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Analog Devices Inc./Maxim Integrated MAX6420UK45+T
- Part No.:
- MAX6420UK45+T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- SC-74A, SOT-753
- Datasheet:
-
MAX6420UK45+T.pdf
- Description:
- IC SUPERVISOR 2 CHANNEL SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:1,557
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Product details
Overview
MAX6420UK45+T from Maxim Integrated is a low-power dual-voltage microprocessor supervisor IC with one factory-trimmed VCC reset threshold (4.5V ±2.5%) and one adjustable RESET IN input (1.26V threshold) for monitoring secondary supply rails. It features an active-low open-drain RESET output, capacitor-adjustable reset timeout (275µs to 5.75ms), manual reset capability via external switch, and guaranteed operation down to VCC = 1V. It is used in automotive ECUs to monitor both main 5V logic and auxiliary 3.3V I/O supplies.
For engineers reviewing the MAX6420UK45+T datasheet, MAX6420UK45+T pinout, MAX6420UK45+T application, or MAX6420UK45+T equivalent, key selection considerations include its dual-threshold architecture, open-drain output compatibility with mixed-voltage µP reset inputs, AEC-Q100 qualification (per /V variants), SOT23-5 package footprint, and capacitor-programmable timeout for flexible system boot sequencing.
Technical Context
The MAX6420UK45+T integrates two independent reset comparators: one laser-trimmed bandgap reference comparator for VCC (nominal 4.5V threshold), and one precision 1.26V reference comparator for the external RESET IN pin. Reset assertion occurs if either voltage falls below its respective threshold or MR is pulled low.
Its reset timeout is generated by a 240nA internal current source charging an external capacitor (CSRT) on the SRT pin; the voltage ramp is compared to a 0.65V internal reference, yielding a linear timeout relationship (tRP = 2.71×10⁶ × CSRT + 275µs). The open-drain RESET output supports pull-up to any voltage ≤5.5V, enabling interoperability with diverse µP logic families.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Reset Threshold | 4.5V ±2.5% over -40°C to +125°C - ensures reliable power-on reset for 5V systems with margin against brownout |
| RESET IN Threshold | 1.26V ±33mV hysteresis - enables precise monitoring of auxiliary rails (e.g., 3.3V via R-divider) down to 1.26V |
| Reset Timeout Range | 275µs to 5.75ms (CSRT = 0 to 1500pF) - allows tuning for µP reset hold time requirements across boot, wake-up, and fault recovery |
| Supply Current | 1.7µA typical at VCC = 2.0V - minimizes battery drain in always-on automotive and portable applications |
| Operating Temperature | -40°C to +125°C - fully specified for under-hood automotive environments and industrial embedded control |
| Output Type | Active-low open-drain - permits wired-OR configuration and level-shifting with external pull-up to 1.8V, 3.3V, or 5V |
| Guaranteed RESET Validity | Valid down to VCC = 1.0V - ensures deterministic reset behavior during deep brownout conditions before system collapse |
Pinout & Package
SOT23-5 package (U5+2A outline, 5-pin, RoHS-compliant, thermal resistance θJA = 255.9°C/W on multilayer board).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - RESET | Open-drain reset output | Asserted low during reset; requires external pull-up; compatible with µP reset inputs referenced to different supply voltages |
| 2 - GND | Ground reference | Common return path for all internal circuitry and external bias networks; must be low-impedance connection |
| 3 - RESET IN | Adjustable threshold input | High-impedance node for external resistor divider; sets secondary voltage monitor point (VMON_TH = 1.26V × (R1+R2)/R2) |
| 4 - SRT | Reset timeout capacitor input | Connects to external timing capacitor; 240nA constant-current source charges CSRT to set timeout period |
| 5 - VCC | Supply and primary monitor input | Powers device and provides input to fixed 4.5V reset comparator; operates from 1.0V to 5.5V |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent voltage monitoring | Simultaneously supervises main VCC (4.5V) and a user-defined auxiliary rail (e.g., 3.3V) without external comparators or logic |
| Capacitor-programmable reset timeout | Enables precise, board-level tuning of reset pulse width (275µs–5.75ms) without firmware changes or BOM revisions |
| Open-drain RESET with wide voltage tolerance | Supports pull-up to 1.8V/3.3V/5V supplies - eliminates level translators when interfacing with heterogeneous µP families |
| Manual reset via external switch | MR function implemented by paralleling switch across R2 on RESET IN divider - no dedicated MR pin required, saving PCB space |
| AEC-Q100 qualified variants available | /V suffix parts meet automotive stress testing requirements - suitable for engine control, ADAS, and body electronics |
Applications
| Engine Control Unit (ECU) | Automotive Infotainment Head Unit |
|---|---|
Use Scenario: Monitoring both 5V microcontroller core supply and 3.3V CAN transceiver supply in a vehicle ECU. IC Role / Device Role / Timing Role: Dual-threshold supervisor asserting RESET until both rails stabilize above 4.5V and 3.3V thresholds, with 4ms timeout ensuring full peripheral initialization. Use Value: Prevents erratic ECU behavior during cold cranking by guaranteeing synchronized reset release only after both critical rails are valid. | Use Scenario: Ensuring clean boot of a multi-core SoC in an infotainment system with separate 1.1V CPU, 1.8V GPU, and 3.3V display interface supplies. IC Role / Device Role / Timing Role: Using RESET IN to monitor a scaled-down 3.3V rail derived from main 5V; VCC monitors primary 5V; open-drain RESET pulled to SoC's 1.8V reset domain. Use Value: Enables single-chip supervision of hierarchical power domains while maintaining logic-level compatibility with low-voltage SoC reset inputs. |
| Medical Patient Monitor | Battery-Powered Industrial Sensor Node |
Use Scenario: Supervising backup battery charger (3.6V) and main 3.3V system rail in a portable patient monitor with fail-safe shutdown. IC Role / Device Role / Timing Role: VCC monitors 3.3V system rail; RESET IN monitors 3.6V battery rail via resistor divider; RESET asserts if either drops below threshold. Use Value: Guarantees immediate system halt upon battery depletion or main rail collapse - critical for regulatory compliance and patient safety. | Use Scenario: Long-life remote sensor node powered by coin cell, requiring ultra-low quiescent current and brownout detection. IC Role / Device Role / Timing Role: VCC monitors 3.0V regulated output; RESET IN monitors raw battery voltage (2.0V–3.3V); 1.7µA ICC extends battery life beyond 10 years. Use Value: Delivers deterministic reset at end-of-life battery voltage while consuming negligible energy during sleep cycles. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-voltage supervisor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS3808G33DBVR | Fixed 3.3V VCC threshold only; no adjustable RESET IN; push-pull output; 1.8µA ICC | Single-rail monitoring only; requires external circuitry for dual-voltage supervision | Select when only main supply monitoring is needed and open-drain output is not required |
| ADM6315-45ARTZ-RL | Fixed 4.5V threshold; no RESET IN; open-drain output; 1.5µA ICC; -40°C to +105°C rating | Lacks dual-monitoring capability; lower temperature grade limits use in under-hood automotive | Select for cost-sensitive industrial applications where auxiliary rail monitoring is unnecessary and extended temp is not required |
Compared with TPS3808G33DBVR and ADM6315-45ARTZ-RL, the MAX6420UK45+T uniquely delivers integrated dual-voltage supervision in a single SOT23-5 package with field-programmable timeout and automotive-grade temperature support - eliminating discrete components and enabling compact, robust power management in safety-critical systems.
Availability
MAX6420UK45+T is available at Aetrix Electronics and suitable for automotive electronic control units, medical diagnostic equipment, and battery-powered industrial sensors requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for MAX6420UK45+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 applications in automotive, industrial, and medical markets.
The MAX6412–MAX6420 family was engineered specifically for high-reliability microprocessor supervision in harsh environments, emphasizing ultra-low power, dual-rail monitoring, and programmable timing - addressing needs in engine control, ADAS, and portable instrumentation.
FAQ
What is the exact reset threshold voltage for VCC on the MAX6420UK45+T?
The MAX6420UK45+T has a factory-trimmed VCC reset threshold of 4.500V, with ±1.25% accuracy at +25°C and ±2.5% over the full -40°C to +125°C operating range. This value is confirmed in the Electrical Characteristics table and corresponds to the "45" suffix in the part number per the Reset Voltages Suffix Table.
Does the MAX6420UK45+T support manual reset functionality, and how is it implemented?
Yes, the MAX6420UK45+T supports manual reset via its RESET IN pin. Unlike the MAX6412–MAX6414 series, it lacks a dedicated MR pin; instead, a normally open momentary switch is placed in parallel with R2 in the external resistor divider network connected to RESET IN. Closing the switch pulls RESET IN to ground, triggering reset - a method validated in the datasheet's Figure 2 and Application Information section.
What is the minimum and maximum reset timeout period achievable with the MAX6420UK45+T?
The MAX6420UK45+T reset timeout period ranges from 275µs (with CSRT = 0F) to 5.75ms (with CSRT = 1500pF), as specified in the Electrical Characteristics table. The relationship is linear: tRP = (2.71 × 10⁶) × CSRT + 275µs, where CSRT is in farads. Ceramic capacitors with leakage <10nA are recommended for accuracy.
Can the MAX6420UK45+T monitor a 3.3V supply using its adjustable RESET IN input?
Yes. The MAX6420UK45+T RESET IN pin has a fixed 1.26V threshold. To monitor a 3.3V rail, connect it through a resistor divider where R1 and R2 satisfy VMON_TH = 1.26V × (R1 + R2)/R2. For 3.3V, selecting R2 = 1MΩ yields R1 ≈ 1.62MΩ. This configuration is explicitly detailed in the Reset Threshold section and Figure 1 of the datasheet.
Is the MAX6420UK45+T qualified for automotive applications?
The base MAX6420UK45+T is rated for -40°C to +125°C and meets general industrial reliability standards. Automotive-qualified versions are designated with a "/V" suffix (e.g., MAX6420UK45/V+T) and are AEC-Q100 qualified. While the +T suffix indicates lead-free RoHS compliance, only /V parts carry formal automotive qualification - confirmed in the Ordering Information and Selector Guide sections.
MAX6420UK45+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:
- Multi-Voltage Supervisor
- Number of Voltages Monitored:
- 2
- Voltage - Threshold:
- 4.5V, Adj
- Output:
- Open Drain or Open Collector
- Reset:
- Active Low
- Reset Timeout:
- Adjustable/Selectable
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
MAX6420UK45+T FAQ
1.How can I place an order for MAX6420UK45+T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6420UK45+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 MAX6420UK45+T reliable?
The price and inventory of MAX6420UK45+T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6420UK45+T is usually 5 days.
3.What payment methods are accepted for MAX6420UK45+T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX6420UK45+T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX6420UK45+T?
MAX6420UK45+T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6420UK45+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 MAX6420UK45+T?
For technical support, including MAX6420UK45+T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6420UK45+T requirements.
6.How does Aetrix verify that MAX6420UK45+T is sourced from the original manufacturer or authorized distributors?
All MAX6420UK45+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 MAX6420UK45+T meets industry standards.
7.What is the process for return or replacement of MAX6420UK45+T?
All MAX6420UK45+T units undergo pre-shipment inspection (PSI). If there is an issue with MAX6420UK45+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 MAX6420UK45+T part is unused and in its original packaging.
Return procedure for MAX6420UK45+T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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