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Analog Devices Inc./Maxim Integrated MAX6865UK20D4S+T
- Part No.:
- MAX6865UK20D4S+T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- SC-74A, SOT-753
- Datasheet:
-
MAX6865UK20D4S+T.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:1,243
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Product details
Overview
The MAX6865UK20D4S+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, combining voltage monitoring, manual reset input (MR), and watchdog timer (WDI) functionality. It asserts an active-low push-pull RESET when VCC drops below 2.000V (±2.5%), MR is pulled low, or the watchdog expires after 3.3s (typ). Designed for ultra-low-power systems, it draws only 170nA (typ) at 2.5V and guarantees valid reset down to VCC = +1.1V.
For engineers reviewing the MAX6865UK20D4S+T datasheet, MAX6865UK20D4S+T pinout, MAX6865UK20D4S+T application, or MAX6865UK20D4S+T equivalent, this device serves as a critical power-on reset and fault recovery element in battery-constrained embedded systems where supply stability, software execution integrity, and long-term energy efficiency are non-negotiable.
Technical Context
The MAX6865UK20D4S+T implements a dual-threshold voltage monitor with factory-trimmed 2.000V reset threshold (±2.5%) and 0.5% hysteresis, ensuring immunity to short VCC transients (e.g., ≤40µs at 100mV overdrive). Its watchdog timer monitors WDI activity with a typical timeout of 3.3s (S-suffix), clearing on any rising/falling edge and disabling during RESET assertion.
This device integrates a 10kΩ internal MR pullup, supports CMOS-level MR/WDI inputs, and delivers a push-pull active-low RESET output with VOL ≤ 0.3V at ISINK = 1.2mA (VCC ≥ 2.38V). The reset timeout is fixed at 1200ms (D4 suffix), guaranteed over –40°C to +85°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold | 2.000V ±2.5% - ensures reliable brownout detection at nominal 2.0V rail without false triggers |
| Supply Current | 170nA (typ) at 2.5V - enables multi-year operation on coin-cell batteries in portable medical devices |
| Reset Timeout | 1200ms (min) - provides sufficient hold time for slow-starting µPs and peripheral initialization sequences |
| Watchdog Timeout | 3.3s (typ), S-suffix - balances responsiveness and tolerance for extended firmware loops in safety-critical applications |
| VCC Valid Range | 1.2V to 5.5V - supports operation across Li-ion, alkaline, and regulated 1.8V/2.5V/3.3V domains |
| RESET Output Type | Push-pull active-low - eliminates need for external pullup and ensures clean logic-level drive into µP reset pin |
| Operating Temp | –40°C to +85°C - qualified for industrial and portable consumer environments without derating |
Pinout & Package
Package: 5-pin SOT23-5, lead-free (RoHS-compliant), footprint-compatible with industry-standard 5-lead SOT23 layouts.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | RESET | Active-low push-pull reset output; sinks up to 1.2mA while asserted; referenced to VCC |
| 2 | GND | Ground reference for all internal circuits and reset timing; must be connected to system ground plane |
| 3 | MR | Active-low manual reset input; internally pulled up to VCC via 10kΩ; accepts CMOS logic levels |
| 4 | WDI | Watchdog input; edge-sensitive (rising/falling); clears internal timer on transition; immune to <150ns glitches |
| 5 | VCC | Supply voltage input and monitored 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 glucose monitors using CR2032 cells |
| Guaranteed RESET validity | RESET remains functional down to VCC = +1.1V - ensures deterministic reset behavior during deep brownout |
| Transient immunity | Immune to VCC glitches ≤40µs at 100mV overdrive - prevents spurious resets in noisy automotive or industrial environments |
| No external components | Integrates MR pullup, precision voltage reference, and watchdog oscillator - reduces BOM count and PCB area |
| Watchdog edge-triggered clear | WDI cleared by any edge (not level), enabling robust software supervision without tight timing constraints |
Applications
| Portable Glucose Monitors | Patient Vital Sign Loggers |
|---|---|
Use Scenario: Continuous blood glucose measurement with Bluetooth LE transmission and LCD display. IC Role / Device Role / Timing Role: Supervisory IC asserting RESET during battery voltage sag or firmware lockup; watchdog monitors main µP's BLE stack heartbeat. Use Value: Prevents corrupted sensor readings or missed alarms by forcing controlled reboot before battery depletion reaches critical levels. |
Use Scenario: Wearable ECG patch recording heart rate, SpO₂, and temperature over 72-hour clinical sessions. IC Role / Device Role / Timing Role: Voltage monitor and watchdog supervisor ensuring µP resumes sampling after transient power interruption or memory corruption. Use Value: Maintains data continuity and regulatory compliance (IEC 62304 Class B) by guaranteeing deterministic reset initiation and recovery timing. |
| Industrial Handheld Scanners | Smart Smoke Detectors |
Use Scenario: Rugged barcode scanner operating on rechargeable Li-ion with cold-temperature exposure (–20°C). IC Role / Device Role / Timing Role: Monitors 3.3V system rail and watches µP firmware execution during decode-intensive bursts. Use Value: Eliminates hang-ups during rapid scanning by triggering hard reset within 3.3s if firmware fails to toggle WDI - no user intervention required. |
Use Scenario: Battery-powered photoelectric smoke detector with self-test and wireless alert reporting. IC Role / Device Role / Timing Role: Ensures reliable power-on initialization and detects µP freeze during monthly self-test routines. Use Value: Meets UL 217 requirement for fail-safe operation by asserting RESET within 1200ms if self-test sequence stalls, preventing silent failure. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6864UK20D4S+T | No active-high RESET option; identical 2.000V threshold, 1200ms timeout, and 3.3s watchdog. | Lacks push-pull active-high RESET output - unsuitable for µPs requiring high-true reset assertion. | Select MAX6865UK20D4S+T when interfacing with µPs that require active-low reset polarity and push-pull drive strength. |
| TPS3836K20DBVR | Higher ICC (1.2µA), fixed 2.0V threshold, no watchdog, 200ms reset timeout, SOT23-5 package. | Provides basic voltage monitoring only - cannot replace watchdog functionality or extended 1200ms timeout. | Choose TPS3836K20DBVR only for cost-sensitive, non-watchdog applications where 200ms reset hold time suffices. |
Compared with MAX6864UK20D4S+T and TPS3836K20DBVR, the MAX6865UK20D4S+T uniquely combines ultra-low 170nA current, 1200ms reset timeout, and 3.3s watchdog in a single active-low push-pull output - making it the only drop-in solution for battery-powered medical and industrial devices demanding both long-duration reset hold and firmware execution supervision.
Availability
MAX6865UK20D4S+T is available at Aetrix Electronics and suitable for portable medical devices, industrial handhelds, smart sensors, and battery-backed IoT endpoints requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.
Supply support for MAX6865UK20D4S+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, mixed-signal, and power management ICs for demanding industrial, medical, and communications applications.
The MAX68xx family delivers nanopower supervisory solutions optimized for battery longevity and fault resilience in portable and remote embedded systems - with emphasis on guaranteed reset behavior under brownout and software lockup conditions.
FAQ
What is the exact reset threshold voltage of the MAX6865UK20D4S+T?
The MAX6865UK20D4S+T has a factory-trimmed reset threshold of 2.000V with ±2.5% tolerance over –40°C to +85°C, as defined by the "20" suffix in its part number per Maxim's Threshold Suffix Guide. This value is guaranteed by design and verified across temperature and supply voltage ranges.
Does the MAX6865UK20D4S+T support active-high reset output?
No, the MAX6865UK20D4S+T provides only an active-low push-pull RESET output (Pin 1). The "65" in the part number denotes the active-low push-pull configuration; active-high variants (e.g., MAX6862) use different suffixes and pinouts and are not functionally interchangeable with the MAX6865UK20D4S+T.
What is the watchdog timeout period for the MAX6865UK20D4S+T?
The MAX6865UK20D4S+T features a watchdog timeout period of 3.3s (typical), indicated by the "S" suffix in its order code. This value is specified with min/typ/max of 1.5s/3.3s/7.75s and is temperature-stable per Maxim's normalized tWD vs. temperature curve.
Can the MAX6865UK20D4S+T operate reliably below 1.8V?
Yes, the MAX6865UK20D4S+T operates from VCC = 1.2V to 5.5V and guarantees valid RESET assertion down to VCC = +1.1V. Its 170nA supply current and 2.000V threshold make it fully functional in 1.5V alkaline and 1.8V LDO-supplied systems, with VOL ≤ 0.3V maintained at ISINK = 1.2mA.
Is the MR input of the MAX6865UK20D4S+T internally pulled up?
Yes, the MR input (Pin 3) of the MAX6865UK20D4S+T includes an internal 10kΩ pullup resistor to VCC, allowing direct connection of a momentary switch to GND without external components. MR accepts CMOS logic levels and has 1µs minimum pulse width and 200ns glitch rejection.
MAX6865UK20D4S+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:
- 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
MAX6865UK20D4S+T FAQ
1.How can I place an order for MAX6865UK20D4S+T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6865UK20D4S+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 MAX6865UK20D4S+T reliable?
The price and inventory of MAX6865UK20D4S+T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6865UK20D4S+T is usually 5 days.
3.What payment methods are accepted for MAX6865UK20D4S+T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX6865UK20D4S+T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX6865UK20D4S+T?
MAX6865UK20D4S+T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6865UK20D4S+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 MAX6865UK20D4S+T?
For technical support, including MAX6865UK20D4S+T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6865UK20D4S+T requirements.
6.How does Aetrix verify that MAX6865UK20D4S+T is sourced from the original manufacturer or authorized distributors?
All MAX6865UK20D4S+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 MAX6865UK20D4S+T meets industry standards.
7.What is the process for return or replacement of MAX6865UK20D4S+T?
All MAX6865UK20D4S+T units undergo pre-shipment inspection (PSI). If there is an issue with MAX6865UK20D4S+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 MAX6865UK20D4S+T part is unused and in its original packaging.
Return procedure for MAX6865UK20D4S+T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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