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Analog Devices Inc./Maxim Integrated MAX6721UTZWD3
- Part No.:
- MAX6721UTZWD3
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- SOT-23-6
- Datasheet:
-
MAX6721UTZWD3.pdf
- Description:
- IC SUPERVISOR 2 CHANNEL SOT23-6
- Quantity:
- Payment:
- Shipping:
Inventory:1,322
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Product details
Overview
MAX6721UTZWD3 from Maxim Integrated is a dual-voltage, ultra-low-voltage microprocessor supervisory circuit in 6-pin SOT23 package, monitoring VCC1 (4.625V threshold) and VCC2 (3.075V threshold) with 210ms reset timeout, watchdog timer (35s startup / 1.12s normal), and push-pull active-low RST output. It ensures reliable system reset during power-up, brownout, or software fault in battery-powered embedded controllers.
For engineers reviewing the MAX6721UTZWD3 datasheet, MAX6721UTZWD3 pinout, MAX6721UTZWD3 application, or MAX6721UTZWD3 equivalent, key selection criteria include dual-supply monitoring capability down to 0.8V operation, guaranteed reset validity across -40°C to +125°C, integrated watchdog with long startup period for boot sequencing, and push-pull RST output referenced to VCC1.
Technical Context
The MAX6721UTZWD3 implements dual independent voltage comparators with factory-trimmed thresholds (VTH1 = 4.625V, VTH2 = 3.075V), a dual-mode watchdog timer with 35s minimum initial timeout and 1.12s minimum normal timeout, and push-pull reset output logic referenced to VCC1. Its internal 50kΩ MR pullup and 200nA WDI unconnected-state detector enable robust manual reset and watchdog disable functionality without external components.
This device operates with VCC1 supply from 0.8V to 5.5V and VCC2 from 0.8V to 5.5V, guarantees valid reset assertion when either supply remains ≥0.8V, and features 20µs VCC-to-reset delay with immunity to sub-100ns VCC transients per typical operating characteristics.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC1 Threshold | 4.625V (factory-trimmed falling threshold; ensures reset assertion when primary supply drops below nominal 4.63V rail) |
| VCC2 Threshold | 3.075V (factory-trimmed falling threshold; monitors secondary 3.3V-compatible rail with 2.25% hysteresis) |
| Reset Timeout | 210ms (minimum duration RST remains asserted after all supplies recover; prevents premature processor release) |
| Watchdog Timeout | 1.12s (minimum normal-mode timeout; detects stalled firmware execution after boot completion) |
| Supply Current | 14µA (typ at 3.6V; enables >10-year battery life in always-on monitoring applications) |
| Operating Temp | -40°C to +125°C (fully specified industrial temperature range; supports under-hood automotive and industrial control) |
| Package | 6-pin SOT23 (2.9mm × 1.6mm footprint; compatible with high-density PCB layouts and automated assembly) |
Pinout & Package
MAX6721UTZWD3 uses a 6-pin SOT23 package with exposed pad (thermal enhancement). Pin 1 is RST/RST1 (active-low push-pull reset output), Pin 2 is GND, Pin 3 is MR (active-low manual-reset input with internal 50kΩ pullup to VCC1), Pin 4 is VCC2 (secondary supply input), Pin 5 is VCC1 (primary supply input), and Pin 6 is WDI (watchdog input with 200nA unconnected-state detection).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | RST/RST1 | Active-low push-pull reset output referenced to VCC1; asserts low on VCC1/VCC2 undervoltage, MR low, or watchdog timeout |
| 2 | GND | Ground reference for all internal comparators, timers, and output drivers; requires low-impedance connection to system ground plane |
| 3 | MR | Active-low manual-reset input with internal 50kΩ pullup to VCC1; debounced by 200ns glitch rejection and 1µs minimum pulse width requirement |
| 4 | VCC2 | Secondary supply input powering VCC2 comparator and RST2 logic; must be ≥0.8V for guaranteed reset validity |
| 5 | VCC1 | Primary supply input powering core logic, VCC1 comparator, and push-pull RST driver; defines VOH level for RST output |
| 6 | WDI | Watchdog input with 200nA unconnected-state detector; transitions reset state on rising/falling edges; left floating disables watchdog |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent voltage monitoring | Simultaneous VCC1 (4.625V) and VCC2 (3.075V) supervision with separate comparators and hysteresis |
| Dual-mode watchdog timer | 35s minimum startup period for safe boot sequence + 1.12s minimum normal timeout for runtime fault detection |
| Guaranteed reset validity | Operates correctly with VCC1 or VCC2 ≥0.8V; eliminates need for external brownout protection circuitry |
| Low-power operation | 14µA typical supply current at 3.6V enables multi-year battery life in portable equipment |
| Robust reset output | Push-pull RST referenced to VCC1 with 0.3V VOL at 3.2mA sink current; eliminates external pullup resistor |
Applications
| Industrial PLC Controller | Automotive Body Control Module |
|---|---|
Use Scenario: Monitoring 5V main MCU supply and 3.3V I/O expander rail in programmable logic controller cabinets exposed to wide ambient temperatures. IC Role / Device Role / Timing Role: Dual-supply supervisor asserting reset during cold-crank voltage sag or hot ambient-induced rail droop. Use Value: Prevents corrupted firmware execution during transient brownouts with guaranteed reset assertion down to 0.8V on either supply rail. | Use Scenario: Supervising 5V infotainment SoC supply and 3.3V CAN transceiver rail in vehicle body electronics modules. IC Role / Device Role / Timing Role: Reset generator with watchdog monitoring MCU activity during ignition cycles and sleep/wake transitions. Use Value: 35s watchdog startup period accommodates full SoC boot sequence before enabling runtime fault detection. |
| Medical Patient Monitor | Smart Energy Meter |
Use Scenario: Ensuring reliable power-on reset and continuous supervision of 5V analog front-end and 3.3V digital processing rails in battery-backed medical devices. IC Role / Device Role / Timing Role: Ultra-low-current (14µA) supervisor maintaining system integrity during extended standby periods. Use Value: Extends battery service life beyond 10 years while guaranteeing reset validity across full industrial temperature range. | Use Scenario: Monitoring 5V metering IC supply and 3.3V RF communication module rail in utility-grade smart meters deployed outdoors. IC Role / Device Role / Timing Role: Dual-rail supervisor with 210ms reset timeout preventing spurious resets during grid voltage fluctuations. Use Value: Factory-trimmed 4.625V/3.075V thresholds match standard power supply tolerances without calibration. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-voltage supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6720UTLTD3-T | No watchdog timer; identical VCC1/VCC2 thresholds and 210ms timeout | Suitable for systems requiring only power-supply monitoring without processor activity checking | Select when watchdog functionality is unnecessary to reduce BOM count and simplify firmware |
| TPS3808G33DBVR | Single-supply monitor (3.3V only); no VCC2 input or dual-threshold capability | Applicable only for single-rail systems; lacks secondary supply monitoring and adjustable RSTIN option | Choose for cost-sensitive designs with only one critical supply to monitor |
Compared with MAX6720UTLTD3-T and TPS3808G33DBVR, the MAX6721UTZWD3 uniquely combines dual-supply monitoring, factory-trimmed thresholds, and dual-mode watchdog in a 6-pin SOT23-enabling compact, reliable supervision of complex multi-rail embedded systems without external components.
Availability
MAX6721UTZWD3 is available at Aetrix Electronics and suitable for industrial PLC controllers, automotive body control modules, medical patient monitors, and smart energy meters requiring stable component supply across extended temperature ranges and long product lifecycles.
Supply support for MAX6721UTZWD3 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, mixed-signal, and power management ICs for demanding industrial, automotive, and medical applications.
The MAX6715A–MAX6729A/MAX6797A family delivers ultra-low-voltage, dual/triple-supply supervision with integrated watchdog and manual reset for space-constrained embedded systems requiring high reliability across harsh environments.
FAQ
What is the exact reset threshold voltage for VCC1 on the MAX6721UTZWD3?
The MAX6721UTZWD3 has a factory-trimmed VCC1 reset threshold of 4.625V (minimum 4.500V, maximum 4.750V) with 0.5% hysteresis. This value is fixed by the "T" suffix in the part number and applies to falling VCC1 transitions. The threshold remains stable across -40°C to +125°C with 20ppm/°C tempco, ensuring accurate brownout detection in industrial environments where the MAX6721UTZWD3 is commonly deployed.
Does the MAX6721UTZWD3 support monitoring a third voltage rail?
No, the MAX6721UTZWD3 does not support third-rail monitoring. It is a dual-supply supervisor with dedicated VCC1 and VCC2 inputs only. Models like MAX6723A–MAX6727A include RSTIN for adjustable third-voltage monitoring, but MAX6721UTZWD3 lacks this pin and internal circuitry. For triple-supply applications, engineers must select an alternative part number from the MAX6715A–MAX6729A family that includes RSTIN functionality and verify compatibility with the MAX6721UTZWD3's pinout and timing parameters.
What is the watchdog timeout behavior after power-on reset for the MAX6721UTZWD3?
After power-on reset, the MAX6721UTZWD3 enters a 35-second minimum startup watchdog period during which no timeout occurs regardless of WDI state. This allows complete system boot before watchdog monitoring begins. After the first valid WDI edge (rising or falling), it switches to normal mode with 1.12-second minimum timeout. If WDI remains static longer than 1.12s in normal mode, the MAX6721UTZWD3 asserts RST for 210ms. This dual-mode architecture prevents false resets during boot while ensuring rapid fault detection during runtime.
Can the MAX6721UTZWD3 operate with VCC1 below 1.0V?
Yes, the MAX6721UTZWD3 guarantees valid reset output logic down to VCC1 = 0.8V, as confirmed in Absolute Maximum Ratings and Electrical Characteristics tables. Below 0.8V, reset behavior is not specified. At 0.8V, VOL remains ≤0.3V with 1µA sink current, and VOH maintains ≥0.8×VCC1. This capability enables use in ultra-low-voltage systems such as energy-harvesting devices or deep-sleep battery applications where the MAX6721UTZWD3 provides reliable supervision during marginal supply conditions.
What package type and dimensions does the MAX6721UTZWD3 use?
The MAX6721UTZWD3 uses a 6-pin SOT23 package (JEDEC MO-178AA) measuring 2.9mm × 1.6mm × 1.1mm with 0.95mm pin pitch. It features an exposed thermal pad on the bottom surface for enhanced heat dissipation. This compact footprint supports high-density PCB layouts in space-constrained applications like portable medical devices and automotive ECUs where the MAX6721UTZWD3 is frequently implemented. The package is RoHS-compliant and rated for reflow soldering per JEDEC J-STD-020.
MAX6721UTZWD3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- SOT-23-6
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Type:
- Multi-Voltage Supervisor
- Number of Voltages Monitored:
- 2
- Voltage - Threshold:
- 1.665V, 2.313V
- 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-23-6
MAX6721UTZWD3 FAQ
1.How can I place an order for MAX6721UTZWD3 through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6721UTZWD3 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 MAX6721UTZWD3 reliable?
The price and inventory of MAX6721UTZWD3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6721UTZWD3 is usually 5 days.
3.What payment methods are accepted for MAX6721UTZWD3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX6721UTZWD3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX6721UTZWD3?
MAX6721UTZWD3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6721UTZWD3 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 MAX6721UTZWD3?
For technical support, including MAX6721UTZWD3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6721UTZWD3 requirements.
6.How does Aetrix verify that MAX6721UTZWD3 is sourced from the original manufacturer or authorized distributors?
All MAX6721UTZWD3 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 MAX6721UTZWD3 meets industry standards.
7.What is the process for return or replacement of MAX6721UTZWD3?
All MAX6721UTZWD3 units undergo pre-shipment inspection (PSI). If there is an issue with MAX6721UTZWD3, 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 MAX6721UTZWD3 part is unused and in its original packaging.
Return procedure for MAX6721UTZWD3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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