Not Recommended for New Designs
The MAX909 was manufactured for Maxim by an outside wafer
foundry using a process that is no longer available. It is not
recommended for new designs. A Maxim replacement or an industry
second-source may be available. The data sheet remains available for
existing users. The other parts on the following data sheet are not
affected.
For further information, please see the QuickView data sheet for this
part or contact technical support for assistance.
MAX907/MAX908/MAX909
Dual/Quad/Single, High-Speed, Ultra-Low-Power,
Single-Supply TTL Comparators
________________________________________________________________ Maxim Integrated Products 1
1
2
3
4
8
7
6
5
V+
OUTB
INB-
INB+
GND
INA+
INA-
OUTA
MAX907
DIP/SO
TOP VIEW
1
2
3
4
14
13
12
11
OUTD
IND-
IND+
GND
V+
INA+
INA-
OUTA
MAX908
DIP/SO
5
6
7
10
9
8
INC+
INC-
OUTC
OUTB
INB-
INB+
Pin Configurations
19-0129; Rev 7; 1/06
General Description
The MAX907/MAX908/MAX909 are dual/quad/single,
high-speed, ultra-low-power voltage comparators
designed for use in systems powered from a single
+5V supply; the MAX909 also accepts dual ±5V sup-
plies. Their 40ns propagation delay (with 5mV input
overdrive) is achieved with a power consumption of
only 3.5mW per comparator. The wide input common-
mode range extends from 200mV below ground (below
the negative supply rail for the MAX909) to within 1.5V
of the positive supply rail.
Because they are micropower, high-speed compara-
tors that operate from a single +5V supply and include
built-in hysteresis, these devices replace a variety of
older comparators in a wide range of applications.
MAX907/MAX908/MAX909 outputs are TTL-compatible,
requiring no external pullup circuitry. All inputs and out-
puts can be continuously shorted to either supply rail
without damage. These easy-to-use comparators incor-
porate internal hysteresis to ensure clean output switch-
ing even when the devices are driven by a slow-moving
input signal.
The MAX909 features complementary outputs and an
output latch. A separate supply pin for extending the
analog input range down to -5V is also provided.
The dual MAX907 and single MAX909 are available in
8-pin DIP and SO packages, and the quad MAX908 is
available in 14-pin DIP and SO packages. These com-
parators are ideal for single +5V-supply applications
that require the combination of high speed, precision,
and ultra-low power dissipation.
Applications
Battery-Powered Systems
High-Speed A/D Converters
High-Speed V/F Converters
Line Receivers
Threshold Detectors/Discriminators
High-Speed Sampling Circuits
Zero-Crossing Detectors
Features
♦40ns Propagation Delay
♦700µA (3.5mW) Supply Current per Comparator
♦Single 4.5V to 5.5V Supply Operation
(or ±5V, MAX909 only)
♦Wide Input Range Includes Ground
(or -5V, MAX909 only)
♦Low, 500µV Offset Voltage
♦Internal Hysteresis Provides Clean Switching
♦TTL-Compatible Outputs
(Complementary on MAX909)
♦Input and Output Short-Circuit Protection
♦Internal Latch (MAX909 only)
Ordering Information
Ordering Information continued at end of data sheet.
*Go to www.maxim-ic.com/PR-1 for details on high-reliability
plastic processing.
Pin Configurations continued at end of data sheet.
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
PART
8SO
-40°C to +85°C
-40°C to +85°CMAX907ESA
8Plastic DIPMAX907EPA
8SO0°C to +70°CMAX907CSA
8Plastic DIP0°C to +70°C
MAX907CPA
PIN-PACKAGETEMP RANGE
8SO-55°C to +125°CMAX907MSA/PR*
MAX907/MAX908/MAX909
Dual/Quad/Single, High-Speed, Ultra-Low-Power,
Single-Supply TTL Comparators
2_______________________________________________________________________________________
Positive Supply Voltage (V+ to GND) ........................+6V
Negative Supply Voltage (V- to GND, MAX909 only) .........-7V
Differential Input Voltage
MAX907/MAX908 ..........................-0.3V to (V+ + 0.3V)
MAX909 ..............................(V- - 0.3V) to (V+ + 0.3V)
Common-Mode Input Voltage
MAX907/MAX908 ..........................-0.3V to (V+ + 0.3V)
MAX909 ..............................(V- - 0.3V) to (V+ + 0.3V)
Latch Input Voltage (MAX909 only) .........-0.3V to (V+ + 0.3V)
Input/Output Short-Circuit Duration to V+ or GND . . . Continuous
Continuous Power Dissipation (TA= +70°C)
8-Pin Plastic DIP (derate 9.09mW/°C above +70°C) .. . 727mW
8-Pin SO (derate 5.88mW/°C above +70°C) ...........471mW
14-Pin Plastic DIP (derate 10.00mW/°C above +70°C) . . . 800mW
14-Pin SO (derate 8.33mW/°C above +70°C) ..........667mW
Operating Temperature Ranges:
MAX90_C_ _ ......................................0°C to +70°C
MAX90_E_ _ ...................................-40°C to +85°C
MAX907MSA/PR ..............................-55°C to +125°C
Storage Temperature Range ...................-65°C to +150°C
Lead Temperature (soldering, 10s) ......................+300°C
ELECTRICAL CHARACTERISTICS
(V+ = 5V, TA= +25°C; MAX909 only: V- = 0V, VLATCH = 0V; unless otherwise noted.)
Stresses beyond those listed under “Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ABSOLUTE MAXIMUM RATINGS
MAX909 only: V- = -5V
V
VOUT = 2.4V to 0.4V, CL= 10pF
VOUT = 0.4V to 2.4V, CL= 10pF
MAX907/MAX908
(Notes 3, 4)
MAX909
MAX909
MAX907/MAX908
MAX907/MAX908/MAX909
SYMBOL
ns6
tf
Output Fall Time
ns12
tr
Output Rise Time
610 mW
3.5 5.5
(Note 8)PD
Power Dissipation per
Comparator
µA60 100MAX909 only: V- = -5VI-Negative Supply Current
1.2 1.8 mA
0.7 1.0
(Note 7)I+
Positive Supply Current per
Comparator
0.4
ISINK = 8mA
0.36 0.475
ISINK = 3.2mA
VOL
Output Low Voltage V
3.0 3.5
ISOURCE = 100µAVOH
Output High Voltage
µV/V50 200(Notes 4, 6)PSRRPower-Supply Rejection Ratio
µV/V50 150(Notes 4, 5)CMRRCommon-Mode Rejection Ratio
-5.2 V+ - 1.5 V
-0.2 V+ - 1.5
VCMR
Input Voltage Range
nA25 50
VCM = 0V, VIN = VOS
IOS
Input Offset Current
nA100 300
VCM = 0V, VIN = VOS
IB
Input Bias Current
mV0.5 2.0(Note 2)
VOS
Input Offset Voltage
mV-2 -4(Note 1)
VTRIP-
Negative Trip Point
mV24(Note 1)
VTRIP+
Positive Trip Point
UNITSMIN TYP MAXCONDITIONSPARAMETER
MAX907/MAX908/MAX909
Dual/Quad/Single, High-Speed, Ultra-Low-Power,
Single-Supply TTL Comparators
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(V+ = 5V, TA= +25°C; MAX909 only: V- = 0V, VLATCH = 0V; unless otherwise noted.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Propagation Delay tPD+, tPD- 40 50 ns
Differential Propagation Delay ∆tPD 1ns
Propagation Delay Skew tPDskew 2ns
Latch Input Voltage High VIH (Note 12) 2.0 V
Latch Input Voltage Low VIL (Note 12) 0.8 V
Latch Input Current IIH, IIL (Note 12) 20 µA
Latch Setup Time ts(Note 12) 2ns
Latch Hold Time th(Note 12) 2ns
VIN = 100mV, VOD = 5mV
(Note 9)
VIN = 100mV, VOD = 5mV
(Note 10)
MAX909 only: VIN = 100mV,
VOD = 5mV (Note 11)
ELECTRICAL CHARACTERISTICS
(V+ = 5V, TA= TMIN to TMAX; MAX909 only: V- = 0V, VLATCH = 0V; unless otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Positive Trip Point
VTRIP+
(Note 1) 2 5 mV
Negative Trip Point
VTRIP-
(Note 1) -2 -5 mV
Input Offset Voltage VOS (Note 2) 1 3.5 mV
Input Bias Current IBVCM = 0V, VIN = VOS
200 500
nA
Input Offset Current IOS VCM = 0V, VIN = VOS 50
100
nA
MAX907/MAX908/MAX909
-0.2
V+ - 1.5
C/E temp.
ranges
(Notes 3, 4) MAX909 only, V- = -5V -5.2
V+ - 1.5
Input Voltage Range
VCMR
M temp. range
(Notes 3, 4) MAX907MSA/PR -0.1
V+ - 1.5
V
Common-Mode Rejection Ratio
CMRR
(Notes 4, 5) 75
300 µV/V
Power-Supply Rejection Ratio
PSRR
(Notes 4, 6) 75
400 µV/V
Output High Voltage VOH ISOURCE = 100µA 2.8 3.5 V
TA = TMAX
0.45
TMIN = 0°C
0.525
Output Low Voltage VOL ISINK = 3.2mA
TMIN = -40°C
0.550
V
MAX907/MAX908 0.8 1.2
Positive Supply Current per
Comparator I+ (Note 7) MAX909 1.2 2.0 mA
Negative Supply Current I- MAX909 only; V- = -5V
100 200
µV
MAX907/MAX908 4 7
Power Dissipation per
Comparator PD (Note 8) MAX909 6 11
mW
MAX907/MAX908/MAX909
Dual/Quad/Single, High-Speed, Ultra-Low-Power,
Single-Supply TTL Comparators
4_______________________________________________________________________________________
Note 1: Trip Point is defined as the input voltage required to make the comparator output change state. The difference
between upper (VTRIP+) and lower (VTRIP-) trip points is equal to the width of the input-referred hysteresis zone (VHYST).
Specified for an input common-mode voltage (VCM) of 0V (see Figure 1).
Note 2: Input Offset Voltage is defined as the center of the input-referred hysteresis zone. Specified for VCM = 0V (see Figure 1).
Note 3: Inferred from the CMRR test. Note that a correct logic result is obtained at the output, provided that at least one input is
within the VCMR limits. Note also that either or both inputs can be driven to the upper or lower absolute maximum limit with-
out damage to the part.
Note 4: Tested with V+ = 5.5V (and V- = 0V for MAX909). MAX909 also tested over the full analog input range (i.e., with
V- = -5.5V).
Note 5: Tested over the full input voltage range (VCMR).
Note 6: Specified over the full tolerance of operating supply voltage: MAX907/MAX908 tested with 4.5V < V+ < 5.5V. MAX909
tested with 4.5V < V+ < 5.5V and with -5.5V < V- < 0V.
Note 7: Positive Supply Current specified with the worst-case condition of all outputs at logic low (MAX907/MAX908), and
with V+ = 5.5V.
Note 8: Typical power specified with V+ = 5V; maximum with V+ = 5.5V (and with V- = -5.5V for MAX909).
Note 9: Due to difficulties in measuring propagation delay with 5mV of overdrive in automatic test equipment, this parameter is
guaranteed by design for the MAX907 and MAX908. Correlation tests show that the specification can be guaranteed if all
other DC parameters are within the specified limits. VOS must be added to the overdrive voltage for low values of overdrive.
For the MAX909, propagation delay is typical only and there is no guaranteed maximum limit.
Note 10: Differential Propagation Delay is specified as the difference between any two channels in the MAX907/MAX908 (both out-
puts making either a low-to-high or a high-to-low transition).
Note 11: Propagation Delay Skew is specified as the difference between any single channel’s output low-to-high transition (tPD+)
and high-to-low transition (tPD-), and also between the QOUT and QOUT transition on the MAX909.
Note 12: Latch specifications apply to MAX909 only (see Figure 2).
ELECTRICAL CHARACTERISTICS (continued)
(V+ = 5V, TA= TMIN to TMAX; MAX909 only: V- = 0V, VLATCH = 0V; unless otherwise noted.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Propagation Delay tPD+, tPD- VIN = 100mV, VOD = 5mV
(Note 9) 45 70 ns
Differential Propagation Delay ∆tPD VIN = 100mV, VOD = 5mV
(Note 10) 2ns
Propagation Delay Skew tPDskew MAX909 only: VIN = 100mV,
VOD = 5mV (Note 11) 4ns
Latch Input Voltage High VIH (Note 12) 2.0 V
Latch Hold Time th(Note 12) 4ns
Latch Input Voltage Low VIL (Note 12) 0.8 V
Latch Input Current IIH, IIL (Note 12) 20 µA
Latch Setup Time ts(Note 12) 4ns
MAX907/MAX908/MAX909
Dual/Quad/Single, High-Speed, Ultra-Low-Power,
Single-Supply TTL Comparators
_________________________________________________________________________________________________ 5
Typical Operating Characteristics
(V+ = 5V, TA= +25°C, unless otherwise noted.)
MAX907/MAX908/MAX909
Dual/Quad/Single, High-Speed, Ultra-Low-Power,
Single-Supply TTL Comparators
6________________________________________________________________________________________________
Typical Operating Characteristics (continued)
(V+ = 5V, TA= +25°C, unless otherwise noted.)
4.0
0
28
MAX908
TOTAL POSITIVE SUPPLY CURRENT
vs. POSITIVE SUPPLY VOLTAGE
(OUTPUTS AT VOH)
1.0
VCC (V)
TOTAL ICC (mA)
6
2.0
357
3.0
4
TA = -55°C
TA = +125°C
TA = +25°C
MAX907 TOC10
200
0
0-1 -3 -6
MAX909
NEGATIVE SUPPLY CURRENT
vs. NEGATIVE SUPPLY VOLTAGE
V- (V)
TOTAL I- (µA)
-2 -4
100
-5 -7
V+ = +5V
TA = +125°C
TA = +25°C
TA = -55°C
MAX907 TOC12
5
-6
-60 -20 60 140
MAX909
INPUT VOLTAGE RANGE
vs. TEMPERATURE
-5
4
TEMPERATURE (°C)
INPUT VOLTAGE RANGE (V)
20 100
VCMR+
VCMR-
V+ = +5V
V- = -5V
-40 40 120080
MAX907 TOC14
MAX907/MAX908/MAX909
Dual/Quad/Single, High-Speed, Ultra-Low-Power,
Single-Supply TTL Comparators
_________________________________________________________________________________________________ 7
MAX907/MAX908
PROPAGATION DELAY (tPD+)
(5mV OVERDRIVE)
INPUT
20mV/div
TTL
THRESHOLD (1.4V)
OUTPUT
GND
10ns/div
tPD+
5mV OVERDRIVE
OUTPUT
500mV/div
INPUT GND
MAX907 TOC19
MAX907/MAX908
PROPAGATION DELAY (tPD-)
(5mV OVERDRIVE)
INPUT
20mV/div OUTPUT
500mV/div
OUTPUT
GND
10ns/div
tPD-
-5mV OVERDRIVE
TTL
THRESHOLD
(1.4V)
INPUT GND
MAX907 TOC20
1V/div
RESPONSE TO 10MHz SINE WAVE
20mVP-P
10MHz SINE WAVE
INPUT
COMPARATOR
OUTPUT
50ns/div
GND
MAX907 TOC23
MAX909
PROPAGATION DELAY (tPD+)
(5mV OVERDRIVE)
INPUT
20mV/div
OUTPUT
GND
5mV OVERDRIVE
INPUT GND
QOUT
1V/div
QOUT
10ns/div
tPD+tPD SKEW
1.4V
MAX907 TOC21
1.4V
MAX909
PROPAGATION DELAY (tPD-)
(5mV OVERDRIVE)
INPUT
20mV/div
OUTPUT
GND
INPUT GND
-5mV OVERDRIVE
QOUT
1V/div
QOUT
10ns/div
tPD- tPD SKEW
MAX907 TOC22
Typical Operating Characteristics (continued)
(V+ = 5V, TA= +25°C, unless otherwise noted.)
MAX907/MAX908/MAX909
Detailed Description
Timing
Noise or undesired parasitic AC feedback cause most
high-speed comparators to oscillate in the linear region
(i.e., when the voltage on one input is at or near the
voltage on the other input). The MAX907/MAX908/
MAX909 eliminate this problem by incorporating inter-
nal hysteresis. When the two comparator input voltages
are equal, hysteresis effectively causes one comparator
input voltage to move quickly past the other, thus taking
the input out of the region where oscillation occurs.
Standard comparators require that hysteresis be added
through the use of external resistors. The
MAX907/MAX908/MAX909’s fixed internal hysteresis
eliminates these resistors (and the equations required
to determine appropriate values).
Adding hysteresis to a comparator creates two trip
points: one for the input voltage rising and one for the
input voltage falling (Figure 1). The difference between
these two input-referred trip points is the hysteresis.
Figure 1 illustrates the case where IN- is fixed and IN+
is varied. If the inputs were reversed, the figure would
look the same, except the output would be inverted.
The MAX909 includes an internal latch, allowing the
result of a comparison to be stored. If LE is low, the
latch is transparent (i.e., the comparator operates as
though the latch is not present). The state of the com-
parator output is stored when LE is high (Figure 2).
Note that the MAX909 can be operated with V- con-
nected to ground or to a negative supply voltage. The
MAX909’s input range extends from (V- - 0.2V) to
(V+ - 1.5V).
Dual/Quad/Single, High-Speed, Ultra-Low-Power,
Single-Supply TTL Comparators
8_______________________________________________________________________________________
Pin Description
The latch is transparent when LE is low. The comparator output is
stored when LE is high.
Inverted Comparator Output
QOUT
8——
Comparator OutputQOUT7——
LE5——
Negative Supply or GroundV-4——
Inverting InputIN-3——
Noninverting InputIN+2——
Comparator D OutputOUTD—14—
Comparator D Inverting InputIND-—13—
Comparator D Noninverting InputIND+—12—
Comparator C Noninverting InputINC+—10—
Comparator C Inverting Input INC- —9—
Comparator C Output OUTC—8—
Positive SupplyV+148
Comparator B OutputOUTB—77
Comparator B Inverting InputINB-—66
Comparator B Noninverting InputINB+—55
GroundGND6114
Comparator A Noninverting InputINA+—33
Comparator A Inverting InputINA-—22
Comparator A OutputOUTA—11
MAX909
MAX908
MAX907 FUNCTIONNAME
PIN
Applications Information
Circuit Layout
Because of the MAX907/MAX908/MAX909’s high gain
bandwidth, special precautions must be taken to real-
ize the full high-speed capability. A printed circuit
board with a good, low-inductance ground plane is
mandatory. Place the decoupling capacitor (a 0.1µF
ceramic capacitor is a good choice) as close to V+ as
possible. Pay close attention to the decoupling capaci-
tor’s bandwidth, keeping leads short. Short lead
lengths on the inputs and outputs are also essential to
avoid unwanted parasitic feedback around the com-
parators. Solder the device directly to the printed circuit
board instead of using a socket.
Overdriving the Inputs
The inputs to the MAX907/MAX908/MAX909 may be
driven beyond the voltage limits given in the Absolute
Maximum Ratings, as long as the current flowing into
the device is limited to 25mA. However, if the inputs are
overdriven, the output may be inverted. The addition of
an external diode prevents this inversion by limiting the
input voltage to 200mV to 300mV below ground
(Figure 3).
Battery-Operated Infrared Data Link
Figure 4's circuit allows reception of infrared data. The
MAX403 converts the photodiode current to a voltage,
and the MAX907 determines whether the amplifier output
is high enough to be called a “1”. The current consump-
tion of this circuit is minimal: The MAX403 and MAX907
require typically 250µA and 700µA, respectively.
MAX907/MAX908/MAX909
Dual/Quad/Single, High-Speed, Ultra-Low-Power,
Single-Supply TTL Comparators
_______________________________________________________________________________________ 9
VTRIP+
VHYST
VTRIP-
VIN+
COMPARATOR
OUTPUT
VOH
VOL
VTRIP+ + VTRIP-
2
VOS =
VIN- = 0V
Figure 1. Input and Output Waveforms, Noninverting Input
Varied
tPD+
tSKEW
VIN
VOD
th
ts
3V
1.4V
0V
VOS
VOH
1.4V
VOL
VOH
1.4V
VOL
COMPARE
LATCH
LE
DIFFERENTIAL
INPUT
VOLTAGE
OUTPUT
(QOUT)
OUTPUT
(
Q
OUT)
Figure 2. MAX909 Timing Diagram
MAX907/MAX908/MAX909
Single/Dual/Quad, High-Speed, Ultra-Low-Power,
Single-Supply TTL Comparators
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
10 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
©2006 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc.
VCLAMP = -200mV TO -300mV
ISRC
V-
1/2 MAX907
Figure 3. Schottky Clamp for Input Driven Below Ground
10pF
1MΩ
+5V
6
7
+5V
0.1µF
DATA
2
3
4
100kΩ
SIEMENS BP-104
PHOTODIODE
100kΩ
+5V
1000pF
1000pF
47kΩ
2
3
0.1µF
4
8
1
MAX907
MAX403
Figure 4. Battery-Operated Infrared Data Link Consumes Only
1mA
Pin Configurations (continued) Ordering Information (continued)
1
2
3
4
8
7
6
5
QOUT
QOUT
GND
LE
V-
IN-
IN+
V+
MAX909
DIP/SO
TOP VIEW
PART TEMP RANGE PIN-PACKAGE
MAX908CPD 0°C to +70°C 14 Plastic DIP
MAX908CSD 0°C to +70°C 14 SO
MAX908EPD -40°C to +85°C 14 Plastic DIP
MAX908ESD -40°C to +85°C 14 SO
MAX909CPA 0°C to +70°C 8 Plastic DIP
MAX909CSA 0°C to +70°C 8 SO
MAX909EPA -40°C to +85°C 8 Plastic DIP
MAX909ESA -40°C to +85°C 8 SO
Chip Information
MAX907 TRANSISTOR COUNT: 262
MAX908 TRANSISTOR COUNT: 536
MAX909 TRANSISTOR COUNT: 140
PROCESS: Bipolar