MAXIM MAX907, MAX908, MAX909 Technical data

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 sup­plies. Their 40ns propagation delay (with 5mV input
overdrive) is achieved with a power consumption of
only 3.5mW per comparator. The wide input common­mode 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 compara­tors 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 out­puts can be continuously shorted to either supply rail
without damage. These easy-to-use comparators incor­porate internal hysteresis to ensure clean output switch­ing 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 com­parators 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

8 Plastic DIPMAX907EPA

8SO0°C to +70°CMAX907CSA

8 Plastic 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 (T

A

= +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, V

LATCH

= 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

V

OUT

= 2.4V to 0.4V, CL= 10pF

V

OUT

= 0.4V to 2.4V, CL= 10pF

MAX907/MAX908

(Notes 3, 4)

MAX909

MAX909

MAX907/MAX908

MAX907/MAX908/MAX909

SYMBOL

ns6

t

f

Output Fall Time

ns12

t

r

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

I

SINK

= 8mA

0.36 0.475

I

SINK

= 3.2mA

V

OL

Output Low Voltage V

3.0 3.5

I

SOURCE

= 100µAV

OH

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

V

CMR

Input Voltage Range

nA25 50

VCM= 0V, VIN= V

OS

I

OS

Input Offset Current

nA100 300

VCM= 0V, VIN= V

OS

I

B

Input Bias Current

mV0.5 2.0(Note 2)

V

OS

Input Offset Voltage

mV-2 -4(Note 1)

V

TRIP-

Negative Trip Point

mV24(Note 1)

V

TRIP+

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, V

LATCH

= 0V; unless otherwise noted.)

PARAMETER

SYMBOL CONDITIONS MIN TYP MAX UNITS

Propagation Delay

t

PD+,tPD-

40 50 ns

Differential Propagation Delay

∆t

PD

1 ns

Propagation Delay Skew

tPDskew

2 ns

Latch Input Voltage High

V

IH

(Note 12) 2.0 V

Latch Input Voltage Low

V

IL

(Note 12) 0.8 V

Latch Input Current

IIH, I

IL

(Note 12) 20 µA

Latch Setup Time

t

s

(Note 12) 2 ns

Latch Hold Time

t

h

(Note 12) 2 ns

VIN= 100mV, VOD= 5mV
(Note 9)

VIN= 100mV, VOD= 5mV
(Note 10)

MAX909 only: VIN= 100mV,
V

OD

= 5mV (Note 11)

ELECTRICAL CHARACTERISTICS

(V+ = 5V, TA= T

MIN

to T

MAX

; MAX909 only: V- = 0V, V

LATCH

= 0V; unless otherwise noted.)

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

Positive Trip Point

(Note 1) 2 5 mV

Negative Trip Point

(Note 1) -2 -5 mV

Input Offset Voltage V

OS

(Note 2) 1 3.5 mV

Input Bias Current I

B

V

CM

= 0V, V

IN

= V

OS

nA

Input Offset Current I

OS

V

CM

=

0V, V

IN

=

V

OS

50

nA

-0.2

C/E temp.
ranges
(Notes 3, 4)

MAX909 only, V- = -5V -5.2

Input Voltage Range

M temp. range
(Notes 3, 4)

MAX907MSA/PR -0.1

V

Common-Mode Rejection Ratio

(Notes 4, 5) 75

Power-Supply Rejection Ratio

(Notes 4, 6) 75

Output High Voltage V

OH

I

SOURCE

= 100µA 2.8 3.5 V

T

A

=

T

MAX

T

MIN

= 0°C

Output Low Voltage V

OL

I

SINK

= 3.2mA

T

MIN

= -40°C

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

µV

MAX907/MAX908 4 7

Power Dissipation per
Comparator

PD (Note 8)

MAX909 6 11

V

TRIP+

V

TRIP-

V

CMR

CMRR

PSRR

MAX907/MAX908/MAX909

200 500

100

V+ - 1.5

V+ - 1.5

V+ - 1.5

300 µV/V

400 µV/V

0.45

0.525

0.550

100 200

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 (V

TRIP

+) and lower (V

TRIP

-) trip points is equal to the width of the input-referred hysteresis zone (V

HYST

).

Specified for an input common-mode voltage (V

CM

) of 0V (see Figure 1).

Note 2: Input Offset Voltage is defined as the center of the input-referred hysteresis zone. Specified for V

CM

= 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 V

CMR

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 (V

CMR

).

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. V

OS

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 (t

PD

+)

and high-to-low transition (t

PD

-), 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= T

MIN

to T

MAX

; MAX909 only: V- = 0V, V

LATCH

= 0V; unless otherwise noted.)

PARAMETER

SYMBOL CONDITIONS MIN TYP MAX UNITS

Propagation Delay

t

PD+,tPD-

VIN= 100mV, VOD= 5mV
(Note 9)

45 70 ns

Differential Propagation Delay

∆t

PD

VIN= 100mV, VOD= 5mV
(Note 10)

2 ns

Propagation Delay Skew

tPDskew

MAX909 only: VIN= 100mV,
V

OD

= 5mV (Note 11)

4 ns

Latch Input Voltage High

V

IH

(Note 12) 2.0 V

Latch Hold Time

t

h

(Note 12) 4 ns

Latch Input Voltage Low

V

IL

(Note 12) 0.8 V

Latch Input Current

IIH, I

IL

(Note 12) 20 µA

Latch Setup Time

t

s

(Note 12) 4 ns

MAX907/MAX908/MAX909

Dual/Quad/Single, High-Speed, Ultra-Low-Power,

Single-Supply TTL Comparators

_________________________________________________________________________________________________ 5

50

10

110100

PROPAGATION DELAY
vs. INPUT OVERDRIVE

INPUT OVERDRIVE (mV)

PROPAGATION DELAY (ns)

30

40

20

tPD+
t

PD

-

RS = 10

Ω

C

LOAD

= 15pF

MAX907 TOC01

80

0

10 100 10k

PROPAGATION DELAY

vs. SOURCE IMPEDANCE

20

SOURCE IMPEDANCE (Ω)

PROPAGATION DELAY (ns)

40

60

1k

VOD = 5mV
C

LOAD

= 15pF

tPD+
tPD-

MAX907 TOC2

70

30

0 120

PROPAGATION DELAY
vs. CAPACITIVE LOAD

40

CAPACITIVE LOAD (pF)

PROPAGATION DELAY (ns)

80

50

20 60 100

60

40

VOD = 5mV
R

S

= 10

Ω

t

PD

+

tPD-

MAX907 TOC03

70

30

-60 -20 60 140

PROPAGATION DELAY

vs. TEMPERATURE

40

60

TEMPERATURE (°C)

PROPAGATION DELAY (ns)

20 100

50

-40 0 8040 120

VOD = 5mV
R

S

= 10

Ω

C

LOAD

= 15pF

tPD+
t

PD

-

MAX907 TOC04

5.0

3.0
110 1000

OUTPUT HIGH VOLTAGE

vs. SOURCE CURRENT

3.5

I

SOURCE

(µA)

V

OH

(V)

4.0

4.5

100

VIN = 100mV

TA = -55°C

TA = +125°C

TA = +25°C

MAX907 TOC05

Typical Operating Characteristics

(V+ = 5V, TA= +25°C, unless otherwise noted.)

0.5

0.1

012

OUTPUT LOW VOLTAGE

vs. SINK CURRENT

0.2

I

SINK

(mA)

V

OL

(V)

8

0.3

2610

0.4

4

VIN = 100mV

TA = -55°C

TA = +125°C

TA = +25°C

MAX907 TOC06

2.0

0

28

MAX907

TOTAL POSITIVE SUPPLY CURRENT

vs. POSITIVE SUPPLY VOLTAGE

(OUTPUTS AT V

OL

)

0.5

V

CC

(V)

TOTAL I

CC

(mA)

6

1.0

357

1.5

4

TA = -55°C

TA = +125°C

TA = +25°C

MAX907 TOC07

2.0

0

28

MAX907

TOTAL POSITIVE SUPPLY CURRENT

vs. POSITIVE SUPPLY VOLTAGE

(OUTPUTS AT V

OH

)

0.5

V

CC

(V)

TOTAL I

CC

(mA)

6

1.0

357

1.5

4

TA = -55°C

TA = +125°C

TA = +25°C

MAX907 TOC08

4.0

0

28

MAX908

TOTAL POSITIVE SUPPLY CURRENT

vs. POSITIVE SUPPLY VOLTAGE

(OUTPUTS AT V

OL

)

1.0

V

CC

(V)

TOTAL I

CC

(mA)

6

2.0

357

3.0

4

TA = -55°C

TA = +125°C

TA = +25°C

MAX907 TOC09

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 V

OH

)

1.0

V

CC

(V)

TOTAL I

CC

(mA)

6

2.0

357

3.0

4

TA = -55°C

TA = +125°C

TA = +25°C

MAX907 TOC10

0.5

-0.5

-60 -20 60 140

INPUT OFFSET VOLTAGE

vs. TEMPERATURE

TEMPERATURE (°C)

V

OS

(mV)

20 100

0

-40 0 8040 120

V

OUT

= 1.4V

V

CM

= 0V

MAX907 TOC16

4

-4

-60 -20 60 140

TRIP POINT

vs. TEMPERATURE

-2

2

TEMPERATURE (°C)

V

OS

(mV)

20 100

0

-40 0 8040 120

VCM = 0V

V

TRIP+

V

TRIP-

MAX907 TOC18

5

-1

-60 -20 60 140

INPUT VOLTAGE RANGE

vs. TEMPERATURE

0

4

TEMPERATURE (°C)

INPUT VOLTAGE RANGE (V)

20 100-40 0 8040 120

V

CMR-

V

CMR+

MAX907 TOC13

2.0

0

23 5 8

MAX909

POSITIVE SUPPLY CURRENT

vs. POSITIVE SUPPLY VOLTAGE

V+ (V)

TOTAL I+ (mA)

46

1.0

7

V- = -5V

TA = +125°C

TA = +25°C

TA = -55°C

MAX907 TOC11

300

100

-60 -20 60 140

INPUT BIAS CURRENT

vs. TEMPERATURE

TEMPERATURE (°C)

INPUT CURRENT (nA)

20 100

200

-40 0 8040 120

VCM = 0V
V

IN

= V

OS

MAX907 TOC17

60

0

-60 -20 60 140

SHORT-CIRCUIT OUTPUT CURRENT

vs. TEMPERATURE

TEMPERATURE (°C)

SHORT-CIRCUIT OUTPUT CURRENT (mA)

20 100

30

-40 0 8040 120

OUTPUT
SHORTED TO
V+ (SINKING)

OUTPUT

SHORTED TO

GND (SOURCING)

MAX907 TOC15

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

T

A

= +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

V

CMR

+

V

CMR

-

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 (t

PD

+)

(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 (t

PD

-)

(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

20mV

P-P

10MHz SINE WAVE

INPUT

COMPARATOR

OUTPUT

50ns/div

GND

MAX907 TOC23

MAX909

PROPAGATION DELAY (t

PD

+)

(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 (t

PD

-)

(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 inter­nal 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 com­parator output is stored when LE is high (Figure 2).

Note that the MAX909 can be operated with V- con­nected 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 real­ize 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 capaci­tor’s bandwidth, keeping leads short. Short lead
lengths on the inputs and outputs are also essential to
avoid unwanted parasitic feedback around the com­parators. 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 consump­tion 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

V

TRIP+

V

HYST

V

TRIP-

V

IN+

COMPARATOR

OUTPUT

V

OH

V

OL

V

TRIP+

+ V

TRIP-

2

V

OS

=

V

IN-

= 0V

Figure 1. Input and Output Waveforms, Noninverting Input
Varied

tPD+

t

SKEW

V

IN

V

OD

t

h

t

s

3V

1.4V

0V

V

OS

V

OH

1.4V

V

OL

V

OH

1.4V

V

OL

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.

V

CLAMP

= -200mV TO -300mV

I

SRC

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