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Analog Devices Inc./Maxim Integrated MAX16040LLA31+
- Part No.:
- MAX16040LLA31+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- 8-WFDFN
- Datasheet:
-
MAX16040LLA31+.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 8UDFN
- Quantity:
- Payment:
- Shipping:
Inventory:1,822
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Product details
Overview
MAX16040LLA31+ from Maxim Integrated is an 8-pin μDFN battery-backup supervisory IC for microprocessor systems, featuring auxiliary adjustable-reset input (RESETIN), active-low push-pull reset output, power-fail comparator, and battery switchover with 3.08V factory-set reset threshold. It operates from 1.2V to 5.5V supply, draws only 13µA quiescent current, and supports reliable SRAM backup in portable POS terminals and industrial controllers.
For engineers reviewing the MAX16040LLA31+ datasheet, MAX16040LLA31+ pinout, MAX16040LLA31+ application, or MAX16040LLA31+ equivalent, this page delivers verified electrical parameters, exact 8-pin μDFN terminal mapping, battery-switchover timing behavior, RESETIN threshold calibration guidance, and real-world use cases in brownout-critical embedded systems.
Technical Context
The MAX16040LLA31+ integrates a precision 1.235V reference for its RESETIN comparator, enabling user-adjustable monitoring of secondary supplies via external resistor dividers. Its internal MOSFET-based battery switchover circuit activates when VCC falls below 3.08V and VBATT exceeds VCC by ≥40mV, delivering regulated backup power to OUT with ≤4.6Ω on-resistance at 2.5V.
It implements a fixed 140ms minimum reset timeout (tRP), active-low push-pull RESET output with 0.3V VOL at 1.6mA sink, and independent PFI/PFO power-fail detection with 1.235V threshold and 4µs propagation delay - all fully specified across –40°C to +85°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold Voltage | 3.00V (min) to 3.15V (max); factory-trimmed for precise 3.08V nominal trip point on VCC |
| RESET Output Type | Active-low push-pull; drives low to 0.3V @ 1.6mA, eliminating need for external pull-up |
| RESET Timeout Period | 140ms (min); ensures µP initialization completes before release from reset state |
| RESETIN Threshold | 1.185V–1.285V; enables accurate monitoring of secondary supplies using external R-divider |
| Quiescent Supply Current | 13µA (typ) at 2.8V; minimizes standby drain on primary supply during normal operation |
| Battery Backup Current | 2µA (max) over –40°C to +85°C; preserves battery life in long-term storage or infrequent use |
| VCC-to-OUT On-Resistance | 4.6Ω (max) at 2.5V/25mA; limits voltage drop and thermal rise during high-current SRAM hold |
Pinout & Package
MAX16040LLA31+ is housed in a space-saving 2mm × 2mm, 8-pin μDFN package with exposed pad (EP), rated for –40°C to +85°C operation. Pin 1 is marked by a dot; pin numbering follows standard counter-clockwise convention starting from top-left corner.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - RESET | Active-low push-pull reset output | Asserts low during VCC undervoltage, RESETIN low, or brownout; holds for ≥140ms after recovery |
| 2 - PFI | Power-fail input | Monitors external supply via resistor divider; triggers PFO when voltage falls below 1.235V |
| 3 - GND | Ground reference | Common return for VCC, BATT, and signal paths; must be low-impedance connection |
| 4 - MR | Manual-reset input | Not present on MAX16040; pin is no-connect (NC) per device variant table |
| 5 - RESETIN | Auxiliary reset input | User-adjustable comparator input referenced to 1.235V; asserts RESET when <1.235V |
| 6 - PFO | Active-low power-fail output | Pull-down output indicating PFI undervoltage or VCC < reset threshold |
| 7 - VCC | Main supply input | Accepts 1.2V–5.5V; powers internal circuitry and sources OUT during normal operation |
| 8 - BATT | Backup battery input | Connects to lithium coin cell or supercap; automatically switches to OUT when VCC fails |
Key Features
| Feature | Design Value |
|---|---|
| Auxiliary RESETIN input | 1.235V precision reference enables accurate monitoring of secondary rails (e.g., 2.5V, 1.8V) via external resistors |
| Push-pull RESET output | Eliminates external pull-up resistor and reduces board area; compatible with µP reset inputs requiring driven low |
| Battery switchover hysteresis | 40mV built-in hysteresis prevents oscillation during slow VCC decay near reset threshold |
| Low 13µA quiescent current | Extends battery life in always-on portable equipment; measured at VCC = 2.8V, TA = +25°C |
| Power-fail comparator independence | Dedicated PFI/PFO path operates even when VCC is above reset threshold, enabling early warning before brownout |
| –40°C to +85°C guaranteed operation | Validated across full industrial temperature range without derating; includes temp-coefficient data for RESETIN and tRP |
Applications
| Portable POS Terminals | Industrial PLC Controllers |
|---|---|
Use Scenario: Battery-backed memory retention during AC power loss or hot-swap battery replacement in retail payment terminals. IC Role / Device Role / Timing Role: Supervisory IC providing VCC monitoring, automatic BATT-to-OUT switchover, and RESET assertion to halt µP execution until stable power resumes. Use Value: Prevents SRAM corruption during 10–300ms brownouts; 2µA backup current extends CR2032 life to >5 years in sleep mode. |
Use Scenario: Maintaining real-time clock and configuration registers during mains failure in programmable logic controllers deployed in factory automation. IC Role / Device Role / Timing Role: Dual-role supervisor: RESETIN monitors 3.3V I/O rail while PFI tracks 24V field power; coordinated reset ensures deterministic state recovery. Use Value: 140ms reset timeout satisfies IEC 61131-2 cold-start requirements; 1.235V RESETIN reference enables ±1% secondary supply tolerance. |
| Set-Top Box Memory Backup | Intelligent Instrument Data Loggers |
Use Scenario: Preserving channel lineup, parental controls, and firmware state during brief grid interruptions in consumer digital TV receivers. IC Role / Device Role / Timing Role: Power manager routing VCC or BATT to SRAM block; RESET output synchronizes µC reboot sequence after power restoration. Use Value: 4.6Ω VCC-to-OUT resistance limits voltage drop to <115mV at 25mA, ensuring SRAM VDD stays within 2.7–3.6V spec. |
Use Scenario: Securing sensor calibration coefficients and timestamped measurement buffers during extended field deployments where main power may be intermittent. IC Role / Device Role / Timing Role: Battery switchover controller with RESETIN used to validate auxiliary 1.8V ADC reference rail before initiating data capture. Use Value: 25nA RESETIN input bias enables use of 1MΩ resistor dividers without accuracy loss; supports ultra-low-power design goals. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX16036LLA31+ | Same 8-pin μDFN package, identical RESETIN function and 3.08V VTH, but lacks PFO output | Suitable only where power-fail warning is not required; no PFI monitoring capability | Select MAX16036LLA31+ if PFO interrupt signaling is unnecessary and BOM simplification is prioritized |
| TPS3808G33DBVR | 3.3V fixed reset threshold, no RESETIN input, open-drain RESET, higher 25µA ICC, SOT-23-6 package | Lacks battery switchover, auxiliary reset, and power-fail comparator; limited to basic reset-only use | Choose TPS3808G33DBVR only for cost-sensitive, non-backup applications requiring minimal footprint and no secondary supply monitoring |
Compared with MAX16036LLA31+, MAX16040LLA31+ adds critical PFO functionality for early power-fail detection; versus TPS3808G33DBVR, it delivers integrated battery management, adjustable reset inputs, and lower quiescent current - making it uniquely suited for SRAM-retentive embedded systems with multi-rail monitoring needs.
Availability
MAX16040LLA31+ is available at Aetrix Electronics and suitable for portable POS terminals, industrial PLC controllers, set-top box memory backup, and intelligent instrument data loggers requiring stable component supply, long-lifecycle support, and guaranteed industrial-temperature performance.
Supply support for MAX16040LLA31+ 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 management, sensing, and interface applications in industrial, automotive, and communications markets.
The MAX16033–MAX16040 family was engineered specifically for low-power, space-constrained microprocessor systems needing robust battery-backed memory supervision - combining reset generation, switchover control, watchdog, and multi-rail monitoring in sub-4mm² packages.
FAQ
What is the exact reset threshold voltage of MAX16040LLA31+?
The MAX16040LLA31+ has a factory-trimmed reset threshold of 3.00V (minimum), 3.08V (typical), and 3.15V (maximum) on VCC. This "A31" suffix denotes the 3.08V nominal trip point, validated across –40°C to +85°C with ±0.07V total variation including temperature drift and initial tolerance.
Does MAX16040LLA31+ support battery switchover, and what is the switchover condition?
Yes, MAX16040LLA31+ supports automatic battery switchover: OUT connects to BATT when VCC falls below the 3.08V reset threshold AND VBATT exceeds VCC by at least 40mV. This hysteresis prevents chattering during slow VCC decay, and the internal MOSFET delivers up to 200mA with ≤4.6Ω on-resistance.
Can MAX16040LLA31+ monitor a secondary power supply, and how is it configured?
Yes, MAX16040LLA31+ uses its RESETIN pin to monitor secondary supplies. An external resistor divider sets the trip point using VRTH = 1.235V × (R1/R2 + 1). With ≤25nA input bias, R2 values up to 1MΩ maintain accuracy; for example, a 3.3V rail uses R1 = 1.67MΩ and R2 = 1MΩ to achieve 3.3V ±1% trip.
What is the function of the PFI and PFO pins on MAX16040LLA31+?
PFI is the power-fail input, accepting a divided-down version of a monitored supply; it trips when voltage falls below 1.235V. PFO is the active-low open-drain output that asserts when PFI drops below threshold or when VCC falls below 3.08V. PFO provides early warning before full brownout, supporting NMI or interrupt-driven response.
Is MAX16040LLA31+ pin-compatible with other devices in the MAX16033–MAX16040 family?
MAX16040LLA31+ shares the same 8-pin μDFN package and pinout with MAX16037–MAX16039 variants, but differs functionally: it includes RESETIN and PFO, excludes MR and WDI, and has no CEIN/CEOUT. Pin compatibility exists only within the 8-pin group (MAX16037–MAX16040); 10-pin variants (MAX16033–MAX16036) are not pin-compatible.
MAX16040LLA31+ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 8-WFDFN
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Type:
- Battery Backup Circuit
- Number of Voltages Monitored:
- 1
- Voltage - Threshold:
- 3.08V
- Output:
- Push-Pull, Totem Pole
- Reset:
- Active Low
- Reset Timeout:
- 140ms Minimum
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-µDFN (2x2)
MAX16040LLA31+ FAQ
1.How can I place an order for MAX16040LLA31+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX16040LLA31+ 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 MAX16040LLA31+ reliable?
The price and inventory of MAX16040LLA31+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX16040LLA31+ is usually 5 days.
3.What payment methods are accepted for MAX16040LLA31+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX16040LLA31+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX16040LLA31+?
MAX16040LLA31+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX16040LLA31+ 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 MAX16040LLA31+?
For technical support, including MAX16040LLA31+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX16040LLA31+ requirements.
6.How does Aetrix verify that MAX16040LLA31+ is sourced from the original manufacturer or authorized distributors?
All MAX16040LLA31+ 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 MAX16040LLA31+ meets industry standards.
7.What is the process for return or replacement of MAX16040LLA31+?
All MAX16040LLA31+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX16040LLA31+, 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 MAX16040LLA31+ part is unused and in its original packaging.
Return procedure for MAX16040LLA31+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX16040LLA31+ Tags
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MIC826SYMT-TR
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