MAX9042A, MAX9042B

Micropower, Single-Supply, UCSP/SOT23 Comparator + Precision Reference ICs

Ideal for Precision Battery Monitoring Applications

Please check latest availability status for a specific part variant.


The MAX9038–MAX9043 and MAX9050–MAX9053 feature combinations of low-power comparators and precision voltage references. Their operating voltage range makes them ideal for both 3V and 5V systems. The MAX9039/MAX9040/MAX9041/MAX9050/MAX9051 have a single comparator and reference consuming only 40µA of supply current. The MAX9042/MAX9043/MAX9052/MAX9053 have dual comparators and one reference, and consume only 55µA of supply current. Low-voltage operation and low supply current make these devices ideal for battery-operated systems.

The comparators feature rail-to-rail inputs and outputs, with a common-mode input voltage range that extends 250mV beyond the supply rails. Input bias current is typically 1.0pA, and input offset voltage is typically 0.5mV. Internal hysteresis ensures clean output switching, even with slow-moving input signals. The output stage features a unique design that limits supply current surges while switching, virtually eliminating supply glitches typical of many other comparators. This design also minimizes overall power consumption under dynamic conditions. The comparator outputs have rail-to- rail, push-pull output stages except the MAX9038 has an open-drain output that sinks and sources up to 8mA. The propagation delay is 400ns, even with the low-operating supply current.

The reference output voltage is set to 1.23V in the MAX9038/MAX9039, to 2.048V in the MAX9040–MAX9043, and to 2.500V in the MAX9050–MAX9053. The MAX9040–MAX9043 and the MAX9050–MAX9053 are offered in two grades: an A grade with 0.4% initial accuracy and 6ppm/°C tempco, and a B grade with 1% initial accuracy (except MAX9038/MAX9039 have an initial accuracy of ±0.4%) and 100ppm/°C tempco. The voltage references feature a proprietary curvature-correction circuit and laser-trimmed thin-film resistors. These series-mode references can sink or source up to 500µA of load current.

MAX9039, MAX9040, MAX9041, MAX9042, MAX9042A, MAX9042B, MAX9043, MAX9043A, MAX9050, MAX9051, MAX9052, MAX9052A, MAX9052B, MAX9053, MAX9053A, MAX9053B: Functional Diagrams MAX9039, MAX9040, MAX9041, MAX9042, MAX9042A, MAX9042B, MAX9043, MAX9043A, MAX9050, MAX9051, MAX9052, MAX9052A, MAX9052B, MAX9053, MAX9053A, MAX9053B: Functional Diagrams Enlarge+

Key Features

  • Comparator + Precision Reference in UCSP/SOT23
  • 2.5V to 5.5V Single-Supply Operation (MAX9038–MAX9043)
  • Low Supply Current (MAX9038/MAX9039/MAX9040/MAX9041/MAX9050/MAX9051)
    • 40µA Quiescent
    • 50µA with 100kHz Switching
    • Open-Drain Output MAX9038
  • 400ns Propagation Delay
  • Rail-to-Rail Inputs
  • Rail-to-Rail Output Stage Sinks and Sources 8mA
  • Internal ±3mV Hysteresis
  • Voltage Reference Offers
    • ±0.4% (max) Initial Accuracy (A Grade)
    • 6ppm/°C (typ) Temperature Coefficient (A Grade)
    • Stable for 0 to 4.7nF Capacitive Loads


  • Digital-Line Receivers
  • IR Receivers
  • Level Translators
  • Precision Battery Management
  • Window Comparators

See parametric specs for Comparators + Reference (48)

Part NumberComparatorsThresh.
Internal Reference Accuracy
Prog. Hyst.VOS
Logic OutOper. Temp.
typminmaxmaxtypmaxSee Notes
MAX9039 11.2310.42.55.5100No19TTL/CMOS-40 to +85
UCSP (B)/6
$0.70 @1k
MAX9040 12.0480.42.5720.57
$1.69 @1k
MAX9041 12.0480.42.572-7
SOIC (N)/8
$1.66 @1k
MAX9042 22.0480.42.5850.57
SOIC (N)/8
$1.99 @1k
MAX9043 22.0480.42.5850.57
$1.84 @1k
$1.52 @1k
SOIC (N)/8
$1.51 @1k
SOIC (N)/8
$1.81 @1k
$1.81 @1k

Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.
Request Reliability Report for: MAX9042A  MAX9042B 
Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C   Material Composition  

Note : The failure rates are summarized by technology and mapped to the associated material part numbers. The failure rates are highly dependent on the number of units tested.

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