ADCMP600BRJZ-R2 Analog Devices Inc, ADCMP600BRJZ-R2 Datasheet - Page 11

• Manufacturer Part Number: ADCMP600BRJZ-R2
• Description: Comparator Single R-R I/P 5.5V 5-Pin SOT-23 T/R
• Manufacturer: Analog Devices Inc
• Type: General Purposer

Specifications of ADCMP600BRJZ-R2

• Package: 5SOT-23
• Typical Voltage Gain Range: 70 to 90 dB
• Rail To Rail: Rail to Rail Input
• Number Of Channels Per Chip: 1
• Minimum Single Supply Voltage: 2.5 V
• Power Supply Type: Single
• Number Of Elements: 1
• Output Type: CMOS, TTL
• Voltage - Supply: 2.5 V ~ 5.5 V
• Mounting Type: Surface Mount
• Package / Case: SC-74A, SOT-753
• Comparator Type: High Speed
• No. Of Comparators: 1
• Response Time: 3.5ns
• Ic Output Type: CMOS, TTL
• Supply Voltage Range: 2.5V To 5.5V
• Amplifier Case Style: SOT-23
• No. Of Pins: 5
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

OPTIMIZING PERFORMANCE
As with any high speed comparator, proper design and layout
techniques are essential for obtaining the specified performance.
Stray capacitance, inductance, inductive power and ground
impedances, or other layout issues can severely limit performance
and often cause oscillation. Large discontinuities along input
and output transmission lines can also limit the specified pulse-
width dispersion performance. The source impedance should
be minimized as much as is practicable. High source impedance,
in combination with the parasitic input capacitance of the
comparator, causes an undesirable degradation in bandwidth at
the input, thus degrading the overall response. Thermal noise
from large resistances can easily cause extra jitter with slowly
slewing input signals; higher impedances encourage undesired
coupling.
COMPARATOR PROPAGATION DELAY
DISPERSION
The ADCMP600/ADCMP601/ADCMP602 comparators are
designed to reduce propagation delay dispersion over a wide
input overdrive range. Propagation delay dispersion is the
variation in propagation delay that results from a change in the
degree of overdrive or slew rate (that is, how far or how fast the
input signal exceeds the switching threshold).
Propagation delay dispersion is a specification that becomes
important in high speed, time-critical applications, such as data
communication, automatic test and measurement, and instru-
mentation. It is also important in event-driven applications, such
as pulse spectroscopy, nuclear instrumentation, and medical
imaging. Dispersion is defined as the variation in propagation
delay as the input overdrive conditions are changed (Figure 18
and Figure 19).
The device dispersion is typically < 2 ns as the overdrive varies
from 10 mV to 125 mV. This specification applies to both
positive and negative signals because the device has very closely
matched delays both positive-going and negative-going inputs.
INPUT VOLTAGE
Q/Q OUTPUT
Figure 18. Propagation Delay—Overdrive Dispersion
500mV OVERDRIVE
10mV OVERDRIVE
DISPERSION
V
N
± V
OS
Rev. A | Page 11 of 16
COMPARATOR HYSTERESIS
The addition of hysteresis to a comparator is often desirable in a
noisy environment, or when the differential input amplitudes
are relatively small or slow moving. Figure 20 shows the transfer
function for a comparator with hysteresis. As the input voltage
approaches the threshold (0.0 V, in this example) from below
the threshold region in a positive direction, the comparator
switches from low to high when the input crosses +V
new switching threshold becomes −V
in the high state until the new threshold, −V
below the threshold region in a negative direction. In this manner,
noise or feedback output signals centered on 0.0 V input cannot
cause the comparator to switch states unless it exceeds the region
bounded by ±V
The customary technique for introducing hysteresis into a
comparator uses positive feedback from the output back to the
input. One limitation of this approach is that the amount of
hysteresis varies with the output logic levels, resulting in
hysteresis that is not symmetric about the threshold. The
external feedback network can also introduce significant
parasitics that reduce high speed performance and induce
oscillation in some cases.
These ADCMP600 features a fixed hysteresis of approximately
2 mV. The ADCMP601 and ADCMP602 comparators offer a
programmable Hysteresis feature that can significantly improve
accuracy and stability. Connecting an external pull-down
resistor or a current source from the LE/HYS pin to GND,
varies the amount of hysteresis in a predictable, stable manner.
ADCMP600/ADCMP601/ADCMP602
INPUT VOLTAGE
Q/Q OUTPUT
Figure 19. Propagation Delay—Slew Rate Dispersion
Figure 20. Comparator Hysteresis Transfer Function
H
/2.
–V
2
H
OUTPUT
V
OL
0
10V/ns
V
OH
1V/ns
H
/2. The comparator remains
+V
2
DISPERSION
H
INPUT
H
/2, is crossed from
V
N
± V
OS
H
/2, and the