LTC1448 Dual 12-Bit Rail-to-Rail Micropower DAC DESCRIPTION FEATURES n SO-8 Package The LTC 1448 is a dual rail-to-rail voltage output, 12-bit n 12-Bit Resolution digital-to-analog converter (DAC). It includes rail-to-rail n Buffered True Rail-to-Rail Voltage Output output buffer amplifiers and an easy-to-use 3-wire serial n External Reference Input Can Be Tied to V interface. It is available in 8-pin SO and PDIP packages and CC n Output Swings from 0V to V provides the smallest footprint of any dual 12-bit DAC. REF n 3V and 5V Supply Operation The LTC1448 has an external reference input pin (REF) n Schmitt Trigger on Clock Input Allows Direct and its outputs swing from 0V to REF. The REF input can Optocoupler Interface be tied to V providing rail-to-rail operation from supplies CC n Power-On Reset Clears DACs to 0V of 2.7V to 5.5V. (For devices with internal reference see the n 3-Wire Serial Interface LTC1446 data sheet.) The LTC1448 dissipates 2.5mW n Maximum DNL Error: 0.5LSB from a 5V supply. n Low Cost The low power supply current and the small SO-8 package U make the LTC1448 ideal for battery-powered applications. APPLICATIONS n Digital Calibration n Industrial Process Control n Automatic Test Equipment , LTC and LT are registered trademarks of Linear Technology Corporation. n Cellular Telephones TYPICAL APPLICATION Functional Block Diagram: 12-Bit Rail-to-Rail Dual DAC Differential Nonlinearity vs Input Code 2.7V TO 5.5V 0.5 7 4 0.4 REF V CC 0.3 0.2 2 D IN + 0.1 V OUT B 8 0 12-BIT 0.1 P DAC B 1 CLK 0.2 24-BIT RAIL-TO-RAIL SHIFT 0.3 3 CS/LD VOLTAGE REG OUTPUTS 0.4 AND DAC 0.5 LATCH + 0 512 1024 1536 2048 2560 3072 3584 4095 V OUT A 5 CODE 12-BIT 1448 TA02 DAC A POWER-ON RESET GND 6 1448 TA01 1 DNL ERROR (LSB) U ULTC1448 ABSOLUTE MAXIMUM RATINGS PACKAGE/ORDER I FOR ATIO V to GND .............................................. 0.5V to 7.5V CC ORDER PART TOP VIEW Logic Inputs to GND ................................ 0.5V to 7.5V NUMBER V , V , REF to GND ........... 0.5V to V + 0.5V CLK 1 V 8 OUT B OUT A OUT B CC LTC1448CN8 Maximum Junction Temperature .......................... 125C D 2 7 V IN CC LTC1448IN8 Operating Temperature Range CS/LD 3 6 GND LTC1448CS8 REF 4 V LTC1448C ............................................ 0C to 70C 5 OUT A LTC1448IS8 LTC1448I......................................... 40C to 85C N8 PACKAGE S8 PACKAGE 8-LEAD PDIP 8-LEAD PLASTIC SO Storage Temperature Range ................ 65C to 150C S8 PART MARKING Lead Temperature (Soldering, 10 sec)................. 300C T = 125C, = 100C/W (N8) JMAX JA 1448 T = 125C, = 150C/W (S8) JMAX JA 1448I Consult factory for Military grade parts. ELECTRICAL CHARACTERISTICS V = 2.7V to 5.5V, V and V unloaded, REF V , T = T to T , unless otherwise noted. CC OUT A OUT B CC A MIN MAX SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS DAC Resolution l 12 Bits Monotonicity l 12 Bits DNL Differential Nonlinearity V V 0.1V (Note 1) l 0.2 0.5 LSB REF CC INL Integral Nonlinearity V V 0.1V (Note 1), T = 25C 5.0 LSB REF CC A V V 0.1V (Note 1) l 5.5 LSB REF CC V Offset Error Measured at Code 20, T = 25C 10 mV OS A Measured at Code 20 l 15 mV V TC Offset Error Temperature 15 V/C OS Coefficient V Full-Scale Voltage V = 4.096V, T = 25C 4.070 4.095 4.120 V FS REF A V = 4.096V l 4.060 4.095 4.130 V REF V TC Full-Scale Voltage 10 ppm/C FS Temperature Coefficient Power Supply V Positive Supply Voltage For Specified Performance l 2.7 5.5 V CC I Supply Current (Note 4) l 450 700 A CC Op Amp DC Performance Short-Circuit Current Low V Shorted to GND l 55 120 mA OUT Short-Circuit Current High V Shorted to V l 65 120 mA OUT CC Output Impedance to GND Input Code = 0 l 30 120 Output Line Regulation Input Code = 4095. V = 4.5V to 5.5V, V = 4.096V l 0.2 1.5 LSB/V CC REF 2 U WU U WWW