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Analog Devices Inc./Maxim Integrated MAX6865UK42D4L+T
- Part No.:
- MAX6865UK42D4L+T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- SC-74A, SOT-753
- Datasheet:
-
MAX6865UK42D4L+T.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:2,197
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Product details
Overview
The MAX6865UK42D4L+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, featuring ultra-low 170nA typical supply current, factory-trimmed 4.200V reset threshold (±2.5%), 1200ms minimum reset timeout, manual reset input (MR), and watchdog timer with 209s typical timeout. It monitors VCC in battery-powered systems to assert active-low push-pull RESET during brownout, power-up, or software fault conditions.
For engineers reviewing the MAX6865UK42D4L+T datasheet, MAX6865UK42D4L+T pinout, MAX6865UK42D4L+T application, or MAX6865UK42D4L+T equivalent, this device is selected for low-power embedded systems requiring guaranteed reset validity down to VCC = +1.1V, immunity to short VCC transients, and dual-fault detection via voltage monitoring and watchdog supervision.
Technical Context
The MAX6865UK42D4L+T implements a dual-monitoring architecture: a precision bandgap-based voltage detector triggers reset when VCC falls below 4.200V, while a dedicated watchdog timer monitors WDI activity-resetting if no edge occurs within 209s (typ). Both reset sources share a common 1200ms minimum timeout period after fault clearance.
Its internal 10kΩ MR pullup enables direct connection to momentary switches; the WDI input accepts CMOS-level edges ≥150ns wide and clears the watchdog on any rising or falling transition. The push-pull active-high RESET output is referenced to VCC and guarantees VOH ≥ 0.8×VCC at ISOURCE = 500µA.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Current | 170nA typical at VCC = 1.8V - enables multi-year operation on coin-cell batteries without compromising supervision reliability. |
| Reset Threshold Voltage | 4.200V ±2.5% - precisely matches 4.2V Li-ion battery full-charge voltage or 4.3V system rail, preventing premature reset during nominal operation. |
| Reset Timeout Period | 1200ms minimum - ensures µP completes full power-up initialization and firmware self-test before release from reset. |
| Watchdog Timeout | 209s typical (L-suffix) - provides long-duration software execution monitoring suitable for infrequent but critical control loops. |
| VCC Validity Range | Reset asserted valid down to VCC = +1.1V - maintains deterministic behavior during deep brownout, avoiding metastable reset states. |
| MR Input Pulse Width | 1µs minimum - supports fast, debounced manual reset via short switch closures without external timing components. |
| WDI Edge Sensitivity | Detects 150ns pulses - allows low-overhead software toggling without dedicated high-speed GPIO resources. |
Pinout & Package
Package: 5-pin SOT23-5, lead-free, -40°C to +85°C operating range.
| Pin | Circuit Role | Design Meaning |
|---|---|---|
| 1 | RESET | Active-high push-pull reset output - drives µP reset pin directly; no external pullup required; sinks 1.2mA at VOL ≤ 0.3V. |
| 2 | GND | Ground reference - must be connected to system ground plane; shared return for all internal circuits. |
| 3 | MR | Active-low manual reset input - internally pulled up to VCC (10kΩ); asserts reset when pulled ≤0.3×VCC for ≥1µs. |
| 4 | WDI | Watchdog input - clears internal timer on any rising or falling edge; ignores static high/low states >209s. |
| 5 | VCC | Supply voltage input - monitored for reset threshold violation; bypass with 0.1µF capacitor to GND for noise immunity. |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low ICC | 170nA typical enables >10-year battery life in glucose monitors using CR2032 cells. |
| Guaranteed reset validity to VCC = +1.1V | Ensures deterministic reset assertion during deep brownout, eliminating race conditions in low-voltage µP startup. |
| No external components required | Integrates MR pullup, reset timer, watchdog oscillator, and voltage reference - reduces BOM count and PCB area by 3+ passives. |
| Immunity to short VCC transients | Rejects ≤40µs glitches at 100mV overdrive - prevents spurious resets in electrically noisy portable environments. |
| CMOS-compatible WDI/MR inputs | Accepts standard logic levels (VIH ≥ 0.7×VCC, VIL ≤ 0.3×VCC) - interfaces directly with µP GPIO without level-shifting. |
Applications
| Portable Medical Devices | Battery-Powered IoT Sensors |
|---|---|
Use Scenario: Continuous glucose monitoring (CGM) patch worn for 14 days on single coin cell. IC Role / Device Role / Timing Role: Supervises 3.3V system rail and validates µP boot sequence; watchdog enforces firmware health check every 200s. Use Value: 170nA ICC extends battery life beyond clinical requirement; 4.200V threshold aligns with Li-ion discharge curve to avoid false resets during normal operation. |
Use Scenario: LoRaWAN soil moisture sensor deployed in remote fields, waking every 6 hours. IC Role / Device Role / Timing Role: Monitors 3.0V LDO output during wake-up; asserts reset if voltage sags below 4.200V due to cold temperature or aging battery. Use Value: 1200ms timeout ensures complete RF initialization before µP exits reset; 209s watchdog catches hung sleep-state transitions. |
| Industrial Handheld Terminals | Wearable Health Trackers |
Use Scenario: Rugged barcode scanner used in warehouses with frequent drop-induced power interruptions. IC Role / Device Role / Timing Role: Detects VCC brownout during mechanical shock; MR input enables field technician-initiated recovery without power cycle. Use Value: 40µs transient immunity prevents false resets from vibration-induced supply noise; MR pulse width tolerance simplifies switch interface design. |
Use Scenario: ECG-enabled smartwatch with 7-day battery runtime and motion-triggered firmware updates. IC Role / Device Role / Timing Role: Supervises 1.8V core rail; watchdog monitors update routine progress to prevent bricking during OTA failure. Use Value: Push-pull active-high RESET eliminates need for external pullup resistor, saving space in ultra-thin form factor; 1.1V VCC validity ensures safe shutdown at end-of-battery. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6864UK42D4L+T | Same 4.200V threshold, 1200ms timeout, and 209s watchdog, but features active-low push-pull RESET output instead of active-high. | Requires µP with active-low reset input; incompatible with designs relying on active-high assertion logic. | Select when existing schematic uses active-low reset signaling or when interfacing with legacy µPs lacking active-high reset support. |
| TPS3838K33DBVR | 3.3V fixed threshold, 200ms timeout, no watchdog; 1.6µA ICC - 10× higher supply current than MAX6865UK42D4L+T. | Suitable only for non-battery-critical applications where watchdog supervision is unnecessary and longer timeout is not required. | Choose only if cost sensitivity outweighs battery life requirements and watchdog functionality is omitted from system architecture. |
Compared with MAX6864UK42D4L+T, the MAX6865UK42D4L+T provides identical supervision accuracy and timing but delivers active-high RESET for direct compatibility with modern low-voltage µPs. Against TPS3838K33DBVR, it offers 10× lower ICC and integrated watchdog-critical for medical and IoT deployments where runtime and fault coverage are non-negotiable.
Availability
MAX6865UK42D4L+T is available at Aetrix Electronics and suitable for portable medical devices, battery-powered IoT sensors, industrial handheld terminals, and wearable health trackers requiring stable component supply across extended production lifecycles.
Supply support for MAX6865UK42D4L+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 in demanding industrial, medical, and communications systems.
The MAX6854–MAX6869 family was engineered specifically for ultra-low-power microprocessor supervision in battery-constrained environments, integrating voltage monitoring, manual reset, and watchdog functions into minimal 5-pin SOT23 packages.
FAQ
What is the exact reset threshold voltage of the MAX6865UK42D4L+T?
The MAX6865UK42D4L+T has a factory-trimmed reset threshold voltage of 4.200V with ±2.5% tolerance over temperature (-40°C to +85°C). This value is confirmed in Table 2 (Threshold Suffix Guide) of the datasheet, where suffix "42" corresponds to 4.200V nominal. The device guarantees valid reset assertion down to VCC = +1.1V, making it suitable for systems with steep Li-ion discharge profiles.
Does the MAX6865UK42D4L+T require external components for basic operation?
No, the MAX6865UK42D4L+T operates autonomously with no external components required. Its internal 10kΩ MR pullup resistor, precision voltage reference, reset timeout capacitor-less timer, and watchdog oscillator eliminate the need for external resistors, capacitors, or crystals. A 0.1µF VCC bypass capacitor is recommended for noise immunity but is not strictly required for functional operation per datasheet specifications.
How does the watchdog timer in the MAX6865UK42D4L+T respond to software faults?
The MAX6865UK42D4L+T watchdog timer expires if no edge (rising or falling) is detected on the WDI pin for longer than 209s (typical, L-suffix). Upon expiration, it asserts the active-high RESET output for the full 1200ms timeout period. The timer clears on any WDI edge, manual reset assertion, or reset output assertion - enabling robust detection of hung code loops without requiring precise software timing margins.
What is the supply current consumption of the MAX6865UK42D4L+T across its operating voltage range?
The MAX6865UK42D4L+T draws 170nA typical supply current at VCC = 1.8V, 190nA at 3.3V, and 210nA at 5.0V (TA = +25°C). Over temperature (-40°C to +85°C), ICC remains below 400nA. This ultra-low current enables multi-year operation on primary batteries and is validated in the Electrical Characteristics table under "Supply Current (ICC)" with test conditions explicitly referencing VCC = 1.8V, 3.3V, and 5.0V.
Can the MAX6865UK42D4L+T be used with microcontrollers that have active-low reset inputs?
No - the MAX6865UK42D4L+T provides an active-high push-pull RESET output, meaning it drives high during reset assertion. It is incompatible with µPs requiring active-low reset signaling. For such systems, the pin-compatible MAX6864UK42D4L+T (active-low push-pull) or MAX6866UK42D4L+T (active-low open-drain) should be selected instead, as confirmed in the Selector Guide and Pin Descriptions sections of the datasheet.
MAX6865UK42D4L+T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- SC-74A, SOT-753
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Type:
- Simple Reset/Power-On Reset
- Number of Voltages Monitored:
- 1
- Voltage - Threshold:
- 4.2V
- Output:
- Push-Pull, Totem Pole
- Reset:
- Active Low
- Reset Timeout:
- 1.2s Minimum
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
MAX6865UK42D4L+T FAQ
1.How can I place an order for MAX6865UK42D4L+T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6865UK42D4L+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 MAX6865UK42D4L+T reliable?
The price and inventory of MAX6865UK42D4L+T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6865UK42D4L+T is usually 5 days.
3.What payment methods are accepted for MAX6865UK42D4L+T?
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4.How is shipping managed for MAX6865UK42D4L+T?
MAX6865UK42D4L+T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6865UK42D4L+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 MAX6865UK42D4L+T?
For technical support, including MAX6865UK42D4L+T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6865UK42D4L+T requirements.
6.How does Aetrix verify that MAX6865UK42D4L+T is sourced from the original manufacturer or authorized distributors?
All MAX6865UK42D4L+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 MAX6865UK42D4L+T meets industry standards.
7.What is the process for return or replacement of MAX6865UK42D4L+T?
All MAX6865UK42D4L+T units undergo pre-shipment inspection (PSI). If there is an issue with MAX6865UK42D4L+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 MAX6865UK42D4L+T part is unused and in its original packaging.
Return procedure for MAX6865UK42D4L+T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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