Maxim MAX909MJA Single/dual/quad high-speed, ultra low-power, single-supply ttl comparator Datasheet

19-0129; Rev. 3; 7/94
Single/Dual/Quad High-Speed, Ultra Low-Power,
Single-Supply TTL Comparators
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 pull-up 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 small-outline packages, and the quad
MAX908 is available in 14-pin DIP and small-outline
packages. These comparators are ideal for single
+5V-supply applications that require the combination
of high speed, precision, and ultra-low power
dissipation.
_______________________Applications
___________________________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
PART
TEMP. RANGE
MAX907CPA
0°C to +70°C
8 Plastic DIP
MAX907CSA
0°C to +70°C
8 SO
MAX907C/D
0°C to +70°C
Dice*
MAX907EPA
-40°C to +85°C
8 Plastic DIP
MAX907ESA
-40°C to +85°C
8 SO
MAX907MJA
-55°C to +125°C
8 CERDIP
Ordering Information continued on last page.
* Dice are specified at +25°C, DC parameters only.
_________________Pin Configurations
TOP VIEW
OUTA
1
8
V+
INA-
2
7
OUTB
INA+ 3
6
INB-
GND 4
5
INB+
High-Speed V/F Converters
Line Receivers
Threshold Detectors/Discriminators
MAX907
DIP/SO
Battery-Powered Systems
High-Speed A/D Converters
PIN-PACKAGE
OUTA
1
14 OUTD
INA-
2
13 IND-
INA+ 3
V+ 4
12 IND+
MAX908
11 GND
High-Speed Sampling Circuits
INB+
Zero Crossing Detectors
INB- 6
9
INC-
OUTB 7
8
OUTC
5
10 INC+
DIP/SO
Pin Configurations continued on last page.
________________________________________________________________ Maxim Integrated Products
Call toll free 1-800-998-8800 for free samples or literature.
1
MAX907/MAX908/MAX909
_______________General Description
The MAX907/MAX908/MAX909 dual, quad, and single
high-speed, ultra low-power voltage comparators are
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.
MAX907/MAX908/MAX909
Single/Dual/Quad High-Speed, Ultra Low-Power,
Single-Supply TTL Comparators
ABSOLUTE MAXIMUM RATINGS
Positive Supply Voltage (V+ to GND) . . . . . . . . . . . . . . . . . . . . . . . . +7V
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
8-Pin CERDIP (derate 8.00mW/°C above +70°C) . . . . . . 640mW
14-Pin Plastic DIP (derate 10.00mW/°C above +70°C) . . .800mW
14-Pin SO (derate 8.33mW/°C above +70°C) . . . . . . . . . . 667mW
14-Pin CERDIP (derate 9.09mW/°C above +70°C) . . . . 727mW
Operating Temperature Ranges:
MAX90_C_ _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to +70°C
MAX90_E_ _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -40°C to +85°C
MAX90_MJ_ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - 55°C to +125°C
Storage Temperature Range . . . . . . . . . . . . . . . . . . . -65°C to +160°C
Lead Temperature (soldering, 10sec). . . . . . . . . . . . . . . . . . . . +300°C
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.
ELECTRICAL CHARACTERISTICS
(V+ = 5V, TA = +25°C; MAX909 only: V- = 0V, VLATCH = 0V; unless otherwise noted.)
SYMBOL
VTRIP+
TYP
MAX
UNITS
Positive Trip Point
PARAMETER
(Note 1)
CONDITIONS
2
4
mV
Negative Trip Point
VTRIP-
(Note 1)
-2
-4
mV
Input Offset Voltage
VOS
0.5
2.0
mV
100
300
nA
25
50
nA
Input Bias Current
IB
(Note 2)
VCM = 0V, VIN = VOS
Input Offset Current
IOS
VCM = 0V, VIN = VOS
MIN
MAX907/908/909
-0.2
V+ - 1.5
MAX909 only: V- = -5V
-5.2
V+ - 1.5
VCMR
(Notes 3, 4)
Common-Mode Rejection Ratio
CMRR
(Notes 4, 5)
50
100
µV/V
Power-Supply Rejection Ratio
PSRR
VOH
(Notes 4, 6)
ISOURCE = 100µA
50
100
µV/V
Input Voltage Range
Output High Voltage
Output Low Voltage
VOL
0.3
ISINK = 8mA
0.4
0.7
1.0
MAX909
1.2
1.8
(Note 7)
Negative Supply Current
I-
MAX909 only: V- = -5V
(Note 8)
MAX907/MAX908
Output Rise Time
tr
MAX909
VOUT = 0.4V to 2.4V, CL = 10pF
Output Fall Time
tf
VOUT = 2.4V to 0.4V, CL = 10pF
2
V
0.4
MAX907/MAX908
I+
PD
3.5
ISINK = 3.2mA
Positive Supply Current per
Comparator
Power Dissipation per
Comparator
3.0
V
60
100
3.5
5.5
6
10
V
mA
µA
mW
12
ns
6
ns
_______________________________________________________________________________________
Single/Dual/Quad High-Speed, Ultra Low-Power,
Single-Supply TTL Comparators
MAX907/MAX908/MAX909
ELECTRICAL CHARACTERISTICS (continued)
(V+ = 5V, TA = +25°C; MAX909 only: V- = 0V, VLATCH = 0V; unless otherwise noted.)
PARAMETER
Propagation Delay
Differential Propagation Delay
SYMBOL
TYP
MAX
UNITS
tPD+, tPD-
VIN = 100mV, VOD = 5mV,
(Note 9)
CONDITIONS
MIN
40
50
ns
∆tPD
VIN = 100mV, VOD = 5mV,
(Note 10)
1
ns
MAX909 only: VIN = 100mV,
VOD = 5mV, (Note 11)
2
ns
Propagation Delay Skew
tPDskew
Latch Input Voltage High
VIH
(Note 12)
Latch Input Voltage Low
VIL
(Note 12)
0.8
V
IIH, IIL
(Note 12)
20
µA
Latch Setup Time
ts
(Note 12)
2
ns
Latch Hold Time
th
(Note 12)
2
ns
Latch Input Current
2.0
V
ELECTRICAL CHARACTERISTICS
(V+ = 5V, TA = TMIN to TMAX; MAX909 only: V- = 0V, VLATCH = 0V; unless otherwise noted.)
SYMBOL
VTRIP+
TYP
MAX
UNITS
Positive Trip Point
(Note 1)
2
5
mV
Negative Trip Point
VTRIP-
(Note 1)
-2
-5
mV
Input Offset Voltage
VOS
(Note 2)
1
3
mV
PARAMETER
CONDITIONS
MIN
Input Bias Current
IB
VCM = 0V, VIN = VOS
200
500
nA
Input Offset Current
IOS
VCM = 0V, VIN = VOS
50
100
nA
Common-Mode Rejection Ratio
CMRR
MAX907/908/909
C/E temp.
ranges
MAX909 only,
(Notes 3, 4) V- = -5V
MAX907/908/909
M temp.
range
MAX909 only,
(Notes 3, 4) V- = -5V
(Notes 4, 5)
Power-Supply Rejection Ratio
PSRR
(Notes 4, 6)
Input Voltage Range
Output High Voltage
Output Low Voltage
VCMR
VOH
VOL
ISOURCE = 100µA
-5.2
V+ - 1.5
-0.1
V+ - 1.5
-5.1
2.8
V+ - 1.5
200
µV/V
75
200
µV/V
3.5
ISINK = 8mA
0.4
0.8
1.2
MAX909
1.2
2.0
Negative Supply Current
I-
MAX909 only: V- = -5V
(Note 8)
V
0.4
MAX907/MAX908
(Note 7)
V
75
0.3
I+
PD
V+ - 1.5
ISINK = 3.2mA
Positive Supply Current per
Comparator
Power Dissipation per Comparator
-0.2
100
200
MAX907/MAX908
4
7
MAX909
6
11
V
mA
µA
mW
_______________________________________________________________________________________
3
MAX907/MAX908/MAX909
Single/Dual/Quad High-Speed, Ultra Low-Power,
Single-Supply TTL Comparators
ELECTRICAL CHARACTERISTICS (continued)
(V+ = 5V, TA = TMIN to TMAX; MAX909 only: V- = 0V, VLATCH = 0V; unless otherwise noted.)
PARAMETER
Propagation Delay
Differential Propagation Delay
SYMBOL
TYP
MAX
UNITS
tPD+, tPD-
VIN = 100mV, VOD = 5mV
(Note 9)
CONDITIONS
MIN
45
70
ns
∆tPD
VIN = 100mV, VOD = 5mV
(Note 10)
2
ns
MAX909 only: VIN = 100mV,
VOD = 5mV (Note 11)
4
ns
Propagation Delay Skew
tPDskew
Latch Input Voltage High
VIH
(Note 12)
Latch Input Voltage Low
VIL
(Note 12)
0.8
V
IIH, IIL
(Note 12)
20
µA
Latch Setup Time
ts
(Note 12)
4
ns
Latch Hold Time
th
(Note 12)
4
ns
Latch Input Current
2.0
V
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 without 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, the
MAX907/MAX908/MAX909 are sample tested to 0.1% AQL with 100mV input overdrive. 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.
Note 10: Differential Propagation Delay is specified as the difference between any two channels in the MAX907/MAX908 (both outputs 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.
Note 1:
4
_______________________________________________________________________________________
Single/Dual/Quad High-Speed, Ultra Low-Power,
Single-Supply TTL Comparators
PROPAGATION DELAY
vs. INPUT OVERDRIVE
PROPAGATION DELAY
vs. SOURCE IMPEDANCE
80
40
tPD+
tPD-
30
20
60
tPD+
tPD40
20
0
10
1
10
VOD = 5mV
RS = 10Ω
60
tPD+
50
tPD-
40
30
10
100
100
10k
1k
0
20
80
100
SOURCE IMPEDANCE (Ω)
CAPACITIVE LOAD (pF)
PROPAGATION DELAY
vs. TEMPERATURE
OUTPUT HIGH VOLTAGE
vs. SOURCE CURRENT
OUTPUT LOW VOLTAGE
vs. SINK CURRENT
VOD = 5mV
RS = 10Ω
CLOAD = 15pF
VIN = 100mV
4.5
TA = -55°C
0.4
TA = +125°C
4.0
VOL (V)
VOH (V)
tPD+
tPD-
50
TA = +25°C
TA = +25°C
0.3
TA = -55°C
3.5
40
-60 -40 -20 0
0.1
1
20 40 60 80 100 120 140
TA = +125°C
0.2
3.0
30
10
1000
100
0
2
4
6
8
10
TEMPERATURE (°C)
ISOURCE (µA)
ISINK (mA)
MAX907
TOTAL POSITIVE SUPPLY CURRENT
vs. POSITIVE SUPPLY VOLTAGE
(OUTPUTS AT VOL)
MAX907
TOTAL POSITIVE SUPPLY CURRENT
vs. POSITIVE SUPPLY VOLTAGE
(OUTPUTS AT VOH)
MAX908
TOTAL POSITIVE SUPPLY CURRENT
vs. POSITIVE SUPPLY VOLTAGE
(OUTPUTS AT VOL)
2.0
TA = +125°C
TA = +125°C
TA = +125°C
TA = +25°C
TA = -55°C
0.5
3.0
TOTAL ICC (mA)
1.5
TOTAL ICC (mA)
1.5
TA = +25°C
TA = -55°C
1.0
0.5
0
4
5
VCC (V)
6
7
8
TA = +25°C
2.0
TA = -55°C
1.0
0
0
3
12
4.0
2.0
1.0
120
0.5
VIN = 100mV
60
2
60
40
INPUT OVERDRIVE (mV)
5.0
70
PROPAGATION DELAY (ns)
70
VOD = 5mV
CLOAD = 15pF
PROPAGATION DELAY (ns)
RS = 10Ω
CLOAD = 15pF
PROPAGATION DELAY (ns)
PROPAGATION DELAY (ns)
50
TOTAL ICC (mA)
PROPAGATION DELAY
vs. CAPACITIVE LOAD
2
3
4
5
VCC (V)
6
7
8
2
3
4
5
6
7
8
VCC (V)
_________________________________________________________________________________________________
5
MAX907/MAX908/MAX909
__________________________________________Typical Operating Characteristics
(V+ = 5V, TA = +25°C, unless otherwise noted.)
____________________________Typical Operating Characteristics (continued)
(V+ = 5V, TA = +25°C, unless otherwise noted.)
MAX908
TOTAL POSITIVE SUPPLY CURRENT
vs. POSITIVE SUPPLY VOLTAGE
(OUTPUTS AT VOH)
MAX909
POSITIVE SUPPLY CURRENT
vs. POSITIVE SUPPLY VOLTAGE
4.0
2.0
200
+125°C
TA = -55°C
TOTAL I- (µA)
TA = +25°C
TOTAL I+ (mA)
TOTAL ICC (mA)
V+ = +5V
+125°C
3.0
2.0
MAX909
NEGATIVE SUPPLY CURRENT
vs. NEGATIVE SUPPLY VOLTAGE
V- = -5V
TA = +125°C
+25°C
1.0
-55°C
100
+25°C
1.0
-55°C
0
3
4
5
6
7
0
8
0
2
3
4
6
7
8
-1
-2
-3
-4
-5
-6
V- (V)
INPUT VOLTAGE RANGE
vs. TEMPERATURE
MAX909
INPUT VOLTAGE RANGE
vs. TEMPERATURE
SHORT-CIRCUIT OUTPUT CURRENT
vs. TEMPERATURE
5
VCMR+
0
VCMR-
INPUT VOLTAGE RANGE (V)
4
VCMR+
4
V+ = +5V
V- = -5V
-5
VCMR-
-1
20 40 60 80 100 120 140
TEMPERATURE (°C)
OUTPUT
SHORTED TO
V+ (SINKING)
30
OUTPUT
SHORTED TO
GND (SOURCING)
-60 -40 -20 0
TRIP POINT
vs. TEMPERATURE
INPUT BIAS CURRENT
vs. TEMPERATURE
4
300
VOUT = 1.4V
VCM = 0V
VCM = 0V
-0.5
2
VOS (mV)
INPUT CURRENT (nA)
VCM = 0V
VIN = VOS
0
200
VTRIP+
0
VTRIP-2
-4
100
20 40 60 80 100 120 140
TEMPERATURE (°C)
20 40 60 80 100 120 140
TEMPERATURE (°C)
TEMPERATURE (°C)
INPUT OFFSET VOLTAGE
vs. TEMPERATURE
-60 -40 -20 0
60
-60 -40 -20 0 20 40 60 80 100 120 140
0.5
-7
0
-6
-60 -40 -20 0
6
0
V+ (V)
5
INPUT VOLTAGE RANGE (V)
5
VCC (V)
SHORT-CIRCUIT OUTPUT CURRENT (mA)
2
VOS (mV)
MAX907/MAX908/MAX909
Single/Dual/Quad High-Speed, Ultra Low-Power,
Single-Supply TTL Comparators
-60 -40 -20 0
20 40 60 80 100 120 140
TEMPERATURE (°C)
-60 -40 -20 0
20 40 60 80 100 120 140
TEMPERATURE (°C)
________________________________________________________________________________________________
Single/Dual/Quad High-Speed, Ultra Low-Power,
Single-Supply TTL Comparators
MAX907/MAX908
PROPAGATION DELAY (tPD-)
(5mV OVERDRIVE)
MAX907/MAX908
PROPAGATION DELAY (tPD+)
(5mV OVERDRIVE)
INPUT GND
-5mV OVERDRIVE
5mV OVERDRIVE
INPUT GND
INPUT
(20mV/div)
INPUT
(20mV/div)
OUTPUT
(500mV/div)
OUTPUT
(500mV/div)
TTL
THRESHOLD
(1.4V)
TTL
THRESHOLD (1.4V)
OUTPUT
GND
OUTPUT
GND
tPD-
tPD+
TIME (10 /di )
MAX909
PROPAGATION DELAY (tPD+)
(5mV OVERDRIVE)
MAX909
PROPAGATION DELAY (tPD-)
(5mV OVERDRIVE)
5mV OVERDRIVE
INPUT GND
INPUT
(20mV/div)
QOUT
(1V/div)
INPUT GND
-5mV OVERDRIVE
INPUT
(20mV/div)
QOUT
(1V/div)
1.4V
OUTPUT
GND
QOUT
tPD+
1.4V
OUTPUT
GND
QOUT
tPD SKEW
tPD-
tPD SKEW
RESPONSE TO 10MHz SINE WAVE
20mVp-p
10MHz SINE WAVE
INPUT
COMPARATOR
OUTPUT
(1V/div)
GND
TIME (50ns/div)
_________________________________________________________________________________________________
7
MAX907/MAX908/MAX909
____________________________Typical Operating Characteristics (continued)
(V+ = 5V, TA = +25°C, unless otherwise noted.)
MAX907/MAX908/MAX909
Single/Dual/Quad High-Speed, Ultra Low-Power,
Single-Supply TTL Comparators
______________________________________________________________Pin Description
PIN
FUNCTION
MAX908
1
1
OUTA
2
2
INA-
Comparator A Inverting Input
3
3
INA+
Comparator A Noninverting Input
8
4
5
5
INB+
Comparator B Noninverting Input
6
6
INB-
Comparator B Inverting Input
7
7
OUTB
Comparator B Output
8
OUTC
Comparator C Output
9
INC-
Comparator C Inverting Input
10
INC+
Comparator C Noninverting Input
GND
Ground
12
IND+
Comparator D Noninverting Input
13
IND-
Comparator D Inverting Input
14
OUTD
4
11
MAX909
NAME
MAX907
1
6
V+
Comparator A Output
Positive Supply
Comparator D Output
2
IN+
Noninverting Input
3
IN-
Inverting Input
4
V-
Negative Supply or Ground
5
LE
The latch is transparent when LE is low. The comparator output is
stored when LE is high.
7
QOUT
Comparator Output
8
QOUT
Inverted Comparator Output
_______________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).
8
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. See 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).
_______________________________________________________________________________________
Single/Dual/Quad High-Speed, Ultra Low-Power,
Single-Supply TTL Comparators
MAX907/MAX908/MAX909
VTRIP+
VHYST
VTRIP-
VIN+
V
+ VTRIPVOS = TRIP+
2
LE
1.4V
VIN- = 0V
0
VOS
VOH
COMPARATOR
OUTPUT
DIFFERENTIAL
INPUT
VOLTAGE
Figure 1. Input and Output Waveforms, Noninverting Input
Varied
__________Applications Information
COMPARE
ts
th
VOD
VIN
VOH
VOL
LATCH
3V
tPD+
OUTPUT
1.4V
(QOUT)
VOL
tSKEW
VOH
OUTPUT
(QOUT) 1.4V
VOL
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.
Figure 2. MAX909 Timing Diagram
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.
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
(see Figure 3).
_______________________________________________________________________________________
9
MAX907/MAX908/MAX909
Single/Dual/Quad High-Speed, Ultra Low-Power,
Single-Supply TTL Comparators
10pF
1M
VCLAMP = -200mV TO -300mV
1/2 MAX907
+5V
+5V
0.1µF
MAX403
2
7
6
SIEMENS BP-104
PHOTODIODE 3
ISRC
3
1
4
100k
47k
2
100k
+5V
V-
0.1µF
8
4
DATA
MAX907
1000pF
1000pF
Figure 3. Schottky Clamp for Input Driven Below Ground
10
Figure 4. Battery-Operated Infrared Data Link Consumes Only
1mA
______________________________________________________________________________________
Single/Dual/Quad High-Speed, Ultra Low-Power,
Single-Supply TTL Comparators
TOP VIEW
_Ordering Information (continued)
PART
TEMP. RANGE
MAX908CPD
0°C to +70°C
14 Plastic DIP
PIN-PACKAGE
14 SO
MAX908CSD
0°C to +70°C
8
QOUT
MAX908EPD
-40°C to +85°C
2
7
QOUT
MAX908ESD
-40°C to +85°C
14 SO
IN- 3
6
GND
MAX908MJD
-55°C to +125°C
14 CERDIP
V- 4
5
LE
V+
1
IN+
MAX909
DIP/SO
14 Plastic DIP
MAX909CPA
0°C to +70°C
8 Plastic DIP
MAX909CSA
0°C to +70°C
8 SO
MAX909C/D
0°C to +70°C
Dice*
MAX909EPA
-40°C to +85°C
8 Plastic DIP
MAX909ESA
-40°C to +85°C
8 SO
MAX909MJA
-55°C to +125°C
8 CERDIP
* Dice are specified at +25°C, DC parameters only.
______________________________________________________________________________________
11
MAX907/MAX908/MAX909
____Pin Configurations (continued)
MAX907/MAX908/MAX909
Single/Dual/Quad High-Speed, Ultra Low-Power,
Single-Supply TTL Comparators
__________________________________________________________Chip Topographies
MAX907
MAX909
V+
INB- INB+
IN+
QOUT
IN-
QOUT
OUTB
GND
V+
0.051"
(1.30mm)
0.057"
(1.45mm)
GND
OUTA
V-
INA-
LE
INA+
0.050"
(1.27mm)
0.055"
(1.40mm)
TRANSISTOR COUNT: 95;
TRANSISTOR COUNT: MAX907:180
MAX908:360
SUBSTRATE CONNECTED TO V-.
SUBSTRATE CONNECTED TO GND.
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.
12 __________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 (408) 737-7600
© 1994 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
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