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Analog Devices Inc./Maxim Integrated MAX6721UTSDD3+T
- Part No.:
- MAX6721UTSDD3+T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- SOT-23-6
- Datasheet:
-
MAX6721UTSDD3+T.pdf
- Description:
- IC SUPERVISOR 2 CHANNEL SOT23-6
- Quantity:
- Payment:
- Shipping:
Inventory:3,195
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Product details
Overview
MAX6721UTSDD3+T from Maxim Integrated is a dual-voltage microprocessor supervisory circuit in 6-pin SOT23 package, monitoring VCC1 (4.625V threshold) and VCC2 (3.075V threshold) with 210ms reset timeout, watchdog input, and manual reset capability - used to ensure reliable power-up and brownout recovery in telecom and industrial embedded systems.
For engineers reviewing the MAX6721UTSDD3+T datasheet, MAX6721UTSDD3+T pinout, MAX6721UTSDD3+T application, or MAX6721UTSDD3+T equivalent, key selection criteria include dual-supply monitoring accuracy (±1.5% VTH), guaranteed reset validity down to VCC = 0.8V, 14µA supply current at 3.6V, and integrated watchdog with 35s startup / 1.12s normal timeout.
Technical Context
The MAX6721UTSDD3+T implements independent voltage comparators for VCC1 and VCC2, each with factory-trimmed thresholds (4.625V and 3.075V respectively), hysteresis of 0.5%, and tempco of 20ppm/°C. Reset assertion occurs on any supply drop below threshold, with minimum 210ms timeout after all supplies recover.
It integrates a dual-mode watchdog timer: 35s minimum initial timeout after reset for system boot, followed by 1.12s minimum normal timeout requiring WDI edge transitions. Manual reset (MR) features internal 50kΩ pullup and 1µs minimum pulse width support.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC1 Threshold | 4.625V (factory-trimmed, ±1.5% tolerance) - ensures precise primary supply monitoring for 5V or 4.8V rails |
| VCC2 Threshold | 3.075V (factory-trimmed, ±1.5% tolerance) - supports accurate secondary supply supervision for 3.3V I/O or core rails |
| Reset Timeout | 210ms (typical) - provides sufficient hold time for processor initialization and peripheral stabilization |
| Watchdog Timeout | 1.12s (min normal mode) - enables rapid fault detection during runtime without false triggers during boot |
| Supply Current | 14µA (typ at 3.6V) - minimizes quiescent power in battery-backed or energy-sensitive applications |
| Operating Temp | -40°C to +85°C - qualified for industrial and telecom equipment operating in extended ambient conditions |
| Reset Valid Down To | VCC1 or VCC2 ≥ 0.8V - guarantees functional reset output even during deep brownout conditions |
Pinout & Package
MAX6721UTSDD3+T is housed in a 6-pin SOT23-6 package (2.9mm × 1.6mm × 1.1mm), RoHS-compliant and lead-free (+T suffix), with thermal pad omitted. Pin 1 marked via dot; pins numbered counterclockwise from marking.
| Pin | Circuit Role | Design Meaning |
|---|---|---|
| 1 | RST | Active-low open-drain reset output - requires external pullup; asserts when VCC1/VCC2 drops below threshold or MR pulled low |
| 2 | GND | Ground reference for all internal comparators, watchdog, and reset logic |
| 3 | MR | Active-low manual reset input - internal 50kΩ pullup to VCC1; 1µs minimum pulse width ensures noise immunity |
| 4 | VCC2 | Secondary supply input - powers internal circuitry when > VCC1 and sets VCC2 threshold reference |
| 5 | VCC1 | Primary supply input - powers device when > VCC2 and defines main reset threshold reference |
| 6 | WDI | Watchdog input - rising/falling edges reset 1.12s timeout; long initial 35s window accommodates boot sequences |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent voltage monitors | Separate precision comparators for VCC1 (4.625V) and VCC2 (3.075V) eliminate need for external resistor dividers |
| Guaranteed reset validity at low VCC | Functional reset output asserted reliably down to VCC1 or VCC2 = 0.8V - critical for brownout resilience |
| Dual-mode watchdog timer | 35s startup timeout prevents spurious resets during boot; 1.12s runtime timeout detects software hangs |
| Low-power operation | 14µA typical supply current at 3.6V enables use in always-on, battery-critical subsystems |
| Immunity to VCC transients | Validated resistance to short negative-going glitches (e.g., <20µs at 100mV overdrive) avoids nuisance resets |
Applications
| Telecom Power Sequencing | Industrial PLC Controller |
|---|---|
Use Scenario: Monitoring dual 5V/3.3V rails in base station power management unit during cold start and hot-swap events. IC Role / Device Role / Timing Role: Dual-supply supervisor asserting reset until both rails stabilize above 4.625V and 3.075V, then holding for 210ms. Use Value: Prevents firmware execution before power integrity is confirmed, eliminating boot failures in field-deployed units. |
Use Scenario: Ensuring deterministic restart after brownout in programmable logic controller with isolated I/O modules. IC Role / Device Role / Timing Role: Supervising main 24V-derived 5V logic rail and 3.3V FPGA core rail, with MR tied to front-panel reset button. Use Value: Guarantees clean reset pulse even if 5V rail dips to 0.9V - meeting IEC 61000-4-11 immunity requirements. |
| Network Switch ASIC Initialization | Medical Diagnostic Imaging Module |
Use Scenario: Coordinating power-up sequence of multi-rail ASIC supply (1.2V core, 1.8V I/O, 3.3V aux) in 10G Ethernet switch line card. IC Role / Device Role / Timing Role: Using VCC1/VCC2 monitoring plus WDI to validate ASIC firmware handshake before enabling high-speed SerDes. Use Value: Dual-mode watchdog prevents lockup during complex register initialization while allowing full boot time via 35s startup window. |
Use Scenario: Securing safe shutdown and restart of FPGA-based image processing module during AC mains interruption. IC Role / Device Role / Timing Role: Monitoring backup 3.3V supercap rail and main 5V DC/DC output, with MR linked to emergency stop circuit. Use Value: 14µA quiescent current extends battery holdup time; 0.8V reset validity ensures last-chance reset before data corruption. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-voltage supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6722UTSDD3+T | Push-pull RST output (vs. open-drain on MAX6721UTSDD3+T); identical thresholds, timeout, and watchdog specs | Eliminates need for external pullup resistor; better suited for direct drive of µP reset pins with weak internal pullups | Select MAX6722UTSDD3+T when interfacing with processors lacking strong reset pin pullups or requiring active-high reset polarity compatibility |
| TPS3808G33DBVR | Single-supply monitor (3.3V only); no watchdog or MR input; 200ms timeout; 1.6µA supply current | Lacks dual-monitoring, watchdog, and manual reset - suitable only for simple 3.3V-only systems | Choose TPS3808G33DBVR only for cost-sensitive, single-rail applications where MAX6721UTSDD3+T features are unused |
Compared with MAX6722UTSDD3+T, the MAX6721UTSDD3+T offers open-drain flexibility for level-shifting and wired-OR configurations; versus TPS3808G33DBVR, it delivers full dual-rail supervision, watchdog, and MR functionality essential for complex embedded systems.
Availability
MAX6721UTSDD3+T is available at Aetrix Electronics and suitable for telecom infrastructure, industrial control, and medical diagnostics requiring stable component supply, long-term lifecycle support, and guaranteed reset reliability under brownout conditions.
Supply support for MAX6721UTSDD3+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 management, sensing, and interface applications across industrial, automotive, and communications markets.
The MAX6715–MAX6729 family targets multivoltage embedded systems needing compact, ultra-low-power supervision with dual/three-rail monitoring, watchdog, and manual reset - optimized for space-constrained telecom and industrial PCBs.
FAQ
What is the exact reset threshold voltage for VCC1 and VCC2 on the MAX6721UTSDD3+T?
The MAX6721UTSDD3+T has factory-trimmed reset thresholds of 4.625V for VCC1 and 3.075V for VCC2, with ±1.5% tolerance over temperature. These values are encoded in the "SD" suffix per Maxim's Reset Voltage Threshold Suffix Guide and verified in the Electrical Characteristics table of the official datasheet.
Does the MAX6721UTSDD3+T support watchdog functionality, and what are its timing modes?
Yes, the MAX6721UTSDD3+T includes a dual-mode watchdog timer: a 35s minimum initial timeout after any reset event (power-up, MR, or watchdog timeout) to accommodate system boot, followed by a 1.12s minimum normal timeout requiring WDI edge transitions during runtime - both timings are production-guaranteed.
What package type and pin count does the MAX6721UTSDD3+T use?
The MAX6721UTSDD3+T uses a 6-pin SOT23-6 package (2.9mm × 1.6mm × 1.1mm), RoHS-compliant and lead-free, with pin 1 identified by a dot marking. This matches the ordering information in the datasheet's "Ordering Information" section for MAX6721UT_ _D_ -T variants.
How does the MAX6721UTSDD3+T ensure valid reset output during deep brownout conditions?
The MAX6721UTSDD3+T guarantees correct reset logic state (asserted low on RST) even when VCC1 or VCC2 drops to 0.8V - documented in the Absolute Maximum Ratings and Detailed Description sections. This is achieved via internal biasing and comparator design, enabling reliable last-chance reset before complete power loss.
Is the manual reset input (MR) of the MAX6721UTSDD3+T internally pulled up, and what is its minimum pulse width?
Yes, the MR pin of the MAX6721UTSDD3+T features an internal 50kΩ pullup resistor to VCC1 and accepts TTL/CMOS logic levels. Its minimum pulse width is 1µs, validated across temperature and supply ranges - ensuring robust noise rejection while supporting momentary switch interfaces without external debounce.
MAX6721UTSDD3+T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- SOT-23-6
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Type:
- Multi-Voltage Supervisor
- Number of Voltages Monitored:
- 2
- Voltage - Threshold:
- 0.788V, 2.925V
- Output:
- Open Drain or Open Collector
- 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
MAX6721UTSDD3+T FAQ
1.How can I place an order for MAX6721UTSDD3+T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6721UTSDD3+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 MAX6721UTSDD3+T reliable?
The price and inventory of MAX6721UTSDD3+T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6721UTSDD3+T is usually 5 days.
3.What payment methods are accepted for MAX6721UTSDD3+T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX6721UTSDD3+T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX6721UTSDD3+T?
MAX6721UTSDD3+T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6721UTSDD3+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 MAX6721UTSDD3+T?
For technical support, including MAX6721UTSDD3+T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6721UTSDD3+T requirements.
6.How does Aetrix verify that MAX6721UTSDD3+T is sourced from the original manufacturer or authorized distributors?
All MAX6721UTSDD3+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 MAX6721UTSDD3+T meets industry standards.
7.What is the process for return or replacement of MAX6721UTSDD3+T?
All MAX6721UTSDD3+T units undergo pre-shipment inspection (PSI). If there is an issue with MAX6721UTSDD3+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 MAX6721UTSDD3+T part is unused and in its original packaging.
Return procedure for MAX6721UTSDD3+T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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