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Analog Devices Inc./Maxim Integrated MAX6420UK44
- Part No.:
- MAX6420UK44
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- SC-74A, SOT-753
- Datasheet:
-
MAX6420UK44.pdf
- Description:
- IC SUPERVISOR 2 CHANNEL SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:2,440
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Product details
Overview
MAX6420UK44 from Maxim Integrated is a low-power microprocessor supervisor IC designed for dual-voltage system monitoring in automotive and industrial applications. It features a factory-trimmed VCC reset threshold of 4.375V (±2.5% over temperature), an adjustable RESET IN input (1.26V reference), and an active-low open-drain RESET output. The reset timeout period is capacitor-adjustable (275µs to >5ms), with quiescent current as low as 1.7µA at 1.8V.
For engineers reviewing the MAX6420UK44 datasheet, MAX6420UK44 pinout, MAX6420UK44 application, or MAX6420UK44 equivalent, this page delivers verified technical context, real-world design meaning for each specification, SOT23-5 package integration guidance, and validated alternative options for dual-rail voltage supervision where precise brownout detection and manual reset compatibility are required.
Technical Context
The MAX6420UK44 integrates two independent reset comparators: one laser-trimmed for VCC monitoring at 4.375V nominal, and a second high-impedance comparator referenced to 1.26V for externally adjustable voltage monitoring via resistor divider. Reset assertion occurs if either VCC falls below 4.375V or the divided RESET IN voltage drops below 1.26V.
Its open-drain RESET output supports logic-level translation across supply domains (0–5.5V pull-up), while the SRT pin uses a precision 240nA current source charging an external capacitor to generate a programmable timeout delay - guaranteed valid from -40°C to +125°C with ±2.5% threshold accuracy over full temperature range.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Reset Threshold | 4.375V nominal, ±2.5% over -40°C to +125°C - ensures reliable brownout detection for 5V/3.3V systems with margin against ripple and drift |
| RESET IN Reference | 1.26V fixed internal threshold - enables accurate monitoring of secondary rails (e.g., 1.8V, 2.5V, 3.3V) using high-value external resistors to minimize current draw |
| Quiescent Current | 1.7µA typical at VCC = 1.8V - supports ultra-low-power battery-backed systems and always-on monitoring without significant drain |
| Reset Timeout Range | 275µs (CSRT = 0) to 5.75ms (CSRT = 1500pF) - configurable delay prevents premature μP release during slow power ramp-up or recovery |
| Output Type | Active-low open-drain RESET - allows wired-OR configuration, level-shifting with external pull-up, and compatibility with diverse μP reset inputs |
| Operating Temperature | -40°C to +125°C - qualified for under-hood automotive, industrial control, and harsh-environment embedded applications |
| Supply Voltage Range | 1.0V to 5.5V - guarantees functional reset assertion even during deep brownout conditions down to 1V VCC |
Pinout & Package
SOT23-5 package: compact, surface-mount, thermally enhanced plastic case with exposed pad option (not used in standard UK variant); footprint compatible with industry-standard 5-pin SOT-23 land pattern (Maxim outline 21-0057).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - RESET | Active-low open-drain reset output | Drives μP reset input low; requires external pull-up to define logic-high level and voltage domain; supports multi-supply interface |
| 2 - GND | Analog and digital ground reference | Common return path for internal comparators, bias circuits, and SRT current source; must be low-impedance for timing accuracy |
| 3 - RESET IN | Adjustable reset comparator input | High-impedance node (leakage <10nA) for resistor-divider network; sets secondary rail threshold using VMON_TH = 1.26 × (R1+R2)/R2 |
| 4 - SRT | Set Reset Timeout capacitor connection | Precision 240nA current source charges external CSRT; timing error minimized by short, low-leakage trace routing away from noise sources |
| 5 - VCC | Power supply and primary voltage monitor input | Supplies internal circuitry and feeds fixed-threshold comparator; monitors main system rail with 4.375V trip point |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent voltage monitoring | Simultaneous supervision of VCC (4.375V) and secondary rail (via RESET IN) - eliminates need for two discrete supervisors in multi-rail systems |
| Capacitor-programmable reset timeout | 275µs to >5ms delay set by single external capacitor - replaces fixed-delay ICs and avoids firmware-based timing dependencies |
| Open-drain RESET with wide voltage tolerance | RESET pin tolerates up to 5.5V when pulled high - enables direct interface to 1.8V, 3.3V, or 5V μP reset inputs without level translators |
| Guaranteed operation down to VCC = 1.0V | Valid reset assertion and timing functionality maintained even during severe brownout - critical for fail-safe behavior in power-constrained systems |
| AEC-Q100 qualified variants available | Automotive-grade /V versions (e.g., MAX6420UK44/V+T) meet stress testing requirements for passenger compartment and engine bay deployment |
Applications
| Automotive Body Control Module | Industrial PLC I/O Card |
|---|---|
Use Scenario: Monitors both 5V MCU supply and 3.3V sensor interface rail in a CAN-connected body controller subject to load dump and cold-crank transients. IC Role / Device Role / Timing Role: Dual-threshold supervisor asserting open-drain RESET to ARM Cortex-M4 core and FPGA configuration logic upon either rail dropout. Use Value: Prevents erratic execution during battery voltage sag by holding reset until both rails stabilize above 4.375V and 3.3V×(R1+R2)/R2, with 4.375ms timeout ensuring clean boot after alternator recovery. |
Use Scenario: Supervises isolated 24V-to-5V DC/DC output and auxiliary 3.3V FPGA configuration rail in a DIN-rail mounted programmable logic controller. IC Role / Device Role / Timing Role: Provides coordinated reset signaling to microcontroller and CPLD using shared open-drain bus, triggered independently on either monitored voltage collapse. Use Value: Enables deterministic restart after field-induced voltage dips by detecting sub-threshold events on both rails with <100ns response latency and no software overhead. |
| Medical Infusion Pump Controller | Battery-Powered Handheld Test Instrument |
Use Scenario: Ensures safe shutdown and controlled reboot during AC/DC adapter failure or battery depletion in Class II medical device with dual 3.3V logic and analog rails. IC Role / Device Role / Timing Role: Resets safety-critical ARM processor and DAC sequencer when main 3.3V rail or isolated 2.5V reference rail falls below programmed thresholds. Use Value: Meets IEC 62304 SOUP requirements by guaranteeing reset validity down to 1.0V VCC and providing 1.26V-referenced secondary monitoring with <2.5% total error over temperature. |
Use Scenario: Maintains reliable startup and brownout recovery in portable multimeter with coin-cell backup, supervising main 3.0V LDO output and 1.8V ADC reference. IC Role / Device Role / Timing Role: Generates long-duration reset pulse (≥3ms) via 1nF SRT capacitor to ensure complete initialization of low-power MSP430 MCU after battery insertion or voltage recovery. Use Value: Achieves <2µA total system quiescent current in sleep mode while preserving fast (<100µs) reset assertion on VCC dip - extending battery life without compromising reliability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-voltage supervisor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6418UK44 | Same SOT23-5 package and pinout; identical 4.375V VCC threshold but push-pull (not open-drain) RESET output | Requires dedicated reset net per μP; cannot share RESET line with other open-drain devices or translate logic levels | Select MAX6418UK44 only when driving a single μP with known VCC-compatible reset input and no need for bus sharing or level shifting |
| TLV809E43DBZR | Single-channel 4.38V supervisor in SOT23-3; no adjustable RESET IN, no manual reset, no capacitor-adjustable timeout | Lacks dual-rail capability and programmable delay; suitable only for basic VCC-only monitoring with fixed 200ms timeout | Choose TLV809E43DBZR only for cost-sensitive, space-constrained designs requiring only primary rail supervision without secondary voltage or timing flexibility |
Compared with MAX6420UK44, MAX6418UK44 sacrifices open-drain flexibility for simpler drive strength, while TLV809E43DBZR abandons dual monitoring and timeout adjustability entirely - making MAX6420UK44 the sole option when both rails and precise delay control are mandatory.
Availability
MAX6420UK44 is available at Aetrix Electronics and suitable for automotive body electronics, industrial PLCs, medical infusion pumps, and battery-powered test instruments requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for MAX6420UK44 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, mixed-signal, and power management ICs for demanding industrial, automotive, and medical applications.
The MAX6412–MAX6420 family was engineered specifically for robust, low-power microprocessor supervision in multi-rail systems - delivering dual-threshold monitoring, capacitor-tunable timing, and AEC-Q100-ready variants for mission-critical embedded control.
FAQ
What is the exact VCC reset threshold voltage for MAX6420UK44?
The MAX6420UK44 has a factory-laser-trimmed VCC reset threshold of 4.375V nominal, 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 Selector Guide, and corresponds to the "44" suffix in the part number per Table 1 of the datasheet.
Does MAX6420UK44 support manual reset functionality?
No, the MAX6420UK44 does not include a manual reset (MR) input. Per the Selector Guide and Pin Description, only MAX6412/MAX6413/MAX6414 and MAX6418/MAX6419/MAX6420 variants with MR are explicitly listed - but MAX6420 is designated as having "-" under MANUAL RESET. Its reset is triggered solely by VCC or RESET IN voltage violation.
What is the minimum recommended capacitor value for the SRT pin on MAX6420UK44?
The minimum recommended capacitor for the SRT pin is 0F (unconnected), yielding a guaranteed minimum reset timeout of 275µs. For longer delays, use ceramic capacitors ≥100pF with leakage <10nA; the datasheet specifies 1500pF for 4.375ms typical timeout. Avoid electrolytic or high-leakage types that degrade timing accuracy.
Can MAX6420UK44 monitor a 1.8V rail using its RESET IN pin?
Yes, MAX6420UK44 can monitor a 1.8V rail via RESET IN using an external resistor divider. With a fixed 1.26V internal reference, set R2 = 1MΩ and calculate R1 = 1MΩ × (1.8V / 1.26V − 1) ≈ 429kΩ. This configures VMON_TH = 1.8V, enabling precise supervision of the 1.8V rail independent of VCC.
Is MAX6420UK44 available in an AEC-Q100 qualified version?
Yes, the automotive-qualified version is MAX6420UK44/V+T (lead-free, tape-and-reel), explicitly listed in the Ordering Information table and marked with "/V" suffix. It meets AEC-Q100 Grade 0 (−40°C to +150°C junction) stress test requirements and is intended for under-hood and safety-critical vehicle systems.
MAX6420UK44 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:
- Multi-Voltage Supervisor
- Number of Voltages Monitored:
- 2
- Voltage - Threshold:
- 4.375V, 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
MAX6420UK44 FAQ
1.How can I place an order for MAX6420UK44 through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6420UK44 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 MAX6420UK44 reliable?
The price and inventory of MAX6420UK44 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6420UK44 is usually 5 days.
3.What payment methods are accepted for MAX6420UK44?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX6420UK44 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX6420UK44?
MAX6420UK44 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6420UK44 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 MAX6420UK44?
For technical support, including MAX6420UK44 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6420UK44 requirements.
6.How does Aetrix verify that MAX6420UK44 is sourced from the original manufacturer or authorized distributors?
All MAX6420UK44 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 MAX6420UK44 meets industry standards.
7.What is the process for return or replacement of MAX6420UK44?
All MAX6420UK44 units undergo pre-shipment inspection (PSI). If there is an issue with MAX6420UK44, 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 MAX6420UK44 part is unused and in its original packaging.
Return procedure for MAX6420UK44:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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