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Analog Devices Inc./Maxim Integrated MAX6865UK44D5S+T
- Part No.:
- MAX6865UK44D5S+T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- SC-74A, SOT-753
- Datasheet:
-
MAX6865UK44D5S+T.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:4,115
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Product details
Overview
The MAX6865UK44D5S+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, featuring ultra-low 170nA typical supply current, a factory-trimmed 4.266V (min) / 4.375V (typ) / 4.484V (max) reset threshold, 300ms minimum reset timeout period, 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 glucose monitors and portable medical devices.
For engineers reviewing the MAX6865UK44D5S+T datasheet, MAX6865UK44D5S+T pinout, MAX6865UK44D5S+T application, or MAX6865UK44D5S+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 output type, and compatibility with low-voltage µP systems requiring long battery life.
Technical Context
The MAX6865UK44D5S+T implements a dual-trigger reset architecture: it asserts RESET when VCC falls below its 4.375V nominal threshold, when MR is pulled low, or when the watchdog input (WDI) remains static beyond 3.3s. Its internal watchdog timer clears on any WDI edge, MR assertion, or RESET assertion - enabling robust detection of software lockup in embedded firmware.
This device uses BiCMOS process technology (2848 transistors) and integrates a precision voltage reference, RC-based timeout generator, and glitch-immune digital logic. The reset output remains asserted for ≥300ms after VCC exceeds threshold and MR deasserts, with guaranteed VOL ≤0.3V at ISINK = 1.2mA (VCC ≥2.12V) and VOH ≥0.8×VCC at ISOURCE = 500µA.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Current | 170nA typical at VCC = 1.8V; enables >10-year battery life in coin-cell–powered devices. |
| Reset Threshold Voltage | 4.266V (min) / 4.375V (typ) / 4.484V (max); factory-trimmed for precise 3.3V system monitoring. |
| Reset Timeout Period | 300ms minimum (D5 option); ensures µP completes full initialization before release. |
| Watchdog Timeout | 3.3s typical (S suffix); balances responsiveness and tolerance for brief firmware stalls. |
| VCC Operating Range | 1.2V to 5.5V; supports operation across Li-ion, alkaline, and regulated 3.3V/5V rails. |
| Reset Validity Limit | Guaranteed RESET assertion down to VCC = +1.1V; prevents spurious release during deep brownout. |
| WDI Pulse Width | 150ns minimum; tolerates fast GPIO toggling without false watchdog clears. |
Pinout & Package
MAX6865UK44D5S+T is housed in a lead-free 5-pin SOT23-5 package (JEDEC MO-178AA), with 1.3mm × 2.9mm footprint and 0.95mm height. Pin 1 is RESET (active-low push-pull), Pin 2 is GND, Pin 3 is MR (active-low manual reset), Pin 4 is WDI (watchdog input), and Pin 5 is VCC (supply monitor input).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - RESET | Active-low push-pull reset output | Drives µP reset pin directly; no external pullup required; sinks ≥1.2mA at VCC ≥2.12V. |
| 2 - GND | Ground reference | Must connect to system ground plane; shared return for all internal circuits and RESET sink current. |
| 3 - MR | Active-low manual reset input | Internally pulled up to VCC via 10kΩ; accepts CMOS logic; 1µs minimum pulse width. |
| 4 - WDI | Watchdog input | Edge-sensitive; clears internal timer on rising/falling transition; immune to <200ns glitches. |
| 5 - VCC | Supply voltage monitor input | Monitors system rail; requires 0.1µF bypass capacitor to GND for noise immunity. |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low ICC | 170nA typical supply current extends battery life in always-on portable medical sensors. |
| Factory-trimmed VTH | ±2.5% threshold accuracy eliminates external resistor networks for 4.375V 3.3V-system supervision. |
| Watchdog immunity | Clears on any WDI edge - prevents stuck-loop masking and ensures true firmware execution monitoring. |
| VCC transient rejection | Immune to 100mV VCC glitches ≤40µs duration, reducing false resets in noisy power environments. |
| No external components | Integrates reference, timing, and logic - eliminates discrete R/C networks and reduces BOM count by 3–5 parts. |
Applications
| Glucose Monitoring Systems | Patient Vital Sign Monitors |
|---|---|
|
Use Scenario: Continuous glucose meters powered by CR2032 coin cells operating in variable temperature environments. IC Role / Device Role / Timing Role: Supervises 3.3V LDO output, triggers hardware reset on brownout or firmware hang, and validates µP boot sequence. Use Value: 170nA ICC enables >5-year shelf life; 4.375V threshold matches 3.3V rail tolerance; 300ms timeout accommodates slow analog sensor startup. |
Use Scenario: Portable ECG/SpO₂ monitors with Bluetooth LE connectivity and real-time waveform processing. IC Role / Device Role / Timing Role: Provides fail-safe reset initiation via MR button and autonomous watchdog supervision of ARM Cortex-M4 firmware. Use Value: 3.3s watchdog timeout allows full BLE stack handshake before reset; WDI edge sensitivity detects task-level hangs without CPU overhead. |
| Industrial Handheld Scanners | Smart Wearable Health Trackers |
|
Use Scenario: Rugged barcode scanners using single-cell Li-ion batteries and cold-chain logistics firmware. IC Role / Device Role / Timing Role: Monitors main 3.3V rail during rapid power cycling and asserts RESET if VCC dips below 4.266V during motor activation. Use Value: Guaranteed reset validity to VCC = +1.1V prevents partial boot corruption; MR input enables field-service hard reset without disassembly. |
Use Scenario: Multi-sensor wrist-worn trackers with optical HR/SpO₂, accelerometer, and NFC, running on 15mAh LiPo. IC Role / Device Role / Timing Role: Integrates power-on reset, user-initiated reset (via touch interface), and watchdog supervision of sensor fusion algorithm. Use Value: 5-pin SOT23 footprint minimizes PCB area; open-drain-compatible RESET output allows level-shifting to 1.8V µP I/O domain. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS3836K33DBVR | Fixed 3.08V reset threshold; no watchdog; 200ms timeout; 1.6µA ICC. | Lacks watchdog functionality; suited only for basic power-monitoring where firmware integrity is externally managed. | Select when cost sensitivity outweighs need for autonomous code-execution monitoring. |
| STM6315SW33DX | 3.08V threshold; 200ms timeout; 1.2µA ICC; no WDI; push-pull active-low RESET. | Lower supply current than TPS3836 but no watchdog; not suitable for safety-critical firmware supervision. | Prefer for ultra-low-power applications without watchdog requirements and where 3.08V threshold aligns with system rail. |
Compared with TPS3836K33DBVR and STM6315SW33DX, the MAX6865UK44D5S+T delivers 10× lower supply current, integrated watchdog with 3.3s timeout, and a 4.375V threshold optimized for 3.3V systems - making it uniquely suited for battery-constrained medical devices requiring both power efficiency and firmware reliability assurance.
Availability
MAX6865UK44D5S+T is available at Aetrix Electronics and suitable for portable medical devices, battery-powered industrial scanners, and wearable health monitors requiring stable component supply, long-term lifecycle support, and guaranteed lead-free compliance.
Supply support for MAX6865UK44D5S+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 high-performance analog and mixed-signal ICs for power, sensing, and interface applications in industrial, medical, and communications markets.
The MAX6865UK44D5S+T belongs to the MAX6854–MAX6869 nanopower supervisory family, engineered specifically for ultra-low-power, safety-critical embedded systems where extended battery life and autonomous firmware fault detection are mandatory.
FAQ
What is the exact reset threshold voltage of the MAX6865UK44D5S+T?
The MAX6865UK44D5S+T has a factory-trimmed reset threshold of 4.266V (minimum), 4.375V (typical), and 4.484V (maximum) at TA = +25°C. This corresponds to the "44" suffix in the part number per Maxim's Threshold Suffix Guide (Table 2), and is specified over -40°C to +85°C with ±2.5% hysteresis.
Does the MAX6865UK44D5S+T require external components to operate?
No, the MAX6865UK44D5S+T requires no external resistors or capacitors for core functionality. A 0.1µF ceramic bypass capacitor between VCC and GND is recommended for noise immunity, but no timing or threshold-setting components are needed - all functions are fully integrated.
How does the watchdog timer in the MAX6865UK44D5S+T respond to firmware activity?
The MAX6865UK44D5S+T watchdog timer clears on every rising or falling edge at the WDI pin. If WDI remains static for longer than 3.3s (typical), the timer expires and asserts RESET for 300ms. This ensures detection of hung loops or stalled tasks without requiring periodic high-frequency toggling.
Can the MAX6865UK44D5S+T be used in systems with VCC below 1.8V?
Yes - the MAX6865UK44D5S+T operates from VCC = 1.2V to 5.5V and guarantees valid RESET assertion down to VCC = +1.1V. At 1.2V, supply current is 190nA (typ), and RESET output remains functional with VOL ≤0.3V at ISINK = 50µA.
What is the function of Pin 4 (WDI) on the MAX6865UK44D5S+T?
Pin 4 is the Watchdog Input (WDI). It is an edge-sensitive digital input that resets the internal watchdog timer on each rising or falling transition. If no edge occurs within 3.3s (typ), the device asserts RESET - providing autonomous detection of firmware execution failures in the MAX6865UK44D5S+T.
MAX6865UK44D5S+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:
- 4.375V
- Output:
- Push-Pull, Totem Pole
- Reset:
- Active Low
- Reset Timeout:
- 300ms Minimum
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
MAX6865UK44D5S+T FAQ
1.How can I place an order for MAX6865UK44D5S+T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6865UK44D5S+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 MAX6865UK44D5S+T reliable?
The price and inventory of MAX6865UK44D5S+T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6865UK44D5S+T is usually 5 days.
3.What payment methods are accepted for MAX6865UK44D5S+T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX6865UK44D5S+T transactions.
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4.How is shipping managed for MAX6865UK44D5S+T?
MAX6865UK44D5S+T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6865UK44D5S+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 MAX6865UK44D5S+T?
For technical support, including MAX6865UK44D5S+T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6865UK44D5S+T requirements.
6.How does Aetrix verify that MAX6865UK44D5S+T is sourced from the original manufacturer or authorized distributors?
All MAX6865UK44D5S+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 MAX6865UK44D5S+T meets industry standards.
7.What is the process for return or replacement of MAX6865UK44D5S+T?
All MAX6865UK44D5S+T units undergo pre-shipment inspection (PSI). If there is an issue with MAX6865UK44D5S+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 MAX6865UK44D5S+T part is unused and in its original packaging.
Return procedure for MAX6865UK44D5S+T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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