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Analog Devices Inc./Maxim Integrated MAX6865UK39D3S+T
- Part No.:
- MAX6865UK39D3S+T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- SC-74A, SOT-753
- Datasheet:
-
MAX6865UK39D3S+T.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:3,145
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Product details
Overview
MAX6865UK39D3S+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in 5-pin SOT23 package, featuring ultra-low 170nA typical supply current, factory-trimmed 3.9V reset threshold (±2.5%), 300ms minimum reset timeout, and integrated watchdog timer with 3.3s typical timeout. It monitors VCC, responds to manual reset (MR), and asserts active-low push-pull RESET during brownout, power-up, or watchdog expiration - used in battery-powered medical and portable electronics.
For engineers reviewing the MAX6865UK39D3S+T datasheet, MAX6865UK39D3S+T pinout, MAX6865UK39D3S+T application, or MAX6865UK39D3S+T equivalent, this page delivers verified electrical specs, functional pin mapping, real-world use cases, and validated alternative parts for low-power µP reset and watchdog supervision in constrained environments.
Technical Context
The MAX6865UK39D3S+T implements a precision voltage monitor with hysteresis (0.5% of VTH) and guaranteed reset validity down to VCC = +1.1V. Its watchdog timer clears on any WDI edge and expires if WDI remains static >3.3s (typ), triggering a full reset timeout cycle.
This device integrates MR input with 10kΩ internal pullup, glitch rejection (200ns), and MR-to-reset delay of 250ns. The push-pull active-low RESET output sinks ≥50µA at 0.3V (VCC ≥1.1V) and supports noise-immune operation in portable systems with transient immunity up to 40µs at 100mV overdrive.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Current | 170nA typ at VCC = 1.8V - enables multi-year battery life in always-on monitoring devices |
| Reset Threshold | 3.900V ±2.5% - factory-trimmed for precise brownout detection at 3.3V/3.6V rail monitoring |
| Reset Timeout | 150ms min / 300ms typ / 300ms max - ensures µP initialization completes before release |
| Watchdog Timeout | 3.3s typ (S-suffix) - balances fault detection speed against false triggers in low-frequency firmware |
| VCC Operating Range | 1.2V to 5.5V - supports single-cell Li-ion, coin-cell, and multi-rail embedded systems |
| RESET Output Type | Push-pull active-low - eliminates external pullup, simplifies interface to 1.8V–5V µP reset inputs |
| MR Input Logic | Active-low with 10kΩ internal pullup - enables direct switch-to-GND connection without external components |
Pinout & Package
Package: 5-pin SOT23-5, lead-free, -40°C to +85°C operating range.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | RESET | Active-low push-pull reset output; drives low during VCC undervoltage, MR assertion, or watchdog timeout |
| 2 | GND | Ground reference for all internal circuits and reset timing; must connect to system ground plane |
| 3 | MR | Active-low manual reset input; internally pulled up to VCC (10kΩ); accepts CMOS-level signals or momentary switch |
| 4 | WDI | Watchdog input; rising/falling edges clear internal timer; static state >3.3s triggers reset |
| 5 | VCC | Main supply input monitored for reset; requires 0.1µF bypass capacitor to GND for noise immunity |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low ICC | 170nA typical supply current enables >10-year operation on CR2032 coin cell in sleep-mode medical sensors |
| Guaranteed reset validity | RESET remains functional down to VCC = +1.1V - ensures reliable reset assertion during deep brownout |
| Watchdog edge sensitivity | Detects WDI pulses as short as 150ns - supports high-speed firmware polling without missing transitions |
| No external components | Internal MR pullup, no RC timing network required - reduces BOM count and PCB area in space-constrained designs |
| Transient immunity | Immune to VCC glitches ≤40µs at 100mV overdrive - prevents spurious resets in noisy automotive or industrial environments |
Applications
| Glucose Monitor | Patient Vital Signs Logger |
|---|---|
Use Scenario: Continuous subcutaneous glucose sensing with Bluetooth LE transmission every 5 minutes. IC Role / Device Role / Timing Role: Supervises 3.3V LDO output powering MCU and sensor ASIC; asserts RESET if VCC drops below 3.9V or firmware hangs. Use Value: Prevents corrupted sensor data uploads by ensuring clean MCU restart after brownout or software lockup. |
Use Scenario: Wearable ECG patch recording heart rate and SpO₂ for 72-hour clinical studies. IC Role / Device Role / Timing Role: Monitors coin-cell-backed 1.8V rail; triggers watchdog reset if BLE stack fails to toggle WDI within 3.3s. Use Value: Eliminates field failures from unresponsive firmware while preserving battery life via 170nA quiescent draw. |
| Industrial Handheld Scanner | Smart Smoke Detector |
Use Scenario: Rugged barcode scanner powered by rechargeable Li-ion, operating in warehouses with ESD events. IC Role / Device Role / Timing Role: Provides MR-initiated reset via front-panel button and guards against VCC transients induced by motor drive coupling. Use Value: Ensures deterministic recovery after ESD-induced latch-up without requiring power cycle or service intervention. |
Use Scenario: Battery-operated smoke detector with self-test routine running every 24 hours. IC Role / Device Role / Timing Role: Supervises 3.0V alkaline stack; uses MR to initiate self-test sequence and watchdog to verify test completion. Use Value: Guarantees regulatory compliance by detecting and recovering from stuck test firmware before end-of-life battery depletion. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6864UK39D3S+T | No CT pin; identical 3.9V threshold, 300ms timeout, and 3.3s watchdog - differs only in RESET polarity (active-low push-pull same as MAX6865) | Same functional role; no design change needed - differs only in top-marking and internal logic mapping | Select MAX6864UK39D3S+T if legacy board layout uses identical pinout but requires cross-check of RESET assertion behavior in existing firmware |
| TPS3836K33DBVR | Fixed 3.08V threshold, 200ms timeout, no watchdog; 1.6µA ICC - higher current, no WDI capability | Suitable only for basic voltage monitoring without firmware supervision; cannot replace watchdog functionality | Choose TPS3836K33DBVR only for cost-sensitive, non-watchdog applications where 3.08V threshold aligns with system rail and 170nA ultra-low ICC is not required |
Compared with MAX6864UK39D3S+T, the MAX6865UK39D3S+T offers identical supervision performance with matching pinout and timing - making it a seamless functional replacement. Against TPS3836K33DBVR, MAX6865UK39D3S+T delivers 10x lower supply current and adds critical watchdog coverage, justifying its use in long-life, safety-critical portable systems.
Availability
MAX6865UK39D3S+T is available at Aetrix Electronics and suitable for glucose monitors, patient vital signs loggers, industrial handheld scanners, and smart smoke detectors requiring stable component supply across extended production lifecycles.
Supply support for MAX6865UK39D3S+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 connectivity in demanding industrial, medical, and portable applications.
The MAX6854–MAX6869 family delivers nanopower supervisory functions - specifically engineered for battery-critical systems needing reliable reset, manual recovery, and watchdog supervision without compromising runtime.
FAQ
What is the exact reset threshold voltage of MAX6865UK39D3S+T?
The MAX6865UK39D3S+T has a factory-trimmed reset threshold of 3.900V 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 "39" corresponds to 3.900V nominal. The device guarantees valid reset assertion down to VCC = +1.1V, supporting robust brownout detection in low-voltage systems.
Does MAX6865UK39D3S+T include a watchdog timer, and what is its timeout?
Yes, MAX6865UK39D3S+T includes an integrated watchdog timer with a typical timeout of 3.3 seconds (S-suffix), as specified in Table 3 (Watchdog Timeout). The timer resets on any rising or falling edge at the WDI pin and expires only if WDI remains static beyond that period - triggering a full reset timeout cycle. This is confirmed in the Pin Description and Selector Guide sections for MAX6865.
What is the reset timeout duration for MAX6865UK39D3S+T?
The MAX6865UK39D3S+T provides a fixed minimum reset timeout of 150ms, typical 300ms, and maximum 300ms (D3 suffix per Table 4). This timeout begins after VCC rises above the 3.9V threshold and MR deasserts, ensuring sufficient hold time for microprocessor initialization before release. The value is guaranteed across −40°C to +85°C.
What package and pin configuration does MAX6865UK39D3S+T use?
MAX6865UK39D3S+T uses a 5-pin SOT23-5 package with pin 1 = RESET (active-low push-pull), pin 2 = GND, pin 3 = MR (active-low manual reset), pin 4 = WDI (watchdog input), and pin 5 = VCC. This mapping is explicitly defined in the MAX6864/MAX6865/MAX6866 Pin Description section and confirmed in the Pin Configurations diagram.
Is MAX6865UK39D3S+T compatible with 1.8V I/O systems?
Yes, MAX6865UK39D3S+T operates from VCC = 1.2V to 5.5V and interfaces cleanly with 1.8V systems: its MR input accepts 0.3×VCC low and 0.7×VCC high thresholds, and its push-pull RESET output drives to <0.3V low (ISINK = 50µA, VCC ≥1.1V) and >0.8×VCC high - fully compliant with 1.8V logic levels when VCC = 1.8V.
MAX6865UK39D3S+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:
- 3.9V
- Output:
- Push-Pull, Totem Pole
- Reset:
- Active Low
- Reset Timeout:
- 150ms Minimum
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
MAX6865UK39D3S+T FAQ
1.How can I place an order for MAX6865UK39D3S+T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6865UK39D3S+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 MAX6865UK39D3S+T reliable?
The price and inventory of MAX6865UK39D3S+T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6865UK39D3S+T is usually 5 days.
3.What payment methods are accepted for MAX6865UK39D3S+T?
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4.How is shipping managed for MAX6865UK39D3S+T?
MAX6865UK39D3S+T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6865UK39D3S+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 MAX6865UK39D3S+T?
For technical support, including MAX6865UK39D3S+T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6865UK39D3S+T requirements.
6.How does Aetrix verify that MAX6865UK39D3S+T is sourced from the original manufacturer or authorized distributors?
All MAX6865UK39D3S+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 MAX6865UK39D3S+T meets industry standards.
7.What is the process for return or replacement of MAX6865UK39D3S+T?
All MAX6865UK39D3S+T units undergo pre-shipment inspection (PSI). If there is an issue with MAX6865UK39D3S+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 MAX6865UK39D3S+T part is unused and in its original packaging.
Return procedure for MAX6865UK39D3S+T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX6865UK39D3S+T Tags
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