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Analog Devices Inc./Maxim Integrated MAX6721UTYDD3+T
- Part No.:
- MAX6721UTYDD3+T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- -
- Datasheet:
-
MAX6721UTYDD3+T.pdf
- Description:
- IC SUPERVISOR MPU SOT23-6
- Quantity:
- Payment:
- Shipping:
Inventory:1,150
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Product details
Overview
MAX6721UTYDD3+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 timer (35s startup / 1.12s normal), and power-fail input. It ensures reliable system reset during brownout in telecom power supplies and industrial controllers.
For engineers reviewing the MAX6721UTYDD3+T datasheet, MAX6721UTYDD3+T pinout, MAX6721UTYDD3+T application, or MAX6721UTYDD3+T equivalent, key selection criteria include dual-supply monitoring range (1.8–5.0V / 0.9–3.3V), guaranteed reset validity down to VCC = 0.8V, low 14µA supply current, and integrated WDI/PFI functionality for fault-tolerant embedded systems.
Technical Context
The MAX6721UTYDD3+T implements independent voltage comparators for VCC1 and VCC2 with factory-trimmed thresholds (4.625V ±125mV and 3.075V ±75mV), hysteresis of 0.5%, and temperature coefficient of 20ppm/°C. Its dual-mode watchdog uses a 35s minimum startup period followed by 1.12s normal timeout, triggered by WDI edge transitions.
This device integrates a power-fail comparator (PFI threshold = 626.5mV ±15.5mV) driving an open-drain PFO output, manual reset input (MR) with 50kΩ internal pullup, and push-pull RST output referenced to VCC1. All reset logic remains valid while either VCC1 or VCC2 ≥ 0.8V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC1 Threshold | 4.625V (±125mV) - sets primary supply brownout detection point for 5V rail monitoring |
| VCC2 Threshold | 3.075V (±75mV) - enables secondary supply supervision for 3.3V I/O or core rails |
| Reset Timeout | 210ms (min) - ensures µP completes boot sequence before releasing reset |
| Watchdog Timeout | 1.12s (min) normal mode - detects software hangs without false triggers during transient noise |
| Supply Current | 14µA (typ at 3.6V) - supports battery-backed systems with multi-year runtime |
| Operating Temp | -40°C to +85°C - qualified for industrial and telecom equipment environments |
| PFI Threshold | 626.5mV (±15.5mV) - allows precise external resistor-divider setup for custom power-fail warning |
Pinout & Package
MAX6721UTYDD3+T is housed in a 6-pin SOT23-6 package (2.9mm × 1.6mm × 1.1mm), RoHS-compliant and lead-free (+T suffix).
| Pin | Circuit Role | Design Meaning |
|---|---|---|
| 1 | RST | Active-low push-pull reset output referenced to VCC1; asserts when VCC1/VCC2 drop below threshold or WDI times out |
| 2 | GND | Ground reference for all internal comparators and output drivers |
| 3 | MR | Active-low manual reset input with 50kΩ internal pullup to VCC1; forces reset on logic-low pulse ≥1µs |
| 4 | VCC2 | Secondary supply input (0.9–3.3V range); powers internal circuitry when > VCC1 and sets VCC2 threshold reference |
| 5 | VCC1 | Primary supply input (1.8–5.0V range); powers device when > VCC2 and sets VCC1 threshold reference |
| 6 | WDI | Watchdog input; rising/falling edge resets 1.12s timeout counter; long idle (>35s) enables startup mode |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent voltage monitoring | Simultaneous supervision of VCC1 (4.625V) and VCC2 (3.075V) with separate comparators and hysteresis |
| Guaranteed reset validity down to 0.8V | Ensures correct RST logic state even during deep brownout-critical for fail-safe shutdown sequences |
| Dual-mode watchdog timer | 35s startup window accommodates complex boot firmware; 1.12s runtime monitoring prevents silent hangs |
| Power-fail input with PFO output | PFI accepts external divider for custom trip point; PFO asserts immediately (no timeout) for early warning interrupts |
| Low quiescent current | 14µA typical at 3.6V enables use in always-on subsystems without compromising battery life |
Applications
| Telecom Power Management | Industrial PLC Controllers |
|---|---|
Use Scenario: Monitoring redundant 48V DC-DC converter outputs and 3.3V FPGA I/O rails in base station power modules. IC Role / Device Role / Timing Role: Dual-supply supervisor asserting RST during simultaneous VCC1/VCC2 undervoltage events; PFO signals power-fail interrupt to MCU. Use Value: Prevents corrupted FPGA configuration by holding reset until both rails stabilize above 4.625V and 3.075V respectively. |
Use Scenario: Supervising 24V fieldbus supply and 5V logic rail in programmable logic controller backplane. IC Role / Device Role / Timing Role: Detects brownout on either rail and initiates controlled I/O shutdown via RST assertion; MR enables emergency local reset. Use Value: Eliminates need for discrete RC reset circuits-reduces BOM count and improves timing accuracy across temperature. |
| Network Router Boot Integrity | Medical Diagnostic Equipment |
Use Scenario: Validating 12V PoE injector output and 1.8V CPU core supply during router cold start. IC Role / Device Role / Timing Role: Enforces 210ms reset hold time after both supplies exceed thresholds; WDI monitors bootloader execution. Use Value: Guarantees CPU does not execute invalid code due to premature release from reset during marginal supply conditions. |
Use Scenario: Ensuring clean power-up of imaging sensor array and ADC reference supply in portable ultrasound units. IC Role / Device Role / Timing Role: Monitors dual supplies with tight threshold tolerances; PFO triggers non-reset alert for battery-level warning display. Use Value: Supports Class II medical safety requirements by providing deterministic reset behavior under low-VCC stress. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-voltage supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6722UTYDD3+T | Push-pull RST output (same pinout), identical thresholds/timing but no PFI/PFO function | Lacks power-fail monitoring capability; suitable only where PFO interrupt is unnecessary | Select MAX6722UTYDD3+T when system requires dual-supply reset only-reduces external component count |
| TPS3808G33DBVR | Single-supply monitor (3.3V threshold), 200ms timeout, no WDI or PFI; SOT23-6 package | Cannot supervise dual rails simultaneously; requires separate IC for second supply | Choose TPS3808G33DBVR only for cost-sensitive single-rail designs where dual monitoring is handled externally |
Compared with MAX6722UTYDD3+T and TPS3808G33DBVR, the MAX6721UTYDD3+T uniquely combines dual-supply monitoring, integrated watchdog, and power-fail detection in one 6-pin SOT23-enabling compact, high-reliability supervision without external components or layout compromises.
Availability
MAX6721UTYDD3+T is available at Aetrix Electronics and suitable for telecom infrastructure, industrial control systems, and medical diagnostics requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for MAX6721UTYDD3+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 in demanding industrial and communications environments.
The MAX6715–MAX6729 family delivers ultra-low-voltage supervisory functions targeting multirail embedded systems where space, power, and reliability constrain discrete reset solutions.
FAQ
What is the exact reset threshold voltage for VCC1 on MAX6721UTYDD3+T?
The MAX6721UTYDD3+T has a factory-trimmed VCC1 reset threshold of 4.625V, with a tolerance of ±125mV over temperature. This value is encoded in the "YD" suffix per Maxim's Reset Voltage Threshold Suffix Guide and is verified across -40°C to +85°C operation. The threshold applies specifically to the primary supply monitored at the VCC1 pin.
Does MAX6721UTYDD3+T support monitoring a third voltage rail?
No, MAX6721UTYDD3+T is a dual-voltage supervisor and does not include the RSTIN input required for triple-voltage monitoring. That function is reserved for MAX6723–MAX6727 variants. MAX6721UTYDD3+T monitors only VCC1 and VCC2, but adds PFI for auxiliary power-fail detection independent of the main supply rails.
What is the watchdog timeout behavior after power-up for MAX6721UTYDD3+T?
Upon power-up or reset assertion, MAX6721UTYDD3+T enters a 35s minimum startup watchdog mode. After the first valid WDI transition (rising or falling edge), it switches to 1.12s minimum normal timeout. This dual-mode architecture prevents false resets during lengthy boot sequences while ensuring rapid hang detection during runtime.
Can MAX6721UTYDD3+T operate with VCC1 = 1.8V and VCC2 = 1.2V?
Yes, MAX6721UTYDD3+T operates with VCC1 as low as 1.8V and VCC2 as low as 0.9V. Its specified VCC1 range is 1.8V–5.0V and VCC2 range is 0.9V–3.3V. The 4.625V/3.075V thresholds remain valid, and reset output logic is guaranteed down to VCC1 or VCC2 = 0.8V-making it compatible with modern low-voltage SoC platforms.
Is the PFO output on MAX6721UTYDD3+T open-drain or push-pull?
The PFO output on MAX6721UTYDD3+T is open-drain, requiring an external pullup resistor. This is confirmed by the Selector Guide (MAX6721 row shows "√" under "POWER-FAIL INPUT/OUTPUT" and "open drain" in parentheses). Unlike MAX6729, it does not offer push-pull PFO-ensuring compatibility with mixed-voltage interrupt lines.
MAX6721UTYDD3+T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- *
- Package/Case:
- -
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Type:
- -
- Number of Voltages Monitored:
- -
- Voltage - Threshold:
- -
- Output:
- -
- Reset:
- -
- Reset Timeout:
- -
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- -
- Supplier Device Package:
- -
MAX6721UTYDD3+T FAQ
1.How can I place an order for MAX6721UTYDD3+T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6721UTYDD3+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 MAX6721UTYDD3+T reliable?
The price and inventory of MAX6721UTYDD3+T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6721UTYDD3+T is usually 5 days.
3.What payment methods are accepted for MAX6721UTYDD3+T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX6721UTYDD3+T transactions.
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4.How is shipping managed for MAX6721UTYDD3+T?
MAX6721UTYDD3+T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6721UTYDD3+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 MAX6721UTYDD3+T?
For technical support, including MAX6721UTYDD3+T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6721UTYDD3+T requirements.
6.How does Aetrix verify that MAX6721UTYDD3+T is sourced from the original manufacturer or authorized distributors?
All MAX6721UTYDD3+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 MAX6721UTYDD3+T meets industry standards.
7.What is the process for return or replacement of MAX6721UTYDD3+T?
All MAX6721UTYDD3+T units undergo pre-shipment inspection (PSI). If there is an issue with MAX6721UTYDD3+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 MAX6721UTYDD3+T part is unused and in its original packaging.
Return procedure for MAX6721UTYDD3+T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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