My Inquiry
My Account
Analog Devices Inc./Maxim Integrated MAX921CPA
- Part No.:
- MAX921CPA
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Comparators
- Package:
- 8-DIP (0.300", 7.62mm)
- Datasheet:
-
MAX921CPA.pdf
- Description:
- IC COMPARATOR 1 W/VOLT REF 8DIP
- Quantity:
- Payment:
- Shipping:
Inventory:4,114
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
The MAX921CPA from Maxim Integrated is a single-channel, micropower voltage 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 0°C to +70°C, and supports rail-to-rail input common-mode range down to V− and within 1.3V of V+. It is used in battery-powered threshold detection where ultra-low power and self-contained reference are critical.
For engineers reviewing the MAX921CPA datasheet, MAX921CPA pinout, MAX921CPA application, or MAX921CPA equivalent, this page delivers verified specifications, validated pin functions, confirmed operating conditions across temperature and supply ranges, and real-world design context for low-power analog sensing and auto-shutdown circuits.
Technical Context
The MAX921CPA integrates a precision 1.182V reference referenced to V− (not GND), enabling stable threshold generation without external components. Its comparator core delivers 12μs propagation delay at 10mV overdrive and supports input voltages from V− to (V+ − 1.3V), making it suitable for single-supply systems with ground-referenced signals.
The unique output stage continuously sources up to 40mA while eliminating crowbar current during transitions-reducing supply-line parasitic feedback and improving layout tolerance. Hysteresis is implemented externally via two resistors between REF and HYST pins, enabling adjustable 0–100mV hysteresis bands without feedback networks or complex calculations.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage Range | +2.5V to +11V single supply; enables direct use with 3V/5V logic rails and battery inputs without regulation |
| Quiescent Current | ≤4μA over 0°C to +70°C; ensures multi-year operation on coin-cell batteries in always-on monitoring |
| Reference Voltage | 1.182V ±1% (0°C to +70°C); provides stable, factory-trimmed threshold source traceable to bandgap physics |
| Propagation Delay | 12μs at 10mV overdrive; supports fast response in wake-up and fault-detection circuits |
| Output Drive | Sources ≥40mA continuously; directly drives LEDs, small relays, or logic inputs without buffer stages |
| Input Common-Mode Range | V− to (V+ − 1.3V); allows full utilization of supply headroom in single-supply sensor interfaces |
| Reference Load Capability | Sinks 4μA / sources 6μA (C temp range); supports resistor-divider hysteresis networks with minimal error |
Pinout & Package
MAX921CPA uses an 8-pin plastic DIP package (0.300" width) with through-hole mounting and industry-standard footprint.
| 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; defines reference and input lower bound |
| 3 | IN+ | Noninverting comparator input; accepts signals from V− to (V+ − 1.3V) with <±10mV offset |
| 4 | IN− | Inverting comparator input; matched leakage (<±5nA) ensures stable DC threshold accuracy |
| 5 | HYST | Hysteresis control input; voltage range REF − 0.05V to REF; sets hysteresis band via resistor divider |
| 6 | REF | 1.182V reference output referenced to V−; supplies bias for HYST network and external thresholds |
| 7 | V+ | Positive supply rail; supports up to +11V; powers internal reference and output stage |
| 8 | OUT | Push-pull output; sinks and sources current; swings rail-to-rail (V+ to GND) for TTL compatibility |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low quiescent current | 4μA max over full commercial temperature range enables >10-year battery life in IoT sensors |
| Integrated precision reference | 1.182V ±1% eliminates need for external voltage reference IC or resistor divider trimming |
| Programmable hysteresis | Adjustable 0–100mV hysteresis via two external resistors-no feedback loop or op-amp required |
| Rail-to-rail output drive | 40mA continuous source current directly interfaces with LEDs, MOSFET gates, or logic inputs |
| No crowbar switching current | Eliminates supply glitches during output transitions-reduces need for local bypass capacitors |
Applications
| Battery-Powered Threshold Detector | Auto-Off Power Switch |
|---|---|
Use Scenario: Monitoring lithium coin-cell voltage to trigger shutdown before deep discharge. IC Role / Device Role / Timing Role: Comparator compares battery voltage against 1.182V reference; HYST pin adds 50mV hysteresis to prevent chatter near cutoff. Use Value: 4μA quiescent current extends operational lifetime; integrated reference reduces BOM count by one component. | Use Scenario: Enabling timed power-down of peripheral circuitry after user inactivity. IC Role / Device Role / Timing Role: MAX921CPA output drives MOSFET gate; RC network on IN+ sets ~90s timeout window. Use Value: 40mA output drives gate directly; no level shifter or driver IC needed-reduces board area and cost. |
| Single-Supply Window Comparator | LED Bar-Graph Level Indicator |
Use Scenario: Detecting valid 3.3V system supply within ±5% tolerance using undervoltage/overvoltage thresholds. IC Role / Device Role / Timing Role: Paired MAX921CPA units compare against upper/lower thresholds derived from REF and resistor dividers. Use Value: Matched input leakage (<±5nA) ensures consistent trip points; rail-to-rail input supports full 0–3.3V sensing range. | Use Scenario: Visual battery level indication using four LEDs driven directly from comparator outputs. IC Role / Device Role / Timing Role: Four MAX921CPA devices compare stepped input against REF-derived thresholds. Use Value: 40mA output drives LEDs at full brightness without series resistors-simplifies layout and improves efficiency. |
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 source; 100μA typical supply current; open-collector output only | Needs external reference and pull-up; unsuitable for direct LED drive or low-power battery systems | Select when cost is primary constraint and reference/hysteresis flexibility is not required |
| TLV3011IDBVR | 2.5μA supply current; integrated 1.24V reference; push-pull output; 10μs propagation delay; SOT-23-6 package | Smaller footprint; lower drive (10mA); no HYST pin-hysteresis requires external feedback | Select for space-constrained PCBs where 10mA drive suffices and external hysteresis is acceptable |
Compared with LM393DR and TLV3011IDBVR, the MAX921CPA uniquely combines ultra-low 4μA supply current, integrated ±1% reference, programmable hysteresis via dedicated HYST pin, and 40mA push-pull output-all in an industry-standard DIP package-making it optimal for long-life, self-contained threshold detection.
Availability
MAX921CPA is available at Aetrix Electronics and suitable for battery-powered systems, threshold detectors, window comparators, and oscillator circuits requiring stable component supply with guaranteed commercial-temperature performance.
Supply support for MAX921CPA 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 consumer systems.
The MAX921CPA belongs to the MAX921–MAX924 micropower comparator family, engineered specifically for ultra-low-power, single-supply sensing applications where integrated reference, hysteresis control, and robust output drive eliminate external components.
FAQ
What is the maximum supply voltage for MAX921CPA in single-supply operation?
The MAX921CPA supports a single-supply voltage range of +2.5V to +11V. When operated with V− tied to GND, the absolute maximum rating for V+ is +12V, but functional operation is guaranteed only up to +11V per datasheet specifications. Exceeding +11V may cause parametric degradation or reliability risk, even if within absolute maximum ratings.
Does MAX921CPA require external hysteresis components?
Yes-the MAX921CPA does not include internal hysteresis. It provides a dedicated HYST pin to accept an externally programmed voltage (REF − 0.05V to REF) via two resistors, enabling precise 0–100mV hysteresis bands. This architecture avoids positive-feedback loops and maintains low quiescent current, unlike comparator ICs requiring external feedback resistors.
Can MAX921CPA operate from a dual supply?
Yes-MAX921CPA supports dual-supply operation from ±1.25V to ±5.5V. In this configuration, V+ connects to the positive rail, V− to the negative rail, and GND remains unconnected. The output swings from V+ to GND, and the internal reference remains referenced to V−, preserving accuracy across bipolar supply conditions.
What is the input offset voltage specification for MAX921CPA?
The MAX921CPA has a maximum input offset voltage of ±10mV at VCM = 2.5V, tested over the 0°C to +70°C commercial temperature range. This value is guaranteed-not typical-and applies to both IN+ and IN− inputs. Offset drift over temperature is not specified separately but is included in the ±10mV limit across the full operating range.
Is the reference output of MAX921CPA referenced to GND or V−?
The reference output (pin 6, REF) of MAX921CPA is explicitly referenced to V−, not GND. This means its voltage is 1.182V above the V− potential. When V− is tied to GND in single-supply mode, REF = 1.182V relative to GND-but if V− is at −2V, REF = −0.818V relative to GND. Proper grounding of V− is essential for correct reference interpretation in all configurations.
MAX921CPA Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Package/Case:
- 8-DIP (0.300", 7.62mm)
- Series:
- -
- Packaging:
- Tube
- 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:
- Through Hole
- :
- 8-PDIP
MAX921CPA FAQ
1.How can I place an order for MAX921CPA through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX921CPA 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 MAX921CPA reliable?
The price and inventory of MAX921CPA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX921CPA is usually 5 days.
3.What payment methods are accepted for MAX921CPA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX921CPA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX921CPA?
MAX921CPA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX921CPA 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 MAX921CPA?
For technical support, including MAX921CPA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX921CPA requirements.
6.How does Aetrix verify that MAX921CPA is sourced from the original manufacturer or authorized distributors?
All MAX921CPA 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 MAX921CPA meets industry standards.
7.What is the process for return or replacement of MAX921CPA?
All MAX921CPA units undergo pre-shipment inspection (PSI). If there is an issue with MAX921CPA, 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 MAX921CPA part is unused and in its original packaging.
Return procedure for MAX921CPA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX921CPA Tags
-
LM2903DR
Texas Instruments
-
LM339DR
Texas Instruments
-
LM339PWR
Texas Instruments
-
LM393DT
STMicroelectronics
-
LM2901PWR
Texas Instruments
-
LM2903DT
STMicroelectronics
-
LM393DR
Texas Instruments
-
LM239DR
Texas Instruments
-
LM339APWR
Texas Instruments
-
LM2903P
Texas Instruments
-
LM393ADR
Texas Instruments
-
NCX2200GMAZ
NXP USA Inc.
Tech Hub
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
LDO regulator guide covering low dropout voltage, power dissipation, thermal design, PSRR, output noise, capacitor stability, adjustable LDO circuits, LDO vs buck converter and datasheet selection chec…
Conditional Access Module guide covering CAM meaning, CI/CI+ interface, smart card authorization, DVB security workflow, TV and set-top box compatibility, internal electronics, ESD protection, connecto…
Guide to electronic component obsolescence covering EOL risk, PCN/PDN notices, last-time buy planning, replacement options, form-fit-function validation, counterfeit risk and BOM lifecycle management.
18650 battery guide covering lithium-ion cell basics, 3.6V/3.7V voltage, 4.2V charging, mAh and Wh capacity, protected cells, chargers, BMS, series-parallel packs, holders, welding and sourcing checks.…
Hall effect sensor guide covering working principle, linear and digital sensors, Arduino circuits, current sensing, speed detection, automotive applications, A3144 examples, signal filtering and datash…
Product Change Notification guide for electronic components, covering PCN meaning, PCN vs PDN/EOL, common change types, risk levels, form-fit-function review, engineering validation, BOM control, LTB/L…
A practical guide to blend door actuators, covering HVAC function, symptoms, location, AC and heater issues, reset and calibration, replacement cost, electrical diagnosis, compatibility checks, and rep…
