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Analog Devices Inc./Maxim Integrated MAX9021AUK-T
- Part No.:
- MAX9021AUK-T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Comparators
- Package:
- SC-74A, SOT-753
- Datasheet:
-
MAX9021AUK-T.pdf
- Description:
- IC COMPARATOR 1 GEN PUR SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:1,498
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Product details
Overview
The MAX9021AUK-T from Analog Devices is a single, micropower, rail-to-rail output comparator optimized for battery-powered portable systems. It operates from 2.5V to 5.5V single supply, consumes only 2.8μA supply current, features 3μs propagation delay and 4mV internal hysteresis, and is housed in a 5-pin SOT23-5 package rated for -40°C to +125°C.
For engineers reviewing the MAX9021AUK-T datasheet, MAX9021AUK-T pinout, MAX9021AUK-T application, or MAX9021AUK-T equivalent, this device is selected for ultra-low-power threshold detection where supply headroom is limited, input common-mode range extends to VSS, and noise immunity against slow-moving signals is required.
Technical Context
The MAX9021AUK-T implements a CMOS input stage with rail-to-rail output swing and built-in 4mV hysteresis to prevent oscillation on noisy or slowly varying inputs. Its input common-mode range spans from VSS to VDD − 1.1V, enabling direct interfacing with sensors operating near ground.
It delivers stable switching performance across its full −40°C to +125°C temperature range with no phase reversal under overdriven inputs, and its output stage minimizes supply-current transients during transitions-reducing power-supply glitches in sensitive analog subsystems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage Range | 2.5V to 5.5V single supply - supports Li-ion, Li-Po, and 3.3V/5V system rails without level-shifting. |
| Supply Current per Comparator | 2.8μA typical - enables multi-year operation on coin-cell batteries in always-on sensor nodes. |
| Propagation Delay | 3μs at VOD = 100mV - balances speed and power for low-frequency event detection (e.g., wake-up triggers). |
| Hysteresis | 4mV internal - eliminates false triggering from EMI or thermal noise without external components. |
| Input Offset Voltage | ±1mV typical - ensures accurate threshold setting in precision voltage monitoring applications. |
| Output Swing | Rail-to-rail - drives logic inputs directly (e.g., MCU GPIO) without pull-ups or level translators. |
| Common-Mode Input Range | VSS to VDD − 1.1V - accepts ground-referenced sensor outputs (e.g., thermistors, photodiodes) without biasing. |
Pinout & Package
The MAX9021AUK-T is packaged in a RoHS-compliant 5-pin SOT23-5 (U5+1) package with 0.95mm pitch, footprint-compatible with industry-standard SOT23 layouts and suitable for high-density PCB designs.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | IN− | Inverting input - connects to reference voltage or signal source requiring negative feedback path. |
| 2 | IN+ | Noninverting input - accepts sensor output, battery voltage divider, or threshold-setting node. |
| 3 | OUT | Push-pull rail-to-rail output - directly interfaces with digital logic or drives small capacitive loads ≤150pF. |
| 4 | VSS | Negative supply / ground - must be connected to system GND; serves as return path for input and output currents. |
| 5 | VDD | Positive supply - requires local 0.1μF ceramic bypass capacitor to minimize supply impedance and suppress switching transients. |
Key Features
| Feature | Design Value |
|---|---|
| No phase reversal on overdrive | Guaranteed correct output polarity even when inputs exceed common-mode range - simplifies fault-tolerant design. |
| Ultra-low quiescent current | 2.8μA per comparator - reduces standby power in battery-backed systems by >90% vs. standard comparators. |
| Internal 4mV hysteresis | Eliminates need for external positive-feedback resistors - saves board space and component count in compact designs. |
| Rail-to-rail output | Swings within 2mV of VSS and VDD at 10μA load - ensures reliable logic-level compatibility across voltage domains. |
| Wide temperature range | Specified from −40°C to +125°C - qualified for automotive cabin, industrial control, and outdoor IoT deployments. |
Applications
| Battery Voltage Monitor | Sensor Threshold Detector |
|---|---|
Use Scenario: Monitoring Li-ion cell voltage to trigger low-battery warning or shutdown before deep discharge. IC Role / Device Role / Timing Role: Single comparator comparing divided battery voltage against a stable reference (e.g., internal bandgap or external resistor divider). Use Value: 2.8μA supply current extends battery life in maintenance-free remote sensors; 4mV hysteresis prevents chatter near cutoff thresholds. | Use Scenario: Detecting motion via PIR sensor output crossing a preset threshold in smart lighting controls. IC Role / Device Role / Timing Role: Threshold discriminator converting analog sensor envelope into clean digital enable signal for MCU wake-up. Use Value: Input common-mode range down to VSS allows direct connection to PIR amplifier output; rail-to-rail output drives MCU interrupt pin without pull-up. |
| Photodiode Preamp Comparator | Keyless Entry RF Signal Detector |
Use Scenario: Converting weak, slow-rising photodiode current into TTL-level pulses for optical encoder or ambient light sensing. IC Role / Device Role / Timing Role: Low-noise, low-input-bias comparator amplifying and digitizing photocurrent after transimpedance stage. Use Value: 3nA max input bias current preserves signal integrity from high-impedance photodiode sources; 4mV hysteresis rejects ambient light ripple. | Use Scenario: Detecting valid RF carrier presence in 315MHz/433MHz key fob receivers to initiate decryption and door unlock sequence. IC Role / Device Role / Timing Role: Envelope detector comparator identifying amplitude-modulated carrier bursts above noise floor. Use Value: 3μs propagation delay enables reliable detection of short-duration RF packets; 2.5V minimum supply supports direct connection to low-voltage LDO rails. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar comparator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TLV3691IDBVR | Lower supply current (350nA), but slower propagation delay (12μs); no internal hysteresis. | Better for nanowatt sleep modes, unsuitable for fast edge detection or noisy environments without external hysteresis. | Select TLV3691IDBVR only when sub-μA quiescent current dominates timing/noise requirements. |
| MAX9060AXK+T | Same 2.8μA supply current and 4mV hysteresis, but wider supply range (1.4V to 5.5V) and lower offset (±0.5mV). | Enables operation from single alkaline cells (1.5V) and improves accuracy in precision thresholding. | Choose MAX9060AXK+T when extending supply range below 2.5V or tightening offset tolerance is critical. |
Compared with TLV3691IDBVR and MAX9060AXK+T, the MAX9021AUK-T offers the optimal balance of ultra-low power, deterministic 3μs response, and integrated noise immunity-making it preferred for cost-sensitive, space-constrained portable systems requiring robust threshold detection without design overhead.
Availability
The MAX9021AUK-T is available at Aetrix Electronics and suitable for battery-powered portable systems, sensor-signal detection circuits, and photodiode preamplifier stages requiring stable component supply across automotive, industrial, and consumer IoT programs.
Supply support for MAX9021AUK-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 MAX9021AUK-T belongs to the MAX90xx micropower comparator family, designed specifically for energy-constrained applications demanding precision threshold detection with minimal board area and zero external hysteresis components.
FAQ
What is the maximum capacitive load the MAX9021AUK-T output can drive without oscillation?
The MAX9021AUK-T output is stable with capacitive loads up to 150pF, as verified in the datasheet's "Maximum Capacitive Load" specification. Driving larger loads may cause ringing or sustained oscillation due to increased output-stage phase shift; for loads exceeding 150pF, add a series resistor (e.g., 10–50Ω) close to the output pin to isolate capacitance and preserve stability. This limit applies across the full −40°C to +125°C temperature range and 2.5V–5.5V supply conditions.
Does the MAX9021AUK-T require external hysteresis for reliable operation with noisy sensor inputs?
No-the MAX9021AUK-T integrates 4mV of internal hysteresis, which provides sufficient noise margin for most slow-moving or low-bandwidth sensor signals (e.g., thermistors, potentiometers, PIR envelopes). External hysteresis is only needed when system-level noise exceeds ±2mV around the trip point or when precise, user-adjustable hysteresis width is required. The internal hysteresis eliminates the need for external feedback resistors in standard threshold-detection configurations.
Can the MAX9021AUK-T operate from a 1.8V supply?
No-the MAX9021AUK-T has a guaranteed operating supply range of 2.5V to 5.5V for single-supply use. Operation below 2.5V is not characterized or supported; parameters such as propagation delay, input offset, and output swing are not specified at 1.8V. For 1.8V systems, consider the MAX9060AXK+T (1.4V–5.5V range) or TLV3691IDBVR (1.4V–5.5V), both of which maintain micropower operation while supporting lower rails.
What is the input bias current specification for the MAX9021AUK-T, and why does it matter in high-impedance circuits?
The MAX9021AUK-T specifies input bias current of 3nA typical (max 80nA) over temperature. This ultra-low value minimizes voltage error across high-value source impedances-for example, a 1MΩ sensor resistor introduces only 3μV offset error. In photodiode preamp or precision voltage-divider applications, keeping bias current below 10nA avoids signal degradation and ensures accurate threshold detection without active compensation or guard traces.
Is the MAX9021AUK-T pin-compatible with other comparators in the MAX90xx family?
No-the MAX9021AUK-T (5-pin SOT23-5) is not pin-compatible with dual or quad variants like the MAX9022 or MAX9024, which use 8-pin and 14-pin packages respectively. Within the MAX9021 series, the SC70-5 (MAX9021AXK+T) shares identical pinout but differs in package dimensions and thermal characteristics. Always verify land pattern and solder reflow profile when substituting between U5+1 and X5+1 variants.
MAX9021AUK-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Package/Case:
- SC-74A, SOT-753
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- 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
- :
- SOT-23-5
MAX9021AUK-T FAQ
1.How can I place an order for MAX9021AUK-T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX9021AUK-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 MAX9021AUK-T reliable?
The price and inventory of MAX9021AUK-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX9021AUK-T is usually 5 days.
3.What payment methods are accepted for MAX9021AUK-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX9021AUK-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX9021AUK-T?
MAX9021AUK-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX9021AUK-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 MAX9021AUK-T?
For technical support, including MAX9021AUK-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX9021AUK-T requirements.
6.How does Aetrix verify that MAX9021AUK-T is sourced from the original manufacturer or authorized distributors?
All MAX9021AUK-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 MAX9021AUK-T meets industry standards.
7.What is the process for return or replacement of MAX9021AUK-T?
All MAX9021AUK-T units undergo pre-shipment inspection (PSI). If there is an issue with MAX9021AUK-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 MAX9021AUK-T part is unused and in its original packaging.
Return procedure for MAX9021AUK-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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