Datasheet LT1394 (Analog Devices)

LT1394 7ns, Low Power, Single Supply, Ground-Sensing Comparator
U FEATURES DESCRIPTIO
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UltraFastTM: 7ns
The LT®1394 is an UltraFast (7ns) comparator with comple- ■
Low Power: 6mA
mentary outputs and latch. The input common mode range ■
Low Offset Voltage: 0.8mV
extends from 1.5V below the positive supply down to the ■ Operates Off Single 5V or Dual ±5V Supplies negative supply rail. Like the LT1016, LT1116 and LT1671, ■ Input Common Mode Extends to Negative Supply this comparator has complementary outputs designed to ■ No Minimum Input Slew Rate Requirement interface directly to TTL or CMOS logic. The LT1394 may ■ Complementary TTL Outputs operate from either a single 5V supply or dual ±5V supplies. ■ Inputs Can Exceed Supplies without Phase Reversal Low offset voltage specifications and high gain allow the ■ Pin Compatible with LT1016, LT1116 and LT1671 LT1394 to be used in precision applications. ■ Output Latch Capability The LT1394 is designed for improved speed and stability for ■ Available in 8-Lead MSOP and SO Packages a wide range of operating conditions. The output stage
U
provides active drive in both directions for maximum speed
APPLICATIO S
into TTL, CMOS or passive loads with minimal cross-conduc- ■ High Speed A/D Converters tion current. Unlike other fast comparators, the LT1394 ■ Zero-Crossing Detectors remains stable even for slow transitions through the active ■ Current Sense for Switching Regulators region, which eliminates the need to specify a minimum input ■ Extended Range V/F Coverters slew rate. ■ Fast Pulse Height/Width Discriminators The LT1394 has an internal, TTL/CMOS compatible latch for ■ High Speed Triggers retaining data at the outputs. The latch holds data as long as ■ Line Receivers the LATCH pin is held high. Device parameters such as gain, ■ High Speed Sampling Circuits offset and negative power supply current are not significantly , LTC and LT are registered trademarks of Linear Technology Corporation. affected by variations in negative supply voltage. UltraFast is a trademark of Linear Technology Corporation.
U TYPICAL APPLICATIO 45MHz Single Supply Adaptive Trigger Propagation Delay vs Input Overdrive
5V 2k 12 6 T 3 A = 25°C 1 5 VSTEP = 100mV Q1 Q2 10 VS = ±5V 5V 2 4 3M 8 500pF 5V + 0.005µF + t A1 PDLH 6 LT1227 A2 t 0.005µF TIME (ns) PDHL – –LT1006 Q1, Q2, Q3, Q4 = CA3096 ARRAY: 4 TIE SUBSTRATE (PIN 16) TO GROUND 13 10 3M 2k 750Ω 510Ω = 1N4148 14 12 5V Q3 Q4 2 36Ω 15 11 470Ω 0 + + 0 10 20 30 40 50 10µF 0.1µF 2k 100µF OVERDRIVE (mV) + 0.1µF TRIGGER 0.1µF LT1394 OUT 1394 TA02 470Ω – INPUT 1394 F18 1