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Analog Devices Inc./Maxim Integrated MAX6422US31-T
- Part No.:
- MAX6422US31-T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- TO-253-4, TO-253AA
- Datasheet:
-
MAX6422US31-T.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL SOT143-4
- Quantity:
- Payment:
- Shipping:
Inventory:12,500
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Product details
Overview
MAX6422US31-T from Maxim Integrated is a low-power, active-high push-pull microprocessor reset supervisor IC in SOT143-4 package, monitoring VCC from 1.6V to 5V with factory-trimmed 3.075V reset threshold (suffix "31"), capacitor-adjustable reset timeout (275µs base + 2.73×10⁶·CSRT), and guaranteed operation down to VCC = 1V. It asserts a high-level RESET signal during brownout and holds it for the timeout period after VCC recovers - used in battery-powered controllers requiring precise power-up sequencing.
For engineers reviewing the MAX6422US31-T datasheet, MAX6422US31-T pinout, MAX6422US31-T application, or MAX6422US31-T equivalent, this page delivers verified technical context, exact pin functions, real-world timing behavior, capacitor-based timeout design guidance, and validated alternative options for voltage-monitoring reset circuits in portable and automotive systems.
Technical Context
The MAX6422US31-T implements a precision bandgap-based voltage detector with ±1.5% threshold accuracy at +25°C and ±2.5% over –40°C to +125°C, paired with an internal 240nA current source charging an external capacitor on the SRT pin to generate the reset timeout delay. Its active-high push-pull output drives logic-high directly without external pullup.
VCC-to-reset delay is 80µs (typ) under 1mV/µs falling edge, and the device remains functional with valid RESET output even as VCC drops to 1.0V - critical for graceful shutdown in low-voltage embedded systems. Immunity to short VCC transients (<50µs for 100mV overdrive) avoids false resets in noisy power environments.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold | 3.075V (nominal, suffix "31"), ±2.5% over full temperature range - sets precise brownout detection point for 3.3V systems |
| Supply Voltage Range | 1.0V to 5.5V - enables operation during deep brownout and compatibility with 1.8V/2.5V/3.3V/5V rails |
| Quiescent Current | 1.6µA (typ) at VCC ≤ 2.0V - extends battery life in always-on monitoring applications |
| Reset Timeout Base | 275µs minimum (CSRT = 0), scalable via external capacitor - supports µP reset hold times from sub-millisecond to >100ms |
| VCC-to-Reset Delay | 80µs (typ) for VCC falling at 1mV/µs - ensures fast response to supply collapse |
| Output Type | Active-high push-pull - eliminates need for external pullup resistor and guarantees rail-to-rail logic levels |
| Operating Temp | –40°C to +125°C - qualified for industrial and automotive under-hood environments |
Pinout & Package
MAX6422US31-T is housed in a 4-pin SOT143-4 package (outline 21-0052), 1.3mm × 1.3mm footprint, 0.95mm height, lead-free compatible. Pin 1 = VCC, Pin 2 = GND, Pin 3 = RESET (active-high push-pull), Pin 4 = SRT (capacitor-adjustable timeout input).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (VCC) | Supply and threshold monitor input | Primary power rail connection; internal circuitry monitors this node for reset condition against 3.075V threshold |
| 2 (GND) | Ground reference | Analog and digital ground return; must be low-impedance path to minimize noise coupling into threshold detection |
| 3 (RESET) | Active-high push-pull output | Drives µP reset input high during fault; sinks current when low, sources current when high - no external components required |
| 4 (SRT) | Reset timeout capacitor input | Accepts external capacitor (CSRT) to set timeout period per tRP = 2.73×10⁶·CSRT + 275µs; sensitive to leakage and stray capacitance |
Key Features
| Feature | Design Value |
|---|---|
| Capacitor-adjustable reset timeout | Enables precise tailoring of reset hold time (275µs to >100ms) using standard ceramic capacitors - avoids fixed-delay limitations |
| Guaranteed RESET validity to VCC = 1V | Ensures deterministic reset assertion during deep brownout, preventing µP runaway before power collapse completes |
| Immunity to short VCC transients | Rejects glitches ≤50µs duration when VCC dips 100mV below threshold - eliminates spurious resets in electrically noisy systems |
| Low 1.6µA quiescent current | Reduces standby power draw by >90% vs. legacy supervisors - critical for multi-year battery operation in IoT sensors |
| Factory-trimmed 3.075V threshold | Eliminates external resistor divider; achieves ±2.5% accuracy across temperature without calibration - simplifies BOM and layout |
Applications
| Battery-Powered Controllers | Automotive Body Control Modules |
|---|---|
Use Scenario: A handheld medical glucose meter operates from a single Li-ion cell (2.8V–4.2V) and must guarantee safe boot only when voltage exceeds 3.0V. IC Role / Device Role / Timing Role: MAX6422US31-T monitors VCC and asserts active-high RESET until voltage stabilizes above 3.075V, then holds RESET high for 50ms to ensure stable clock and memory initialization. Use Value: Prevents corrupted firmware execution during marginal battery conditions, meeting IEC 62304 safety requirements for Class B medical devices. |
Use Scenario: A door module MCU powers from vehicle battery (9V–16V) through a 3.3V LDO; transient load dumps cause brief VCC sags. IC Role / Device Role / Timing Role: MAX6422US31-T detects sags below 3.075V and asserts RESET high for ≥100ms (CSRT = 33nF), blocking MCU operation until LDO output recovers fully. Use Value: Avoids erratic actuator control during load-dump events, satisfying ISO 16750-2 pulse 4a immunity requirements. |
| Industrial Sensor Nodes | Set-Top Box Power Sequencing |
Use Scenario: An RS-485 sensor node sleeps at 1.8V but wakes to 3.3V; brownout must trigger controlled shutdown before EEPROM write corruption. IC Role / Device Role / Timing Role: MAX6422US31-T monitors the 3.3V rail and asserts RESET high for 20ms upon crossing 3.075V downward, halting CPU before supply falls below 2.7V. Use Value: Guarantees atomic flash writes complete before power loss, eliminating data inconsistency in Modbus RTU field deployments. |
Use Scenario: A dual-rail STB uses 1.2V core and 3.3V I/O; the 3.3V rail must stabilize before releasing the 1.2V domain's reset. IC Role / Device Role / Timing Role: MAX6422US31-T on the 3.3V rail generates a 100ms active-high RESET pulse that gates the 1.2V supervisor's enable input via logic AND. Use Value: Enforces strict power-rail sequencing without custom timing circuitry, reducing component count and board area by 30% vs. discrete RC solutions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor reset supervision applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6422XS31-T | Same electrical specs and reset threshold, but in SC70-4 package (smaller 1.0mm × 1.0mm footprint) | Preferred for ultra-compact PCBs where SOT143 thermal mass or height (0.95mm vs. 0.6mm) is constrained | Select when board space is premium and thermal dissipation <320mW suffices |
| TLV803E31DBZR | Fixed 3.08V threshold, 200ms min timeout (non-adjustable), 0.5µA IQ, SOT23-3 package | Lacks capacitor-adjustable timeout and operates down to only VCC = 1.6V - unsuitable for deep-brownout detection | Choose only if fixed timeout and lowest possible quiescent current outweigh flexibility and 1V operation needs |
Compared with MAX6422US31-T, MAX6422XS31-T offers identical functionality in a smaller package but lower thermal rating, while TLV803E31DBZR trades timeout adjustability and 1V operation for ultra-low IQ and simpler 3-pin layout - selection depends on whether timing flexibility or minimal footprint/IQ dominates the design priority.
Availability
MAX6422US31-T is available at Aetrix Electronics and suitable for battery-powered controllers, automotive body electronics, and industrial sensor nodes requiring stable component supply, long-lifecycle support, and guaranteed RoHS-compliant sourcing.
Supply support for MAX6422US31-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 power, sensing, and interface applications, with emphasis on reliability and integration for harsh environments.
The MAX6421–MAX6426 family delivers low-power, capacitor-programmable reset supervision for space-constrained, battery-sensitive systems - targeting portable, automotive, and medical equipment where deterministic power-up behavior is non-negotiable.
FAQ
What is the exact reset threshold voltage of MAX6422US31-T?
The MAX6422US31-T has a factory-trimmed nominal reset threshold of 3.075V, with tolerance of ±1.5% at +25°C and ±2.5% over the full –40°C to +125°C operating range. This value is confirmed by the "31" suffix in the part number and documented in Table 1 of the MAX6421–MAX6426 datasheet. The threshold is laser-trimmed during production and does not require external calibration.
How do I calculate the reset timeout period for MAX6422US31-T?
The reset timeout period (tRP) for MAX6422US31-T is calculated as tRP = (2.73 × 10⁶) × CSRT + 275µs, where CSRT is the capacitor value in farads connected between the SRT pin and GND. For example, a 33nF capacitor yields tRP ≈ 91.4ms. This formula is derived from the internal 240nA ramp current source and 0.65V trip threshold, and is validated across temperature in the datasheet's Typical Operating Characteristics.
Does MAX6422US31-T require an external pullup resistor on the RESET pin?
No, MAX6422US31-T does not require an external pullup resistor because it features an active-high push-pull RESET output. Unlike open-drain variants (e.g., MAX6423), the MAX6422US31-T internally sources and sinks current to drive the RESET line rail-to-rail - ensuring clean, fast transitions without external components. This reduces BOM cost and improves noise immunity in dense layouts.
Can MAX6422US31-T operate reliably when VCC drops below 1.6V?
Yes, MAX6422US31-T is guaranteed to assert and maintain a valid RESET signal down to VCC = 1.0V, as specified in the Electrical Characteristics table. This capability enables robust brownout detection in systems powered by depleting batteries or unstable supplies - a key differentiator from many competitors whose reset outputs become indeterminate below 1.6V.
What package type and dimensions does MAX6422US31-T use?
MAX6422US31-T uses the 4-pin SOT143-4 package (package code U4+1, outline 21-0052), measuring 1.3mm × 1.3mm with 0.95mm maximum height and 0.65mm pin pitch. This land-pattern-compatible package supports reflow soldering and is offered in both leaded and lead-free versions (the "-T" suffix denotes lead-free). Footprint and solder mask details are published in Maxim's package database.
MAX6422US31-T 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:
- 3.075V
- Output:
- Push-Pull, Totem Pole
- Reset:
- Active High
- Reset Timeout:
- Adjustable/Selectable
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-4
MAX6422US31-T FAQ
1.How can I place an order for MAX6422US31-T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6422US31-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 MAX6422US31-T reliable?
The price and inventory of MAX6422US31-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6422US31-T is usually 5 days.
3.What payment methods are accepted for MAX6422US31-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX6422US31-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX6422US31-T?
MAX6422US31-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6422US31-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 MAX6422US31-T?
For technical support, including MAX6422US31-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6422US31-T requirements.
6.How does Aetrix verify that MAX6422US31-T is sourced from the original manufacturer or authorized distributors?
All MAX6422US31-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 MAX6422US31-T meets industry standards.
7.What is the process for return or replacement of MAX6422US31-T?
All MAX6422US31-T units undergo pre-shipment inspection (PSI). If there is an issue with MAX6422US31-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 MAX6422US31-T part is unused and in its original packaging.
Return procedure for MAX6422US31-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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