The MAX921–MAX924 single, dual, and quad micropower, low-voltage comparators feature the lowest
power consumption available. These comparators draw
less than 4µA supply current over temperature
(MAX921/MAX922), and include an internal 1.182V
±1% voltage reference, programmable hysteresis, and
TTL/CMOS outputs that sink and source current.
Ideal for 3V or 5V single-supply applications, the
MAX921–MAX924 operate from a single +2.5V to +11V
supply (or a ±1.25V to ±5V dual supply), and each
comparator’s input voltage range swings from the
negative supply rail to within 1.3V of the positive
supply.
The MAX921–MAX924’s unique output stage continuously sources as much as 40mA. And by eliminating
power-supply glitches that commonly occur when comparators change logic states, the MAX921–MAX924
minimize parasitic feedback, which makes them easier to
use.
The single MAX921 and dual MAX923 provide a unique
and simple method for adding hysteresis without
feedback and complicated equations, simply by using
the HYST pin and two resistors.
PART
INTERNAL 1%
PRECISION
REFERENCE
COMPARATORS
PER
PACKAGE
INTERNAL
HYSTERESIS
MAX921Yes1Yes
MAX922No2No
MAX923Yes2Yes
MAX924Yes4No
PACKAGE
8-Pin
DIP/SO/µMAX
8-Pin
DIP/SO/µMAX
8-Pin
DIP/SO/µMAX
16-Pin
DIP/SO/µMAX
________________________Applications
Battery-Powered Systems
Threshold Detectors
Window Comparators
Oscillator Circuits
____________________________Features
♦ µMAX Package—Smallest 8-Pin SO
(MAX921/MAX922/MAX923)
♦ Ultra-Low 4µA Max Quiescent Current
Over Extended Temp. Range (MAX921)
♦ Power Supplies:
Single +2.5V to +11V
Dual ±1.25V to ±5.5V
♦ Input Voltage Range Includes Negative Supply
♦ Internal 1.182V ±1% Bandgap Reference
♦ Adjustable Hysteresis
♦ TTL/CMOS-Compatible Outputs
♦ 12µs Propagation Delay (10mV Overdrive)
♦ No Switching Crowbar Current
♦ 40mA Continuous Source Current
______________Ordering Information
PARTTEMP. RANGEPIN-PACKAGE
MAX921CPA
MAX921CSA0°C to +70°C8 SO
MAX921CUA0°C to +70°C8 µMAX
MAX921C/D0°C to +70°CDice*
MAX921EPA-40°C to +85°C8 Plastic DIP
MAX921ESA-40°C to +85°C8 SO
MAX921MJA-55°C to +125°C8 CERDIP**
Ordering Information continued at end of data sheet.
* Dice are tested at T
** Contact factory for availability and processing to MIL-STD-883.
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
MAX921–MAX924
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS: 5V OPERATION
(V+ = 5V, V- = GND = 0V, TA= T
PARAMETER
POWER REQUIREMENTS
Supply Voltage Range
Supply CurrentIN+ = IN- + 100mV
COMPARATOR
Input Offset Voltage
Input Leakage Current (HYST)
Input Common-Mode Voltage Range
Common-Mode Rejection Ratio
Power-Supply Rejection Ratio
Voltage Noise
Hysteresis Input Voltage RangeREF- 0.05VREFV
to T
MIN
, unless otherwise noted.)
MAX
(Note 1)
VCM= 2.5V
IN+ = IN- = 2.5V
MAX921, MAX923
V- to (V+ – 1.3V)
V+ = 2.5V to 11V
100Hz to 100kHz
MAX921, MAX923
MAX92_C_ _ .......................................................0°C to +70°C
MAX92_E_ _.....................................................-40°C to +85°C
MAX92_MJ_ ..................................................-55°C to +125°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10sec).............................+300°C
MIN TYP MAXUNITS
2.511V
MAX921,
HYST = REF
MAX922
MAX923,
HYST = REF
MAX924
TA= +25°C
C/E temp. ranges
M temp. range
TA= +25°C
C/E temp. ranges
M temp. range
TA= +25°C
C/E temp. ranges
M temp. range
TA= +25°C
C/E temp. ranges
M temp. range
C temp. range
E temp. range
M temp. range
TA= +25°C
M temp. range4
TA= +25°C
C/E temp. ranges4
M temp. range
section for more details.
ELECTRICAL CHARACTERISTICS: 3V OPERATION
(V+ = 3V, V- = GND = 0V, TA= T
PARAMETER
POWER REQUIREMENTS
Supply Current
COMPARATOR
Input Offset Voltage
Input Leakage Current (HYST)
MIN
to T
, unless otherwise noted.)
MAX
CONDITIONS
HYST = REF,
IN+ = (IN- + 100mV)
VCM= 1.5V
IN+ = IN- = 1.5V
MAX921, MAX923
MAX921
MAX922
MAX923
MAX924
TA= +25°C
C/E temp. ranges
M temp. range
TA= +25°C
C/E temp. ranges
M temp. range
TA= +25°C
C/E temp. ranges
M temp. range
TA= +25°C
C/E temp. ranges
M temp. range
Input Common-Mode Voltage RangeVV-V+ – 1.3
Common-Mode Rejection Ratio0.21mV/V
Power-Supply Rejection Ratio
Voltage Noise
Hysteresis Input Voltage RangeREF- 0.05VREFV
MAX921–MAX924
Output Low Voltage
V- to (V+ – 1.3V)
V+ = 2.5V to 11V
100Hz to 100kHz
MAX921, MAX923
TA= +25°C, 100pF load
MAX92_
MAX922/
MAX923
MAX921/
MAX924
C/E temp. ranges: I
M temp. range: I
C/E temp. ranges: I
M temp. range: I
C/E temp. ranges: I
M temp. range: I
Overdrive = 10mV
Overdrive = 100mV
= 10mA;
OUT
= 6mA
OUT
= 0.8mA;
OUT
= 0.6mA
OUT
= 0.8mA;
OUT
= 0.6mA
OUT
0.11mV/V
20µV
14
5
V+ – 0.4
V- + 0.4
GND + 0.4
REFERENCE
Source Current
C temp. range
E temp. range
M temp. range
TA= +25°C
C/E temp. ranges6