19-4209; Rev 1; 10/08 KIT ATION EVALU E L B AVAILA Pin-/Software-Compatible, 16-/12-Bit, Voltage-Output DACs The MAX5134–MAX5137 is a family of pin-compatible and software-compatible 16-bit and 12-bit DACs. The MAX5134/MAX5135 are low-power, quad 16-/12-bit, buffered voltage-output, high-linearity DACs. The MAX5136/MAX5137 are low-power, dual 16-/12-bit, buffered voltage-output, high-linearity DACs. They use a precision internal reference or a precision external reference for rail-to-rail operation. The MAX5134–MAX5137 accept a wide +2.7V to +5.25V supply-voltage range to accommodate most low-power and low-voltage applications. These devices accept a 3-wire SPITM-/QSPITM/MICROWIRETM-/DSP-compatible serial interface to save board space and reduce the complexity of optically isolated and transformer-isolated applications. The digital interface’s double-buffered hardware and software LDAC provide simultaneous output updates. The serial interface features a READY output for easy daisy-chaining of several MAX5134–MAX5137 devices and/or other compatible devices. The MAX5134–MAX5137 include a hardware input to reset the DAC outputs to zero or midscale upon power-up or reset, providing additional safety for applications that drive valves or other transducers that need to be off during power-up. The high linearity of the DACs makes these devices ideal for precision control and instrumentation applications. The MAX5134– MAX5137 are available in an ultra-small (4mm x 4mm), 24-pin TQFN package and are specified over the -40°C to +105°C extended industrial temperature range. Applications Automatic Test Equipment Automatic Tuning Features ♦ 16-/12-Bit Resolution in a 4mm x 4mm, 24-Pin TQFN Package ♦ Hardware-Selectable to Zero/Midscale DAC Output on Power-Up or Reset ♦ Double-Buffered Input Registers ♦ LDAC Asynchronously Updates DAC Outputs Simultaneously ♦ READY Facilitates Daisy Chaining ♦ High-Performance 10ppm/°C Internal Reference ♦ Guaranteed Monotonic Over All Operating Conditions ♦ Wide +2.7V to +5.25V Supply Range ♦ Rail-to-Rail Buffered Output Operation ♦ Low Gain Error (Less Than ±0.5%FS) and Offset (Less Than ±10mV) ♦ 30MHz 3-Wire SPI-/QSPI-/MICROWIRE-/ DSP-Compatible Serial Interface ♦ CMOS-Compatible Inputs with Hysteresis ♦ Low-Power Consumption (ISHDN = 2µA max) Ordering Information PINPACKAGE PART Pin Configuration OUT1 N.C. M/Z LDAC N.C. OUT2** TOP VIEW Gain and Offset Adjustment 18 17 16 15 14 13 Portable Instrumentation GND 19 12 SCLK Power-Amplifier Control N.C. 20 11 N.C. 10 CS 9 DIN 8 N.C. 7 GND Process Control and Servo Loops Programmable Voltage and Current Sources REF0 21 MAX5134– MAX5137 REFI 22 N.C. 23 3 4 5 6 OUT3** 2 N.C. 1 READY + N.C. MICROWIRE is a trademark of National Semiconductor Corp. AVDD 24 DVDD SPI and QSPI are trademarks of Motorola Inc. *EP OUT0 Functional Diagrams and Typical Operating Circuit appear at end of data sheet. INL (LSB) MAX5134AGTG+ 24 TQFN-EP* 16 Quad ±8 MAX5135GTG+ 24 TQFN-EP* 12 Quad ±1 MAX5136AGTG+ 24 TQFN-EP* 16 Dual ±8 MAX5137GTG+ 24 TQFN-EP* 12 Dual ±1 +Denotes a lead-free/RoHS-compliant package. *EP = Exposed pad. Note: All devices are specified over the -40°C to +105°C operating temperature range. Communication Systems Data Acquisition RESOLUTION (BITS) THIN QFN *EXPOSED PAD. 4mm x 4mm **N.C. FOR THE MAX5136/MAX5137. ________________________________________________________________ Maxim Integrated Products 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. 1 MAX5134–MAX5137 General Description MAX5134–MAX5137 Pin-/Software-Compatible, 16-/12-Bit, Voltage-Output DACs ABSOLUTE MAXIMUM RATINGS AVDD to GND...........................................................-0.3V to +6V DVDD to GND...........................................................-0.3V to +6V OUT0–OUT3 to GND ....................................-0.3V to the lower of (AVDD + 0.3V) and +6V REFI, REFO, M/Z to GND .............................-0.3V to the lower of (AVDD + 0.3V) and +6V SCLK, DIN, CS to GND ................................-0.3V to the lower of (DVDD + 0.3V) and +6V LDAC, READY to GND .................................-0.3V to the lower of (DVDD + 0.3V) and +6V Continuous Power Dissipation (TA = +70°C) 24-Pin TQFN (derate at 17.5mW/°C above +70°C)....2222.2mW Maximum Current into Any Input or Output with the Exception of M/Z Pin .......................................±50mA Maximum Current into M/Z Pin ...........................................±5mA Operating Temperature Range .........................-40°C to +105°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10s) .................................+300°C 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. ELECTRICAL CHARACTERISTICS (VAVDD = 2.7V to 5.25V, VDVDD = 2.7V to 5.25V, VAVDD ≥ VDVDD, VGND = 0, VREFI = VAVDD - 0.25V, COUT = 200pF, ROUT = 10kΩ, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS STATIC ACCURACY (Notes 1, 2) Resolution N MAX5134/MAX5136 16 MAX5135/MAX5137 12 (Note 3) Integral Nonlinearity (MAX5134/MAX5136) INL VREFI = 5V, AVDD = 5.25V Integral Nonlinearity (MAX5135/MAX5137) INL VREFI = 5V, AVDD = 5.25V Differential Nonlinearity DNL Offset Error -8 ±2 TA = +25°C +10 ±6 -1 +0.25 Guaranteed monotonic -1.0 OE (Note 4) -10 ±1 GE (Note 4) -0.5 ±0.2 Offset-Error Drift Gain Error Bits +1 LSB +1.0 LSB +10 mV +0.5 % of FS ±4 Gain Temperature Coefficient LSB µV/°C ppm FS/°C ±2 REFERENCE INPUT Reference-Input Voltage Range VREFI AVDD = 3V to 5.25V 2 AVDD AVDD = 2.7V to 3V 2 AVDD 0.2 Reference-Input Impedance 113 V kΩ INTERNAL REFERENCE Reference Voltage VREFO Reference Temperature Coefficient (Note 5) Reference Output Impedance Line Regulation Maximum Capacitive Load 2 TA = +25°C CR 2.437 2.440 2.443 V 10 25 ppm/°C 1 Ω 100 ppm/V 0.1 nF _______________________________________________________________________________________ Pin-/Software-Compatible, 16-/12-Bit, Voltage-Output DACs (VAVDD = 2.7V to 5.25V, VDVDD = 2.7V to 5.25V, VAVDD ≥ VDVDD, VGND = 0, VREFI = VAVDD - 0.25V, COUT = 200pF, ROUT = 10kΩ, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS AVDD - 0.02 V DAC OUTPUT VOLTAGE (Note 2) Output Voltage Range No load 0.02 0.1 Ω Series resistance = 0Ω 0.2 nF Series resistance = 500Ω 15 DC Output Impedance Maximum Capacitive Load (Note 5) CL Resistive Load RL Short-Circuit Current ISC Power-Up Time µF 2 AVDD = 5.25V AVDD = 2.7V kΩ ±35 -40 From power-down mode ±20 +40 25 mA µs DIGITAL INPUTS (SCLK, DIN, CS, LDAC) (Note 6) Input High Voltage VIH Input Low Voltage VIL Input Leakage Current IIN Input Capacitance CIN 0.7 x DVDD VIN = 0 or DVDD -1 V ±0.1 0.3 x DVDD V +1 µA 10 pF DIGITAL OUTPUTS (READY) Output High Voltage VOH ISOURCE = 3mA Output Low Voltage VOL ISINK = 2mA Voltage-Output Slew Rate SR Positive and negative Voltage-Output Settling Time tS DVDD - 0.5 V 0.4 V DYNAMIC PERFORMANCE Digital Feedthrough 1.25 V/µs 1/4 scale to 3/4 scale VREFI = AVDD = 5V settle to ±2 LSB (Note 5) 5 µs Code 0, all digital inputs from 0 to DVDD 0.5 nV•s 12 nV•s nV/√Hz Major Code Transition Analog Glitch Impulse Output Noise 10kHz 120 Integrated Output Noise 1Hz to 10kHz 18 µV 25 nV•s DAC-to-DAC Crosstalk _______________________________________________________________________________________ 3 MAX5134–MAX5137 ELECTRICAL CHARACTERISTICS (continued) MAX5134–MAX5137 Pin-/Software-Compatible, 16-/12-Bit, Voltage-Output DACs ELECTRICAL CHARACTERISTICS (continued) (VAVDD = 2.7V to 5.25V, VDVDD = 2.7V to 5.25V, VAVDD ≥ VDVDD, VGND = 0, VREFI = VAVDD - 0.25V, COUT = 200pF, ROUT = 10kΩ, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL CONDITIONS POWER REQUIREMENTS (Note 7) Analog Supply Voltage Range AVDD Digital Supply Voltage Range DVDD IAVDD Supply Current No load, all digital inputs at 0 or DVDD (MAX5134/MAX5135) IDVDD IAVDD Supply Current No load, all digital inputs at 0 or DVDD (MAX5136/MAX5137) IDVDD IAVPD Power-Down Supply Current No load, all digital inputs at 0 or DVDD IDVPD TIMING CHARACTERISTICS (Note 8) (Figure 1) Serial-Clock Frequency fSCLK SCLK Pulse-Width High tCH SCLK Pulse-Width Low tCL CS Fall-to-SCLK Fall Setup Time tCSS SCLK Fall-to CS-Rise Hold Time tCSH DIN-to-SCLK Fall Setup Time tDS DIN-to-SCLK Fall Hold Time tDH SCLK Fall to READY Transition tSRL (Note 9) CS Pulse-Width High tCSW LDAC Pulse Width tLDACPWL MIN TYP MAX UNITS 2.5 1 1.5 1 0.2 0.1 5.25 AVDD 3.6 10 2.3 10 2 2 V V mA µA mA µA 30 MHz ns ns ns ns ns ns ns ns ns 2.7 2.7 0 13 13 8 5 10 2 30 33 33 µA Static accuracy tested without load. Linearity is tested within 20mV of GND and AVDD, allowing for gain and offset error. Codes above 2047 are guaranteed to be within ±8 LSB. Gain and offset tested within 100mV of GND and AVDD. Guaranteed by design. Device draws current in excess of the specified supply current when a digital input is driven with a voltage of VI < DVDD - 0.6V or VI > 0.5V. At VI = 2.2V with DVDD = 5.25V, this current can be as high as 2mA. The SPI inputs are CMOS-input level compatible. The 30MHz clock frequency cannot be guaranteed for a minimum signal swing. Note 7: Excess current from AVDD is 10mA when powered without DVDD. Excess current from DVDD is 1mA when powered without AVDD. Note 8: All timing specifications are with respect to the digital input and output thresholds. Note 9: Maximum daisy-chain clock frequency is limited to 25MHz. Note 1: Note 2: Note 3: Note 4: Note 5: Note 6: tCSW COMMAND EXECUTED ON 24TH FALLING EDGE OF SCLK CS tCL tCSS tCH tCSH SCLK tDS DIN X C7 C6 C5 D3 tDH D2 D1 D0 X tSRL READY X = DON'T CARE. Figure 1. Serial-Interface Timing Diagram 4 _______________________________________________________________________________________ Pin-/Software-Compatible, 16-/12-Bit, Voltage-Output DACs 7 5 0 -3 -6 -9 16384 32768 49152 1 -1 3 1 -1 -3 -3 -5 -5 -7 -7 -9 2.7 65536 3.2 3.7 4.2 4.7 -40 5.2 -20 0 20 40 60 80 100 DIGITAL INPUT CODE (LSB) AVDD ( V ) TEMPERATURE (°C) MAX5134/MAX5136 DIFFERENTIAL NONLINEARITY vs. DIGITAL INPUT CODE MAX5134/MAX5136 DIFFERENTIAL NONLINEARITY vs. ANALOG SUPPLY VOLTAGE MAX5134/MAX5136 DIFFERENTIAL NONLINEARITY vs. TEMPERATURE 0.6 0.4 DNL (LSB) 0.4 0.2 0 -0.2 1.0 0.2 0 -0.2 0.8 0.6 0.4 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 16384 32768 49152 65536 -1.0 2.7 3.2 3.7 4.2 4.7 5.2 -40 0 20 40 60 80 100 AVDD ( V ) TEMPERATURE (°C) MAX5134/MAX5136 OFFSET ERROR vs. ANALOG SUPPLY VOLTAGE MAX5135/MAX5137 DIFFERENTIAL NONLINEARITY vs. DIGITAL INPUT CODE MAX5135/MAX5137 INTEGRAL NONLINEARITY vs. DIGITAL INPUT CODE 6 0.06 0.04 DNL (LSB) 4 0.08 2 0 -2 0.02 0 -0.02 -4 -0.04 -6 -0.06 -8 -0.08 -10 3.7 4.2 AVDD ( V ) 4.7 5.2 0.75 0.50 0.25 0 -0.25 -0.50 -0.75 -1.00 -0.10 3.2 1.00 INL (LSB) 8 MAX5134-MAX5137 toc09 0.10 MAX5134-MAX5137 toc07 10 2.7 -20 DIGITAL INPUT CODE (LSB) MAX5134-MAX5137 toc08 0 MAX5134-MAX5137 toc06 0.6 0.8 DNL (LSB) 0.8 MAX5134-MAX5137 toc05 1.0 MAX5134-MAX5137 toc04 1.0 DNL (LSB) 5 -9 0 OFFSET ERROR (mV) 7 INL (LSB) 3 INL (LSB) 3 9 MAX5134-MAX5137 toc02 6 INL (LSB) 9 MAX5134-MAX5137 toc01 9 MAX5134/MAX5136 INTEGRAL NONLINEARITY vs. TEMPERATURE MAX5134/MAX5136 INTEGRAL NONLINEARITY vs. ANALOG SUPPLY VOLTAGE MAX5134-MAX5137 toc03 MAX5134/MAX5136 INTEGRAL NONLINEARITY vs. DIGITAL INPUT CODE 0 1024 2048 3072 DIGITAL INPUT CODE (LSB) 4096 0 1024 2048 3072 4096 DIGITAL INPUT CODE (LSB) _______________________________________________________________________________________ 5 MAX5134–MAX5137 Typical Operating Characteristics (TA = +25°C, unless otherwise noted.) Typical Operating Characteristics (continued) (TA = +25°C, unless otherwise noted.) GAIN ERROR vs. ANALOG SUPPLY VOLTAGE -0.3 -0.4 0.4 0.3 0.2 0.1 0 -0.1 0.086 0.084 VAVDD = 5.25V VREFI = 5V 0 20 40 60 80 100 2.7 3.2 3.7 4.2 4.7 -40 5.2 -20 0 20 40 80 100 TEMPERATURE (°C) ANALOG SUPPLY CURRENT vs. ANALOG SUPPLY VOLTAGE ANALOG SUPPLY CURRENT vs. TEMPERATURE ANALOG SUPPLY CURRENT vs. SUPPLY VOLTAGE (POWER-DOWN MODE) VOUT_ = VREFO (MAX5136/MAX5137) 1700 1500 VOUT_ = 0 (MAX5136/MAX5137) IAVDD (MAX5136/MAX5137) 2000 1500 1000 0.45 0.40 IDVDD 3.7 4.2 4.7 5.2 0.30 0.25 TA = +105°C 0.20 TA = +25°C 0.15 0.05 0 3.2 TA = -40°C 0.35 0.10 500 900 MAX5134-MAX5137 toc15 MAX5134-MAX5137 toc14 2500 0.50 SUPPLY CURRENT (µA) 1900 IAVDD (MAX5134/MAX5135) SUPPLY CURRENT (µA) MAX5134-MAX5137 toc13 VOUT_ = 0 (MAX5134/MAX5135) 3000 1100 0 -40 -20 0 20 40 60 80 100 2.7 3.2 3.7 4.2 4.7 SUPPLY VOLTAGE (V) TEMPERATURE (°C) SUPPLY VOLTAGE (V) EXITING/ENTERING POWER-DOWN MODE MAJOR CODE TRANSITION SETTLING TIME UP MAX5134-MAX5137 toc16 5.2 MAX5134-MAX5137 toc18 MAX5134-MAX5137 toc17 500mV/div CH1 10mV/div 500mV/div 500mV/div CH0 4µs/div 6 60 AVDD ( V ) VOUT_ = VREFO (MAX5134/MAX5135) 2.7 VAVDD = 2.7V 0.070 TEMPERATURE (°C) 2300 1300 0.076 0.072 -0.4 2500 2100 0.078 0.074 -0.5 -20 0.080 -0.3 -0.6 -40 VAVDD = 5.25V 0.082 -0.2 -0.5 MAX5134-MAX5137 toc12 -0.2 MAX5134-MAX5137 toc11 VAVDD = 2.7V VREFI = 2.5V GAIN ERROR vs. TEMPERATURE 0.5 GAIN ERROR (%FS) OFFSET ERROR (mV) -0.1 MAX5134-MAX5137 toc10 0 GAIN ERROR (%FS) OFFSET ERROR vs. TEMPERATURE SUPPLY CURRENT (µA) MAX5134–MAX5137 Pin-/Software-Compatible, 16-/12-Bit, Voltage-Output DACs 1µs/div 400ns/div _______________________________________________________________________________________ Pin-/Software-Compatible, 16-/12-Bit, Voltage-Output DACs CROSSTALK SETTLING TIME DOWN DIGITAL FEEDTHROUGH MAX5134-MAX5137 toc20 MAX5134-MAX5137 toc19 MAX5134-MAX5137 toc21 10mV/div SCLK 5V/div 2V/div VOUT_ 50mV/div 500mV/div 400ns/div 4µs/div 40ns/div DIGITAL SUPPLY CURRENT vs. DIGITAL SUPPLY VOLTAGE REFERENCE VOLTAGE vs. SUPPLY VOLTAGE REFERENCE VOLTAGE vs. TEMPERATURE 2.0 1.5 2.46 TA = +25°C 2.44 2.4400 2.4395 2.4390 2.4385 2.4380 1.0 TA = +105°C TA = -40°C 2.42 2.4375 2.40 0 3.2 3.7 4.2 4.7 2.7 5.2 3.2 3.7 4.2 4.7 2.4370 -40 5.2 -20 0 20 40 60 80 SUPPLY VOLTAGE (V) SUPPLY VOLTAGE (V) TEMPERATURE (°C) DIGITAL SUPPLY CURRENT vs. DIGITAL INPUT VOLTAGE FULL-SCALE OUTPUT vs. TEMPERATURE OUTPUT VOLTAGE vs. OUTPUT CURRENT 2500 UP 2000 1500 DOWN 1000 2.51 2.50 2.49 EXTERNAL REFERENCE 2.500V 2.48 2.47 2.46 INTERNAL REFERENCE 2.45 100 2.50 VAVDD = 5V 2.45 2.40 OUTPUT VOLTAGE (V) VAVDD = VDVDD = 5.25V MAX5134-MAX5137 toc26 MAX5134-MAX5137 toc25 3000 OUTPUT VOLTAGE (V) 2.7 2.35 MAX5134-MAX5137 toc27 0.5 DIGITAL SUPPLY CURRENT (µA) MAX5134-MAX5137 toc24 2.4405 VREFO (V) 2.5 2.48 VREFO (V) SUPPLY CURRENT (nA) 3.0 MAX5134-MAX5137 toc23 VAVDD = 5.25V 3.5 2.50 MAX5134-MAX5137 toc22 4.0 2.30 2.25 VAVDD = 3.3V 2.20 2.15 2.10 500 2.44 0 2.05 2.43 0 1 2 3 4 DIGITAL INPUT VOLTAGE (V) 5 2.00 -40 -20 0 20 40 60 TEMPERATURE (°C) 80 100 MAX5134–MAX5137 Typical Operating Characteristics (continued) (TA = +25°C, unless otherwise noted.) 0 5 10 15 20 25 30 OUTPUT CURRENT (mA) _______________________________________________________________________________________ 7 Typical Operating Characteristics (continued) (TA = +25°C, unless otherwise noted.) REFERENCE INPUT BANDWIDTH vs. FREQUENCY ZERO-SCALE REFERENCE FEEDTHROUGH MAX5134-MAX5137 toc28 MAX5134-MAX5137 toc29 5 MAX5134-MAX5137 toc30 FULL-SCALE REFERENCE FEEDTHROUGH 0 VOUT_ 500mV REF 500mV -5 500mV/div VREF ATTENUATION (dB) MAX5134–MAX5137 Pin-/Software-Compatible, 16-/12-Bit, Voltage-Output DACs -10 -15 -20 -25 -30 VOUT_ 10mV/div 0V VOU -35 -40 0V VRE -45 20µs/div 1 10 100 1000 10,000 INPUT FREQUENCY (kHz) POWER-UP GLITCH, ZERO SCALE, EXTERNAL REFERENCE POWER-UP GLITCH, MIDSCALE, EXTERNAL REFERENCE POWER-UP GLITCH, ZERO SCALE, INTERNAL REFERENCE MAX5134-MAX5137 toc31 MAX5134-MAX5137 toc33 MAX5134-MAX5137 toc32 2V/div VAVDD 2V/div 2V/div VAVDD VAVDD 1V/div VOUT_ 1V/div 1V/div VOUT_ POWER-UP GLITCH, MIDSCALE, INTERNAL REFERENCE VOUT_ DC NOISE SPECTRUM, FFT PLOT MAX5134-MAX5137 toc35 MAX5134-MAX5137 toc34 -40dBm 2V/div VAVDD 10dB/div 1V/div VOUT_ 2.5kHz/div 8 25kHz _______________________________________________________________________________________ Pin-/Software-Compatible, 16-/12-Bit, Voltage-Output DACs PIN MAX5134 MAX5135 MAX5136 MAX5137 NAME 1 1 OUT0 2, 5, 8, 11, 14, 17, 20, 23 2, 5, 6, 8, 11, 13, 14, 17, 20, 23 N.C. 3 3 DVDD 4 4 READY 6 7, 19 9 10 12 13 15 — 7, 19 9 10 12 — 15 OUT3 GND DIN CS SCLK OUT2 LDAC 16 16 M/Z 18 21 18 21 OUT1 REFO 22 22 REFI 24 24 AVDD — — EP FUNCTION Channel 0 Buffered DAC Output No Connection. Not internally connected. Digital Power Supply. Bypass DVDD with a 0.1µF capacitor to GND. Active-Low Ready. Indicated configuration ready. Use READY as CS for consecutive part or as feedback to the µC. Channel 3 Buffered DAC Output Ground Data In Active-Low Chip-Select Input Serial-Clock Input Channel 2 Buffered DAC Output Load DAC Input. Active-low hardware load DAC input. Power-Up Reset Select. Connect M/Z to DVDD to power up the DAC outputs to midscale. Connect M/Z to GND to power up the DAC outputs to zero. Channel 1 Buffered DAC Output Reference Voltage Output Reference Voltage Input. Bypass REFI with a 0.1µF capacitor to GND when using external reference. Analog Power Supply. Bypass AVDD with a 0.1µF capacitor to GND. Exposed Pad. Internally connected to GND. Connect to a large ground plane to maximize thermal performance. Not intended as an electrical connection point. Detailed Description The MAX5134–MAX5137 is a family of pin-compatible and software-compatible 16-bit and 12-bit DACs. The MAX5134/MAX5135 are low-power, quad 16-/12-bit, buffered voltage-output, high-linearity DACs. The MAX5136/MAX5137 are low-power, dual 16-/12-bit, buffered voltage-output, high-linearity DACs. The MAX5134–MAX5137 minimize the digital noise feedthrough from input to output by powering down the SCLK and DIN input buffers after completion of each 24bit serial input. On power-up, the MAX5134–MAX5137 reset the DAC outputs to zero or midscale, depending on the state of the M/Z input, providing additional safety for applications that drive valves or other transducers that need to be off on power-up. The MAX5134– MAX5137 contain a segmented resistor string-type DAC, a serial-in parallel-out shift register, a DAC register, poweron reset (POR) circuit, and control logic. On the falling edge of the clock (SCLK) pulse, the serial input (DIN) data is shifted into the device, MSB first. During power-down, an internal 80kΩ resistor pulls DAC outputs to GND. Output Amplifiers (OUT0–OUT3) The MAX5134–MAX5137 include internal buffers for all DAC outputs. The internal buffers provide improved load regulation and transition glitch suppression for the DAC outputs. The output buffers slew at 1.25V/µs and drive up to 2kΩ in parallel with 200pF. The analog supply voltage (AVDD) determines the maximum output voltage range of the device as AVDD powers the output buffers. DAC Reference Internal Reference The MAX5134–MAX5137 feature an internal reference with a nominal output of +2.44V. Connect REFO to REFI when using the internal reference. Bypass REFO to GND with a 47pF (maximum 100pF) capacitor. Alternatively if heavier decoupling is required, use a 1kΩ series resistor with a 1µF capacitor to ground. REFO can deliver up to 100µA of current with no degradation in performance. Configure other reference voltages by applying a resistive potential divider with a total resistance greater than 33kΩ from REFO to GND. _______________________________________________________________________________________ 9 MAX5134–MAX5137 Pin Description MAX5134–MAX5137 Pin-/Software-Compatible, 16-/12-Bit, Voltage-Output DACs External Reference The external reference input features a typical input impedance of 113kΩ and accepts an input voltage from +2V to AVDD. Connect an external voltage supply between REFI and GND to apply an external reference. Leave REFO unconnected. Visit www.maxim-ic.com/products/references for a list of available external voltage-reference devices. high-to-low transition, the data is shifted synchronously and latched into the input register on each falling edge of the serial-clock input (SCLK). Each serial word is 24 bits. The first 8 bits are the control word followed by 16 data bits (MSB first), as shown in Table 1. The serial input register transfers its contents to the input registers after loading 24 bits of data. To initiate a new data transfer, drive CS high, keep CS high for a minimum of 33ns before the next write sequence. The SCLK can be either high or low between CS write pulses. Figure 1 shows the timing diagram for the complete 3-wire serialinterface transmission. The MAX5134–MAX5137 digital inputs are double buffered. Depending on the command issued through the serial interface, the input register(s) can be loaded without effecting the DAC register(s) using the write command. To update the DAC registers, either pulse the LDAC input low to asynchronously update all DAC outputs, or use the software LDAC command. Use the writethrough commands (see Table 1) to update the DAC outputs immediately after the data is received. Only use the writethrough command to update the DAC output immediately. AVDD as Reference Connect AVDD to REFI to use AVDD as the reference voltage. Leave REFO unconnected. Serial Interface The MAX5134–MAX5137 3-wire serial interface is compatible with MICROWIRE, SPI, QSPI, and DSPs (Figures 2, 3). The interface provides three inputs, SCLK, CS, and DIN and one output, READY. Use READY to verify communication or to daisy-chain multiple devices (see the READY section). READY is capable of driving a 20pF load with a 30ns (max) delay from the falling edge of SCLK. The chip-select input (CS) frames the serial data loading at DIN. Following a chip-select input’s Table 1. Operating Mode Truth Table* 24-BIT WORD CONTROL BITS DATA BITS MSB LSB C7 C6 C5 C4 C3 0 0 0 0 0 C2 C1 0 0 C0 D15 D14 D13 D12 D11 D10 D9 0 X X X X 0 0 0 0 0 0 0 1 X X X X 0 0 0 0 0 0 1 0 X X X X 0 0 0 0 0 0 1 1 X X X X 0 0 0 0 0 1 0 1 0 0 0 0 0 0 0 1 X X X X X X 0 0 LIN 0 0 1 0 0 1 0 0 0 X X X X D6–D0 X X X X X X FUNCTION NOP No operation. Move contents of input to DAC registers indicated by 1’s. No effect on registers indicated by 0’s. X X LDAC X X CLR DAC DAC DAC DAC READY_EN 3 2 1 0 DAC DAC DAC DAC 1 D15 D14 D13 D12 D11 D10 D9 3 2 1 0 0 D7 X DAC DAC DAC DAC 3 2 1 0 DAC DAC DAC DAC D15 D14 D13 D12 D11 D10 D9 3 2 1 0 0 D8 DESC Software clear. X Power down DACs Power indicated by 1’s. Control Set READY_EN = 1 to enable READY. Linearity Optimize DAC linearity. 0 0 0 D8 D7 D6 D8 D7 D6 X X X Write Write to selected input registers (DAC output not affected). Write to selected input Write- and DAC registers, through DAC outputs updated (writethrough). NOP No operation. *For the MAX5136/MAX5137, DAC2 and DAC3 do not exist. For the MAX5135/MAX5137, D0–D3 are don’t-care bits. 10 ______________________________________________________________________________________ Pin-/Software-Compatible, 16-/12-Bit, Voltage-Output DACs D15–D0 are the data bits that are written to the internal register. 3) After clocking in the last data bit, drive CS high. CS must remain high for 33ns before the next transmission is started. Figure 1 shows a write operation for the transmission of 24 bits. If CS is driven high at any point prior to receiving 24 bits, the transmission is discarded. Connect the MAX5134–MAX5137 DVDD supply to the supply of the host DSP or microprocessor. The AVDD supply may be set to any voltage within the operating range of 2.7V to 5.25V, but must be greater than or equal to the DVDD supply. READY Connect READY to a microcontroller (µC) input to monitor the serial interface for valid communications. The READY pulse appears 24 clock cycles after the negative edge of CS (Figure 4). Since the MAX5134– MAX5137 look at the first 24 bits of the transmission following the falling edge of CS, it is possible to daisy chain devices with different command word lengths. READY goes high 16ns after CS is driven high. Writing to the Devices Write to the MAX5134–MAX5137 using the following sequence: 1) Drive CS low, enabling the shift register. 2) Clock 24 bits of data into DIN (C7 first and D0 last), observing the specified setup and hold times. Bits +5V SK SCLK SS MISO* READY* MAX5134– DIN MAX5137 SO MICROWIRE PORT MAX5134– DIN MAX5137 MOSI SPI/QSPI PORT SI* READY* SCK SCLK I/O CS I/O CS *THE READY-TO-SI CONNECTION IS NOT REQUIRED FOR WRITING TO THE DEVICES *BUT MAY BE USED FOR TRANSMISSION VERIFICATION. *THE READY-TO-MISO CONNECTION IS NOT REQUIRED FOR WRITING TO THE DEVICES BUT MAY BE USED FOR TRANSMISSION VERIFICATION. Figure 3. Connections for SPI/QSPI Figure 2. Connections for MICROWIRE CS DIN SLAVE 1 DATA SLAVE 2 DATA SLAVE 3 DATA SCLK 1 2 3 4 20 21 22 23 24 1 2 3 4 5 21 22 23 24 1 2 3 4 5 21 22 23 24 READY 1 READY 2 READY 3 Figure 4. READY Timing ______________________________________________________________________________________ 11 MAX5134–MAX5137 The MAX5134/MAX5136 DAC code is unipolar binary with V OUT_ = (code/65,536) x V REF. The MAX5135/ MAX5137 DAC code is unipolar binary with VOUT_ = (code/4096) x VREF. See Table 1 for the serial interface commands. MAX5134–MAX5137 Pin-/Software-Compatible, 16-/12-Bit, Voltage-Output DACs Daisy chain multiple MAX5134–MAX5137 devices by connecting the first device conventionally, then connect its READY output to the CS of the following device. Repeat for any other devices in the chain, and drive the SCLK and DIN lines in parallel (Figure 5). When sending commands to daisy-chained devices, the devices are accessed serially starting with the first device in the chain. The first 24 data bits are read by the first device, the second 24 data bits are read by the second device and so on (Figure 4). Figure 6 shows the configuration when CS is not driven by the µC. These devices can be daisy chained with other compatible devices such as the MAX15500 output conditioner. To perform a daisy-chain write operation, drive CS low and output the data serially to DIN. The propagation of the READY signal then controls how the data is read by each device. As the data propagates through the daisy chain, each individual command in the chain is executed on the 24th falling clock edge following the falling edge of the respective CS input. To update just one device in a daisy chain, send the no-op command to the other devices in the chain. If READY is not required, write command 0x03 (power control) and set READY_EN = 0 (see Table 1) to disable the READY output. Clear Command The MAX5134–MAX5137 feature a software clear command (0x02). The software clear command acts as a software POR, erasing the contents of all registers. All outputs return to the state determined by the M/Z input. Power-Down Mode The MAX5134–MAX5137 feature a software-controlled individual power-down mode for each channel. The internal reference and biasing circuits power down to conserve power when all 4 channels are powered down. In power-down, the outputs disconnect from the buffers and are grounded with an internal 80kΩ resistor. The DAC register holds the retained code so that the output is restored when the channel powers up. The serial interface remains active in power-down mode. Load DAC (LDAC) Input The MAX5134–MAX5137 feature an active-low LDAC logic input that allows the outputs to update asynchronously. Keep LDAC high during normal operation (when the device is controlled only through the serial interface). Drive LDAC low to simultaneously update all DAC outputs with data from their respective input registers. Figure 7 shows the LDAC timing with respect to OUT_. Holding LDAC low causes the input registers to become transparent and data written to the DAC registers to immediately update the DAC outputs. A software command can also activate the LDAC operation. To activate LDAC by software, set control word 0x01 and data bits A11–A8 to select which DAC to load, and all other data bits to don’t care. See Table 1 for the data format. This operation updates only the DAC outputs that are flagged with a 1. DAC outputs flagged with a 0 remain unchanged. µC MOSI SCK SLAVE 1 I/O SLAVE 2 SLAVE 3 MAX5134– MAX5134– MAX5134– DIN MAX5137 SCLK READY CS DIN MAX5137 SCLK READY CS DIN MAX5137 SCLK READY CS Figure 5. Daisy-Chain Configuration 12 ______________________________________________________________________________________ Pin-/Software-Compatible, 16-/12-Bit, Voltage-Output DACs MAX5134–MAX5137 TO OTHER CHIPS/CHAINS CSm µC CS1 CS SCLK DWRITE DREAD INT SLAVE 1 CS SCLK DIN MAX5134– MAX5137 READY SLAVE 2 CS SCLK DIN MAX5134– MAX5137 READY SLAVE N CS SCLK MAX15500 DIN DOUT ERROR READY Figure 6. Daisy Chain (CS Not Used) ______________________________________________________________________________________ 13 MAX5134–MAX5137 Pin-/Software-Compatible, 16-/12-Bit, Voltage-Output DACs tLDACPWL LDAC tS ±2 LSB OUT_ Figure 7. Output Timing Applications Information Power-On Reset (POR) On power-up, the input registers are set to zero, DAC outputs power up to zero or midscale, depending on the configuration of M/Z. Connect M/Z to GND to power the outputs to GND. Connect M/Z to AVDD to power the outputs to midscale. To optimize DAC linearity, wait until the supplies have settled. Set the LIN bit in the DAC linearity register; wait 10ms, and clear the LIN bit. Unipolar Output The MAX5134–MAX5137 unipolar output voltage range is 0 to VREFI. The output buffers each drive a load of 2kΩ in parallel with 200pF. Layout Considerations Digital and AC transient signals on GND inputs can create noise at the outputs. Connect both GND inputs 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 MAX5134–MAX5137 GND. Carefully lay out the traces between channels to reduce AC crosscoupling and crosstalk. Do not use wire-wrapped boards and sockets. Use shielding to improve noise immunity. Do not run analog and digital signals parallel to one another (especially clock signals) and avoid routing digital lines underneath the MAX5134–MAX5137 package. Definitions Bipolar Output Use the MAX5134–MAX5137 in bipolar applications with additional external components (see the Typical Operating Circuit). Power Supplies and Bypassing Considerations For best performance, use a separate supply for the MAX5134–MAX5137. Bypass both DVDD and AVDD 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 both MAX5134–MAX5137 GND inputs to the analog ground plane. Table 2. MAX5134/MAX5136 Input Code vs. Output Voltage DAC LATCH CONTENTS MSB 1111 1111 1111 1111 14 ANALOG OUTPUT, VOUT_ LSB Integral Nonlinearity (INL) INL is the deviation of the measured transfer function from a best fit straight line drawn between two codes. For the MAX5134/MAX5136, this best fit line is a line drawn between codes 3072 and 64,512 of the transfer function, once offset and gain errors have been nullified. For the MAX5135/MAX5137, this best fit line is a line drawn between codes 192 and 4032 of the transfer function, 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 is greater than -1 LSB, the DAC guarantees no missing codes and is monotonic. Table 3. MAX5135/MAX5137 Input Code vs. Output Voltage DAC LATCH CONTENTS MSB ANALOG OUTPUT, VOUT_ LSB VREF x (65,535/65,536) 1111 1111 1111 XXXX VREF x (4095/4096) 1000 0000 0000 0000 VREF x (32,768/65,536) = 1/2 VREF 1000 0000 0000 XXXX VREF x (2048/4096) 0000 0000 0000 0001 VREF x (1/65,536) 0000 0000 0001 XXXX VREF x (1/4096) 0000 0000 0000 0000 0 0000 0000 0000 XXXX 0 ______________________________________________________________________________________ Pin-/Software-Compatible, 16-/12-Bit, Voltage-Output DACs Digital-to-Analog Glitch Impulse Gain Error 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. 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. 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. 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-to-Analog Power-Up Glitch Impulse DC DAC-to-DAC Crosstalk Crosstalk is the amount of noise that appears on a DAC output set to 0 when the other DAC is updated from 0 to AVDD Chip Information Digital Feedthrough Digital feedthrough is the amount of noise that appears on the DAC output when the DAC digital control lines are toggled. PROCESS: BiCMOS ______________________________________________________________________________________ 15 MAX5134–MAX5137 Offset Error 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. Pin-/Software-Compatible, 16-/12-Bit, Voltage-Output DACs MAX5134–MAX5137 Functional Diagrams AVDD DVDD GND REFI REFO REFERENCE M/Z MAX5134 MAX5135 POR CONTROL LOGIC POWER-DOWN CONTROL INPUT REGISTER DAC REGISTER 12-/16-BIT DAC BUFFER INPUT REGISTER DAC REGISTER 12-/16-BIT DAC BUFFER INPUT REGISTER DAC REGISTER 12-/16-BIT DAC BUFFER INPUT REGISTER DAC REGISTER 12-/16-BIT DAC BUFFER OUT0 CS SCLK SERIAL-TOPARALLEL CONVERTER OUT1 DIN READY 16 LDAC ______________________________________________________________________________________ OUT2 OUT3 Pin-/Software-Compatible, 16-/12-Bit, Voltage-Output DACs AVDD DVDD GND REFI REFO REFERENCE M/Z MAX5136 MAX5137 CONTROL LOGIC CS SCLK POR POWER-DOWN CONTROL INPUT REGISTER DAC REGISTER 12-/16-BIT DAC BUFFER INPUT REGISTER DAC REGISTER 12-/16-BIT DAC BUFFER SERIAL-TOPARALLEL CONVERTER DIN READY OUT0 OUT1 LDAC ______________________________________________________________________________________ 17 MAX5134–MAX5137 Functional Diagrams (continued) Pin-/Software-Compatible, 16-/12-Bit, Voltage-Output DACs MAX5134–MAX5137 Typical Operating Circuit DIGITAL POWER SUPPLY ANALOG POWER SUPPLY 100nF 100nF 100nF DVDD AVDD M/Z LDAC CS OUT DAC SCLK DIN READY MAX5134– MAX5137 REFO R1 R2 REFI 47pF GND *SHOWN IN BIPOLAR CONFIGURATION Package Information For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. 18 PACKAGE TYPE PACKAGE CODE DOCUMENT NO. 24 TQFN-EP T2444-4 21-0139 ______________________________________________________________________________________ Pin-/Software-Compatible, 16-/12-Bit, Voltage-Output DACs REVISION NUMBER REVISION DATE DESCRIPTION 0 7/08 Initial release of MAX5134 1 10/08 Initial release of MAX5135/MAX5136/MAX5137 PAGES CHANGED — 1–19 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. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 19 © 2008 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc. MAX5134–MAX5137 Revision History