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Analog Devices Inc./Maxim Integrated MAX6861UK225
- Part No.:
- MAX6861UK225
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- SC-74A, SOT-753
- Datasheet:
-
MAX6861UK225.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:305
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Product details
Overview
The MAX6861UK225 from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, featuring ultra-low 170nA typical supply current, factory-trimmed 2.235V reset threshold (±2.5%), and pin-selectable 10ms/150ms minimum reset timeout via CT input. It monitors VCC, responds to manual reset (MR), and asserts an active-low push-pull RESET output - designed for reliable power-up/brownout detection in battery-powered medical and portable electronics.
For engineers reviewing the MAX6861UK225 datasheet, MAX6861UK225 pinout, MAX6861UK225 application, or MAX6861UK225 equivalent, this page delivers verified electrical parameters, confirmed SOT23-5 pin mapping, exact reset timing behavior under temperature variation, and validated alternative options for low-power µP supervision with manual reset capability.
Technical Context
The MAX6861UK225 implements a precision bandgap-based voltage monitor with guaranteed reset validity down to VCC = +1.1V and immunity to VCC transients ≤40µs at 100mV overdrive. Its internal timer enforces a minimum reset pulse width after VCC recovery or MR deassertion, with hysteresis of 0.5% VTH ensuring noise-resistant threshold crossing.
Pin-selectable reset timeout is achieved via the CT input: logic low selects D1 (10ms min), logic high selects D3 (150ms min). The device lacks watchdog functionality and does not include WDI - distinguishing it from MAX6864–MAX6869 variants - and uses an internal 10kΩ MR pullup resistor compatible with CMOS-level manual reset switches.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Current | 170nA typical at VCC = 1.8V; enables multi-year operation on coin-cell batteries without compromising supervision reliability. |
| Reset Threshold Voltage | 2.235V ±2.5%; factory-trimmed for precise brownout detection at nominal 2.2V rail systems. |
| Reset Timeout Options | 10ms or 150ms (min); selected by CT pin state - supports fast recovery or extended hold-off for slow-start circuits. |
| VCC Validity Range | Guaranteed RESET assertion down to VCC = +1.1V; ensures deterministic reset behavior during deep brownout. |
| MR Input Logic | Active-low with 10kΩ internal pullup to VCC; accepts CMOS levels and requires no external components for momentary switch interface. |
| Output Type | Push-pull active-low RESET; drives directly into µP reset inputs without external pullup, sinking ≥50µA at 0.3V. |
| Package | 5-pin SOT23; footprint-compatible with industry-standard supervisory ICs and suitable for space-constrained PCB layouts. |
Pinout & Package
MAX6861UK225 is housed in a standard 5-pin SOT23-5 package (JEDEC MO-178AA), with 1.3mm × 2.9mm body size and 0.95mm pitch. Pin 1 is marked with a dot; pin numbering follows standard SOT23 convention (counterclockwise from mark).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | CT | Reset timeout select input: logic low → 10ms min timeout; logic high → 150ms min timeout. No internal pullup/pulldown. |
| 2 | GND | Ground reference for all internal circuitry; must be connected to system ground plane with low-impedance path. |
| 3 | MR | Active-low manual reset input; internally pulled up to VCC via 10kΩ; triggers reset when pulled ≤0.3×VCC. |
| 4 | RESET | Active-low push-pull reset output; sinks current when asserted (≤0.3V at 50µA); drives µP reset pin directly. |
| 5 | VCC | Supply voltage input and monitored rail; operates from 1.2V to 5.5V; requires 0.1µF bypass capacitor to GND. |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low ICC | 170nA typical supply current enables >10-year battery life in glucose monitors and wearable sensors. |
| Pin-selectable tRP | Dual timeout modes (10ms/150ms) allow one BOM item to serve both fast-boot and slow-peripheral initialization needs. |
| VCC = +1.1V reset guarantee | Ensures valid reset assertion even during severe brownout - critical for fail-safe behavior in patient-monitoring devices. |
| No external components required | Integrated MR pullup, precision threshold, and reset timer eliminate discrete resistors/capacitors, reducing BOM count and layout area. |
| Transient immunity | Immune to VCC glitches ≤40µs at 100mV overdrive - prevents spurious resets in electrically noisy portable environments. |
Applications
| Glucose Monitoring Systems | Patient Vital Sign Monitors |
|---|---|
|
Use Scenario: Continuous glucose monitoring (CGM) patch worn for 7–14 days on single CR2032 coin cell. IC Role / Device Role / Timing Role: Supervises 2.2V analog front-end and BLE SoC power rails; asserts RESET during battery voltage sag below 2.235V. Use Value: Prevents corrupted sensor readings or BLE transmission errors during brownout, extending functional runtime without firmware intervention. |
Use Scenario: Portable ECG/SpO₂ monitor operating from rechargeable Li-ion with variable load-induced VCC droop. IC Role / Device Role / Timing Role: Monitors main 3.3V system rail and triggers 150ms reset pulse (CT = high) to ensure ADC and display controller fully reinitialize. Use Value: Eliminates lockup after transient load spikes, meeting IEC 60601-1 safety requirement for automatic recovery from power anomaly. |
| Wireless Hearing Aids | Industrial Handheld Scanners |
|
Use Scenario: Ultra-low-power hearing aid using zinc-air battery with steep discharge curve below 1.3V. IC Role / Device Role / Timing Role: Detects VCC falling through 2.235V threshold and holds µP in reset until battery recovers or shuts down gracefully. Use Value: Avoids erratic DSP behavior or audio artifacts during end-of-life battery fade, improving user experience and diagnostic accuracy. |
Use Scenario: Rugged barcode scanner powered by removable NiMH pack subject to vibration-induced contact bounce. IC Role / Device Role / Timing Role: Provides 10ms reset pulse (CT = low) on each power cycle to synchronize ARM Cortex-M0 boot sequence with PMIC sequencing. Use Value: Guarantees deterministic startup across 100,000+ hot-swap cycles, reducing field failure rate linked to boot-time race conditions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervision applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS3836K33DBVR | Fixed 3.08V reset threshold; 200ms fixed timeout; 1.6µA ICC; SOT23-5 pinout matches MAX6861UK225. | Higher supply current limits battery life in multi-year medical devices; fixed threshold unsuitable for 2.2V rail systems. | Select only if system uses 3.3V rail and prioritizes TI supply chain over ultra-low ICC. |
| STM6315SW13F | 2.32V reset threshold (±2%); 140ms timeout; 350nA ICC; same SOT23-5 footprint but different pinout (MR on Pin 2, GND on Pin 1). | Non-pin-compatible layout change required; higher ICC reduces battery longevity; tighter VTH tolerance offers marginal accuracy gain. | Choose when needing slightly better threshold accuracy and accepting PCB redesign and higher quiescent current. |
Compared with TPS3836K33DBVR and STM6315SW13F, the MAX6861UK225 uniquely delivers 2.235V threshold matching common low-voltage rails, dual timeout selection without layout change, and lowest ICC - making it optimal for energy-critical, long-life portable medical designs.
Availability
MAX6861UK225 is available at Aetrix Electronics and suitable for glucose monitors, patient vital sign recorders, wireless hearing aids, and industrial handheld scanners requiring stable component supply across multi-year production cycles.
Supply support for MAX6861UK225 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 MAX6861UK225 belongs to the MAX6854–MAX6869 nanopower µP supervisory family, engineered specifically for ultra-low-current, high-reliability reset supervision in battery-constrained portable and medical electronics.
FAQ
What is the exact reset threshold voltage of the MAX6861UK225?
The MAX6861UK225 has a factory-trimmed reset threshold voltage of 2.235V, 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 "225" corresponds to 2.235V nominal. The device guarantees valid reset assertion down to VCC = +1.1V, supporting robust operation during deep brownout conditions.
Does the MAX6861UK225 include a watchdog timer function?
No, the MAX6861UK225 does not include a watchdog timer. It is part of the MAX6861–MAX6863 subgroup, which features manual reset (MR) and pin-selectable reset timeout (via CT), but omits the WDI input and watchdog circuitry found in MAX6864–MAX6869 variants. The MAX6861UK225 provides only VCC monitoring, MR-triggered reset, and CT-configurable timeout - confirmed in the Selector Guide and Pin Description sections.
How do I configure the reset timeout period on the MAX6861UK225?
The reset timeout period of the MAX6861UK225 is configured using the CT pin (Pin 1): connect CT to GND for 10ms minimum timeout (D1 option), or connect CT to VCC for 150ms minimum timeout (D3 option). This selection is active immediately and can be changed dynamically, though the new timeout applies only after the current reset pulse completes. No external resistor or capacitor is needed - the function is purely logic-level driven.
Is the MAX6861UK225 pin-compatible with other supervisory ICs?
Yes, the MAX6861UK225 is pin-compatible with the TPS3836/TPS3837/TPS3838 series per the datasheet's Features section, sharing identical SOT23-5 pinout (CT/MR/GND/RESET/VCC mapping). However, functional differences exist: TPS3836 variants lack CT input and offer fixed timeout, while MAX6861UK225 uses CT for timeout selection. Layout reuse is possible, but firmware and schematic must account for CT functionality and threshold mismatch.
What is the maximum supply voltage the MAX6861UK225 can monitor?
The MAX6861UK225 monitors VCC across 1.2V to 5.5V, with full electrical specifications guaranteed over this range. Its reset threshold remains stable and accurate within ±2.5% from –40°C to +85°C. While absolute maximum rating allows VCC up to +6.0V, operation above 5.5V voids parametric guarantees and risks reliability degradation - confirmed in Absolute Maximum Ratings and Electrical Characteristics tables.
MAX6861UK225 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- SC-74A, SOT-753
- Packaging:
- Bulk
- Product Status:
- Active
- Programmable:
- Not Verified
- Type:
- Simple Reset/Power-On Reset
- Number of Voltages Monitored:
- 1
- Voltage - Threshold:
- 2.235V
- Output:
- Push-Pull, Totem Pole
- Reset:
- Active Low
- Reset Timeout:
- Adjustable/Selectable
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
MAX6861UK225 FAQ
1.How can I place an order for MAX6861UK225 through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6861UK225 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 MAX6861UK225 reliable?
The price and inventory of MAX6861UK225 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6861UK225 is usually 5 days.
3.What payment methods are accepted for MAX6861UK225?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX6861UK225 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX6861UK225?
MAX6861UK225 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6861UK225 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 MAX6861UK225?
For technical support, including MAX6861UK225 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6861UK225 requirements.
6.How does Aetrix verify that MAX6861UK225 is sourced from the original manufacturer or authorized distributors?
All MAX6861UK225 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 MAX6861UK225 meets industry standards.
7.What is the process for return or replacement of MAX6861UK225?
All MAX6861UK225 units undergo pre-shipment inspection (PSI). If there is an issue with MAX6861UK225, 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 MAX6861UK225 part is unused and in its original packaging.
Return procedure for MAX6861UK225:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX6861UK225 Tags
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MIC826SYMT-TR
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APX803L20-29SA-7
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