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Analog Devices Inc./Maxim Integrated MAX9021AXK
- Part No.:
- MAX9021AXK
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Comparators
- Package:
- 5-TSSOP, SC-70-5, SOT-353
- Datasheet:
-
MAX9021AXK.pdf
- Description:
- IC COMPARATOR 1 GEN PUR SC70-5
- Quantity:
- Payment:
- Shipping:
Inventory:1,541
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Product details
Overview
MAX9021AXK from Maxim Integrated is a micropower single-supply comparator optimized for ultra-low power and portable applications. It delivers 3µs propagation delay, 2.8µA supply current per comparator, and 4mV internal hysteresis across -40°C to +125°C, operating from 2.5V to 5.5V. Its rail-to-rail output swing and input common-mode range extending to VDD − 1.1V make it suitable for photodiode preamps and battery-powered threshold detection.
For engineers reviewing the MAX9021AXK datasheet, MAX9021AXK pinout, MAX9021AXK application, or MAX9021AXK equivalent, key selection considerations include its SC70-5 package footprint, guaranteed hysteresis for noise immunity, single-supply operation down to 2.5V, and absence of phase reversal under overdriven inputs.
Technical Context
The MAX9021AXK implements a CMOS input stage with rail-to-rail output buffering and built-in 4mV hysteresis to suppress oscillation on slow-moving signals. Its input bias current is as low as 3nA (typ), enabling high-impedance sensor interfacing without significant loading error.
Propagation delay remains stable at 3µs (typ) across supply voltages from 2.5V to 5.5V and temperatures from -40°C to +125°C, with no degradation due to supply ripple thanks to 60dB PSRR (min). The output stage minimizes switching current transients, eliminating power-supply glitches during transitions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Current | 2.8µA (typ) - enables >10-year battery life in coin-cell–powered IoT sensors |
| Propagation Delay | 3µs (typ, RL = 10kΩ, CL = 15pF) - supports reliable signal edge detection up to ~100kHz |
| Hysteresis | 4mV (fixed, internal) - provides noise immunity without external feedback components |
| Input Common-Mode Range | VSS to VDD − 1.1V - allows direct interface with 0–3.3V sensor outputs using 3.3V supply |
| Output Swing | Rail-to-rail (VOL ≤ 400mV at ISINK = 4mA; VOH ≥ VDD − 400mV at ISOURCE = 4mA) - ensures full logic-level compatibility with 1.8V/3.3V MCUs |
| Operating Temperature | -40°C to +125°C - qualified for automotive cabin and industrial control environments |
| Supply Voltage Range | 2.5V to 5.5V (single supply) - supports Li-ion, Li-Po, and dual-AA battery systems without regulation |
Pinout & Package
The MAX9021AXK is housed in a 5-pin SC70 package (package code X5-1), measuring 2.0mm × 1.25mm × 0.9mm - half the footprint of standard SOT23-5 - with wettable flanks for automated optical inspection.
| Pin | Circuit Role | Design Meaning |
|---|---|---|
| 1 | VSS | Negative supply terminal; must be connected to system ground or negative rail; reference for all input/output voltage levels |
| 2 | OUT | Open-drain compatible rail-to-rail output; sinks up to 50mA short-circuit current; requires pull-up for logic-high assertion |
| 3 | IN− | Inverting input; accepts DC or slowly varying signals within VSS to VDD − 1.1V; 3nA max input bias current minimizes source impedance error |
| 4 | IN+ | Noninverting input; identical electrical characteristics to IN−; differential input voltage limited to ±6.6V |
| 5 | VDD | Positive supply terminal; bypass with 0.1µF ceramic capacitor directly to VSS to suppress supply noise coupling into comparator core |
Key Features
| Feature | Design Value |
|---|---|
| No phase reversal on overdriven inputs | Prevents erroneous output latching when input exceeds common-mode range - critical for unconditioned sensor inputs |
| Ultra-low quiescent current | 2.8µA per comparator enables multi-year operation from CR2032 batteries in wireless sensor nodes |
| Internal 4mV hysteresis | Eliminates need for external positive feedback resistors - reduces BOM count and PCB area in space-constrained designs |
| Rail-to-rail output swing | Ensures full logic-level compatibility with 1.8V, 2.5V, and 3.3V microcontrollers without level-shifting circuitry |
| SC70-5 package | 2.0mm × 1.25mm footprint saves >50% board area vs. SOT23-5 - ideal for wearables and miniaturized medical devices |
Applications
| Photodiode Preamp Threshold Detection | Battery-Voltage Monitoring |
|---|---|
|
Use Scenario: Detecting weak photocurrent pulses from ambient-light or pulse-oximetry sensors. IC Role / Device Role / Timing Role: Comparator front-end converting analog photocurrent into clean digital edges for MCU wake-up or counting. Use Value: 3nA input bias current avoids signal attenuation; 4mV hysteresis rejects EMI-induced false triggers in noisy medical environments. |
Use Scenario: Monitoring Li-ion cell voltage to trigger low-battery alerts or shutdown before deep discharge. IC Role / Device Role / Timing Role: Precision threshold detector comparing battery voltage against stable reference (e.g., internal bandgap or resistor divider). Use Value: 2.8µA supply current extends system standby time; -40°C to +125°C rating supports automotive under-hood deployment. |
| Keyless Entry RF Signal Discrimination | Digital Line Receiver for Legacy Industrial Bus |
|
Use Scenario: Extracting valid 315MHz/433MHz ASK/OOK data bursts from antenna frontend in car key fobs. IC Role / Device Role / Timing Role: High-SNR comparator recovering digital envelope after RF envelope detection. Use Value: 3µs propagation delay preserves timing integrity of short-pulse protocols; rail-to-rail output drives CMOS logic directly. |
Use Scenario: Converting legacy RS-422/RS-485 differential bus signals to single-ended logic levels for microcontroller GPIO. IC Role / Device Role / Timing Role: Single-ended receiver stage following line driver and termination network. Use Value: Input common-mode range to VDD − 1.1V accommodates wide common-mode offsets; no phase reversal prevents lockup during bus contention. |
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), but slower propagation delay (12µs); no internal hysteresis; SC70-5 package | Better for ultra-long-life applications where speed is secondary; requires external hysteresis resistors | Choose TLV3691IDCKR only if sub-1µA quiescent current is mandatory and response time >10µs is acceptable. |
| MAX9060AXK+T | Higher speed (1.5µs), same 2.8µA supply current, 2mV hysteresis, SC70-5; operates down to 1.6V | Supports lower-voltage battery systems (e.g., single Alkaline); tighter hysteresis improves resolution in precision thresholding | Choose MAX9060AXK+T when faster response or 1.6V–5.5V supply flexibility outweighs need for 4mV hysteresis margin. |
Compared with TLV3691IDCKR and MAX9060AXK+T, the MAX9021AXK uniquely balances 3µs speed, 4mV factory-trimmed hysteresis, and 2.5V minimum supply - making it optimal for cost-sensitive, space-constrained 3.3V sensor interfaces requiring robust noise immunity without design overhead.
Availability
MAX9021AXK is available at Aetrix Electronics and suitable for battery-powered portable systems, mobile communications modules, and sensor-signal detection circuits requiring stable component supply across automotive and industrial temperature ranges.
Supply support for MAX9021AXK 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
Maxim Integrated (now part of Analog Devices) is a U.S.-based semiconductor company specializing in precision analog, mixed-signal, and power-management ICs for industrial, automotive, and communications markets.
The MAX9021AXK belongs to Maxim's micropower comparator family, engineered specifically for ultra-low-power, space-constrained sensing and battery-monitoring applications where reliability across extended temperature ranges is essential.
FAQ
What is the maximum capacitive load the MAX9021AXK output can drive without oscillation?
The MAX9021AXK is specified to drive up to 150pF without sustained oscillations, as confirmed in the Absolute Maximum Ratings and Typical Operating Characteristics. Driving loads beyond this value may increase propagation delay and risk instability; for heavier loads, use a buffer stage or reduce trace capacitance via layout optimization.
Does the MAX9021AXK require external hysteresis for reliable operation with noisy sensor inputs?
No - the MAX9021AXK integrates 4mV of factory-trimmed hysteresis, explicitly designed to prevent chatter on slow-moving or noisy inputs. This eliminates the need for external positive-feedback resistors in most threshold-detection applications, simplifying design and reducing component count.
Can the MAX9021AXK operate from a 1.8V supply?
No - the MAX9021AXK has a minimum specified supply voltage of 2.5V. Operation below 2.5V is not guaranteed and may result in degraded performance or failure to switch. For 1.8V systems, consider the pin-compatible MAX9060AXK+T, which supports 1.6V to 5.5V operation.
Is the MAX9021AXK output open-drain or push-pull?
The MAX9021AXK features a rail-to-rail CMOS output stage that functions as an active push-pull driver - it actively sources and sinks current without requiring an external pull-up. However, it can interface with open-drain buses by adding an external pull-up resistor if level translation or wired-OR functionality is needed.
How does the MAX9021AXK handle input overvoltage conditions beyond its common-mode range?
The MAX9021AXK guarantees no phase reversal when inputs exceed the common-mode range (VSS to VDD − 1.1V), a key reliability feature. Inputs may safely swing to VSS − 0.3V or VDD + 0.3V per Absolute Maximum Ratings, but sustained operation outside the specified common-mode range may increase offset drift or delay variation - the MAX9021AXK remains functional and predictable.
MAX9021AXK Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Package/Case:
- 5-TSSOP, SC-70-5, SOT-353
- Series:
- MAX9021
- Packaging:
- Bulk
- Product Status:
- Active
- Type:
- General Purpose
- Number of Elements:
- 1
- Output Type:
- Push-Pull
- Voltage - Supply, Single/Dual (±):
- 2.5V ~ 5.5V
- :
- 8mV @ 5V
- Voltage - Input Offset (Max):
- 0.08µA @ 5V
- Current - Input Bias (Max):
- 50mA @ 5V
- Current - Output (Typ):
- 5µA
- Current - Quiescent (Max):
- 100dB, 80dB PSRR
- CMRR, PSRR (Typ):
- 8µs (Typ)
- Propagation Delay (Max):
- 4mV
- Hysteresis:
- -40°C ~ 125°C
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- Surface Mount
- :
- SC-70-5
MAX9021AXK FAQ
1.How can I place an order for MAX9021AXK through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX9021AXK 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 reliable?
The price and inventory of MAX9021AXK are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX9021AXK is usually 5 days.
3.What payment methods are accepted for MAX9021AXK?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX9021AXK transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX9021AXK?
MAX9021AXK orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX9021AXK 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?
For technical support, including MAX9021AXK datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX9021AXK requirements.
6.How does Aetrix verify that MAX9021AXK is sourced from the original manufacturer or authorized distributors?
All MAX9021AXK 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 meets industry standards.
7.What is the process for return or replacement of MAX9021AXK?
All MAX9021AXK units undergo pre-shipment inspection (PSI). If there is an issue with MAX9021AXK, 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 part is unused and in its original packaging.
Return procedure for MAX9021AXK:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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