My Inquiry
My Account
Analog Devices Inc./Maxim Integrated MAX6866UK31D3S+T
- Part No.:
- MAX6866UK31D3S+T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- SC-74A, SOT-753
- Datasheet:
-
MAX6866UK31D3S+T.pdf
- Description:
- IC MPU SUPERVISOR SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:4,016
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
MAX6866UK31D3S+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in 5-pin SOT23 package, featuring 3.075V factory-trimmed reset threshold (suffix '31'), 150ms minimum reset timeout (D3), and 3.3s typical watchdog timeout (S). It monitors VCC, asserts active-low open-drain RESET on brownout/manual reset/watchdog expiry, and guarantees valid reset down to VCC = +1.1V. Used in battery-powered glucose monitors and portable medical devices for reliable power-on reset and firmware crash recovery.
For engineers reviewing the MAX6866UK31D3S+T datasheet, MAX6866UK31D3S+T pinout, MAX6866UK31D3S+T application, or MAX6866UK31D3S+T equivalent, key selection criteria include its ultra-low 170nA supply current, 3.075V ±2.5% reset threshold accuracy, 150ms–300ms reset timeout tolerance, 3.3s watchdog period, and compatibility with noisy low-voltage systems requiring guaranteed reset assertion below 1.2V.
Technical Context
The MAX6866UK31D3S+T integrates voltage monitoring, manual reset input (MR), and watchdog timer (WDI) in a single BiCMOS IC. Its reset logic asserts open-drain RESET low when VCC falls below 3.075V, MR is pulled low, or WDI remains static beyond 3.3s - with reset held for ≥150ms after recovery.
It features internal 10kΩ MR pullup, 150ns WDI pulse detection, immunity to ≤40µs VCC transients at 100mV overdrive, and guaranteed RESET validity down to VCC = +1.1V. No external components are required beyond standard 0.1µF VCC bypass.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold | 3.075V ±2.5% - factory-trimmed for precise brownout detection at nominal 3.0V rail |
| Supply Current | 170nA typical at +25°C - enables multi-year operation on coin-cell batteries |
| Reset Timeout | 150ms min (D3 option) - ensures µP completes power stabilization before release |
| Watchdog Timeout | 3.3s typical (S suffix) - balances fault detection speed against false-trigger risk in embedded firmware |
| VCC Operating Range | 1.2V to 5.5V - supports wide-input battery systems including single Li-ion and dual alkaline |
| RESET Output Type | Open-drain active-low - allows level-shifting to diverse µP I/O voltages up to 5.5V |
| Guaranteed Reset Validity | Down to VCC = +1.1V - ensures deterministic reset state during deep brownout |
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 open-drain reset output; requires external pullup; sinks 50µA at VCC ≥1.1V |
| 2 | GND | Ground reference for all internal circuitry and reset timing |
| 3 | MR | Active-low manual reset input; internally pulled up to VCC via 10kΩ; 1µs minimum pulse width |
| 4 | WDI | Watchdog input; clears internal timer on any edge; detects pulses ≥150ns |
| 5 | VCC | Supply voltage input and monitored rail; bypass with 0.1µF capacitor to GND |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low ICC | 170nA typical - extends battery life in always-on portable medical sensors |
| Factory-trimmed VTH | 3.075V ±2.5% - eliminates external resistor divider for accurate 3.0V system supervision |
| Watchdog immunity | Detects WDI edges ≥150ns - robust against PCB trace noise and slow GPIO transitions |
| VCC transient rejection | Immune to ≤40µs glitches at 100mV overdrive - prevents spurious resets in noisy environments |
| No external components | Self-contained supervision - reduces BOM count and layout area in space-constrained wearables |
Applications
| Glucose Monitoring Systems | Patient Vital Sign Loggers |
|---|---|
Use Scenario: Continuous glucose meter (CGM) with Bluetooth LE transmission running on CR2032 coin cell. IC Role / Device Role / Timing Role: Supervises 3.0V LDO output; triggers hardware reset if firmware hangs or battery sags below 2.9V. Use Value: Prevents corrupted sensor readings or missed BLE connection attempts by enforcing clean restart within 150ms of fault detection. |
Use Scenario: Portable ECG/SpO₂ logger recording data to internal flash during ambulatory use. IC Role / Device Role / Timing Role: Monitors main 3.3V supply and watches WDI toggled by ADC sampling ISR every 200ms. Use Value: Guarantees recovery from stuck firmware loops without user intervention, preserving clinical data integrity. |
| Smart Hearing Aids | Wearable Fall Detectors |
Use Scenario: Rechargeable hearing aid with ultra-low-power DSP and MEMS microphone. IC Role / Device Role / Timing Role: Provides power-on reset and watchdog supervision of audio processing firmware. Use Value: Enables <1µA shutdown current and ensures reliable boot after battery insertion or charging cycle. |
Use Scenario: Battery-powered wearable detecting falls via 3-axis accelerometer and alerting caregivers. IC Role / Device Role / Timing Role: Supervises 2.8V buck converter output and monitors WDI toggled by motion-detection algorithm. Use Value: Eliminates risk of silent failure during critical fall event by forcing reset if motion analysis stalls. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6864UK31D3S+T | Same 3.075V threshold, 150ms timeout, 3.3s watchdog, but push-pull active-low RESET output | Requires no external pullup; not suitable where level-shifting to higher voltage rails is needed | Select when driving 3.0V µP directly and minimizing external components is prioritized over voltage translation flexibility |
| TPS3836K33DBVR | 3.3V fixed threshold, 200ms reset timeout, no watchdog timer, 1.6µA ICC | Lacks WDI functionality; higher supply current limits battery lifetime in always-on designs | Choose only for cost-sensitive, non-watchdog applications where 3.3V rail supervision suffices and µA-level ICC is acceptable |
Compared with MAX6866UK31D3S+T, MAX6864UK31D3S+T offers identical supervision parameters but different output drive architecture, while TPS3836K33DBVR trades off watchdog capability and nanopower operation for lower unit cost in simpler systems.
Availability
MAX6866UK31D3S+T is available at Aetrix Electronics and suitable for portable medical devices, battery-powered wearables, and low-power IoT edge sensors requiring stable component supply across extended product lifecycles.
Supply support for MAX6866UK31D3S+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 demanding industrial, medical, and communications applications.
The MAX6854–MAX6869 family delivers nanopower supervision for battery-critical systems, with the MAX6866UK31D3S+T specifically engineered for 3.0V–3.3V portable medical electronics needing both voltage monitoring and firmware watchdog protection.
FAQ
What is the exact reset threshold voltage of the MAX6866UK31D3S+T?
The MAX6866UK31D3S+T has a factory-trimmed reset threshold of 3.075V, 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 '31' corresponds to 3.075V nominal. The device guarantees valid reset assertion down to VCC = +1.1V, making it suitable for deep brownout conditions.
Does the MAX6866UK31D3S+T require external components for basic operation?
No, the MAX6866UK31D3S+T operates autonomously with no external components required for core supervision. A 0.1µF ceramic capacitor from VCC to GND is recommended for noise suppression, and an external pullup resistor on the open-drain RESET pin is necessary for proper logic-level translation. The MR input includes a built-in 10kΩ pullup to VCC, eliminating need for external biasing.
What is the watchdog timeout behavior of the MAX6866UK31D3S+T?
The MAX6866UK31D3S+T features a 3.3s typical watchdog timeout period (S suffix), with min/max values of 1.5s and 7.75s. The internal timer resets on any rising or falling edge at WDI and triggers RESET if WDI remains static beyond this period. Watchdog operation is disabled during active reset assertion and resumes immediately upon reset deassertion.
Can the MAX6866UK31D3S+T supervise a 1.8V microcontroller supply?
Yes, the MAX6866UK31D3S+T operates over VCC = 1.2V to 5.5V and guarantees valid RESET output down to VCC = +1.1V. Its 3.075V reset threshold is intended for monitoring higher rails (e.g., 3.0V or 3.3V), but it can supervise a 1.8V system if configured to monitor a scaled or regulated auxiliary voltage. Direct 1.8V rail supervision would require a different threshold variant (e.g., suffix '18' = 1.800V).
How does the MAX6866UK31D3S+T handle short VCC transients?
The MAX6866UK31D3S+T is immune to VCC transients ≤40µs in duration when the overdrive is 100mV above the 3.075V threshold, per the "Maximum VCC Transient Duration vs. Reset Threshold Overdrive" graph. This design prevents spurious resets caused by switching noise or load-step events, ensuring supervision reliability in electrically noisy portable equipment.
MAX6866UK31D3S+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:
- Active
- Programmable:
- Not Verified
- Type:
- Simple Reset/Power-On Reset
- Number of Voltages Monitored:
- 1
- Voltage - Threshold:
- 3.075V
- 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
MAX6866UK31D3S+T FAQ
1.How can I place an order for MAX6866UK31D3S+T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6866UK31D3S+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 MAX6866UK31D3S+T reliable?
The price and inventory of MAX6866UK31D3S+T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6866UK31D3S+T is usually 5 days.
3.What payment methods are accepted for MAX6866UK31D3S+T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX6866UK31D3S+T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX6866UK31D3S+T?
MAX6866UK31D3S+T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6866UK31D3S+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 MAX6866UK31D3S+T?
For technical support, including MAX6866UK31D3S+T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6866UK31D3S+T requirements.
6.How does Aetrix verify that MAX6866UK31D3S+T is sourced from the original manufacturer or authorized distributors?
All MAX6866UK31D3S+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 MAX6866UK31D3S+T meets industry standards.
7.What is the process for return or replacement of MAX6866UK31D3S+T?
All MAX6866UK31D3S+T units undergo pre-shipment inspection (PSI). If there is an issue with MAX6866UK31D3S+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 MAX6866UK31D3S+T part is unused and in its original packaging.
Return procedure for MAX6866UK31D3S+T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX6866UK31D3S+T Tags
-
MIC826SYMT-TR
Microchip Technology
-
APX803S-31SA-7
Diodes Incorporated
-
APX803L20-29SA-7
Diodes Incorporated
-
TPS3828-33DBVR
Texas Instruments
-
V6340RSP3B+
EM Microelectronic
-
EM6325CXSP5B-2.9+
EM Microelectronic
-
MCP120T-300I/TT
Microchip Technology
-
MCP130T-315I/TT
Microchip Technology
-
MCP120T-475I/TT
Microchip Technology
-
MCP111T-300E/TT
Microchip Technology
-
MCP120T-315I/TT
Microchip Technology
-
MCP809T-315I/TT
Microchip Technology
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
