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Analog Devices Inc./Maxim Integrated MAX921CSA-T
- Part No.:
- MAX921CSA-T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Comparators
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
MAX921CSA-T.pdf
- Description:
- IC COMPARATOR 1 W/VOLT REF 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,889
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Product details
Overview
The MAX921CSA-T from Maxim Integrated is a single, ultra-low-power, rail-to-rail input 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 4μA max quiescent current over –40°C to +85°C, and is widely used in battery-powered threshold detection circuits.
For engineers reviewing the MAX921CSA-T datasheet, MAX921CSA-T pinout, MAX921CSA-T application, or MAX921CSA-T equivalent, key selection considerations include its guaranteed input common-mode range (V− to V+ − 1.3V), absence of crowbar current during switching, 12μs propagation delay at 10mV overdrive, and compatibility with both single-supply (V− = GND) and dual-supply configurations.
Technical Context
The MAX921CSA-T integrates a precision 1.182V reference referenced to V− (not GND), enabling accurate threshold generation without external components. Its comparator input stage supports rail-to-rail operation down to the negative supply rail and up to within 1.3V of V+, with input leakage ≤±5nA over extended temperature.
The output stage delivers continuous 40mA source current and sinks ≥5mA while eliminating switching crowbar current-critical for stable operation in noisy or poorly decoupled environments. Hysteresis is implemented externally via the HYST pin using two resistors, enabling adjustable hysteresis bands up to 100mV without feedback networks or complex calculations.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage Range | +2.5V to +11V single supply; ±1.25V to ±5.5V dual supply - enables direct interface with 3V/5V logic and bipolar sensor signals. |
| Quiescent Current | ≤4μA over –40°C to +85°C - ensures multi-year battery life in portable instrumentation and remote sensors. |
| Reference Voltage | 1.182V ±1% (0°C to +70°C), referenced to V− - provides stable, factory-trimmed threshold without external voltage dividers. |
| Propagation Delay | 12μs at 10mV overdrive - supports reliable timing-critical detection in low-frequency monitoring applications. |
| Output Drive | Sources 40mA continuously; sinks ≥5mA - directly drives LEDs, small relays, or logic inputs without buffer stages. |
| Input Common-Mode Range | V− to (V+ − 1.3V) - allows sensing near ground or high-side signals in single-supply systems. |
| Hysteresis Control | HYST pin accepts REF − 50mV to REF - enables precise, resistor-programmable hysteresis up to 100mV peak-to-peak. |
Pinout & Package
MAX921CSA-T is housed in an 8-pin SO (Small Outline) package, pin-compatible with industry-standard SOIC-8 footprints. The device uses a standard 8-pin layout with GND on Pin 1, OUT on Pin 2, V− on Pin 3, IN+ on Pin 4, IN− on Pin 5, HYST on Pin 6, REF on Pin 7, and V+ on Pin 8.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | GND | Ground reference for single-supply operation; connects to V− when using dual supplies. |
| 2 | OUT | Comparator output; TTL/CMOS-compatible, sources up to 40mA, sinks ≥5mA, swings from V+ to GND. |
| 3 | V− | Negative supply terminal; tied to GND in single-supply mode; sets reference and output swing baseline. |
| 4 | IN+ | Noninverting input; supports common-mode range from V− to V+ − 1.3V; leakage ≤±5nA. |
| 5 | IN− | Inverting input; identical electrical characteristics to IN+; enables standard comparator configurations. |
| 6 | HYST | Hysteresis control input; voltage range REF − 50mV to REF; used with two external resistors for adjustable hysteresis. |
| 7 | REF | 1.182V ±1% bandgap reference output referenced to V−; sources up to 25μA, sinks up to 15μA. |
| 8 | V+ | Positive supply input; supports up to +11V; defines upper rail for input common-mode and output swing. |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low quiescent current | ≤4μA over –40°C to +85°C enables decade-scale battery operation in IoT endpoint sensors. |
| Integrated precision reference | 1.182V ±1% bandgap reference eliminates need for external voltage references or trimming resistors. |
| No crowbar current | Eliminates supply-line glitches during output transitions, reducing EMI and improving stability without bypass caps. |
| Programmable hysteresis | HYST pin enables resistor-based hysteresis setup without feedback loops-reducing component count and layout sensitivity. |
| Rail-to-rail input capability | Input common-mode extends to V− and within 1.3V of V+, supporting direct sensing of ground-referenced or high-side signals. |
Applications
| Battery-Powered Threshold Detector | Single-Supply Window Comparator |
|---|---|
|
Use Scenario: Detecting low-battery condition in portable medical devices using a 3.3V Li-ion cell. IC Role / Device Role / Timing Role: MAX921CSA-T compares battery voltage against 2.8V threshold generated by REF and resistor divider; HYST pin adds 50mV hysteresis to prevent chatter. Use Value: 4μA quiescent current preserves battery life; internal reference ensures accuracy across temperature without calibration. |
Use Scenario: Monitoring 5V system rail for undervoltage (4.5V) and overvoltage (5.5V) in industrial controllers. IC Role / Device Role / Timing Role: Two MAX921CSA-T units configured as high- and low-threshold comparators; outputs ANDed to generate power-good signal. Use Value: Independent hysteresis programming per channel avoids interaction; TTL-compatible outputs interface directly with FPGA I/O banks. |
| Oscillator Circuit with Hysteresis | Auto-Shutoff Power Switch |
|
Use Scenario: Building a low-power relaxation oscillator for clocking sleep-mode microcontrollers. IC Role / Device Role / Timing Role: MAX921CSA-T configured as Schmitt trigger with RC network on IN+; HYST pin sets hysteresis band to define frequency. Use Value: 12μs propagation delay and no crowbar current ensure stable oscillation; 4μA supply enables sub-1μA total circuit current. |
Use Scenario: Enabling timed shutdown of peripheral circuitry after user button press in handheld test equipment. IC Role / Device Role / Timing Role: MAX921CSA-T drives MOSFET gate via RC timing network; OUT sources 40mA to sustain gate drive during active period. Use Value: High output drive eliminates external driver; internal reference ensures consistent trip point across battery discharge curve. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar comparator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LMV331IDBVR | No internal reference; requires external voltage source; 17μA supply current; rail-to-rail input only (not output). | Lacks integrated reference and hysteresis control; suitable only where external reference exists and lower accuracy is acceptable. | Select LMV331IDBVR only if board space permits external reference and hysteresis circuitry, and >4× higher supply current is tolerable. |
| TLV3691DBVR | 250nA supply current; no internal reference; open-drain output; 3.5μs propagation delay; operates down to 1.4V. | Optimized for ultra-low-power wake-up detection but lacks reference and push-pull drive; requires pull-up and external threshold. | Choose TLV3691DBVR for nanowatt wake-up triggers where output drive and reference integration are unnecessary. |
Compared with LMV331IDBVR and TLV3691DBVR, the MAX921CSA-T uniquely combines micropower operation (≤4μA), integrated ±1% reference, programmable hysteresis, and 40mA push-pull output-enabling complete threshold detection functionality in a single 8-pin SO package without external support components.
Availability
MAX921CSA-T is available at Aetrix Electronics and suitable for battery-powered systems, threshold detectors, window comparators, and oscillator circuits requiring stable component supply, long-term lifecycle support, and guaranteed commercial-temperature performance.
Supply support for MAX921CSA-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 communications systems.
The MAX921CSA-T belongs to the MAX921–MAX924 family of ultra-low-power comparators engineered specifically for energy-constrained, single-supply sensing applications where reference integration, hysteresis flexibility, and robust output drive are critical.
FAQ
What is the operating temperature range for the MAX921CSA-T?
The MAX921CSA-T is specified for operation from –40°C to +85°C (Extended temperature range). This is confirmed by its ordering suffix "ESA" and Electrical Characteristics tables labeled "C/E temp. ranges", where parameters including supply current (≤4μA), reference voltage (1.158V to 1.206V), and input offset (±10mV) are guaranteed across this full range.
Does the MAX921CSA-T require external hysteresis components?
Yes-the MAX921CSA-T uses the HYST pin to implement programmable hysteresis via two external resistors (R1 between REF and HYST, R2 between HYST and V−). This method avoids feedback networks and enables precise hysteresis bands up to 100mV. If no hysteresis is needed, connect HYST directly to REF.
Can the MAX921CSA-T operate from a 3V single supply?
Yes-the MAX921CSA-T supports single-supply operation from +2.5V to +11V. At +3V, it maintains full functionality: input common-mode range spans 0V to 1.7V, reference remains stable at 1.182V ±1%, and propagation delay is 14μs (10mV overdrive), as verified in the "Electrical Characteristics: 3V OPERATION" section.
What is the maximum continuous output source current of the MAX921CSA-T?
The MAX921CSA-T continuously sources up to 40mA, as explicitly stated in the General Description and confirmed in Typical Operating Characteristics (Figure MAX121/124-TOC17). This capability is maintained across the full supply range (+2.5V to +11V) and enables direct driving of LEDs, small solenoids, or logic inputs without external buffers.
Is the internal reference of the MAX921CSA-T referenced to GND or V−?
The internal 1.182V reference of the MAX921CSA-T is referenced to V−, not GND. This is clearly stated in the "Voltage Reference" section ("REF voltage is referenced to V−, not to GND") and impacts circuit design: when using dual supplies (e.g., ±5V), REF = –5V + 1.182V = –3.818V, not +1.182V relative to system GND.
MAX921CSA-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:
- Obsolete
- 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:
- 0°C ~ 70°C
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- Surface Mount
- :
- 8-SOIC
MAX921CSA-T FAQ
1.How can I place an order for MAX921CSA-T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX921CSA-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 MAX921CSA-T reliable?
The price and inventory of MAX921CSA-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX921CSA-T is usually 5 days.
3.What payment methods are accepted for MAX921CSA-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX921CSA-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX921CSA-T?
MAX921CSA-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX921CSA-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 MAX921CSA-T?
For technical support, including MAX921CSA-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX921CSA-T requirements.
6.How does Aetrix verify that MAX921CSA-T is sourced from the original manufacturer or authorized distributors?
All MAX921CSA-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 MAX921CSA-T meets industry standards.
7.What is the process for return or replacement of MAX921CSA-T?
All MAX921CSA-T units undergo pre-shipment inspection (PSI). If there is an issue with MAX921CSA-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 MAX921CSA-T part is unused and in its original packaging.
Return procedure for MAX921CSA-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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