LT1720 Datasheet, PDF (1/28 Pages) Linear Technology – Dual/Quad, 4.5ns, Single Supply 3V/5V Comparators with Rail-to-Rail Outputs

FEATURES
s _{UltraFast: 4.5ns at 20mV Overdrive}
7ns at 5mV Overdrive
s _{Low Power: 4mA per Comparator}
s _{Optimized for 3V and 5V Operation}
s _{Pinout Optimized for High Speed Ease of Use}
s _{Input Voltage Range Extends 100mV}
Below Negative Rail
s _{TTL/CMOS Compatible Rail-to-Rail Outputs}
s _{Internal Hysteresis with Specified Limits}
s _{Low Dynamic Current Drain; 15µA/(V-MHz),}
Dominated by Load In Most Circuits
U
APPLICATIO S
s _{High Speed Differential Line Receiver}
s _{Crystal Oscillator Circuits}
s _{Window Comparators}
s _{Threshold Detectors/Discriminators}
s _{Pulse Stretchers}
s _{Zero-Crossing Detectors}
s _{High Speed Sampling Circuits}
TYPICAL APPLICATIO
2.7V to 6V Crystal Oscillator with TTL/CMOS Output
2.7V TO 6V
2k
1MHz TO 10MHz
CRYSTAL (AT-CUT)
220Ω
620Ω
GROUND
+
CASE
C1
1/2 LT1720
–
2k
0.01µF
1.8k
OUTPUT
1720/21 TA01
LT1720/LT1721
Dual/Quad,
4.5ns, Single Supply
3V/5V Comparators
with Rail-to-Rail Outputs
DESCRIPTIO
The LT^®1720/LT1721 are UltraFast^TM dual/quad compara-
tors optimized for single supply operation, with a supply
voltage range of 2.7V to 6V. The input voltage range extends
from 100mV below ground to 1.2V below the supply voltage.
Internal hysteresis makes the LT1720/LT1721 easy to use
even with slow moving input signals. The rail-to-rail outputs
directly interface to TTL and CMOS. Alternatively, the sym-
metric output drive can be harnessed for analog applications
or for easy translation to other single supply logic levels.
The LT1720 is available in the 8-pin MSOP and SO packages;
three pins per comparator plus power and ground. The
LT1721 is available in the 16-pin SSOP and S packages.
The pinouts of the LT1720/LT1721 minimize parasitic effects
by placing the most sensitive inputs (inverting) away from the
outputs, shielded by the power rails. The LT1720/LT1721 are
ideal for systems where small size and low power are
paramount.
, LTC and LT are registered trademarks of Linear Technology Corporation.
UltraFast is a trademark of Linear Technology Corporation.
Propagation Delay vs Overdrive
8
7
6
RISING EDGE
(t_PDLH)
5
25°C
V_STEP = 100mV
V_CC = 5V
C_LOAD = 10pF
4
FALLING EDGE
3
(t_PDHL)
2
1
0
0
10
20
30
40
50
OVERDRIVE (mV)
1720/21 TA02
1