Rail-to-Rail, Very Fast, 2.5 V to 5.5 V,
Single-Supply TTL/CMOS Comparators
ADCMP600/ADCMP601/ADCMP602
FEATURES
Fully specified rail to rail at VCC = 2.5 V to 5.5 V
Input common-mode voltage from −0.2 V to VCC + 0.2 V
Low glitch CMOS-/TTL-compatible output stage
3.5 ns propagation delay
10 mW at 3.3 V
Shutdown pin
Single-pin control for programmable hysteresis and latch
Power supply rejection > 50 dB
Improved replacement for MAX999
−40°C to +125°C operation
APPLICATIONS
High speed instrumentation
Clock and data signal restoration
Logic level shifting or translation
Pulse spectroscopy
High speed line receivers
Threshold detection
Peak and zero-crossing detectors
High speed trigger circuitry
Pulse-width modulators
Current/voltage-controlled oscillators
Automatic test equipment (ATE)
FUNCTIONAL BLOCK DIAGRAM
NONINVERTING
INPUT
INVERTING
INPUT
LE/HYS
(EX CE P T ADCMP600)
Q OUTPUT
SDN
(ADCMP 602 ONLY )
ADCMP600/
ADCMP601/
ADCMP602
05914-001
Figure 1.
GENERAL DESCRIPTION
The ADCMP600, ADCMP601, and ADCMP602 are very fast
comparators fabricated on XFCB2, an Analog Devices, Inc.
proprietary process. These comparators are exceptionally
versatile and easy to use. Features include an input range from
GND − 0.5 V to VCC + 0.2 V, low noise, TTL-/CMOS-compatible
output drivers, and latch inputs with adjustable hysteresis
and/or shutdown inputs.
The device offers 5 ns propagation delay with 10 mV overdrive
on 3 mA typical supply current.
A flexible power supply scheme allows the devices to operate
with a single +2.5 V positive supply and a −0.5 V to +2.8 V
input signal range up to a +5.5 V positive supply with a −0.5 V
to +5.8 V input signal range. Split input/output supplies with no
sequencing restrictions on the ADCMP602 support a wide
input signal range while still allowing independent output
swing control and power savings.
The TTL-/CMOS-compatible output stage is designed to drive
up to 5 pF with full timing specs and to degrade in a graceful
and linear fashion as additional capacitance is added. The
comparator input stage offers robust protection against large
input overdrive, and the outputs do not phase reverse when the
valid input signal range is exceeded. Latch and programmable
hysteresis features are also provided with a unique single-pin
control option.
The ADCMP600 is available in 5-lead SC70 and SOT-23
packages, the ADCMP601 is available in a 6-lead SC70 package,
and the ADCMP602 is available in an 8-lead MSOP package.
Rev. A
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rights of third parties that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700 www.analog.com
Fax: 781.461.3113 ©2006–2011 Analog Devices, Inc. All rights reserved.
ADCMP600/ADCMP601/ADCMP602
Rev. A | Page 2 of 16
TABLE OF CONTENTS
Features .............................................................................................. 1
Applications ....................................................................................... 1
Functional Block Diagram .............................................................. 1
General Description ......................................................................... 1
Revision History ............................................................................... 2
Specifications ..................................................................................... 3
Electrical Characteristics ............................................................. 3
Timing Information ......................................................................... 5
Absolute Maximum Ratings ............................................................ 6
Thermal Resistance ...................................................................... 6
ESD Caution .................................................................................. 6
Pin Configuration and Function Descriptions ............................. 7
Typical Performance Characteristics ............................................. 8
Application Information ................................................................ 10
Power/Ground Layout and Bypassing ..................................... 10
TTL-/CMOS-Compatible Output Stage ................................. 10
Using/Disabling the Latch Feature ........................................... 10
Optimizing Performance ........................................................... 11
Comparator Propagation Delay Dispersion ........................... 11
Comparator Hysteresis .............................................................. 11
Crossover Bias Point .................................................................. 12
Minimum Input Slew Rate Requirement ................................ 12
Typical Application Circuits ......................................................... 13
Outline Dimensions ....................................................................... 14
Ordering Guide .......................................................................... 16
REVISION HISTORY
1/11—Rev. 0 to Rev. A
Changed VEE Pin to GND ............................................. Throughout
Changes to Common-Mode Dispersion Conditions................... 4
Changes to Figure 15 and Figure 16 ............................................... 9
Changes to Comparator Hysteresis Section ................................ 12
Updated Outline Dimensions ....................................................... 14
Changes to Ordering Guide .......................................................... 15
10/06—Revision 0: Initial Version
ADCMP600/ADCMP601/ADCMP602
Rev. A | Page 3 of 16
SPECIFICATIONS
ELECTRICAL CHARACTERISTICS
VCCI = VCCO = 2.5 V, T A = 25°C, unless otherwise noted.
Table 1.
Parameter Symbol Conditions Min Typ Max Unit
DC INPUT CHARACTERISTICS
Voltage Range V
P
, V
N
V
CC
= 2.5 V to 5.5 V −0.5 V
CC
+ 0.2 V
Common-Mode Range VCC = 2.5 V to 5.5 V −0.2 VCC + 0.2 V
Differential Voltage VCC = 2.5 V to 5.5 V VCC + 0.8 V
Offset Voltage VOS −5.0 ±2 +5.0 mV
Bias Current IP, IN −5.0 ±2 +5.0 µA
Offset Current −2.0 +2.0 µA
Capacitance C
P
, C
N
1 pF
Resistance, Differential Mode −0.1 V to VCC 200 700 kΩ
Resistance, Common Mode −0.5 V to VCC + 0.5 V 100 350 kΩ
Active Gain AV 85 dB
Common-Mode Rejection Ratio CMRR VCCI = 2.5 V, VCCO = 2.5 V,
V
CM
= −0.2 V to +2.7 V
50 dB
V
CCI
= 2.5 V, V
CCO
= 5.5 V 50 dB
Hysteresis (ADCMP600) 2 mV
Hysteresis (ADCMP601/ADCMP602) RHYS = ∞ 0.1 mV
LATCH ENABLE PIN CHARACTERISTICS
(ADCMP601/ADCMP602 Only)
VIH Hysteresis is shut off 2.0 VCC V
VIL Latch mode guaranteed −0.2 +0.4 +0.8 V
IIH VIH = VCC −6 +6 µA
IOL VIL = 0.4 V −0.1 +0.1 mA
HYSTERESIS MODE AND TIMING
(ADCMP601/ADCMP602 Only)
Hysteresis Mode Bias Voltage Current −1 μA 1.145 1.25 1.35 V
Resistor Value Hysteresis = 120 mV 65 80 120 kΩ
Hysteresis Current Hysteresis = 120 mV −18 −12 −7 µA
Latch Setup Time tS VOD = 50 mV −2 ns
Latch Hold Time tH VOD = 50 mV 2.6 ns
Latch-to-Output Delay t
PLOH
, t
PLOL
V
OD
= 50 mV 27 ns
Latch Minimum Pulse Width tPL VOD = 50 mV 21 ns
SHUTDOWN PIN CHARACTERISTICS
(ADCMP602 Only)
VIH Comparator is operating 2.0 VCCO V
VIL Shutdown guaranteed −0.2 +0.4 +0.6 V
IIH VIH = VCC −6 6 µA
IOL VIL = 0 V −100 µA
Sleep Time tSD ICCO < 500 µA 20 ns
Wake-Up Time tH VOD = 100 mV, output valid 50 ns
DC OUTPUT CHARACTERISTICS VCCO = 2.5 V to 5.5 V
Output Voltage High Level V
OH
I
OH
= 8 mA, V
CCO
= 2.5 V V
CC
− 0.4 V
Output Voltage Low Level VOL IOL = 8 mA, VCCO = 2.5 V 0.4 V
Output Voltage High Level at −40°C VOH IOH = 6 mA, VCCO = 2.5 V VCC − 0.4 V
Output Voltage Low Level at− 40°C VOL IOL = 6 mA, VCCO = 2.5 V 0.4 V
ADCMP600/ADCMP601/ADCMP602
Rev. A | Page 4 of 16
Parameter Symbol Conditions Min Typ Max Unit
AC PERFORMANCE1
Rise Time /Fall Time tR tF 10% to 90%, VCCO = 2.5 V 2.2 ns
10% to 90%, VCCO = 5.5 V 4 ns
Propagation Delay tPD VOD = 50 mV, VCCO = 2.5 V 3.5 ns
VOD = 50 mV, VCCO = 5.5 V 4.3 ns
VOD = 10 mV, VCCO = 2.5 V 5 ns
Propagation Delay Skew—Rising to
Falling Transition
VCCO = 2.5 V to 5.5 V
VOD = 50 mV
500 ps
Overdrive Dispersion 10 mV < VOD < 125 mV 1.2 ns
Common-Mode Dispersion −0.2 V < VCM < VCCI + 0.2 V
VOD = 50 mV
200 ps
Minimum Pulse Width PWMIN VCCI = VCCO = 2.5 V
PWOUT = 90% of PWIN
3 ns
VCCI = VCCO = 5.5 V
PWOUT = 90% of PWIN
4.5 ns
POWER SUPPLY
Input Supply Voltage Range VCCI 2.5 5.5 V
Output Supply Voltage Range V
CCO
2.5 5.5 V
Positive Supply Differential VCCI − VCCO Operating −3.0 +3.0 V
(ADCMP602 Only)
VCCI − VCCO Nonoperating −5.5 +5.5 V
Positive Supply Current
(ADCMP600/ADCMP601)
IVCC VCC = 2.5 V
V
CC
= 5.5 V
3
3.5
3.5
4.0
mA
Input Section Supply Current IVCCI VCCI = 2.5 V 0.9 1.4 mA
(ADCMP602 Only) VCCI = 5.5 V 1.2 2.0 mA
Output Section Supply Current IVCCO VCCO = 2.5 V 1.45 3.0 mA
(ADCMP602 Only) VCCO = 5.5 V 2.1 3.5 mA
Power Dissipation PD VCC = 2.5 V 7 9 mW
P
D
V
CC
= 5.5 V 20 23 mW
Power Supply Rejection Ratio PSRR VCCI = 2.5 V to 5 V −50 dB
Shutdown Mode ICCI VCC = 2.5 V 240 400 µA
(ADCMP602 Only)
Shutdown Mode ICCO VCC =2.5 V 30 µA
(ADCMP602 Only)
1 VIN = 100 mV square input at 50 MHz, VCM = 0 V, CL = 5 pF, VCCI = VCCO =2.5 V, unless otherwise noted.
ADCMP600/ADCMP601/ADCMP602
Rev. A | Page 5 of 16
TIMING INFORMATION
Figure 2 illustrates the ADCMP600/ADCMP601/ADCMP602 latch timing relationships. Table 2 provides definitions of the terms shown
in Figure 2.
1.1V
50%
V
N
± V
OS
DIFFERENTIAL
INPUT VOLTAGE
LATCH ENABL E
Q OUTPUT
t
H
t
PDL
t
PLOH
t
F
V
IN
V
OD
t
S
t
PL
05914-025
Figure 2. System Timing Diagram
Table 2. Timing Descriptions
Symbol Timing Description
tPDH Input to output high delay Propagation delay measured from the time the input signal crosses the reference (± the
input offset voltage) to the 50% point of an output low-to-high transition.
tPDL Input to output low delay Propagation delay measured from the time the input signal crosses the reference (± the
input offset voltage) to the 50% point of an output high-to-low transition.
tPLOH Latch enable to output high delay Propagation delay measured from the 50% point of the latch enable signal low-to-high
transition to the 50% point of an output low-to-high transition.
tPLOL Latch enable to output low delay Propagation delay measured from the 50% point of the latch enable signal low-to-high
transition to the 50% point of an output high-to-low transition.
tH Minimum hold time Minimum time after the negative transition of the latch enable signal that the input signal
must remain unchanged to be acquired and held at the outputs.
tPL Minimum latch enable pulse width Minimum time that the latch enable signal must be high to acquire an input signal change.
tS Minimum setup time Minimum time before the negative transition of the latch enable signal occurs that an
input signal change must be present to be acquired and held at the outputs.
tR Output rise time
Amount of time required to transition from a low to a high output as measured at the 20%
and 80% points.
tF Output fall time
Amount of time required to transition from a high to a low output as measured at the 20%
and 80% points.
VOD Voltage overdrive Difference between the input voltages VA and VB.
ADCMP600/ADCMP601/ADCMP602
Rev. A | Page 6 of 16
ABSOLUTE MAXIMUM RATINGS
Table 3.
Parameter Rating
Supply Voltages
Input Supply Voltage (VCCI to GND) −0.5 V to +6.0 V
Output Supply Voltage
(VCCO to GND)
−0.5 V to +6.0 V
Positive Supply Differential
(V
− V
)
−6.0 V to +6.0 V
Input Voltages
Input Voltage −0.5 V to VCCI + 0.5 V
Differential Input Voltage ±(VCCI + 0.5 V)
Maximum Input/Output Current ±50 mA
Shutdown Control Pin
Applied Voltage (HYS to GND) −0.5 V to VCCO + 0.5 V
Maximum Input/Output Current ±50 mA
Latch/Hysteresis Control Pin
Applied Voltage (HYS to GND) −0.5 V to VCCO + 0.5 V
Maximum Input/Output Current ±50 mA
Output Current ±50 mA
Temperature
Operating Temperature, Ambient −40°C to +125°C
Operating Temperature, Junction 150°C
Storage Temperature Range −65°C to +150°C
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
THERMAL RESISTANCE
θJA is specified for the worst-case conditions, that is, a device
soldered in a circuit board for surface-mount packages.
Table 4. Thermal Resistance
Package Type θ
JA
1 Unit
ADCMP600 SC70 5-Lead 426 °C/W
ADCMP600 SOT-23 5-Lead 302 °C/W
ADCMP601 SC70 6-Lead 426 °C/W
ADCMP602 MSOP 5-Lead 130 °C/W
1 Measurement in still air.
ESD CAUTION
ADCMP600/ADCMP601/ADCMP602
Rev. A | Page 7 of 16
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
Q1
VP3
GND 2
VCCI/VCCO
5
VN
4
ADCMP600
TOP VIEW
(Not t o Scale)
05914-002
Q1
GND 2
VP3
VCCI/VCCO
6
LE/HYS
5
VN
4
ADCMP601
TOP VIEW
(Not t o Scale)
05914-003
V
CCI 1
V
P2
V
N3
S
DN 4
V
CCO
8
Q
7
GND
6
LE/HYS
5
ADCMP602
TOP VIEW
(Not t o Scale)
05914-004
Figure 3. ADCMP600 Pin Configuration Figure 4. ADCMP601 Pin Configuration Figure 5. ADCMP602 Pin Configuration
Table 5. ADCMP600 (SOT-23-5 and SC70-5) Pin Function Descriptions
Pin No. Mnemonic Description
1 Q Noninverting Output. Q is at logic high if the analog voltage at the noninverting input, VP, is greater
than the analog voltage at the inverting input, V
N
.
2 GND Negative Supply Voltage.
3 VP Noninverting Analog Input.
4 VN Inverting Analog Input.
5 VCCI/VCCO Input Section Supply/Output Section Supply. Shared pin.
Table 6. ADCMP601 (SC70-6) Pin Function Descriptions
Pin No. Mnemonic Description
1 Q Noninverting Output. Q is at logic high if the analog voltage at the noninverting input, VP, is greater
than the analog voltage at the inverting input, VN, if the comparator is in compare mode.
2 GND Negative Supply Voltage.
3 VP Noninverting Analog Input.
4 VN Inverting Analog Input.
5 LE/HYS Latch/Hysteresis Control. Bias with resistor or current for hysteresis adjustment; drive low to latch.
6 V
CCI
/V
CCO
Input Section Supply/Output Section Supply. Shared pin.
Table 7. ADCMP602 (MSOP-8) Pin Function Descriptions
Pin No. Mnemonic Description
1 VCCI Input Section Supply.
2 VP Noninverting Analog Input.
3 VN Inverting Analog Input.
4 SDN Shutdown. Drive this pin low to shut down the device.
5 LE/HYS Latch/Hysteresis Control. Bias with resistor or current for hysteresis adjustment; drive low to latch.
6 GND Negative Supply Voltage.
7 Q Noninverting Output. Q is at logic high if the analog voltage at the noninverting input, VP, is greater
than the analog voltage at the inverting input, VN, if the comparator is in compare mode.
8 VCCO Output Section Supply.
ADCMP600/ADCMP601/ADCMP602
Rev. A | Page 8 of 16
TYPICAL PERFORMANCE CHARACTERISTICS
VCCI = VCCO = 2.5 V, TA = 25°C, unless otherwise noted.
–800–1 01234567
–600
–400
–200
0
200
400
600
800
05914-007
CURRENT ( µ A)
LE/HYS (V)
V
CC
= 5.5V
V
CC
= 2.5V
Figure 6. LE/HYS Pin I/V Characteristics
150
–150
–100
–50
0
50
100
–1 10 2 3 54 76
05914-027
CURRENT ( µ A)
SHUTDOWN PIN VOLTAGE (V)
V
CC
= 2.5V V
CC
= 5.5V
Figure 7. SDN Pin I/V Characteristics
05914-005
IB (µA)
COMMON-MODE VOLT AGE (V)
–20
–15
15
–10
10
–5
5
0
20
–1.0 –0.5 00.5 1.0 1.5 2.0 2.5 3.0 3.5
IB @ +125°C
IB @ +25°C
VCC = 2.5V
IB @ –40°C
Figure 8. Input Bias Current vs. Input Common Mode
20
–5
5
0
–10
10
–15
15
–20
–1.0 –0.2 0.2 0.6–0.6 1.0 1.4 1.8 2.2 2.6 3.0 3.4
09514-011
LOAD CURRENT ( mA)
V
OUT
(V)
I
OH
VS V
OH
I
OL
VS V
OL
Figure 9. VOH/VOL vs. Current Load
050 150 250 450350 550 650
50
100
150
200
250
05914-008
HYSTERESIS (mV)
HYSTERESIS RESISTOR (kΩ)
V
CC
= 5.5V
V
CC
= 2.5V
Figure 10. Hysteresis vs. RHYS Control Resistor
450
0
50
100
150
200
250
300
350
400
0–5 –10 –15 –20
05914-026
HYSTERESIS (mV)
PI N CURRE NT (µA)
LOT 1
LOT 2
Figure 11. Hysteresis vs. Pin Current
ADCMP600/ADCMP601/ADCMP602
Rev. A | Page 9 of 16
4.8
3.0
3.2
3.4
3.6
3.8
4.0
4.2
4.4
4.6
010 20 30 40 50 60 70 80 90 100 110 120 130 140
05914-009
PRO P AGATION DE LAY (ns)
OVERDRIVE (mV)
Figure 12. Propagation Delay vs. Input Overdrive at VCC = 2.5 V
4.0
3.8
3.4
3.6
3.2
3.0
–0.6 00.6 1.2 1.8 2.4 3.0
05914-028
PRO P AGATION DE LAY (ns)
COMMON-MODE VOLT AGE (V)
VCM AT VCC = 2.5V
RISE
FALL
Figure 13. Propagation Delay vs. Input Common-Mode Voltage
at VCC = 2.5 V
5.0
3.0
3.2
3.4
3.6
3.8
4.0
4.2
4.4
4.6
4.8
2.5 3.0 3.5 4.0 6.05.55.04.5
05914-029
PRO P AGATION DE LAY (ns)
V
CCO
(V)
RISE
FALL
Figure 14. Propagation Delay vs. VCCO
05914-012
1.00V/DIV M4.00ns
Figure 15. 50 MHz Output Waveform VCC = 5.5 V
05914-013
500mV/DIV M4.00ns
Figure16. 50 MHz Output Waveforms @ 2.5 V
ADCMP600/ADCMP601/ADCMP602
Rev. A | Page 10 of 16
APPLICATION INFORMATION
POWER/GROUND LAYOUT AND BYPASSING
The ADCMP600/ADCMP601/ADCMP602 comparators are very
high speed devices. Despite the low noise output stage, it is essential
to use proper high speed design techniques to achieve the specified
performance. Because comparators are uncompensated amplifiers,
feedback in any phase relationship is likely to cause oscillations or
undesired hysteresis. Of critical importance is the use of low
impedance supply planes, particularly the output supply plane
(VCCO) and the ground plane (GND). Individual supply planes are
recommended as part of a multilayer board. Providing the lowest
inductance return path for switching currents ensures the best
possible performance in the target application.
It is also important to adequately bypass the input and output
supplies. Multiple high quality 0.01 µF bypass capacitors should
be placed as close as possible to each of the VCCI and VCCO supply
pins and should be connected to the GND plane with redundant
vias. At least one of these should be placed to provide a physically
short return path for output currents flowing back from ground
to the VCC pin. High frequency bypass capacitors should be
carefully selected for minimum inductance and ESR. Parasitic
layout inductance should also be strictly controlled to maximize
the effectiveness of the bypass at high frequencies.
If the package allows and the input and output supplies have
been connected separately such that VCCI ≠ VCCO, care should be
taken to bypass each of these supplies separately to the GND
plane. A bypass capacitor should never be connected between
them. It is recommended that the GND plane separate the VCCI
and VCCO planes when the circuit board layout is designed to
minimize coupling between the two supplies and to take
advantage of the additional bypass capacitance from each
respective supply to the ground plane. This enhances the
performance when split input/output supplies are used. If the
input and output supplies are connected together for single-supply
operation such that VCCI = VCCO, coupling between the two supplies
is unavoidable; however, careful board placement can help keep
output return currents away from the inputs.
TTL-/CMOS-COMPATIBLE OUTPUT STAGE
Specified propagation delay performance can be achieved only
by keeping the capacitive load at or below the specified minimums.
The outputs of the devices are designed to directly drive one
Schottky TTL or three low power Schottky TTL loads or the
equivalent. For large fan outputs, buses, or transmission lines,
use an appropriate buffer to maintain the excellent speed and
stability of the comparator.
With the rated 5 pF load capacitance applied, more than half of
the total device propagation delay is output stage slew time,
even at 2.5 V VCC. Because of this, the total prop delay decreases
as VCCO decreases, and instability in the power supply may
appear as excess delay dispersion.
This delay is measured to the 50% point for the supply in use;
therefore, the fastest times are observed with the VCC supply at
2.5 V, and larger values are observed when driving loads that
switch at other levels.
When duty cycle accuracy is critical, the logic being driven
should switch at 50% of VCC and load capacitance should be
minimized. When in doubt, it is best to power VCCO or the
entire device from the logic supply and rely on the input PSRR
and CMRR to reject noise.
Overdrive and input slew rate dispersions are not significantly
affected by output loading and VCC variations.
The TTL-/CMOS-compatible output stage is shown in the
simplified schematic diagram (Figure 17). Because of its
inherent symmetry and generally good behavior, this output
stage is readily adaptable for driving various filters and other
unusual loads.
OUTPUT
Q2
Q1
+IN
–IN
OUTPUT STAGE
V
LOGIC
GAIN STAGE
A2
A1
A
V
05914-014
Figure 17. Simplified Schematic Diagram of
TTL-/CMOS-Compatible Output Stage
USING/DISABLING THE LATCH FEATURE
The latch input is designed for maximum versatility. It can
safely be left floating for fixed hysteresis or be tied to VCC to
remove the hysteresis, or it can be driven low by any standard
TTL/CMOS device as a high speed latch.
In addition, the pin can be operated as a hysteresis control pin
with a bias voltage of 1.25 V nominal and an input resistance of
approximately 7000 Ω. This allows the comparator hysteresis to
be easily and accurately controlled by either a resistor or an
inexpensive CMOS DAC.
Hysteresis control and latch mode can be used together if an
open drain, an open collector, or a three-state driver is connected
parallel to the hysteresis control resistor or current source.
Due to the programmable hysteresis feature, the logic threshold
of the latch pin is approximately 1.1 V regardless of VCC.
ADCMP600/ADCMP601/ADCMP602
Rev. A | Page 11 of 16
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.
Q/Q OUTPUT
INPUT VOLT AG E
500mV O V E RDRIVE
10mV OV ERDRI V E
DISPERSION
V
N
± V
OS
05914-015
Figure 18. Propagation Delay—Overdrive Dispersion
Q/Q OUTPUT
INPUT VOLTAGE
10V/ns
1V/ns
DISPERSION
V
N
± V
OS
05914-016
Figure 19. Propagation Delay—Slew Rate Dispersion
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 +VH/2, and the
new switching threshold becomes −VH/2. The comparator remains
in the high state until the new threshold, −VH/2, is crossed from
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 ±VH/2.
OUTPUT
INPUT
0
VOL
VOH
+VH
2
–VH
2
05914-017
Figure 20. Comparator Hysteresis Transfer Function
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
Rev. A | Page 12 of 16
Leaving the LE/HYS pin disconnected results in a fixed
hysteresis of 2 mV; driving this pin high removes hysteresis. The
maximum hysteresis that can be applied using this pin is
approximately 160 m V. Figure 21 illustrates the amount of
hysteresis applied as a function of the external resistor value,
and Figure 11 illustrates hysteresis as a function of the current.
The hysteresis control pin appears as a 1.25 V bias voltage seen
through a series resistance of 7 kΩ. The bias voltage changes
± 20% throughout the hysteresis control range. The advantages
of applying hysteresis in this manner are improved accuracy,
improved stability, reduced component count, and maximum
versatility. An external bypass capacitor is not recommended on
the HYS pin because it impairs the latch function and often
degrades the jitter performance of the device. As described in the
Using/Disabling the Latch Feature section, hysteresis control
need not compromise the latch function.
CROSSOVER BIAS POINT
In both op amps and comparators, rail-to-rail inputs of this type
have a dual front-end design. Certain devices are active near the
VCC rail and others are active near the GND rail. At some predeter-
mined point in the common-mode range, a crossover occurs. At
this point, normally VCC/2, the direction of the bias current reverses
and the measured offset voltages and currents change.
The ADCMP600/ADCMP601/ADCMP602 comparators
slightly elaborate on this scheme. Crossover points can be found
at approximately 0.8 V and 1.6 V.
050 150 250 450350 550 650
50
100
150
200
250
05914-030
HYSTERESIS (mV)
HYSTERESIS RESISTOR (kΩ)
V
CC
= 5.5V
V
CC
= 2.5V
Figure 21. Hysteresis vs. RHYS Control Resistor
MINIMUM INPUT SLEW RATE REQUIREMENT
With the rated load capacitance and normal good PC Board
design practice, as discussed in the Optimizing Performance
section, these comparators should be stable at any input slew
rate with no hysteresis. Broadband noise from the input stage is
observed in place of the violent chattering seen with most other
high speed comparators. With additional capacitive loading or
poor bypassing, oscillation is observed. This oscillation is due to
the high gain bandwidth of the comparator in combination with
feedback parasitics in the package and PC board. In many
applications, chattering is not harmful.
ADCMP600/ADCMP601/ADCMP602
Rev. A | Page 13 of 16
TYPICAL APPLICATION CIRCUITS
OUTPUT
ADCMP600
0.1µF
5V
0.1µF
2kΩ
2kΩ
05914-019
Figure 22. Self-Biased, 50% Slicer
CMOS
ADCMP600
CMOS
VDD
2.5V TO 5V
100Ω
05914-020
Figure 23. LVDS-to-CMOS Receiver
OUTPUT
1.5M Hz TO 30M Hz
LE/HYS
ADCMP601
2.5V
82pF
10kΩ
100kΩ
100kΩ
20kΩ
20kΩ
CONTROL
VOLTAGE
0V T O 2.5V
05914-021
Figure 24. Voltage-Controlled Oscillator
CMOS
PWM
OUTPUT
ADCMP600
2.5V
INPUT
1.25V
REF
INPUT
1.25V
±50mV
LE/HYS
ADCMP601
82pF
10kΩ
10kΩ
40kΩ
10kΩ
05914-022
Figure 25. Oscillator and Pulse-Width Modulator
ADCMP601
2.5V TO 5V
10kΩ
LE/HYS
DIGITAL
INPUT
HYSTERESIS
CURRENT
74 AHC
1G07
05914-023
Figure 26. Hysteresis Adjustment with Latch
ADCMP600/ADCMP601/ADCMP602
Rev. A | Page 14 of 16
OUTLINE DIMENSIONS
COMPLIANT TO JEDEC STANDARDS MO-203-AA
1.00
0.90
0.70
0.46
0.36
0.26
2.20
2.00
1.80
2.40
2.10
1.80
1.35
1.25
1.15
072809-A
0.10 MAX
1.10
0.80
0.40
0.10
0.22
0.08
3
1 2
45
0.65 BSC
COPLANARITY
0.10
SEATING
PLANE
0.30
0.15
Figure 27. 5-Lead Thin Shrink Small Outline Transistor Package (SC70)
(KS-5)
Dimensions shown in millimeters
COMPLIANT TO JEDEC STANDARDS MO-178-AA
10°
5°
0°
SEATING
PLANE
1.90
BSC
0.95 BSC
0.60
BSC
5
1 2 3
4
3.00
2.90
2.80
3.00
2.80
2.60
1.70
1.60
1.50
1.30
1.15
0.90
0.15 MAX
0.05 MIN
1.45 MAX
0.95 MIN
0.20 MAX
0.08 MIN
0.50 MAX
0.35 MIN
0.55
0.45
0.35
11-01-2010-A
Figure 28. 5-Lead Small Outline Transistor Package (SOT-23)
(RJ-5)
Dimensions shown in millimeters
ADCMP600/ADCMP601/ADCMP602
Rev. A | Page 15 of 16
1.30 BSC
COMPLIANT TO JEDEC STANDARDS MO-203-AB
1.00
0.90
0.70
0.46
0.36
0.26
2.20
2.00
1.80
2.40
2.10
1.80
1.35
1.25
1.15
072809-A
0.10 MAX
1.10
0.80
0.40
0.10
0.22
0.08
3
1 2
46 5
0.65 BSC
COPLANARITY
0.10
SEATING
PLANE
0.30
0.15
Figure 29. 6-Lead Thin Shrink Small Outline Transistor Package (SC70)
(KS-6)
Dimensions shown in millimeters
COMPLIANT TO JEDEC STANDARDS MO-187-AA
6°
0°
0.80
0.55
0.40
4
8
1
5
0.65 BSC
0.40
0.25
1.10 MAX
3.20
3.00
2.80
COPLANARITY
0.10
0.23
0.09
3.20
3.00
2.80
5.15
4.90
4.65
PIN 1
IDENTIFIER
15° MAX
0.95
0.85
0.75
0.15
0.05
10-07-2009-B
Figure 30. 8-Lead Mini Small Outline Package (MSOP)
(RM-8)
Dimensions shown in millimeters
ADCMP600/ADCMP601/ADCMP602
Rev. A | Page 16 of 16
ORDERING GUIDE
Model1 Temperature Range Package Description Package Option Branding
ADCMP600BRJZ-R2 −40°C to +125°C 5-Lead SOT23 RJ-5 G0C
ADCMP600BRJZ-RL −40°C to +125°C 5-Lead SOT23 RJ-5 G0C
ADCMP600BRJZ-REEL7 −40°C to +125°C 5-Lead SOT23 RJ-5 G0C
ADCMP600BKSZ-R2 −40°C to +125°C 5-Lead SC70 KS-5 G0C
ADCMP600BKSZ-RL −40°C to +125°C 5-Lead SC70 KS-5 G0C
ADCMP600BKSZ-REEL7 −40°C to +125°C 5-Lead SC70 KS-5 G0C
ADCMP601BKSZ-R2 −40°C to +125°C 6-Lead SC70 KS-6 G0N
ADCMP601BKSZ-RL −40°C to +125°C 6-Lead SC70 KS-6 G0N
ADCMP601BKSZ-REEL7 −40°C to +125°C 6-Lead SC70 KS-6 G0N
ADCMP602BRMZ −40°C to +125°C 8-Lead MSOP RM-8 GF
ADCMP602BRMZ-REEL −40°C to +125°C 8-Lead MSOP RM-8 GF
ADCMP602BRMZ-REEL7 −40°C to +125°C 8-Lead MSOP RM-8 GF
EVAL-ADCMP600BRJZ Evaluation Board
EVAL-ADCMP600BKSZ Evaluation Board
EVAL-ADCMP601BKSZ Evaluation Board
EVAL-ADCMP602BRMZ Evaluation Board
1 Z = RoHS Compliant Part.
©2006–2011 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D05914-0-1/11(A)