Datasheet LT6703-2, LT6703-3, LT6703HV-2, LT6703HV-3 (Analog Devices) - 10

LT6703-2/LT6703-3 LT6703HV-2/LT6703HV-3
TYPICAL PERFORMANCE CHARACTERISTICS Propagation Delay Rise and Fall Times Noninverting and Inverting vs Input Overdrive vs Output Pull-Up Resistor Comparator Propagation Delay
60 100 T LH NONINV A = 25°C VS = 5V VO(NINV) HL NONINV CL = 20pF 5V/DIV 50 LH INV TA = 25°C DC HL INV 10 VO(INV) 40 RISE 5V/DIV DC FALL 30 1 VIN 20 10mV/DIV AC PROPAGATION DELAY (μs) RISE AND FALL TIME (μs) 0.1 10 670323 G27 VS = 5V 20μs/DIV TA = 25°C 0 0.01 RLOAD = 10k CONNECTED TO VS 0 20 40 60 80 100 0.1 1 10 100 1000 VIN(OVERDRIVE) = 10mV OVER THE INPUT INPUT OVERDRIVE (mV) OUTPUT PULL-UP RESISTOR (kΩ) VOLTAGE THRESHOLDS 670323 G26 670323 G25
APPLICATIONS INFORMATION
The LT6703-2/LT6703-3/LT6703HV-2/LT6703HV-3 devices
Internal Reference
are micropower comparators with a built-in 400mV refer- Each comparator has one input available externally. The two ence. Features include wide supply voltage range (1.4V to versions of the part differ by the polarity of the available 18V), Over-The-Top input and output range, 2% accurate input (i.e., inverting or noninverting). The other comparator rising input threshold voltage and 6.5mV typical built-in input is connected internally to the 400mV reference. The hysteresis. rising input threshold voltage of the comparator is designed to be equal to that of the reference (i.e., ≈400mV). The R3 reference voltage is established with respect to the device GND connection. VS R4 R1
Hysteresis
V +IN LT6703-3 OUT IN VOUT Each comparator has built-in 6.5mV (typical) of hysteresis R2 GND to simplify designs, to insure stable operation in the pres- 670323 F01 ence of noise at the inputs, and to reject supply rail noise that might be induced by state change load transients. The THRESHOLD EQUATIONS: hysteresis is designed such that the falling input threshold 1 1 VIN (L TO H) = (400mV) • (R1) • + + voltage is nominally 393.5mV. External positive feedback 1R1 R2 R3 circuitry can be employed to increase effective hysteresis 1 1 VIN (H TO L) = (393mV) • (R1) • + + – if desired, but such circuitry will provide an apparent effect 1 VS • R1 R3 + R4 R1 R2 R3 + R4 on both the rising and falling input thresholds (the actual internal thresholds remain unaffected).
Figure 1. Additional Hysteresis Circuit
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