W202C2+1 21-0059 Refer to Application Note 1891 ��������������������������������������������������������������� Maxim Integrated Products 34 MAX5723/MAX5724/MAX5725 Ultra-Small, Octal-Channel, 8-/10-/12-Bit Buffered Output DACs with Internal Reference and SPI Interface Revision History REVISION NUMBER REVISION DATE 0 3/12 DESCRIPTION Initial release PAGES CHANGED — Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2012 Maxim Integrated Products 35 Maxim is a registered trademark of Maxim Integrated Products, Inc.