My Inquiry
My Account
Analog Devices Inc./Maxim Integrated MAX981CSA+
- Part No.:
- MAX981CSA+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Comparators
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
MAX981CSA+.pdf
- Description:
- IC COMPARATOR 1 W/VOLT REF 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:221
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
The MAX981CSA+ from Maxim Integrated is a single, ultra-low-power, open-drain comparator with integrated 1.182V ±2% voltage reference and programmable hysteresis via HYST pin. It operates from 2.5V to 11V single supply (or ±1.25V to ±5.5V dual), draws ≤4µA supply current over temperature, supports rail-to-rail input down to V− and within 1.3V of V+, and features separate GND for output transistor-enabling bipolar-to-single-ended level translation in battery-powered threshold detection.
For engineers reviewing the MAX981CSA+ datasheet, MAX981CSA+ pinout, MAX981CSA+ application, or MAX981CSA+ equivalent, this page delivers verified specifications, validated pin functions, confirmed use cases in low-voltage sensing and level shifting, and two technically documented alternative comparators with explicit functional and application differences.
Technical Context
The MAX981CSA+ integrates a precision bandgap reference referenced to V− (not GND) and a single comparator with open-drain output sinking to GND. Its HYST pin enables hysteresis programming using two external resistors without feedback loops-delivering deterministic 100mV max hysteresis band with <50mV REF–HYST differential.
It supports true single-supply operation (V− = GND) and dual-supply mode (V− = negative rail), with guaranteed input common-mode range from V− to (V+ − 1.3V) and output voltage swing up to 11V above V−-making it suitable for level translation between ±5V and 3.3V/5V logic domains.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage Range | 2.5V to 11V single supply (or ±1.25V to ±5.5V dual); enables direct interface with Li-ion, 3.3V, and 5V systems. |
| Quiescent Supply Current | ≤4µA over −40°C to +85°C; ensures multi-year battery life in always-on sensor nodes. |
| Reference Voltage Accuracy | 1.182V ±2% at 0°C to +70°C; provides stable threshold generation without external precision reference. |
| Input Common-Mode Range | V− to (V+ − 1.3V); allows direct sensing of signals near supply rails, e.g., battery voltage monitoring. |
| Propagation Delay | 12µs at 10mV overdrive (100pF load, 1MΩ pullup); balances speed and ultra-low power in wake-up circuits. |
| Output Configuration | Open-drain with dedicated GND pin; permits wire-ORing and level-shifting across incompatible voltage domains. |
| Input Offset Voltage | ±10mV max; ensures reliable detection of small signal differentials in precision threshold applications. |
Pinout & Package
MAX981CSA+ is housed in an 8-pin SO (Small Outline) package with gull-wing leads, JEDEC MS-012AC compliant, 150-mil body width, and 1.27mm pitch.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - GND | Ground reference for output stage | Connects to system GND; output sinks to this pin-not V−-enabling level translation when V− ≠ GND. |
| 2 - V− | Negative supply rail | Connect to GND for single-supply operation; sets reference baseline for internal 1.182V bandgap (VREF = V− + 1.182V). |
| 3 - IN+ | Noninverting comparator input | Accepts signals from V− to (V+ − 1.3V); used for active-high threshold detection. |
| 4 - IN− | Inverting comparator input | Accepts same input range as IN+; forms differential pair with IN+ for window or over/under-voltage sensing. |
| 5 - HYST | Hysteresis control input | Accepts voltage from (VREF − 50mV) to VREF; sets hysteresis band width via resistor divider from REF. |
| 6 - REF | Internal reference output | Provides 1.182V ±2% referenced to V−; supplies bias for HYST and external circuitry; max source/sink 25µA/15µA. |
| 7 - V+ | Positive supply rail | Accepts 2.5V–11V; powers comparator core and reference; gate drive strength affects output sink capability. |
| 8 - OUT | Open-drain comparator output | Sinks current to GND pin (Pin 1); requires external pullup; supports 11V output swing independent of V+. |
Key Features
| Feature | Design Value |
|---|---|
| Programmable hysteresis via HYST pin | Enables precise, low-component-count hysteresis (up to 100mV band) without feedback resistors or op-amp overhead. |
| Separate GND for output transistor | Decouples output sink path from V−, allowing safe interfacing between bipolar supplies (e.g., ±5V) and single-ended logic (e.g., 3.3V). |
| Ultra-low 4µA supply current | Reduces average power to <20µW at 5V, enabling multi-year operation on coin-cell batteries in IoT endpoints. |
| 1.182V ±2% internal reference | Eliminates need for external reference IC or resistor divider, saving board space and improving long-term stability vs. discrete solutions. |
| Rail-to-rail input with 1.3V headroom | Permits direct monitoring of battery voltage (e.g., 0–4.2V Li-ion) using only V+ and V− as supply rails-no level-shifting required. |
Applications
| Battery Voltage Monitor | Power-Good Indicator |
|---|---|
Use Scenario: Monitoring Li-ion cell voltage during charging/discharging to trigger low-battery shutdown or charge termination. IC Role / Device Role / Timing Role: Single comparator compares sensed battery voltage against 1.182V reference scaled by resistor divider; HYST pin adds noise immunity. Use Value: Achieves ±2% threshold accuracy over temperature with no external reference, extending usable battery capacity by avoiding premature cutoff. | Use Scenario: Validating stable 3.3V or 5V rail before enabling microcontroller reset or peripheral power sequencing. IC Role / Device Role / Timing Role: Comparator detects rail crossing preset threshold; open-drain output pulls low to assert /RESET or enable signal after hysteresis delay. Use Value: Eliminates external pullup and reference components, reducing BOM count while ensuring glitch-free power-up sequencing. |
| Level Translator (±5V → 3.3V) | Window Detector (Undervoltage + Overvoltage) |
Use Scenario: Converting analog signals from ±5V op-amp stages to 3.3V logic-compatible levels for ADC input or MCU GPIO. IC Role / Device Role / Timing Role: Uses V− = −5V, V+ = 5V, GND = system ground; output swings 0–3.3V via external pullup to 3.3V rail. Use Value: Leverages dedicated GND pin to isolate output sink path-prevents ground loop errors and enables clean single-ended conversion without isolation amplifiers. | Use Scenario: Detecting out-of-range supply voltage in industrial sensors or medical devices where both under- and over-voltage must be flagged. IC Role / Device Role / Timing Role: Two MAX981CSA+ units configured as high-threshold (overvoltage) and low-threshold (undervoltage) detectors; outputs wire-ORed. Use Value: Delivers full-window detection with independent hysteresis per threshold, eliminating need for quad comparator or complex discrete design. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar comparator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX971CSA+ | Same pinout and package; ±1% reference accuracy (vs. ±2%); no change in supply current or propagation delay. | Better reference stability suits precision voltage monitoring where ±10mV threshold error is unacceptable. | Select MAX971CSA+ when reference accuracy dominates system error budget; otherwise MAX981CSA+ offers cost advantage with identical footprint and drive capability. |
| TLV3701IDBVR | Single micropower comparator (600nA), no internal reference; rail-to-rail input; push-pull output (not open-drain). | Requires external reference and pullup redesign; unsuitable for wire-OR or level-shifting without added MOSFET. | Choose TLV3701IDBVR only if ultra-low current (<1µA) is critical and open-drain functionality is not required-otherwise MAX981CSA+ provides integrated reference and output flexibility. |
Compared with MAX971CSA+, the MAX981CSA+ trades ±1% reference accuracy for lower cost while retaining identical pinout, power consumption, and level-shifting capability; versus TLV3701IDBVR, it eliminates external reference and pullup components but consumes slightly more current-making it optimal for space-constrained, low-component-count designs requiring open-drain outputs.
Availability
MAX981CSA+ is available at Aetrix Electronics and suitable for battery-powered systems, threshold detectors, level translators, and oscillator circuits requiring stable component supply and long-lifecycle support.
Supply support for MAX981CSA+ 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, automotive, and computing markets.
The MAX981CSA+ belongs to Maxim's ultra-low-power comparator family targeting energy-constrained systems-designed specifically for reliable threshold detection and level translation where minimal quiescent current and integrated reference reduce bill-of-materials complexity.
FAQ
What is the reference voltage tolerance of the MAX981CSA+ over its operating temperature range?
The MAX981CSA+ features an internal 1.182V bandgap reference with ±2% accuracy over the commercial temperature range (0°C to +70°C). This specification is explicitly confirmed in the Electrical Characteristics table for MAX981–MAX984 devices. The reference is referenced to V−, not GND, and its output remains stable across supply voltages from 2.5V to 11V. MAX981CSA+ does not guarantee tighter tolerance outside this range.
Can the MAX981CSA+ operate from a 1.8V single supply?
No, the MAX981CSA+ has a minimum guaranteed single-supply voltage of 2.5V. While some comparators in the MAX971–MAX984 family (e.g., MAX974/MAX984) may function below 2.5V, the MAX981CSA+ datasheet explicitly states that operation below 2.5V is not specified and results in degraded performance-including loss of reference regulation and increased propagation delay. For 1.8V systems, consider alternatives like the TLV3701.
How is hysteresis implemented on the MAX981CSA+?
Hysteresis on the MAX981CSA+ is implemented 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-yielding up to 100mV total hysteresis. This method avoids external feedback and preserves ultra-low supply current. MAX981CSA+ does not support hysteresis via output feedback.
Does the MAX981CSA+ require a bypass capacitor on the REF pin?
No, the MAX981CSA+ datasheet explicitly instructs: "Do not bypass the REF output." Bypassing REF can destabilize the internal reference and increase noise. The reference is designed for direct connection to the HYST pin or external resistor dividers. Power supply bypassing (e.g., 100nF at V+) is recommended only for high-impedance or long-trace supplies-not for REF.
What is the maximum output sink current of the MAX981CSA+ at 3.3V supply?
At V+ = 3.3V, the MAX981CSA+ output (OUT) sinks up to 0.8mA while maintaining VOL ≤ GND + 0.4V, as specified in the 3V Operation Electrical Characteristics table. This value decreases at lower supply voltages due to reduced gate drive for the output N-channel MOSFET. The absolute maximum continuous sink current is 50mA, but practical design limits should follow the 0.8mA spec at 3.3V for guaranteed logic-level compatibility.
MAX981CSA+ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Series:
- -
- Packaging:
- Tube
- Product Status:
- Active
- Type:
- with Voltage Reference
- Number of Elements:
- 1
- Output Type:
- -
- Voltage - Supply, Single/Dual (±):
- 2.5V ~ 11V, ±1.25V ~ 5.5V
- :
- 10mV @ 5V
- Voltage - Input Offset (Max):
- -
- Current - Input Bias (Max):
- -
- Current - Output (Typ):
- 4µA
- Current - Quiescent (Max):
- 80dB CMRR, 80dB PSRR
- CMRR, PSRR (Typ):
- -
- Propagation Delay (Max):
- 50mV
- Hysteresis:
- 0°C ~ 70°C
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- Surface Mount
- :
- 8-SOIC
MAX981CSA+ FAQ
1.How can I place an order for MAX981CSA+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX981CSA+ 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 MAX981CSA+ reliable?
The price and inventory of MAX981CSA+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX981CSA+ is usually 5 days.
3.What payment methods are accepted for MAX981CSA+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX981CSA+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX981CSA+?
MAX981CSA+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX981CSA+ 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 MAX981CSA+?
For technical support, including MAX981CSA+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX981CSA+ requirements.
6.How does Aetrix verify that MAX981CSA+ is sourced from the original manufacturer or authorized distributors?
All MAX981CSA+ 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 MAX981CSA+ meets industry standards.
7.What is the process for return or replacement of MAX981CSA+?
All MAX981CSA+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX981CSA+, 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 MAX981CSA+ part is unused and in its original packaging.
Return procedure for MAX981CSA+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX981CSA+ 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…
