LTC1666/LTC1667/LTC1668 12-Bit, 14-Bit, 16-Bit, 50Msps DACs FEATURES DESCRIPTIO n The LTC 1666/LTC1667/LTC1668 are 12-/14-/16-bit, 50Msps Update Rate n 50Msps differential current output DACs implemented on Pin Compatible 12-Bit, 14-Bit and 16-Bit Devices n a high performance BiCMOS process with laser trimmed, High Spectral Purity: 87dB SFDR at 1MHz f OUT n thin-film resistors. The combination of a novel current- 5pV-s Glitch Impulse n steering architecture and a high performance process Differential Current Outputs n produces DACs with exceptional AC and DC performance. 20ns Settling Time n The LTC1668 is the first 16-bit DAC in the marketplace to Low Power: 180mW from 5V Supplies n exhibit an SFDR (spurious free dynamic range) of 87dB TTL/CMOS (3.3V or 5V) Inputs n for an output signal frequency of 1MHz. Small Package: 28-Pin SSOP Operating from 5V supplies, the LTC1666/LTC1667/ U LTC1668 can be configured to provide full-scale output APPLICATIO S currents up to 10mA. The differential current outputs of n Cellular Base Stations the DACs allow single-ended or true differential operation. n Multicarrier Base Stations The 1V to 1V output compliance of the LTC1666/ n Wireless Communication LTC1667/LTC1668 allows the outputs to be connected n Direct Digital Synthesis (DDS) directly to external resistors to produce a differential out- n xDSL Modems put voltage without degrading the converters linearity. Al- n Arbitrary Waveform Generation ternatively, the outputs can be connected to the summing n Automated Test Equipment junction of a high speed operational amplifier, or to a n Instrumentation transformer. The LTC1666/LTC1667/LTC1668 are pin compatible and are available in a 28-pin SSOP and are fully specified over the industrial temperature range. , LTC and LT are registered trademarks of Linear Technology Corporation. TYPICAL APPLICATION LTC1668, 16-Bit, 50Msps DAC 5V 0.1F LTC1668 SFDR vs f and f OUT CLOCK 100 V LTC1668 REFOUT DD 2.5V 5MSPS REFERENCE R SET 0.1F 2k I 90 REFIN 25MSPS 52.3 I OUT A 80 50MSPS + + 16-BIT 1V P-P HIGH SPEED 52.3 V OUT DIFFERENTIAL I DAC OUT B 70 COMP1 60 LADCOM COMP2 C1 0.1F C2 V AGND DGND CLK DB15 DB0 DIGITAL AMPLITUDE = 0dBFS SS 50 0.1F 1666/7/8 TA01 0.1 1.0 10 100 f (MHz) OUT CLOCK 16-BIT DATA 0.1F 1666/7/8 G05 INPUT INPUT 5V 1 SFDR (dB) U ULTC1666/LTC1667/LTC1668 ABSOLUTE AXI U RATI GS (Note 1) Supply Voltage (V ) ................................................ 6V Power Dissipation............................................. 500mW DD Negative Supply Voltage (V ) ............................... 6V Operating Temperature Range SS Total Supply Voltage (V to V ) .......................... 12V LTC1666C/LTC1667C/LTC1668C ........... 0 C to 70 C DD SS Digital Input Voltage .................... 0.3V to (V + 0.3V) LTC1666I/LTC1667I/LTC1668I .......... 40 C to 85 C DD Analog Output Voltage Storage Temperature Range ................ 65 C to 150 C (I and I ) ........ (V 0.3V) to (V + 0.3V) Lead Temperature (Soldering, 10 sec).................. 300 C OUT A OUT B SS DD UUW PACKAGE/ORDER I FOR ATIO TOP VIEW ORDER PART DB9 1 28 DB10 NUMBER DB8 2 27 DB11 (MSB) DB7 3 26 CLK LTC1666CG DB6 4 25 V LTC1666IG DD DB5 5 24 DGND DB4 6 23 V SS DB3 7 22 COMP2 DB2 8 21 COMP1 DB1 9 20 I OUT A DB0 (LSB) 10 19 I OUT B NC 11 18 LADCOM NC 12 17 AGND NC 13 16 I REFIN NC 14 15 REFOUT G PACKAGE 28-LEAD PLASTIC SSOP T = 110 C, q = 100 C/W JMAX JA TOP VIEW TOP VIEW ORDER PART ORDER PART NUMBER NUMBER DB13 1 28 DB14 DB11 1 28 DB12 DB12 2 27 DB15 (MSB) DB10 2 27 DB13 (MSB) LTC1667CG LTC1668CG DB11 3 26 CLK DB9 3 26 CLK LTC1667IG LTC1668IG DB10 4 25 V DB8 4 25 V DD DD DB9 5 24 DGND DB7 5 24 DGND DB8 6 23 V DB6 6 23 V SS SS DB7 7 22 COMP2 DB5 7 22 COMP2 DB6 8 21 COMP1 DB4 8 21 COMP1 DB5 9 20 I DB3 9 20 I OUT A OUT A DB4 10 19 I 10 19 I OUT B DB2 OUT B DB3 11 18 LADCOM 11 18 LADCOM DB1 DB2 12 17 AGND 12 17 AGND DB0 (LSB) DB1 13 16 I 13 16 I REFIN NC REFIN DB0 (LSB) 14 15 REFOUT 14 15 REFOUT NC G PACKAGE G PACKAGE 28-LEAD PLASTIC SSOP 28-LEAD PLASTIC SSOP T = 110 C, q = 100 C/W T = 110 C, q = 100 C/W JMAX JA JMAX JA Consult LTC Marketing for parts specified with wider operating temperature ranges. 2 U WWW