LTC7106-1 A 7-Bit Current DAC with SPI Interface FEATURES DESCRIPTION n 0.8% I Positive Output Current Accuracy The LTC 7106-1 is a precision, SPI controlled, bidirec- DAC (OverTemp) tional current digital-to-analog converter that adjusts the n 1.5% I Negative Output Current Accuracy output voltage of any conventional V referenced regu- DAC FB (OverTemp) lator. The LTC7106-1 can work with the vast majority of n Input Voltage Range: 2.5V to 5.5V power management controllers or regulators to enable n High Impedance at IDAC Output When Disabled digital control of the output voltage. Internal power-on n Wide IDAC Operation Voltage (0.4V to 2.0V) reset circuitry keeps the DAC output current at zero (high n 7-Bit Programmable DAC Output Current for DC/DC impedance IDAC) until a valid write takes place. V Control OUT Features include a range bit for easy interfacing to almost n Wide Range IDAC Output Current: 16Ato 256A any impedance resistor divider, and an open-drain GPO n Programmable Slew Rate: 500ns ~ 3ms per Bit output for controlling the Run or Enable pin of the DC/ n Available in a 10-Lead (3mm 2mm) DFN Package DC regulator. For most applications, the current DAC error is significantly attenuated with proper design. See more detail about V accuracy in the Applications Information OUT APPLICATIONS section of this data sheet. The LTC7106 shares the same n General Purpose Power Systems 2 current DAC, but is controlled by an I C PMBus interface. n Telecom Systems All registered trademarks and trademarks are the property of their respective owners. n Industrial Applications TYPICAL APPLICATION Using LTC7106-1 to Vary V of DC/DC Converter Margin High and Margin Low OUT L1 CIRCUIT OF FIGURE 8 SW V OUT V V IN IN I = 50A DAC C2 330F R FB1 DC/DC V = 28V OUT V REF V OUT V (0.4V to 2V) FB 5V/DIV I = 0A RUN R FB2 DAC I = 50A DAC R4 10k EN V DD 0A TO 63A 5V/DIV 2.5V 7106-1 TA01b C1 TO 5.5V 100ms/DIV 1F 1k 10k* 10k* R3 R2 R1 V DD EN GPO 64A TO 0A SDI SDI SCLK SCLK SPI INTERFACE SDO LTC7106-1 IDAC SDO CSB CSB GND GPO INV 7106-1 TA01a *OPTIONAL Rev 0 1 Document Feedback For more information www.analog.comLTC7106-1 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) TOP VIEW All Pins Except GND .................................. 0.3V to 6.0V SDI 1 10 CSB Operating Junction Temperature Range ... 40C to 125C SCLK 2 9 SDO Storage Temperature Range .................. 65C to 150C V 3 8 GPO DD GPO INV 4 7 EN GND 5 6 IDAC DDB PACKAGE 10-LEAD (3mm 2mm) PLASTIC DFN = 55C/W, = 16.8C/W JA JC NOTE: THE EXPOSED PAD IS FLOATING INTERNALLY ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC7106EDDB-1 PBF LTC7106EDDB-1 TRPBF LHCH 10-Lead (3mm 2mm) Plastic DFN 40C to 125C LTC7106IDDB-1 PBF LTC7106IDDB-1 TRPBF LHCH 10-Lead (3mm 2mm) Plastic DFN 40C to 125C Consult ADI Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. Tape and reel specifications. Some packages are available in 500 unit reels through designated sales channels with TRMPBF suffix. ELECTRICAL CHARACTERISTICSThe l denotes the specifications which apply over the specified operating junction temperature range, otherwise specifications are at T = 25C (Note 2), V = 3.3V, unless otherwise specified. A DD SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS V Power Supply 2.5 5.5 V DD I Supply Quiescent Current EN High 1.3 1.5 mA Q V Undervoltage Rising Threshold V Rising 2.35 V UVLO R DD V Undervoltage Falling Threshold V Falling 2.15 V UVLO F DD V Enable Rising Threshold V Rising 1.35 V EN R EN V Enable Falling Threshold V Falling 0.8 V EN F EN IDAC OUT l I Accuracy Full Scale Positive Range = Normal 62.5 63.0 63.5 A DAC 0.4 V 2V (Note 3) IDAC Range = Low l 15.50 15.75 16.00 A l Range = High 246.7 252.0 255.3 A Full Scale Negative Range = Normal 64.6 64.0 63.0 A 0.4 V 2V (Note 3) (0C to 85C) IDAC l Range = Normal 65 64.0 63 A Range = Low l 16.4 16.0 15.6 A l Range = High 263.5 256.0 249.5 A LSB 0.4 V 2V Range = Normal 1.0 A IDAC Range = Low 0.25 A Range = High 4.0 A Rev 0 2 For more information www.analog.com