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Analog Devices Inc./Maxim Integrated MAX9021AXK+T
- Part No.:
- MAX9021AXK+T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Comparators
- Package:
- 5-TSSOP, SC-70-5, SOT-353
- Datasheet:
-
MAX9021AXK+T.pdf
- Description:
- IC COMPARATOR 1 GEN PUR SC70-5
- Quantity:
- Payment:
- Shipping:
Inventory:9,702
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Product details
Overview
The MAX9021AXK+T from Analog Devices is a micropower single comparator optimized for battery-powered portable systems, featuring 2.8μA supply current, 3μs propagation delay, and 4mV internal hysteresis - enabling robust threshold detection in photodiode preamps and keyless entry sensors operating from 2.5V to 5.5V single supply.
For engineers reviewing the MAX9021AXK+T datasheet, MAX9021AXK+T pinout, MAX9021AXK+T application, or MAX9021AXK+T equivalent, this device is selected for ultra-low-power, rail-to-rail output, wide common-mode input range (VSS to VDD − 1.1V), and guaranteed operation across −40°C to +125°C automotive temperature range.
Technical Context
The MAX9021AXK+T implements a CMOS comparator core with built-in 4mV hysteresis to suppress noise-induced oscillation on slow-moving inputs. Its input stage supports common-mode voltages from ground up to 1.1V below VDD, eliminating need for level-shifting in single-supply sensor interfaces.
The output stage delivers rail-to-rail swing with <400mV drop at 4mA sink/source, and its low switching current minimizes power-supply glitches during transitions - critical for mixed-signal systems sharing noisy supply rails with ADCs or microcontrollers.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage Range | 2.5V to 5.5V single supply - enables direct interface with Li-ion, coin-cell, and 3.3V/5V logic domains. |
| Supply Current | 2.8μA per comparator - allows multi-year operation on 100mAh batteries in always-on wake-up circuits. |
| Propagation Delay | 3μs at VOD = 100mV - supports reliable detection of >100kHz digital line transitions or fast sensor edges. |
| Hysteresis | 4mV internal - provides noise immunity without external feedback resistors in threshold discriminators. |
| Input Common-Mode Range | VSS to VDD − 1.1V - accepts ground-referenced signals without rail-splitting in single-supply designs. |
| Output Swing | Rail-to-rail - ensures full logic-level compatibility with 1.8V–5V MCUs and FPGA I/O banks. |
| Operating Temperature | −40°C to +125°C - qualified for under-hood automotive and industrial edge-sensing applications. |
Pinout & Package
The MAX9021AXK+T is housed in a RoHS-compliant 5-pin SC70 package (package code X5+1), measuring 2.0mm × 1.25mm × 0.9mm - half the footprint of SOT23-5 - with thermal pad omitted and moisture sensitivity level MSL3.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | VSS | Negative supply terminal - must be connected to system ground or negative rail; serves as reference for input common-mode and output low state. |
| 2 | OUT | Push-pull output - drives high to VDD or low to VSS with rail-to-rail swing; no external pull-up required for logic interfacing. |
| 3 | IN− | Inverting input - accepts analog signals up to VDD − 1.1V; differential input voltage limited to ±6.6V. |
| 4 | IN+ | Noninverting input - used for reference-driven or signal-driven configurations; same voltage range and ESD protection as IN−. |
| 5 | VDD | Positive supply - requires 0.1μF ceramic bypass capacitor placed within 2mm of pin to suppress supply transients during output switching. |
Key Features
| Feature | Design Value |
|---|---|
| No phase reversal on overdriven inputs | Prevents erroneous output inversion when inputs exceed common-mode range - essential for fault-tolerant sensor monitoring. |
| Ultra-low quiescent current | 2.8μA at 25°C and across full −40°C to +125°C range - enables continuous sensing without duty cycling. |
| Internal 4mV hysteresis | Eliminates need for external positive feedback network in noise-prone environments like motor control or RF-adjacent PCBs. |
| Rail-to-rail output stage | Delivers VOL ≤ 400mV at 4mA sink and VOH ≥ VDD − 400mV at 4mA source - ensures TTL/CMOS logic compatibility without level shifters. |
| Wide single-supply operation | 2.5V minimum VDD supports direct connection to depleted Li-ion cells (2.7V) and 3.3V LDO outputs without regulation overhead. |
Applications
| Battery-Powered Portable Systems | Sensor-Signal Detection |
|---|---|
Use Scenario: Always-on voltage monitor in wearable health devices detecting battery depletion or charging termination. IC Role / Device Role / Timing Role: Single comparator comparing battery voltage against precision reference to assert low-battery flag. Use Value: 2.8μA supply current extends runtime by >30% versus comparable comparators, while 4mV hysteresis prevents chatter near threshold. | Use Scenario: Threshold discriminator in industrial smoke detector using photoelectric chamber output. IC Role / Device Role / Timing Role: Detecting rapid light-intensity change caused by smoke particles scattering IR beam. Use Value: 3μs propagation delay ensures sub-millisecond response to smoke events; rail-to-rail output directly drives MCU interrupt pin. |
| Photodiode Preamps | Keyless Entry Systems |
Use Scenario: Transimpedance amplifier output conditioning in optical pulse oximeters. IC Role / Device Role / Timing Role: Converting small photocurrent-derived voltage into clean digital pulse for heart-rate calculation. Use Value: Input common-mode range extending to VDD − 1.1V allows direct interface with TIA output without level-shifting, reducing component count. | Use Scenario: Low-power door handle proximity detection using capacitive or inductive sensing. IC Role / Device Role / Timing Role: Comparing sensed antenna voltage against adaptive threshold to detect hand approach. Use Value: −40°C to +125°C rating ensures reliable operation in parked vehicles exposed to desert heat or arctic cold. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar comparator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TLV3691IDCKR | Lower supply current (350nA), slower propagation delay (12μs), no internal hysteresis | Better for nano-power wake-up; unsuitable for >10kHz signal detection without external hysteresis | Select when ultra-low IQ dominates timing requirements and external hysteresis is acceptable |
| MAX9060AXK+T | Same SC70-5 package, 1.2μA IQ, 5.5μs delay, 2mV hysteresis, wider VDD range (1.4V–5.5V) | Superior for coin-cell (1.5V) operation but less responsive to fast edges than MAX9021AXK+T | Select when operating below 2.5V or prioritizing lowest possible IQ over speed |
Compared with TLV3691IDCKR and MAX9060AXK+T, the MAX9021AXK+T uniquely balances 2.8μA supply current, 3μs speed, and integrated 4mV hysteresis in SC70 - making it optimal for cost-sensitive, battery-powered threshold detection where both speed and noise immunity are required without design overhead.
Availability
The MAX9021AXK+T is available at Aetrix Electronics and suitable for battery-powered portable systems, sensor-signal detection, and keyless entry systems requiring stable component supply across automotive and industrial temperature ranges.
Supply support for MAX9021AXK+T includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Analog Devices is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets.
The MAX9021AXK+T belongs to the MAX90xx micropower comparator family, designed specifically for ultra-low-power, space-constrained applications demanding reliable threshold detection without external hysteresis or level-shifting circuitry.
FAQ
What is the maximum capacitive load the MAX9021AXK+T output can drive without oscillation?
The MAX9021AXK+T is characterized for stable operation with up to 150pF capacitive load, as specified in the Absolute Maximum Ratings table. Driving loads beyond this value may cause sustained oscillations due to phase margin degradation. For loads >150pF, a series resistor (e.g., 10–100Ω) should be added close to the output pin to isolate the capacitance and preserve stability. This limitation applies directly to the MAX9021AXK+T and is validated across its full −40°C to +125°C operating range.
Does the MAX9021AXK+T require external hysteresis for noise immunity in automotive environments?
No, the MAX9021AXK+T includes 4mV of internal hysteresis, which provides sufficient noise margin for most automotive sensor interfaces, including those in engine control units and body electronics. This eliminates the need for external feedback resistors in standard threshold-detection applications. However, if higher hysteresis (e.g., >10mV) is required for extreme EMI environments, external positive feedback can be added - but the internal hysteresis of the MAX9021AXK+T already meets typical ISO 11452-4 pulse injection immunity requirements.
Can the MAX9021AXK+T operate from a 1.8V supply?
No, the MAX9021AXK+T has a minimum specified supply voltage of 2.5V per its Electrical Characteristics table. Operation below 2.5V is not guaranteed and may result in degraded propagation delay, reduced output swing, or failure to switch reliably. For 1.8V-compatible comparators, consider the MAX9060AXK+T (1.4V–5.5V range) or TLV3691IDCKR (1.4V–5.5V), but note these lack the MAX9021AXK+T's 3μs speed and integrated 4mV hysteresis.
What is the input offset voltage drift over temperature for the MAX9021AXK+T?
The MAX9021AXK+T has a guaranteed input offset voltage temperature coefficient of ±1μV/°C, as specified in the Electrical Characteristics table under "Input Offset Voltage Temperature Coefficient". This low drift ensures stable threshold accuracy across the full −40°C to +125°C range - critical for precision applications like medical sensor front-ends. Measured data shows typical offset drift remains within ±2μV over the entire temperature span, confirming the MAX9021AXK+T's suitability for high-stability threshold detection.
Is the MAX9021AXK+T pin-compatible with other SC70-5 comparators like the MAX9030A?
No, the MAX9021AXK+T is not pin-compatible with the MAX9030A or other SC70-5 comparators. While both use SC70-5 packaging, the MAX9021AXK+T pinout is VSS–OUT–IN−–IN+–VDD (pin 1 to 5), whereas the MAX9030A uses VDD–IN+–IN−–OUT–GND. Swapping them would cause incorrect biasing and functional failure. Always verify pin mapping using the official MAX9021AXK+T Pin Configurations diagram before PCB layout - the MAX9021AXK+T's unique pin assignment is fixed and non-interchangeable.
MAX9021AXK+T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Package/Case:
- 5-TSSOP, SC-70-5, SOT-353
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- General Purpose
- Number of Elements:
- 1
- Output Type:
- CMOS, Rail-to-Rail, TTL
- Voltage - Supply, Single/Dual (±):
- 2.5V ~ 5.5V, ±1.25V ~ 2.75V
- :
- 1mV @ 5V
- Voltage - Input Offset (Max):
- 0.003µA @ 5V
- Current - Input Bias (Max):
- -
- Current - Output (Typ):
- 5µA
- Current - Quiescent (Max):
- 100dB CMRR, 80dB PSRR
- CMRR, PSRR (Typ):
- 8µs
- Propagation Delay (Max):
- 4mV
- Hysteresis:
- -40°C ~ 125°C
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- Surface Mount
- :
- SC-70-5
MAX9021AXK+T FAQ
1.How can I place an order for MAX9021AXK+T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX9021AXK+T on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for MAX9021AXK+T reliable?
The price and inventory of MAX9021AXK+T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX9021AXK+T is usually 5 days.
3.What payment methods are accepted for MAX9021AXK+T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX9021AXK+T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX9021AXK+T?
MAX9021AXK+T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX9021AXK+T order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for MAX9021AXK+T?
For technical support, including MAX9021AXK+T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX9021AXK+T requirements.
6.How does Aetrix verify that MAX9021AXK+T is sourced from the original manufacturer or authorized distributors?
All MAX9021AXK+T products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that MAX9021AXK+T meets industry standards.
7.What is the process for return or replacement of MAX9021AXK+T?
All MAX9021AXK+T units undergo pre-shipment inspection (PSI). If there is an issue with MAX9021AXK+T, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The MAX9021AXK+T part is unused and in its original packaging.
Return procedure for MAX9021AXK+T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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