LT1720/LT1721 Dual/Quad, 4.5ns, Single Supply 3V/5V Comparators with Rail-to-Rail Outputs FEATURES DESCRIPTION TM n UltraFast: 4.5ns at 20mV Overdrive The LT 1720/LT1721 are UltraFast dual/quad compara- 7ns at 5mV Overdrive tors optimized for single supply operation, with a supply n Low Power: 4mA per Comparator voltage range of 2.7V to 6V. The input voltage range extends n Optimized for 3V and 5V Operation from 100mV below ground to 1.2V below the supply volt- n Pinout Optimized for High Speed Ease of Use age. Internal hysteresis makes the LT1720/LT1721 easy to n Input Voltage Range Extends 100mV use even with slow moving input signals. The rail-to-rail Below Negative Rail outputs directly interface to TTL and CMOS. Alternatively, n TTL/CMOS Compatible Rail-to-Rail Outputs the symmetric output drive can be harnessed for analog n Internal Hysteresis with Speci ed Limits applications or for easy translation to other single supply n Low Dynamic Current Drain 15A/(V-MHz), logic levels. Dominated by Load In Most Circuits The LT1720 is available in three 8-pin packages three pins n Tiny 3mm 3mm 0.75mm DFN Package (LT1720) per comparator plus power and ground. In addition to SO and MSOP packages, a 3mm 3mm low pro le (0.8mm) APPLICATIONS dual ne pitch leadless package (DFN) is available for space n High Speed Differential Line Receiver limited applications. The LT1721 is available in the 16-pin n Crystal Oscillator Circuits SSOP and S packages. n Window Comparators The pinouts of the LT1720/LT1721 minimize parasitic n Threshold Detectors/Discriminators effects by placing the most sensitive inputs (inverting) n Pulse Stretchers away from the outputs, shielded by the power rails. The n Zero-Crossing Detectors LT1720/LT1721 are ideal for systems where small size and n High Speed Sampling Circuits low power are paramount. L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. UltaFast is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. TYPICAL APPLICATION Propagation Delay vs Overdrive 2.7V to 6V Crystal Oscillator with TTL/CMOS Output 8 2.7V TO 6V 25C 7 V = 100mV STEP 1MHz TO 10MHz V = 5V CC 2k CRYSTAL (AT-CUT) RISING EDGE 6 C = 10pF 220 LOAD (t ) PDLH 5 620 GROUND 4 CASE FALLING EDGE + (t ) 3 PDHL C1 OUTPUT 1/2 LT1720 2 1 2k 17201 TA01 0 10 20 40 0 30 50 0.1F 1.8k OVERDRIVE (mV) 17201 TA02 17201fc 1 DELAY (ns)LT1720/LT1721 (Note 1) ABSOLUTE MAXIMUM RATINGS Supply Voltage, V to GND ........................................7V Storage Temperature Range ................... 65C to 150C CC Input Current ....................................................... 10mA (DD Package) ..................................... 65C to 125C Output Current (Continuous) ............................. 20mA Operating Temperature Range Junction Temperature .......................................... 150C C Grade ................................................... 0C to 70C (DD Package) ....................................................125C I Grade ............................................... 40C to 85C Lead Temperature (Soldering, 10 sec) .................. 300C PIN CONFIGURATION TOP VIEW +IN A 1 8 V TOP VIEW CC IN A 2 7 OUT A +IN A 1 8 V CC 9 IN A 2 7 OUT A IN B OUT B 3 6 IN B 3 6 OUT B +IN B 4 5 GND 5 GND +IN B 4 MS8 PACKAGE 8-LEAD PLASTIC MSOP DD PACKAGE 8-LEAD (3mm s 3mm) PLASTIC DFN T = 150C, = 230C/W JMAX JA T = 125C, = 160C/W JMAX JA UNDERSIDE METAL INTERNALLY CONNECTED TO GND TOP VIEW IN A 1 16 IN D +IN A 2 15 +IN D TOP VIEW GND 3 14 V CC +IN A 1 8 V CC OUT A 4 13 OUT D IN A 2 7 OUT A OUT B 5 12 OUT C IN B 3 6 OUT B GND 6 11 V CC +IN B 4 5 GND +IN B 7 10 +IN C S8 PACKAGE IN B 8 9 IN C 8-LEAD PLASTIC SO GN PACKAGE S PACKAGE T = 150C, = 200C/W JMAX JA 16-LEAD NARROW 16-LEAD PLASTIC SO PLASTIC SSOP T = 150C, = 135C/W (GN) JMAX JA T = 150C, = 115C/W (S) JMAX JA 17201fc 2