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Analog Devices Inc./Maxim Integrated MAX6865UK18D2L+T
- Part No.:
- MAX6865UK18D2L+T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- SC-74A, SOT-753
- Datasheet:
-
MAX6865UK18D2L+T.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:4,033
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Product details
Overview
The MAX6865UK18D2L+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in 5-pin SOT23 package, combining voltage monitoring (1.8V reset threshold), manual reset input (MR), and watchdog timer (209s typical timeout) with ultra-low 170nA supply current. It asserts an active-high push-pull RESET signal during VCC brownout, MR assertion, or watchdog timeout, maintaining reset for 40ms minimum after recovery - ideal for battery-powered glucose monitors and portable medical devices.
For engineers reviewing the MAX6865UK18D2L+T datasheet, MAX6865UK18D2L+T pinout, MAX6865UK18D2L+T application, or MAX6865UK18D2L+T equivalent, key selection criteria include its guaranteed reset validity down to VCC = +1.1V, immunity to short VCC transients (<40µs at 100mV overdrive), pin-selectable reset timeout options, and compatibility with low-voltage µP systems requiring long battery life and robust fault detection.
Technical Context
This device implements a precision bandgap-based voltage monitor with ±2.5% reset threshold accuracy and 0.5% hysteresis, coupled with a digital watchdog timer that clears on any WDI edge transition and expires if WDI remains static beyond 209s (typ). Its internal 10kΩ MR pullup and glitch rejection (200ns) enable direct switch interfacing without external components.
The active-high push-pull RESET output delivers VOH ≥ 0.8×VCC (ISOURCE = 500µA) and VOL ≤ 0.3V (ISINK = 1.2mA), ensuring reliable logic-level signaling across 1.2V–5.5V VCC range. Reset assertion is guaranteed valid down to VCC = +1.1V, supporting operation during deep brownout conditions common in energy-constrained embedded systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold Voltage | 1.800V ±2.5% - factory-trimmed for precise brownout detection at nominal 1.8V supply rails |
| Supply Current (typ) | 170nA at VCC = 1.8V - enables multi-year battery life in always-on portable medical sensors |
| Reset Timeout Period | 40ms (min) - ensures µP initialization completes before release, preventing premature code execution |
| Watchdog Timeout | 209s (typ), L-suffix - provides long-duration software execution monitoring for infrequent but critical tasks |
| VCC Operating Range | 1.2V to 5.5V - supports wide-input battery systems including single-cell Li-ion and coin-cell applications |
| Reset Output Type | Active-high push-pull - eliminates need for external pullup resistor, simplifies PCB layout and reduces BOM count |
| Guaranteed Reset Validity | Down to VCC = +1.1V - maintains deterministic reset behavior during severe undervoltage events |
Pinout & Package
Package: 5-pin SOT23-5, lead-free, surface-mount, 2.9mm × 1.6mm footprint.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | RESET (active-high) | Push-pull output asserted high during fault; sinks 1.2mA max, sources 500µA min at VCC ≥ 2.38V |
| 2 | GND | Ground reference for all internal circuits; must connect to system ground plane with low-impedance path |
| 3 | MR (active-low) | Manual reset input with 10kΩ internal pullup to VCC; accepts CMOS logic levels; 1µs minimum pulse width |
| 4 | WDI | Watchdog input cleared by rising/falling edges; detects pulses ≥150ns; resets internal timer on each transition |
| 5 | VCC | Primary supply and monitored voltage rail; 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 battery life in coin-cell-powered patient monitors |
| Reset threshold accuracy | ±2.5% over -40°C to +85°C ensures consistent brownout response across industrial temperature range |
| Watchdog immunity | Clears on any WDI edge - prevents false timeouts from noisy or slow-rising signals in embedded firmware |
| VCC transient immunity | Immune to <40µs VCC glitches at 100mV overdrive - avoids spurious resets in electrically noisy portable environments |
| No external components | Integrated MR pullup, precision voltage reference, and timing elements eliminate discrete BOM items |
Applications
| Glucose Monitoring Systems | Patient Vital Sign Loggers |
|---|---|
Use Scenario: Continuous glucose sensing with Bluetooth LE transmission powered by CR2032 coin cell. IC Role / Device Role / Timing Role: Supervises 1.8V MCU supply, triggers reset on battery sag or firmware hang via WDI monitoring. Use Value: Prevents corrupted sensor readings or missed BLE advertisements by enforcing deterministic restart within 40ms of fault detection. |
Use Scenario: Wearable ECG patch recording heart rate and SpO₂ for 72-hour clinical trials. IC Role / Device Role / Timing Role: Monitors 3.3V LDO output feeding ADC and BLE SoC; asserts RESET on brownout or software lockup. Use Value: Ensures data integrity by halting logging during undervoltage and restarting cleanly - no lost waveform segments. |
| Portable Diagnostic Handhelds | Low-Power IoT Edge Sensors |
Use Scenario: Battery-operated ultrasound probe with FPGA-based beamforming and ARM Cortex-M4 host. IC Role / Device Role / Timing Role: Provides dual-fault protection: VCC supervision (1.8V core rail) and watchdog monitoring of FPGA configuration state machine. Use Value: Guarantees safe power-up sequencing and recovers from FPGA bitstream corruption without manual intervention. |
Use Scenario: Soil moisture/temperature node using LoRaWAN, sleeping >99.9% of time on AA alkaline cells. IC Role / Device Role / Timing Role: Enables ultra-deep sleep mode while continuously monitoring VCC decay and waking MCU only on valid WDI activity. Use Value: Extends field lifetime to 5+ years by eliminating leakage paths and enabling sub-200nA system sleep current. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6864UK18D2S+T | Lacks long watchdog timeout; uses S-suffix (3.3s typ) instead of L-suffix (209s typ) | Suitable for fast-recovery systems where frequent watchdog refresh is feasible | Select when firmware can guarantee WDI toggling every ~2 seconds; not appropriate for infrequent-task monitoring |
| TPS3837K33DBVR | Fixed 3.3V reset threshold; no watchdog; 1.2µA supply current (7× higher than MAX6865UK18D2L+T) | Targeted at simpler power-good monitoring without software fault detection | Choose only if watchdog functionality is unnecessary and 3.3V rail supervision suffices |
Compared with MAX6864UK18D2S+T and TPS3837K33DBVR, the MAX6865UK18D2L+T uniquely combines 1.8V precision reset, 209s watchdog timeout, and 170nA quiescent current - making it optimal for long-duration, low-voltage medical and industrial sensors requiring both brownout and software-execution supervision.
Availability
MAX6865UK18D2L+T is available at Aetrix Electronics and suitable for glucose monitors, patient vital sign loggers, portable diagnostic handhelds, and low-power IoT edge sensors requiring stable component supply with full lifecycle support.
Supply support for MAX6865UK18D2L+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 industrial, medical, and communications markets.
The MAX6854–MAX6869 family was engineered specifically for ultra-low-power microprocessor supervision in battery-critical systems, emphasizing nanoscale current consumption, guaranteed reset validity at sub-1.2V VCC, and integrated watchdog reliability.
FAQ
What is the exact reset threshold voltage of the MAX6865UK18D2L+T?
The MAX6865UK18D2L+T has a factory-trimmed reset threshold voltage of 1.800V with ±2.5% tolerance over the full -40°C to +85°C operating temperature range. This value is confirmed in Table 2 (Threshold Suffix Guide) of the datasheet, where suffix '18' corresponds to 1.800V nominal. The device guarantees reset assertion when VCC falls below this threshold and deassertion only after VCC exceeds it by sufficient margin to ensure hysteresis.
Does the MAX6865UK18D2L+T require external components for basic operation?
No, the MAX6865UK18D2L+T operates autonomously with no external components required. It integrates a 10kΩ internal pullup on the MR pin, precision voltage reference, reset timeout timer, and watchdog circuitry. Only a 0.1µF ceramic bypass capacitor from VCC to GND is recommended for noise immunity - this is standard practice, not a functional requirement for reset generation.
How does the watchdog timer in the MAX6865UK18D2L+T behave during reset assertion?
While RESET is asserted (high), the MAX6865UK18D2L+T watchdog timer is disabled and does not count. The timer resumes counting only after RESET deasserts. This prevents spurious timeouts during power-up or recovery sequences. The timer clears on any WDI edge transition (rising or falling), and expires only if WDI remains static longer than the 209s (typ) L-suffix timeout period.
What is the minimum VCC level at which the MAX6865UK18D2L+T guarantees valid RESET output?
The MAX6865UK18D2L+T guarantees valid RESET output down to VCC = +1.1V, as explicitly stated in the Electrical Characteristics table and Detailed Description section. Below this voltage, RESET behavior is not specified. This specification ensures deterministic reset signaling during deep brownout conditions common in battery-discharge scenarios.
Is the MAX6865UK18D2L+T pin-compatible with other devices in the MAX68xx family?
The MAX6865UK18D2L+T shares the same 5-pin SOT23-5 package and pinout as MAX6864/MAX6866/MAX6867/MAX6868/MAX6869 variants, with identical assignments: Pin 1 = RESET (active-high), Pin 2 = GND, Pin 3 = MR, Pin 4 = WDI, Pin 5 = VCC. However, it is not pin-compatible with MAX6854–MAX6863 series, which lack WDI or use CT pin instead of WDI.
MAX6865UK18D2L+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:
- 1.8V
- Output:
- Push-Pull, Totem Pole
- Reset:
- Active Low
- Reset Timeout:
- 40ms Minimum
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
MAX6865UK18D2L+T FAQ
1.How can I place an order for MAX6865UK18D2L+T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6865UK18D2L+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 MAX6865UK18D2L+T reliable?
The price and inventory of MAX6865UK18D2L+T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6865UK18D2L+T is usually 5 days.
3.What payment methods are accepted for MAX6865UK18D2L+T?
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4.How is shipping managed for MAX6865UK18D2L+T?
MAX6865UK18D2L+T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6865UK18D2L+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 MAX6865UK18D2L+T?
For technical support, including MAX6865UK18D2L+T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6865UK18D2L+T requirements.
6.How does Aetrix verify that MAX6865UK18D2L+T is sourced from the original manufacturer or authorized distributors?
All MAX6865UK18D2L+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 MAX6865UK18D2L+T meets industry standards.
7.What is the process for return or replacement of MAX6865UK18D2L+T?
All MAX6865UK18D2L+T units undergo pre-shipment inspection (PSI). If there is an issue with MAX6865UK18D2L+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 MAX6865UK18D2L+T part is unused and in its original packaging.
Return procedure for MAX6865UK18D2L+T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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