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Analog Devices Inc./Maxim Integrated MAX921ESA+T
- Part No.:
- MAX921ESA+T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Comparators
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
MAX921ESA+T.pdf
- Description:
- IC COMPARATOR 1 W/VOLT REF 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,991
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Product details
Overview
The MAX921ESA+T from Maxim Integrated is a single-channel, ultra-low-power comparator with integrated 1.182V ±1% bandgap reference, programmable hysteresis via HYST pin, and TTL/CMOS-compatible output capable of sourcing up to 40mA. It operates from +2.5V to +11V single supply (or ±1.25V to ±5.5V dual supply), features rail-to-rail input range down to V− and within 1.3V of V+, and draws only 4μA max quiescent current over −40°C to +85°C - ideal for battery-powered threshold detection in portable instrumentation.
For engineers reviewing the MAX921ESA+T datasheet, MAX921ESA+T pinout, MAX921ESA+T application, or MAX921ESA+T equivalent, this page delivers verified technical context, exact pin functions, real-world use cases in low-power sensing, and validated alternative options - all grounded in Maxim's official electrical characteristics and typical operating circuits.
Technical Context
The MAX921ESA+T integrates a precision 1.182V reference referenced to V− (not GND), enabling self-contained threshold generation without external components. Its comparator input common-mode range extends from V− to (V+ − 1.3V), supporting operation near supply rails in single- or dual-supply configurations.
The output stage continuously sources up to 40mA while sinking ≥1.2mA, eliminates crowbar current during transitions, and drives directly into capacitive loads up to 100pF with 12μs propagation delay (10mV overdrive). Hysteresis is implemented externally via two resistors between REF and HYST pins - no feedback loop required.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage Range | +2.5V to +11V single supply; ±1.25V to ±5.5V dual supply - supports direct interfacing with 3V/5V logic and bipolar sensor signals. |
| Quiescent Supply Current | 4μA max over −40°C to +85°C - enables multi-year battery life in always-on monitoring systems. |
| Reference Voltage | 1.182V ±1% at V−, stable over temperature - provides accurate, drift-compensated threshold without trimming. |
| Input Common-Mode Range | V− to (V+ − 1.3V) - allows direct sensing of signals near ground or high-side rails without level-shifting. |
| Propagation Delay | 12μs typical (10mV overdrive, 100pF load) - sufficient for slow-varying analog thresholds like battery voltage monitoring. |
| Output Drive Capability | Sources 40mA continuously, sinks ≥1.2mA - drives LEDs, small relays, or logic inputs directly without buffer stages. |
| Input Offset Voltage | ±10mV max - sets minimum detectable signal differential in precision threshold applications. |
Pinout & Package
MAX921ESA+T uses an 8-pin SO (Small Outline) package, industrial temperature grade (−40°C to +85°C), with pin 1 marked by beveled corner or dot.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | GND | Ground reference; connects to V− for single-supply operation; output swings from V+ to GND. |
| 2 | V− | Negative supply rail; tied to GND in single-supply mode; reference output (REF) is referenced to this pin. |
| 3 | IN+ | Noninverting comparator input; accepts signals from V− to (V+ − 1.3V); <5nA leakage ensures high-impedance sensing. |
| 4 | IN− | Inverting comparator input; identical voltage range and leakage as IN+; used for fixed or adjustable threshold comparison. |
| 5 | HYST | Hysteresis control input; voltage range = REF − 0.05V to REF; enables precise hysteresis band setting (up to 100mV) with two resistors. |
| 6 | REF | 1.182V ±1% reference output referenced to V−; sources up to 25μA (25°C), sinks up to 15μA - powers external resistor networks for hysteresis. |
| 7 | V+ | Positive supply rail; supports up to +11V; determines output high level (V+ − 0.4V min under load). |
| 8 | OUT | Push-pull comparator output; sinks and sources current; swings from V+ to GND - TTL/CMOS compatible with +5V supply. |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low quiescent current | 4μA max across −40°C to +85°C - enables >10-year battery life in coin-cell–powered devices. |
| Integrated precision reference | 1.182V ±1% bandgap reference referenced to V− - eliminates need for external voltage reference IC or resistor divider. |
| Programmable hysteresis | Adjustable via HYST pin using two resistors - avoids unstable switching near threshold without requiring op-amp feedback loops. |
| No crowbar current | Eliminates supply glitches during output transitions - prevents parasitic feedback and ensures stability on poorly decoupled PCBs. |
| High-output drive | 40mA continuous source current - directly drives LEDs, optocouplers, or logic gates without external transistors. |
Applications
| Battery Voltage Monitor | Low-Power Threshold Detector |
|---|---|
|
Use Scenario: Monitoring lithium-ion cell voltage to trigger auto-shutdown below 3.0V or wake-up above 3.6V in wearable health sensors. IC Role / Device Role / Timing Role: Single comparator compares divided battery voltage against internal 1.182V reference; HYST pin configures 100mV hysteresis to prevent chatter near cutoff. Use Value: 4μA supply current extends coin-cell lifetime beyond 5 years; direct V+ to GND output swing interfaces cleanly with microcontroller GPIO. |
Use Scenario: Detecting door-open events in smart locks using magnetic reed switch closure across a pull-up resistor. IC Role / Device Role / Timing Role: Comparator senses switch-induced voltage drop at IN−; IN+ tied to REF; HYST pin adds noise immunity against EMI-induced false triggers. Use Value: Rail-to-rail input range accommodates full 0–5V swing; 40mA output drives lock solenoid directly, eliminating discrete driver transistor. |
| Auto-Off Power Switch | Window Detector (with MAX923) |
|
Use Scenario: Enabling timed power-down in handheld test equipment after 90 seconds of inactivity. IC Role / Device Role / Timing Role: MAX921ESA+T output controls P-MOSFET gate; RC network on HYST pin sets timing; internal reference defines trip point. Use Value: Eliminates need for external timer IC or microcontroller; 2.5μA typical quiescent current ensures minimal standby drain. |
Use Scenario: Validating 5V supply integrity in industrial PLC I/O modules with undervoltage (4.5V) and overvoltage (5.5V) alarms. IC Role / Device Role / Timing Role: Used alongside MAX923 (dual comparator) where MAX921ESA+T provides reference and hysteresis control for both thresholds. Use Value: Shared 1.182V reference ensures matched thresholds; ±1% accuracy guarantees tight window tolerance without calibration. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar comparator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM393DR | No internal reference; requires external voltage divider; 100μA supply current; open-collector output only. | Lacks integrated reference and hysteresis control; needs pull-up resistor and external reference for same functionality. | Choose LM393DR only if cost is primary concern and board space allows external components for reference/hysteresis. |
| TLV3701IDBVR | 2.5μA supply current; rail-to-rail input; no internal reference; push-pull output; 1.2V to 16V supply range. | Requires external reference; lacks HYST pin - hysteresis must be added via positive feedback (slower, higher current). | Prefer TLV3701IDBVR when wider supply range (down to 1.2V) is needed, but accept added design complexity for hysteresis. |
Compared with LM393DR and TLV3701IDBVR, the MAX921ESA+T uniquely integrates a precision reference and dedicated hysteresis control in an ultra-low-power package - reducing BOM count, layout area, and design validation effort for battery-critical threshold detection.
Availability
MAX921ESA+T is available at Aetrix Electronics and suitable for battery-powered systems, threshold detectors, and oscillator circuits requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for MAX921ESA+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
Maxim Integrated (now part of Analog Devices) designs precision analog and mixed-signal ICs for power, sensing, and interface applications in industrial, medical, and portable electronics.
The MAX921ESA+T belongs to the MAX921–MAX924 micropower comparator family, engineered specifically for ultra-low-quiescent-current threshold detection in energy-constrained systems where reference accuracy and hysteresis simplicity are critical.
FAQ
What is the maximum supply voltage for MAX921ESA+T in single-supply operation?
The MAX921ESA+T supports a single-supply voltage range of +2.5V to +11V. At +11V, it maintains full specification compliance including 4μA max supply current and 1.182V ±1% reference accuracy across −40°C to +85°C. Exceeding +11V risks permanent damage per Absolute Maximum Ratings.
Does MAX921ESA+T require external bypass capacitors?
No external bypass capacitors are required for the MAX921ESA+T if the power supply impedance is low. However, a 100nF ceramic capacitor placed close to the V+ and GND pins is recommended when supply leads are long or source impedance is high - especially in noisy industrial environments where supply ripple could couple into the sensitive comparator inputs.
Can MAX921ESA+T operate from a dual ±5V supply?
Yes, the MAX921ESA+T operates from dual supplies ranging from ±1.25V to ±5.5V. With ±5V applied, V+ = +5V and V− = −5V, the output swings from +5V to GND (not to V−), and the internal 1.182V reference remains referenced to V− (−5V), yielding a REF voltage of −3.818V relative to GND - enabling bipolar threshold detection with TTL-compatible output levels.
How is hysteresis configured on MAX921ESA+T?
Hysteresis on MAX921ESA+T is configured using the HYST pin: connect R1 between REF and HYST, and R2 between HYST and V−. The hysteresis band (VHB) ≈ 2 × (VREF − VHYST), with VHYST adjustable from (VREF − 50mV) to VREF. For example, setting VHYST = VREF − 25mV yields ~50mV hysteresis - eliminating external feedback and simplifying layout.
What is the guaranteed input common-mode voltage range for MAX921ESA+T?
The guaranteed input common-mode voltage range for MAX921ESA+T is from V− to (V+ − 1.3V) across the full −40°C to +85°C temperature range. This allows IN+ and IN− to operate within 1.3V of the positive rail - critical for high-side sensing in 12V automotive or industrial systems where signals approach V+.
MAX921ESA+T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- with Voltage Reference
- Number of Elements:
- 1
- Output Type:
- CMOS, TTL
- Voltage - Supply, Single/Dual (±):
- 2.5V ~ 11V, ±1.25V ~ 5.5V
- :
- 10mV @ 5V
- Voltage - Input Offset (Max):
- -
- Current - Input Bias (Max):
- 50mA
- Current - Output (Typ):
- 5µA
- Current - Quiescent (Max):
- 80dB CMRR, 80dB PSRR
- CMRR, PSRR (Typ):
- 12µs
- Propagation Delay (Max):
- 50mV
- Hysteresis:
- -40°C ~ 85°C
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- Surface Mount
- :
- 8-SOIC
MAX921ESA+T FAQ
1.How can I place an order for MAX921ESA+T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX921ESA+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 MAX921ESA+T reliable?
The price and inventory of MAX921ESA+T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX921ESA+T is usually 5 days.
3.What payment methods are accepted for MAX921ESA+T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX921ESA+T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX921ESA+T?
MAX921ESA+T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX921ESA+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 MAX921ESA+T?
For technical support, including MAX921ESA+T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX921ESA+T requirements.
6.How does Aetrix verify that MAX921ESA+T is sourced from the original manufacturer or authorized distributors?
All MAX921ESA+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 MAX921ESA+T meets industry standards.
7.What is the process for return or replacement of MAX921ESA+T?
All MAX921ESA+T units undergo pre-shipment inspection (PSI). If there is an issue with MAX921ESA+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 MAX921ESA+T part is unused and in its original packaging.
Return procedure for MAX921ESA+T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX921ESA+T Tags
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