Data Sheet LTC2672 Five-Channel, Low Dropout, 300 mA, Current Source Output, 12-/16-Bit SoftSpan DAC FEATURES FUNCTIONAL BLOCK DIAGRAM Per channel programmable output current ranges: 300 mA, LTC2672 IO V 200 mA, 100 mA, 50 mA, 25 mA, 12.5 mA, 6.25 mA, and VCC DD0 29 25 3.125 mA TGP DAC0 2 Flexible 2.1 V to V output supply voltages CC OUT0 24 Flexible single- or dual-supply operation SDI 3 0.6 V maximum dropout voltage guaranteed SPAN0 V SDO 4 Separate voltage supply per output channel SERIAL INTERFACE V DD1 SCK Internal switches to optional negative supply 22 5 Full 12-bit and 16-bit resolution at all ranges DAC1 CS/LD 6 OUT1 Guaranteed operation 40C to 125C (H-grade) 23 LDAC Precision internal reference (10 ppm/C maximum V 7 REF SPAN1 V temperature coefficient) or external reference CLR 31 Analog multiplexer monitors voltages and currents V DD2 21 A/B toggle via SPI or dedicated pin GND 1, 8, 14, 32 DAC2 1.71 V to V digital input and output supply voltage CC OUT2 20 32-lead lead frame chip scale package (LFCSP), see the FAULT FAULT 30 DETECT Outline Dimensions section SPAN2 V APPLICATIONS V DD3 18 FSADJ 12 Tunable lasers DAC3 FULL SCALE Semiconductor optical amplifier biasing ADJUST OUT3 9 REFLO 19 Resistive heaters REF SPAN3 10 V Current mode biasing INTERNAL REFERENCE REFCOMP V 11 DD4 17 GENERAL DESCRIPTION V CC 13, 27 DAC4 The LTC2672 is a family of five-channel, 12-/16-bit current source, OUT4 MUX 16 ANALOG digital-to-analog converters (DACs) that provide five high compli- 28 MUX ance, current source outputs with guaranteed 0.6 V dropout at V SPAN4 15, 26 V 200 mA. There are eight current ranges that are programmable per channel with full-scale outputs of up to 300 mA. The channels can be paralleled to allow either ultrafine adjustments of large Figure 1. currents or combined outputs of up to 1.5 A. A dedicated supply pin is provided for each output channel. Each channel can be operated from 2.1 V to V , and internal switches allow any output CC to be pulled to the optional negative supply. The LTC2672 includes a precision integrated 1.25 V reference (10 ppm/C maximum), with the option to use an external reference. The serial peripheral interface (SPI)-compatible, 3 wire serial interface operates on logic levels as low as 1.71 V and at clock rates as high as 50 MHz. Note that throughout this data sheet, multifunction pins, such as CS/LD, are referred to by the entire pin name or by a single function of the pin. Rev. A Information furnished by Analog Devices is believed to be accurate and reliableas i. However, no responsibility is assumed by Analog DOCUMENT FEEDBACK Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and TECHNICAL SUPPORT registered trademarks are the property of their respective owners. 001Data Sheet LTC2672 TABLE OF CONTENTS Features................................................................ 1 Monitor Multiplexer Precharge Applications........................................................... 1 Considerations............................................... 20 General Description...............................................1 Toggle Operations............................................ 21 Functional Block Diagram......................................1 Toggle Select Register (TSR)...........................21 Specifications........................................................ 4 Writing to Input Register A and Input Timing Characteristics........................................7 Register B.......................................................21 Absolute Maximum Ratings...................................9 Toggling Between Register A and Register B.. 21 Thermal Resistance........................................... 9 Daisy-Chain Operation.....................................23 ESD Caution.......................................................9 Echo Readback................................................23 Pin Configuration and Function Descriptions...... 10 Fault Register...................................................23 Typical Performance Characteristics...................12 Fault Indicator Pin (FAULT, Pin 30)..................23 Terminology......................................................... 15 Fault Conditions and Thermal Overload Theory of Operation.............................................16 Protection....................................................... 23 Load Termination and Combining Channels.... 16 Configuration Command.................................. 23 Power-On Reset...............................................16 Power-Down Mode...........................................24 Power Supply Sequencing............................... 16 Safe Supply Ranges.........................................24 Data Transfer Function.....................................16 Current Outputs................................................24 Applications Information...................................... 17 Switch to V Mode............................................25 Serial Interface................................................. 17 Gain Adjustment Using the FSADJ Pin............25 Input and DAC Registers..................................17 Offset Current and Code 0............................... 25 Output Ranges and SoftSpan Operation..........17 Reference Modes.............................................25 Monitor Multiplexer...........................................20 Board Layout....................................................25 Current Measurement Using the Multiplexer....20 Outline Dimensions............................................. 26 Die Temperature Measurement Using the Ordering Guide.................................................26 Multiplexer......................................................20 Evaluation Boards............................................ 27 REVISION HISTORY 4/2021Rev. 0 to Rev. A Added 12-Bit to Product Title........................................................................................................................... 1 Changes to Features Section.......................................................................................................................... 1 Changes to General Description Section.........................................................................................................1 Changes to Figure 1........................................................................................................................................ 1 Changes to Table 1..........................................................................................................................................4 Changes to Figure 2, Figure 3 Caption, and Figure 4 Caption........................................................................ 8 Changed UH-32 to 05-08-1693 in Table 5....................................................................................................... 9 Change to Figure 5........................................................................................................................................ 10 Added Figure 7 and Figure 11 Renumbered Sequentially............................................................................12 Changes to Integral Nonlinearity (INL) Section..............................................................................................15 Changes to Differential Nonlinearity (DNL) Section.......................................................................................15 Changes to Current Offset Error (IOS) Section............................................................................................. 15 Changes to Theory of Operation Section.......................................................................................................16 Changes to Load Termination and Combining Channels Section..................................................................16 Changes to Serial Interface Section.............................................................................................................. 17 Added Figure 23............................................................................................................................................ 17 Changes to Offset Current and Code 0 Section............................................................................................ 25 Updated Outline Dimensions......................................................................................................................... 26 Changes to Ordering Guide...........................................................................................................................26 Added Evaluation Boards Section................................................................................................................. 27 analog.com Rev. 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