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Analog Devices Inc./Maxim Integrated MAX6444US29L+
- Part No.:
- MAX6444US29L+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- TO-253-4, TO-253AA
- Datasheet:
-
MAX6444US29L+.pdf
- Description:
- MAX6444 UP RESET CIRCUITS WITH L
- Quantity:
- Payment:
- Shipping:
Inventory:1,028
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Product details
Overview
MAX6444US29L+ from Maxim Integrated is a single-supply, fixed-threshold microprocessor reset supervisor IC with active-low open-drain RESET output, 2.925V VCC reset threshold, and 6.72s extended manual reset setup period (MR1). It monitors VCC only, asserts RESET when VCC drops below threshold or MR1 is held low ≥6.72s, and guarantees valid reset down to VCC = 1.0V. Used in consumer electronics power sequencing and front-panel reset control.
For engineers reviewing the MAX6444US29L+ datasheet, MAX6444US29L+ pinout, MAX6444US29L+ application, or MAX6444US29L+ equivalent, key selection factors include its SOT143-4 package, 6µA supply current, 140ms min reset timeout, immunity to <100ns glitches on MR1, and compatibility with 1.0V–5.5V VCC operation.
Technical Context
The MAX6444US29L+ implements a precision bandgap-based voltage monitor for VCC with factory-trimmed 2.925V threshold (±1.5% over -40°C to +85°C) and 60ppm/°C tempco. Its internal timing circuit enforces a fixed 6.72s low assertion on MR1 before generating a one-shot RESET pulse.
RESET is open-drain with 1µA max leakage when deasserted and guaranteed VOL ≤0.4V at ISINK = 3.2mA (VCC ≥4.25V). The device ignores MR1 transitions shorter than 6.72s and provides 210ms typical reset timeout after VCC recovery.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Reset Threshold | 2.925V ±1.5% - precisely triggers reset during brownout at nominal 3.0V rail |
| Manual Reset Setup Period (tMR) | 6.72s - prevents nuisance resets from brief front-panel button presses |
| Reset Timeout Period (tRP) | 140ms min / 210ms typ - ensures µP completes full reset initialization cycle |
| Supply Current (ICC) | 6µA typ at 3.6V - enables battery-backed systems with multi-year standby life |
| Operating Voltage Range | 1.0V to 5.5V - supports valid RESET assertion even during deep brownout |
| MR1 Input Pullup | 50kΩ internal - eliminates external resistor for pushbutton interface |
| RESET Output Type | Open-drain - allows level-shifting to µP I/O voltage (e.g., 1.8V, 2.5V, 3.3V) |
Pinout & Package
SOT143-4 package: 1.3mm × 2.9mm footprint, 0.95mm height, lead-free (RoHS-compliant), thermal pad not present.
| Pin | Circuit Role | Design Meaning |
|---|---|---|
| 1 | GND | Ground reference for all internal comparators and logic; must connect to system ground plane |
| 2 | RESET | Active-low open-drain output; requires external pullup (≥20kΩ to VCC or other logic rail) |
| 3 | MR1 | Active-low manual reset input; internally pulled up to VCC via 50kΩ; assert low ≥6.72s to trigger one-shot reset |
| 4 | VCC | Main power supply input and monitored voltage rail; powers internal circuitry and sets RESET sink capability |
Key Features
| Feature | Design Value |
|---|---|
| Extended MR1 setup period | 6.72s - eliminates false resets from accidental or momentary button closure |
| Precision VCC threshold | 2.925V ±1.5% - matches common 3.0V supply rails without external trimming |
| Ultra-low ICC | 6µA typ - reduces quiescent load on backup batteries or energy-harvesting sources |
| Valid RESET down to VCC = 1.0V | Guaranteed VOL ≤0.4V at VCC ≥4.25V and ISINK = 3.2mA - ensures reliable µP reset initiation |
| Glitch-immune MR1 input | Rejects transients <100ns - no external RC filtering required for noisy mechanical switches |
Applications
| Consumer Set-Top Box Power Management | DVD Player Front-Panel Reset Control |
|---|---|
Use Scenario: System recovers from firmware hang or corrupted boot sequence using front-panel power button. IC Role / Device Role / Timing Role: MAX6444US29L+ monitors 3.3V main rail and detects MR1 press ≥6.72s to generate 140ms min RESET pulse. Use Value: Prevents accidental reset during normal channel navigation while enabling deliberate hard reset for recovery. |
Use Scenario: User holds DVD player power button to force cold restart after unresponsive UI. IC Role / Device Role / Timing Role: MAX6444US29L+ acts as dedicated reset sequencer, asserting open-drain RESET to baseband processor only after validated long-press. Use Value: Eliminates need for µP firmware debounce logic; reduces BOM count by integrating timing and voltage monitoring. |
| Cable Modem Brownout Recovery | MP3 Player Battery-Sensitive Reset |
Use Scenario: Modem maintains network sync during AC line sags; recovers automatically when 3.3V rail recovers. IC Role / Device Role / Timing Role: MAX6444US29L+ monitors VCC and asserts RESET for 210ms typical duration after VCC exceeds 2.925V. Use Value: Ensures clean state restoration without requiring µP watchdog intervention during transient undervoltage. |
Use Scenario: Portable MP3 player uses coin-cell backup; must retain valid reset function during battery decay. IC Role / Device Role / Timing Role: MAX6444US29L+ guarantees RESET assertion down to VCC = 1.0V, enabling reset even at end-of-life battery voltage. Use Value: Extends usable battery life by maintaining supervisory function deeper into discharge curve than standard supervisors. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor reset applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6443US29L+ | Same 2.925V threshold and 6.72s tMR, but push-pull RESET output | Requires no external pullup; incompatible with level-shifting or wired-OR configurations | Select when driving µP with 3.3V-tolerant reset input and no shared bus requirements |
| TPS3808G33DBVR | 2.93V threshold, 200ms fixed timeout, 2.5µA ICC, SOT23-5 package | Lacks extended manual reset; uses standard 100ms–200ms MR debounce, not long-setup | Select when only basic power-on reset and short-press MR are needed; not suitable for nuisance-reset prevention |
Compared with MAX6443US29L+, the MAX6444US29L+ offers open-drain flexibility for mixed-voltage systems; compared with TPS3808G33DBVR, it delivers unique long-setup MR1 immunity essential for consumer front-panel reliability.
Availability
MAX6444US29L+ is available at Aetrix Electronics and suitable for consumer electronics, industrial equipment, and medical devices requiring stable component supply, long-term manufacturability, and RoHS-compliant packaging.
Supply support for MAX6444US29L+ 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, sensing, and interface applications, with emphasis on high-reliability, low-power solutions.
The MAX6443–MAX6452 family was designed specifically for robust microprocessor supervision in cost-sensitive consumer and industrial systems where front-panel reset reliability and ultra-low ICC are critical.
FAQ
What is the exact reset threshold voltage of the MAX6444US29L+?
The MAX6444US29L+ has a factory-trimmed VCC reset threshold of 2.925V, with ±1.5% tolerance over the full -40°C to +85°C temperature range. This value is confirmed in Table 1 of the datasheet and corresponds to the "29" suffix in the part number. The threshold exhibits 60ppm/°C tempco, ensuring stability across operating conditions.
Does the MAX6444US29L+ support manual reset with immediate response?
No. The MAX6444US29L+ provides only one manual reset input (MR1) with an extended 6.72s setup period - it does not support immediate or short-debounce manual reset. Devices like MAX6447US29L+ or MAX6451US29L+ add an immediate MR2 input, but MAX6444US29L+ is strictly long-setup only, per its position in the selector guide.
Can the MAX6444US29L+ monitor a voltage other than VCC?
No. The MAX6444US29L+ monitors VCC only. Adjustable external voltage monitoring via RSTIN is exclusive to MAX6449–MAX6452 variants. The MAX6444US29L+ pinout lacks RSTIN, and its internal architecture is dedicated to single-rail VCC supervision, as confirmed in the Pin Description and Selector Guide tables.
What is the minimum VCC required for the MAX6444US29L+ to assert a valid RESET?
The MAX6444US29L+ guarantees valid RESET assertion down to VCC = 1.0V, with VOL ≤0.4V at ISINK = 3.2mA when VCC ≥4.25V. Below 1.0V, reset functionality is not specified. This 1.0V lower limit is explicitly stated in the Electrical Characteristics table and enables operation during deep brownout scenarios.
Is the MAX6444US29L+ pin-compatible with other parts in the MAX6443–MAX6452 family?
Yes - the MAX6444US29L+ uses the SOT143-4 package and shares identical pinout (GND, RESET, MR1, VCC) with MAX6443USxxL+, MAX6444USxxL+, and MAX6445UKxxL+ (though the latter is SOT23-5). However, pin compatibility does not imply functional equivalence: MAX6444US29L+ has open-drain RESET and no RSTIN or MR2, unlike higher-pin-count variants.
MAX6444US29L+ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- TO-253-4, TO-253AA
- Packaging:
- Bulk
- Product Status:
- Active
- Programmable:
- Not Verified
- Type:
- Simple Reset/Power-On Reset
- Number of Voltages Monitored:
- 1
- Voltage - Threshold:
- 2.925V
- Output:
- Open Drain or Open Collector
- Reset:
- Active Low
- Reset Timeout:
- 140ms Minimum
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-4
MAX6444US29L+ FAQ
1.How can I place an order for MAX6444US29L+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6444US29L+ 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 MAX6444US29L+ reliable?
The price and inventory of MAX6444US29L+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6444US29L+ is usually 5 days.
3.What payment methods are accepted for MAX6444US29L+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX6444US29L+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX6444US29L+?
MAX6444US29L+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6444US29L+ 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 MAX6444US29L+?
For technical support, including MAX6444US29L+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6444US29L+ requirements.
6.How does Aetrix verify that MAX6444US29L+ is sourced from the original manufacturer or authorized distributors?
All MAX6444US29L+ 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 MAX6444US29L+ meets industry standards.
7.What is the process for return or replacement of MAX6444US29L+?
All MAX6444US29L+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX6444US29L+, 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 MAX6444US29L+ part is unused and in its original packaging.
Return procedure for MAX6444US29L+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX6444US29L+ Tags
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