19-1141; Rev 2; 2/07
Single/Dual, +3V/+5V Dual-Speed
Comparators with Auto-Standby
The MAX975/MAX977 single/dual comparators feature
three different operating modes, and are optimized for
+3V and +5V single-supply applications. The operating
modes are as follows: high speed, high speed with
auto-standby, and low power. Propagation delay is 28ns
in high-speed mode, while supply current is only 250µA.
Supply current is reduced to 3µA in low-power mode.
The auto-standby feature allows the comparator to
automatically change from low-power mode to highspeed mode upon receipt of an input signal. In the
absence of an input signal, the comparator reverts
back to low-power mode after an adjustable timeout
period. The timeout period for the MAX975 to enter
standby is set by a single capacitor. The dual MAX977
features independently adjustable timeout periods for
each comparator using separate capacitors.
The MAX975/MAX977’s inputs have a common-mode
voltage range of -0.2V to (VCC - 1.2V). The differential
input voltage range extends rail to rail. The outputs are
capable of rail-to-rail operation without external pull-up
circuitry, making these devices ideal for interface with
CMOS/TTL logic. All inputs and outputs can tolerate a
continuous short-circuit fault condition to either rail. The
comparator’s internal hysteresis in high-speed mode
ensures clean output switching, even with slow-moving
input signals.
____________________________Features
♦ Three Operating Modes:
High Speed
High Speed with Auto-Standby
Low Power
♦ 28ns Propagation Delay (high-speed mode)
♦ 5µA Max Supply Current in Low-Power/
Auto-Standby Modes
♦ +3V/+5V Single-Supply Operation
♦ Rail-to-Rail Outputs
♦ Ground-Sensing Input
♦ Internal Hysteresis (high-speed mode)
♦ Adjustable Timeout Period
♦ µMAX Package (MAX975)
QSOP-16 Package (MAX977)
Ordering Information
TEMP RANGE
PINPACKAGE
MAX975ESA
-40°C to +85°C
8 SO
S8-2
MAX975EUA-T
-40°C to +85°C
8 µMAX-8
U8-1
MAX977ESD
-40°C to +85°C
14 SO
S14-1
MAX977EEE
-40°C to +85°C
16 QSOP
E16-1
PART
The single MAX975 is available in 8-pin SO and 8-pin
µMAX® packages, while the dual MAX977 is available
in 14-pin SO and 16-pin QSOP packages.
Functional Diagram
VCC
________________________Applications
Battery-Powered Systems
RF ID Tags
Keyless Entry
Threshold Detectors/Discriminators
3V Systems
IR Receivers
Digital-Line Receivers
PKG
CODE
MAX975
IN+
LP
HIGH SPEED
OUT
ENABLE
TRANSITION
MONITOR
GND
LOW POWER
ENABLE
IN-
µMAX is a registered trademark of Maxim Integrated Products, Inc.
STAT
TIMING
CIRCUIT
STO
Pin Configurations appear at end of data sheet.
________________________________________________________________ Maxim Integrated Products
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.
1
MAX975/MAX977
General Description
MAX975/MAX977
Single/Dual, +3V/+5V Dual-Speed
Comparators with Auto-Standby
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (VCC) ............................................................+6V
All Other Pins..............................................-0.3V to (VCC + 0.3V)
Current into Input Pins ......................................................±20mA
Duration of Output Short Circuit to GND_ or VCC ......Continuous
Continuous Power Dissipation (TA = +70°C)
8-Pin SO (derate 5.88mW/°C above +70°C)..................471mW
8-Pin µMAX (derate 4.10mW/°C above +70°C) .............330mW
14-Pin SO (derate 8.33mW/°C above +70°C)................667mW
16-Pin QSOP (derate 8.33mW/°C above +70°C)...........667mW
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°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
(VCC = +2.7V to +5.25V, specifications are for high-speed mode, TA = -40°C to +85°C, unless otherwise noted. Typical values are at
TA = +25°C.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
5.25
V
POWER SUPPLY
Supply-Voltage
Operating Range
VCC
2.7
High-speed mode
Supply Current
Per Comparator
Power-Supply
Rejection Ratio
ICC
Auto-standby/low-power modes
PSRR
VCM = 1V,
2.7V ≤ VCC ≤ 5.25V
VCMR
(Note 2)
250
500
SO
3
5
µMAX/QSOP
3
6
High-speed mode
63
Low-power mode
90
µA
dB
77
COMPARATOR INPUTS
Common-Mode
Voltage Range
-0.2
High-speed mode, TA = +25°C
Input Offset Voltage
(Note 3)
Input-Referred Hysteresis
Input Bias Current
VOS
VHYS
IB
VCM = 1V,
VCC = 5V
VCC - 1.2
+0.2
High-speed mode, TA = TMIN to TMAX
Auto-standby/
low-power modes,
TA = TMIN to TMAX
VCM = 1V, VCC = 5V (Note 4)
High-speed mode
SO
±1
±5
µMAX/QSOP
±1
±7
0.5
2
4
µMAX/QSOP
0.3
2
4
SO
-100
-300
µMAX/QSOP
-100
-400
nA
±100
nA
IOS
±20
CIN
3
2
High-speed mode
Low-power mode
mV
-5
Input Capacitance
-0.2V ≤ VCM
≤ VCC - 1.2V
mV
SO
Input Offset Current
CMRR
±2
±3
Auto-standby/low-power modes
Common-Mode
Rejection Ratio
V
SO
66
µMAX/QSOP
54
pF
90
dB
82
_______________________________________________________________________________________
Single/Dual, +3V/+5V Dual-Speed
Comparators with Auto-Standby
(VCC = +2.7V to +5.25V, specifications are for high-speed mode, TA = -40°C to +85°C, unless otherwise noted. Typical values are at
TA = +25°C.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
0.7 x VCC
VCC / 2
MAX
UNITS
DIGITAL INPUTS
LP Input Voltage High
VLPIH
LP Input Voltage Low
VLPIL
VCC / 2
LP Fall Time
tLP
LP Input Current
ILPB
STO_ Input Voltage Low
VCIL
STO_ Source Current
ISTO
VCC = 3V
OUT_ Output Voltage High
VOH
ISOURCE = 2mA, all modes
OUT_ Output Voltage Low
VOL
ISINK = 2mA, all modes
tPD+
CLOAD = 10pF,
VCC = 5V
V
0.3 x VCC
V
10
µs
0.01
±1
µA
VCC / 2
0.3 x VCC
(Note 5)
0.15
V
µA
DIGITAL OUTPUTS
Propagation Delay, Low to High
(Note 6)
Propagation Delay, High to Low
(Note 6)
Propagation-Delay Skew (Note 6)
Propagation-Delay Matching
tPD-
tSKEW
∆tPD
CLOAD = 10pF,
VCC = 5V
V
0.1
0.4
V
High-speed mode,
overdrive = 5mV
28
50
ns
Low-power mode,
overdrive = 10mV
0.82
1.6
µs
High-speed mode,
overdrive = 5mV
28
50
ns
Low-power mode,
overdrive = 10mV
0.48
1.6
µs
CLOAD = 10pF
MAX977 only, CLOAD = 10pF
CLOAD = 10pF,
VCC = 5.0V
Rise/Fall Time
VCC - 0.4 VCC - 0.1
2
ns
1
ns
High-speed mode
1.6
Low-power mode
1.6
STAT_ Output Voltage High
VSH
ISOURCE = 3mA, all modes
STAT_ Output Voltage Low
VSL
ISINK = 400µA, all modes
ns
VCC - 0.4
V
0.4
V
Note 1: The MAX975EUA is 100% production tested at TA = +25°C; all temperature specifications are guaranteed by design.
Note 2: Inferred by CMRR. Either input can be driven to the absolute maximum limit without false output inversion, as long as the
other input is within the specified common-mode input voltage range.
Note 3: VOS is defined as the mean of trip points. The trip points are the extremities of the differential input voltage required to make
the comparator output change state (Figure 1).
Note 4: The difference between the upper and lower trip points is equal to the width of the input-referred hysteresis zone (Figure 1).
Note 5: Guaranteed by design. The LP pin is sensitive to noise. If fall times larger than 10µs are expected, bypass LP to ground
using a 0.1µF capacitor.
Note 6: Propagation delay is guaranteed by design. For low-overdrive conditions, VOS is added to the overdrive. The following
equation defines propagation-delay skew: tSKEW = tPD+ - tPD-.
_______________________________________________________________________________________
3
MAX975/MAX977
ELECTRICAL CHARACTERISTICS (continued)
MAX975/MAX977
Single/Dual, +3V/+5V Dual-Speed
Comparators with Auto-Standby
ELECTRICAL CHARACTERISTICS (continued)
(VCC = +2.7V to +5.25V, specifications are for high-speed mode, TA = -40°C to +85°C, unless otherwise noted. Typical values are at
TA = +25°C.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
5
10
16
ms
AUTO-STANDBY/LOW-POWER TIMING (Note 7; Figure 2)
Auto-Standby Timeout
tASB
(Note 8)
Auto-Standby Enable Time
tASBE
(Note 9)
3
Auto-Standby Wake-Up Time
tASD
10mV overdrive (Note 10)
2
Auto-Standby Wake-Up Input
or LP Pulse Width
tPWD
10mV overdrive (Note 11)
Auto-Standby Comparator
Disable
tASCD
(Note 12)
0.8
µs
tLPE
(Note 13)
3
µs
High-Speed Enable Time
tHSE
(Note 14)
1.1
Low-Power Comparator Disable
tLPCD
(Note 15)
0.7
µs
Low-Power STAT_ High
tLPSH
(Note 16)
20
ns
Low-Power Enable Time
Note 7:
Note 8:
Note 9:
Note 10:
Note 11:
Note 12:
Note 13:
Note 14:
Note 15:
Note 16:
4
µs
4
1.6
µs
µs
4
µs
Timing specifications are guaranteed by design.
Set by 1000pF external capacitor at the STO_ pin. tASB is defined as the time from last input transition to STAT_ = high.
Does not include time to go into standby condition (tASBE).
tASBE is defined as the time from when STAT_ goes high to when the supply current drops to 5µA.
tASD is defined as the time from the last input transition to when STAT_ goes low. The comparator is in high-speed mode
before STAT_ is low.
tPWD is defined as the minimum input or LP pulse width to trigger fast-mode operation from auto-standby.
tASCD is defined as the time from the last input transition to when the supply current increases to 300µA.
tLPE is defined as the time from when LP is driven high to when the supply current drops to 5µA.
tHSE is defined as the time from when LP goes low to when STAT goes low. The comparator is in high-speed mode before
STAT_ is low.
tLPCD is defined as the time from when LP goes low to when the supply current increases to 300µA.
tLPSH is defined as the time from when LP goes high to when STAT_ goes high.
_______________________________________________________________________________________
Single/Dual, +3V/+5V Dual-Speed
Comparators with Auto-Standby
-0.85
-0.90
-0.95
-1.00
-1.05
-1.10
-1.15
-1.20
0
20
40
60
80
100
LOW-POWER MODE
10
1
0.01k 0.1k
100
-70
VCC = 3V
-90
-110
VCC = 5V
-130
-170
1k
10k 100k 1M
10M 100M
-60 -40 -20
20
40
60
80
100
LOW-POWER INPUT BIAS CURRENT
vs. TEMPERATURE
HIGH-SPEED VOLTAGE TRIP POINTS/INPUT
OFFSET VOLTAGE vs. TEMPERATURE
HIGH-SPEED VOLTAGE TRIP POINTS/INPUT
OFFSET VOLTAGE vs. TEMPERATURE
5.5
VCC = 5V
5.0
4.5
VCC = 3V
4.0
3.5
MAX977-05
TRIP POINTS/OFFSET VOLTAGE (mV)
MAX977-04
6.0
1.0
VCC = 5V
0.8
0.6
VTRIP+
0.4
0.2
0
VOS
-0.2
VTRIP-
-0.4
-0.6
-0.8
-1.0
3.0
-60 -40 -20
0
20
40
60
80
-60 -40 -20
100
0
20
40
60
80
1.2
1.0
0.8
0.6
0.4
MAX977-06
TEMPERATURE (°C)
TRIP POINTS/OFFSET VOLTAGE (mV)
TRANSITION FREQUENCY (kHz)
6.5
VCC = 3V
VTRIP+
0.2
0
-0.2
-0.4
VOS
-0.6
VTRIP-
-0.8
-1.0
-1.2
100
-60 -40 -20
0
20
40
60
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
LOW-POWER PROPAGATION DELAY
vs. CAPACITIVE LOAD
LOW-POWER PROPAGATION DELAY
vs. INPUT OVERDRIVE
AUTO-STANDBY TIMEOUT
vs. TEMPERATURE
tPD+
500
450
VCC = 3V
400
350
VCC = 3V
300
tPD-
tPD+
450
VCC = 3V
350
300
50mV OVERDRIVE
200
VCC = 3V
VCC = 5V
100
150
CAPACITIVE LOAD (pF)
200
250
100
MAX977-09
VCC = 3V
9.8
9.7
9.6
VCC = 5V
9.4
150
50
9.9
9.5
tPD-
200
80
10.0
500
400
100
10.1
VCC = 5V
550
80
10.2
600
250
VCC = 5V
250
CLOAD =15pF
TIMEOUT (ms)
VCC = 5V
650
PROPAGATION DELAY (ns)
550
MAX977-08
700
MAX977-07
600
0
0
TEMPERATURE (°C)
7.0
INPUT BIAS CURRENT (nA)
HIGH-SPEED MODE
1000
-150
-60 -40 -20
PROPAGATION DELAY (ns)
-50
MAX977-03
10000
INPUT BIAS CURRENT (nA)
VCC = 3V
MAX977-02
MAX977-01
-0.60
-0.65
-0.70
-0.75
-0.80
HIGH-SPEED INPUT BIAS CURRENT
vs. TEMPERATURE
SUPPLY CURRENT PER COMPARATOR
vs. OUTPUT TRANSITION FREQUENCY
SUPPLY CURRENT
PER COMPARATOR (µA)
OFFSET VOLTAGE (mV)
LOW-POWER OFFSET VOLTAGE
vs. TEMPERATURE
9.3
0
40
80
120
160
INPUT OVERDRIVE (mV)
200
240
-60 -40 -20
0
20
40
60
TEMPERATURE (°C)
_______________________________________________________________________________________
5
MAX975/MAX977
__________________________________________Typical Operating Characteristics
(VCC = 3.0V, TA = +25°C, unless otherwise noted.)
____________________________Typical Operating Characteristics (continued)
(VCC = 3.0V, TA = +25°C, unless otherwise noted.)
OUTPUT HIGH VOLTAGE
vs. OUTPUT SOURCE CURRENT
3.0
100
2.0
1.5
VCC = 3V
3.0
OUTPUT VOLTAGE (V)
1000
TA = -40°C
2.5
3.5
MAX977-11
VCC = 3V
OUTPUT VOLTAGE (V)
10000
TIMEOUT (µs)
3.5
MAX977-10
100000
OUTPUT LOW VOLTAGE
vs. OUTPUT SINK CURRENT
TA = +85°C
1.0
MAX977-12
AUTO-STANDBY TIMEOUT
vs. TIMEOUT CAPACITOR
TA = +25°C
TA = +85°C
2.5
2.0
TA = -40°C
1.5
1.0
10
0.5
0.5
TA = +25°C
0.0
1
10
100
1000
5
10
15
20
25
30
35
0
15
20
25
30
35
SINK CURRENT (mA)
HIGH-SPEED PROPAGATION DELAY
vs. TEMPERATURE (VCC = 5V)
HIGH-SPEED PROPAGATION DELAY
vs. TEMPERATURE (VCC = 3V)
HIGH-SPEED SUPPLY CURRENT
PER COMPARATOR
vs. TEMPERATURE (VCC = 5V)
PROPAGATION DELAY (ns)
26
tPD22
tPD+
18
14
31
CLOAD = 15pF
VOD = 50mV
29
27
25
23
tPDtPD+
21
19
-60 -40 -20
0
20
40
60
80
-60 -40 -20
100
OUT_ = HIGH
275
250
225
200
OUT_ = LOW
175
150
125
100
15
10
400
375
350
325
300
0
20
40
60
80
100
-60 -40 -20
0
20
40
60
80
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
HIGH-SPEED SUPPLY CURRENT
PER COMPARATOR
vs. TEMPERATURE (VCC = 3V)
STANDBY/LOW-POWER SUPPLY
CURRENT PER COMPARATOR
vs. TEMPERATURE (VCC = 5V)
STANDBY/LOW POWER-SUPPLY
CURRENT PER COMPARATOR
vs. TEMPERATURE (VCC = 3V)
SUPPLY CURRENT (µA)
4.0
OUT_ = HIGH
240
220
200
180
OUT_ = LOW
160
140
OUT_ = LOW
3.5
3.0
OUT_ = HIGH
2.5
3.4
3.2
3.0
OUT = LOW
2.8
2.6
2.4
2.2
2.0
2.0
120
100
1.5
-60 -40 -20
0
20
40
TEMPERATURE (°C)
60
80
100
100
MAX977-18
3.6
SUPPLY CURRENT (µA)
280
3.8
MAX977-17
4.5
MAX977-16
300
40
MAX977-15
33
SUPPLY CURRENT (µA)
MAX977-13
35
17
6
10
SOURCE CURRENT (mA)
CLOAD = 15pF
VOD = 50mV
260
5
CAPACITANCE (pF)
30
PROPAGATION DELAY (ns)
0.0
0
10,000
MAX977-14
1
SUPPLY CURRENT (µA)
MAX975/MAX977
Single/Dual, +3V/+5V Dual-Speed
Comparators with Auto-Standby
OUT = HIGH
1.8
-60 -40 -20
0
20
40
TEMPERATURE (°C)
60
80
100
-60 -40 -20
0
20
40
TEMPERATURE (°C)
_______________________________________________________________________________________
60
80
100
Single/Dual, +3V/+5V Dual-Speed
Comparators with Auto-Standby
tPD+
tPDVCC = +5V
tPD+
22.5
20.0
17.5
15.0
VCC = +3V
20
tPD+ VCC = +5V
15
10
5
50
100
150
200
250
520
480
440
tPD+
400
360
tPD-
320
280
200
0
20 40 60 80 100 120 140 160 180 200
CAPACITIVE LOAD (pF)
-60 -40 -20
INPUT OVERDRIVE (mV)
LOW-POWER PROPAGATION DELAY
vs. TEMPERATURE (VCC = 5V)
0
60
80
100
INPUT
5mV/div
VOS
VCC
tPD+
VCC/2
tPD-
300
40
PROPAGATION DELAY tPD+
HIGH-SPEED MODE (VCC = +3V)
CLOAD = 15pF
VOD = 50mV
500
450
400
350
20
TEMPERATURE (°C)
MAX977-22
750
700
650
600
550
CLOAD = 15pF
VOD = 50mV
560
240
CLOAD = 15pF
0
0
600
PROPAGATION DELAY (ns)
tPD-
32.5
30.0
27.5
25.0
25
PROPAGATION DELAY (ns)
VCC = +3V
tPD-
MAX977-21
30
LOW-POWER PROPAGATION DELAY
vs. TEMPERATURE (VCC = 3V)
MAX977-20
CLOAD = 15pF
VOD = 50mV
HIGH-SPEED PROPAGATION DELAY
vs. INPUT OVERDRIVE
MAX977-19
45.0
42.5
40.0
37.5
35.0
PROPAGATION DELAY (ns)
PROPAGATION DELAY (ns)
HIGH-SPEED PROPAGATION DELAY
vs. CAPACITIVE LOAD
OUTPUT
1V/div
GND
250
200
150
MAX975/977 TOC23
-60 -40 -20
0
20
40
60
80
100
5ns/div
tPD+
TEMPERATURE (°C)
PROPAGATION DELAY tPDHIGH-SPEED MODE (VCC = +5V)
PROPAGATION DELAY tPDHIGH-SPEED MODE (VCC = +3V)
VOS
INPUT
5mV/div
VOS
OUTPUT
1V/div
VCC
INPUT
5mV/div
VCC
VCC/2
OUTPUT
2V/div
VCC/2
GND
GND
MAX975/977 TOC24
5ns/div
tPD-
MAX975/977 TOC25
5ns/div
tPD-
_______________________________________________________________________________________
7
MAX975/MAX977
____________________________Typical Operating Characteristics (continued)
(VCC = 3.0V, TA = +25°C, unless otherwise noted.)
MAX975/MAX977
Single/Dual, +3V/+5V Dual-Speed
Comparators with Auto-Standby
____________________________Typical Operating Characteristics (continued)
(VCC = 3.0V, TA = +25°C, unless otherwise noted.)
PROPAGATION DELAY tPDLOW-POWER MODE (VCC = +3V)
PROPAGATION DELAY tPD+
HIGH-SPEED MODE (VCC = +5V)
INPUT
5mV/div
VOS
INPUT
5mV/div
VOS
VCC
VCC/2
VCC
OUTPUT
2V/div
VCC/2
OUTPUT
1V/div
GND
GND
MAX975/977 TOC27
MAX975/977 TOC26
5ns/div
100ns/div
tPD+
tPD-
PROPAGATION DELAY tPD+
LOW-POWER MODE (VCC = +3V)
INPUT
5mV/div
VOS
VCC
VCC/2
OUTPUT
1V/div
GND
MAX975/977 TOC28
100ns/div
tPD+
PROPAGATION DELAY tPD+
LOW-POWER MODE (VCC = +5V)
PROPAGATION DELAY tPDLOW-POWER MODE (VCC = +3V)
INPUT
5mV/div
VOS
VCC
INPUT
5mV/div
VOS
VCC
OUTPUT
2V/div
VCC/2
GND
OUTPUT
2V/div
VCC/2
GND
MAX975/977 TOC29
100ns/div
8
tPD+
MAX975/977 TOC30
100ns/div
tPD-
_______________________________________________________________________________________
Single/Dual, +3V/+5V Dual-Speed
Comparators with Auto-Standby
100kHz RESPONSE
LOW-POWER MODE (VCC = +3V)
100kHz RESPONSE
LOW-POWER MODE (VCC = +5V)
INPUT
5mV/div
VOS
INPUT
5mV/div
VOS
VCC
VCC
OUTPUT
2V/div
OUTPUT
1V/div
GND
GND
MAX975/977 TOC32
2µs/div
MAX975/977 TOC31
2µs/div
10MHz RESPONSE
HIGH-SPEED MODE (VCC = +5V)
INPUT
5mV/div
VOS
VCC
OUTPUT
2V/div
GND
MAX975/977 TOC34
20ns/div
MAX975
AUTO-STANDBY OPERATION
10MHz RESPONSE
HIGH-SPEED MODE (VCC = +3V)
+100mV
INPUT
5mV/div
VOS
Inp
VCC
-100mV
3V
OUTPUT
1V/div
GND
OUT
0V
ICC
250µA
0µA
MAX975/977 TOC35
MAX975/977 TOC33
20ns/div
1ms/div
CSTO_ = 100pF
_______________________________________________________________________________________
9
MAX975/MAX977
____________________________Typical Operating Characteristics (continued)
(VCC = 3.0V, TA = +25°C, unless otherwise noted.)
MAX975/MAX977
Single/Dual, +3V/+5V Dual-Speed
Comparators with Auto-Standby
_____________________________________________________________Pin Descriptions
MAX975
PIN
NAME
FUNCTION
1
VCC
Positive Supply Voltage, +2.7V to +5.25V
2
IN+
Noninverting Comparator Input
3
IN-
Inverting Comparator Input
4
STAT
Mode Status Pin. Indicates the operating mode. STAT is high for auto-standby mode or low-power
mode, and during the transition to high-speed mode. STAT = low indicates that the comparator is in
high-speed mode. STAT can source 3mA to power additional circuitry.
5
STO
Set Timeout Input. Connect a capacitor from STO to GND to program the time the comparator may
remain idle before entering standby mode. Connect STO to GND to disable the auto-standby feature. Calculate timeout with the following relationship: tASB = 10 x C µs, where C is in pF.
6
GND
Ground
7
OUT
Comparator Output
8
LP
Low Power Mode Input. Drive LP high for low-power mode. Drive LP low for high-speed mode
(STO = GND) or for high-speed mode with auto-standby. Connect to GND if low-power mode will
not be used. Connect to VCC if high-speed mode will not be used.
MAX977
QSOP
NAME
FUNCTION
1, 8
1, 9
STOA,
STOB
Set Idle Timeout Input A/B. Connect a capacitor from STOA/STOB to GND to program
the time in which comparator A/B may remain idle before entering standby mode.
Connect STOA/STOB to GND to disable the auto-standby feature for comparator A/B.
Calculate timeout with the following relationship: tASB = 10 x C µs, where C is in pF.
2, 9
2, 10
GNDA, GNDB
Ground for Comparator A/B
3, 10
3, 11
OUTA, OUTB
Output for Comparator A/B
4
4, 5
VCC
5, 12
6, 14
INB+, INA+
6, 13
7, 15
INB-, INA-
SO
7, 14
8, 16
STATB,
STATA
—
12
N.C.
11
10
13
LP
Positive Supply Voltage, +2.7V to +5.25V. For QSOP, connect pin 4 to pin 5.
Noninverting Input for Comparator B/A
Inverting Input for Comparator B/A
Mode Status Pin B/A. Indicates the operating mode of comparator B/A.
STATB/STATA is high for auto-standby mode or for low-power mode, and during
the transition to high-speed mode. STATB/STATA = low indicates that comparator
B/A is in high-speed mode. STATB/STATA can source 3mA to power additional
circuitry.
No Connection. Not internally connected.
Low Power Mode Input for both comparators. Drive LP high for low-power mode.
Drive LP low for high-speed mode (STO_ = GND) or for high-speed mode with autostandby. Connect to GND if low-power mode will not be used. Connect to VCC if
high-speed mode will not be used.
______________________________________________________________________________________
Single/Dual, +3V/+5V Dual-Speed
Comparators with Auto-Standby
MAX975/MAX977
Table 1. Programming
INPUTS
STAT
OUTPUT
MODE
LP
STO_
IDLE TIME
L
tASB = CSTO x 10µs/pF
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