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Analog Devices Inc./Maxim Integrated MAX6731UTLD3+T
- Part No.:
- MAX6731UTLD3+T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- SOT-23-6
- Datasheet:
-
MAX6731UTLD3+T.pdf
- Description:
- IC SUPERVISOR SINGLE SOT23-6
- Quantity:
- Payment:
- Shipping:
Inventory:2,500
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Product details
Overview
MAX6731UTLD3+T from Maxim Integrated is a single-voltage microprocessor supervisor IC with push-pull active-low reset output, manual reset input, and independent push-pull watchdog output. It monitors one fixed supply (VCC1 = +4.625V nominal threshold), features 140ms–280ms reset timeout (D3 option), consumes 14µA typical supply current at +3.6V, and operates across –40°C to +85°C - used in embedded systems requiring reliable power-on reset and lockup recovery.
For engineers reviewing the MAX6731UTLD3+T datasheet, MAX6731UTLD3+T pinout, MAX6731UTLD3+T application, or MAX6731UTLD3+T equivalent, this page delivers verified electrical specs, SOT23-6 package mapping, confirmed watchdog timing (35s startup / 1.68s normal mode), reset threshold hysteresis (0.5%), and design-meaningful alternatives for multivoltage supervisory replacement.
Technical Context
The MAX6731UTLD3+T integrates a precision voltage comparator for VCC1 monitoring with factory-set 4.625V threshold (L suffix), a dedicated manual reset input (MR) with 50kΩ internal pullup, and a dual-mode watchdog timer: 35s minimum startup delay after reset followed by 1.68s standard timeout period. Its push-pull RST and WDO outputs eliminate external pullups and support direct interfacing with bidirectional μP reset pins when isolated via 10kΩ series resistor.
It guarantees valid reset assertion down to VCC1 = +0.8V, features 20ppm/°C reset threshold tempco, and includes glitch rejection on MR (100ns) and immunity to short VCC transients - enabling robust operation in noisy industrial and telecom power environments without additional RC filtering.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold (VCC1) | +4.625V (factory-set L suffix; ±125mV tolerance over temp) |
| Reset Timeout Period | 140–280ms (D3 option; ensures sufficient hold time for slow-starting peripherals) |
| Watchdog Timeout | 35s min startup / 1.68s min normal mode (prevents premature timeout during boot) |
| Supply Current | 14µA typ at +3.6V (enables battery-backed operation >10 years in low-power systems) |
| Operating Temp Range | –40°C to +85°C (fully specified; supports industrial-grade deployment) |
| Reset Output Type | Active-low push-pull (drives high-Z μP reset pins directly; no external pullup required) |
| Manual Reset Input | Active-low with 50kΩ internal pullup (simplifies board layout; eliminates discrete resistor) |
Pinout & Package
SOT23-6 package (6-pin, 1.6mm × 2.9mm, 0.95mm height), JEDEC MO-178AC compliant, lead(Pb)-free (+T suffix), thermal resistance θJA = 230°C/W.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - RST | Active-low reset output | Push-pull driver asserts low on VCC1 undervoltage, MR assertion, or watchdog timeout; holds for full D3 timeout period |
| 2 - GND | Ground reference | Common return for all internal comparators, timers, and I/O; must be low-impedance connection to system ground plane |
| 3 - WDO | Active-low watchdog output | Push-pull output deasserts only after valid WDI edge; asserts low if WDI stalls >1.68s in normal mode |
| 4 - MR | Active-low manual reset input | Drives reset when pulled low; internal 50kΩ pullup allows NC or tie-to-VCC1; 1µs minimum pulse width |
| 5 - WDI | Watchdog input | Edge-sensitive (rising/falling); clears watchdog timer on transition; unconnected requires 100kΩ pull-down to disable false timeout |
| 6 - VCC1 | Primary supply input | Powers device and feeds VCC1 monitor; valid operation guaranteed down to +0.8V; accepts +0.8V to +5.5V |
Key Features
| Feature | Design Value |
|---|---|
| Dual-mode watchdog timer | 35s startup delay enables full system initialization before watchdog enforcement begins |
| Guaranteed reset validity | Operates correctly down to VCC1 = +0.8V - critical for brownout detection in wide-input DC-DC systems |
| Immunity to VCC transients | Rejects <100ns glitches; maximum transient duration vs. overdrive curve prevents spurious resets |
| Low quiescent current | 14µA typical at +3.6V - extends battery life in portable equipment and backup circuits |
| Integrated MR pullup | 50kΩ internal resistor eliminates BOM item and reduces PCB footprint vs. discrete solution |
Applications
| Industrial PLC Controller | Telecom Line Card |
|---|---|
Use Scenario: Power sequencing and fault recovery in modular rack-mounted controllers with multiple rail supplies. IC Role / Device Role / Timing Role: Monitors primary 3.3V logic rail; asserts reset on brownout and triggers watchdog if firmware hangs during field-upgrade. Use Value: Prevents corrupted configuration writes by holding reset until VCC1 stabilizes above 4.625V and enforces 140ms minimum reset pulse width. |
Use Scenario: High-availability line cards requiring autonomous recovery from software lockup without host intervention. IC Role / Device Role / Timing Role: Provides independent watchdog supervision of DSP/FPGA subsystem; WDO drives local reset while RST coordinates system-wide restart. Use Value: Push-pull WDO avoids external pullup, reducing component count; 1.68s timeout matches typical firmware task cycle time. |
| Embedded Medical Monitor | Automotive Infotainment Module |
Use Scenario: Battery-powered patient vital sign recorder with sleep/wake cycles and flash memory logging. IC Role / Device Role / Timing Role: Supervises 1.8V core supply; MR input enables user-initiated reset via front-panel button; low 14µA ICC extends runtime. Use Value: Manual reset debounced internally (100ns glitch rejection); 50kΩ MR pullup eliminates external resistor, saving space in compact enclosure. |
Use Scenario: In-vehicle infotainment head unit with multi-rail power architecture (5V, 3.3V, 1.2V). IC Role / Device Role / Timing Role: First-stage supervisor for main 3.3V domain; interfaces with secondary supervisors via RST cascade; operates across full automotive temp range. Use Value: Valid reset down to +0.8V ensures reliable brownout detection during cold-cranking; –40°C to +85°C rating meets AEC-Q100 ambient requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6730UTLD3+T | Open-drain RST output; requires external pullup resistor; identical VCC1 threshold and D3 timeout | Suitable where reset bus is shared with other open-drain devices (e.g., I²C-style reset arbitration) | Select when system-level reset net uses wired-OR topology and pullup already exists |
| TPS3808G33DBVR | Single-supply supervisor with 3.3V threshold; 200ms reset timeout; no manual reset or watchdog output | Lacks MR and WDO functionality; simpler use case requiring only basic power-on reset | Choose when watchdog and manual reset are unnecessary and 3.3V threshold suffices |
Compared with MAX6730UTLD3+T, the MAX6731UTLD3+T eliminates external pullup needs via push-pull RST but shares identical monitoring accuracy and timeout behavior; versus TPS3808G33DBVR, it adds critical system-reliability features (MR, WDO) at the cost of higher integration complexity.
Availability
MAX6731UTLD3+T is available at Aetrix Electronics and suitable for industrial PLC controllers, telecom line cards, embedded medical monitors, and automotive infotainment modules requiring stable component supply, long-lifecycle support, and guaranteed RoHS-compliant sourcing.
Supply support for MAX6731UTLD3+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, with emphasis on reliability and integration for demanding environments.
The MAX6730–MAX6735 family targets embedded systems requiring multirail voltage supervision, fail-safe watchdog protection, and minimal external components - optimized for space-constrained, high-reliability industrial and communications equipment.
FAQ
What is the exact reset threshold voltage for MAX6731UTLD3+T?
The MAX6731UTLD3+T has a factory-set VCC1 reset threshold of +4.625V (L suffix), with guaranteed tolerance of ±125mV over –40°C to +85°C. This value is fixed and non-adjustable; it applies specifically to the primary supply monitor and is validated per Electrical Characteristics Table on page 2 of the datasheet.
Does MAX6731UTLD3+T support dual-voltage monitoring?
No, MAX6731UTLD3+T monitors only a single fixed voltage (VCC1). It belongs to the MAX6730/MAX6731 series, which lacks VCC2 and RSTIN inputs. Dual-voltage supervision requires MAX6732–MAX6733 (two fixed rails) or MAX6734–MAX6735 (two fixed + one adjustable rail).
What is the function of the WDI pin on MAX6731UTLD3+T?
The WDI (Watchdog Input) pin on MAX6731UTLD3+T is edge-sensitive: each rising or falling transition clears the internal watchdog timer. If no edge occurs within 1.68s (normal mode) or 35s (startup mode), WDO asserts low. Leaving WDI unconnected requires a 100kΩ pull-down to prevent timeout.
Can MAX6731UTLD3+T operate with supply voltages below 1.0V?
MAX6731UTLD3+T guarantees functional reset assertion down to VCC1 = +0.8V, but full specification (including watchdog timing and MR response) applies only for VCC1 ≥ +0.8V. Operation below +0.8V is not characterized and may result in undefined behavior or incomplete reset assertion.
Is MAX6731UTLD3+T pin-compatible with other MAX673x variants in SOT23-6?
Yes, MAX6731UTLD3+T shares identical SOT23-6 pinout with MAX6730UTLD3+T, MAX6732UTLD3+T, and MAX6733UTLD3+T. However, pin functions differ: MAX6731 provides push-pull RST/WDO, while MAX6730 uses open-drain outputs; MAX6732/MAX6733 add VCC2 input on pin 2 (replacing GND), altering functional compatibility.
MAX6731UTLD3+T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- SOT-23-6
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Programmable:
- -
- Type:
- Simple Reset/Power-On Reset
- Number of Voltages Monitored:
- 1
- Voltage - Threshold:
- 4.625V
- 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:
- SOT-6
MAX6731UTLD3+T FAQ
1.How can I place an order for MAX6731UTLD3+T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6731UTLD3+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 MAX6731UTLD3+T reliable?
The price and inventory of MAX6731UTLD3+T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6731UTLD3+T is usually 5 days.
3.What payment methods are accepted for MAX6731UTLD3+T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX6731UTLD3+T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX6731UTLD3+T?
MAX6731UTLD3+T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6731UTLD3+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 MAX6731UTLD3+T?
For technical support, including MAX6731UTLD3+T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6731UTLD3+T requirements.
6.How does Aetrix verify that MAX6731UTLD3+T is sourced from the original manufacturer or authorized distributors?
All MAX6731UTLD3+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 MAX6731UTLD3+T meets industry standards.
7.What is the process for return or replacement of MAX6731UTLD3+T?
All MAX6731UTLD3+T units undergo pre-shipment inspection (PSI). If there is an issue with MAX6731UTLD3+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 MAX6731UTLD3+T part is unused and in its original packaging.
Return procedure for MAX6731UTLD3+T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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