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Analog Devices Inc./Maxim Integrated MAX6373KA
- Part No.:
- MAX6373KA
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- SOT-23-8
- Datasheet:
-
MAX6373KA.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL SOT23-8
- Quantity:
- Payment:
- Shipping:
Inventory:4,950
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Product details
Overview
MAX6373KA from Maxim Integrated is a pin-selectable watchdog timer IC designed to supervise microprocessor activity in safety-critical embedded systems. It features open-drain active-low WDO output with 100ms pulse width, selectable startup delay (200µs to 60s or first-edge mode), and watchdog timeout period (30µs to 10s), operating from +2.5V to +5.5V supply. Used in industrial controllers and automotive ECUs to detect software hangs and trigger system reset.
For engineers reviewing the MAX6373KA datasheet, MAX6373KA pinout, MAX6373KA application, or MAX6373KA equivalent, key selection criteria include its first-edge startup capability, µA-level supply current (8µA typical), SOT23-8 package compatibility, and precise timing configurability without power cycling.
Technical Context
The MAX6373KA implements a dual-phase supervision architecture: an initial startup delay phase (programmable via SET0–SET2) followed by continuous watchdog timeout monitoring. Its internal transition detector ignores WDI during tSETUP (≤300µs after power-up or setting change) and during WDO assertion.
Timing configuration is fully static-SET0, SET1, and SET2 pins accept logic-high/low inputs to select among eight discrete timeout combinations, including two first-edge modes where the timer starts only upon the first valid WDI edge. The open-drain WDO output requires an external pull-up and sinks ≥1.2mA at VCC > 2.7V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage Range | +2.5V to +5.5V - supports wide-input industrial and automotive rails without LDO. |
| Supply Current (ICC) | 8µA typical - enables always-on supervision in battery-backed or low-power systems. |
| WDO Output Type | Open-drain active-low - allows level-shifting and wired-OR with other supervisors. |
| WDO Pulse Width | 100ms minimum - ensures reliable reset pulse capture by µP reset input circuits. |
| Startup Delay Options | 200µs to 60s or first-edge mode - accommodates fast-boot MCUs and long-initialization systems. |
| Watchdog Timeout Range | 30µs to 10s minimum - covers high-speed real-time loops and slow background tasks. |
| Input Logic Thresholds | VIH = 0.8×VCC, VIL = 0.6V - compatible with 3.3V and 5V logic families without level shifters. |
Pinout & Package
MAX6373KA is housed in an 8-pin SOT23-8 package (top mark AADG), footprint-compatible with industry-standard SOT23-8 layouts and reflow profiles.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - WDI | Watchdog Input | Edge-sensitive input; rising/falling transitions clear internal timer; ignored during tSETUP and WDO assertion. |
| 2 - GND | Ground Reference | Primary return path for supply and output current; must be low-impedance for noise immunity. |
| 3 - N.C. | No Connection | Internally unconnected; leave floating or grounded per layout best practice - no circuit function. |
| 4 - SET0 | Timing Configuration Input | LSB of 3-bit timing select code; sets startup delay and timeout period per Table 1 in datasheet. |
| 5 - SET1 | Timing Configuration Input | Mid-bit of 3-bit timing select code; enables first-edge mode when combined with SET2=1, SET0=1 or 0. |
| 6 - SET2 | Timing Configuration Input | MSB of 3-bit timing select code; determines whether startup delay is fixed, selectable, or first-edge. |
| 7 - WDO | Watchdog Output | Open-drain active-low output; requires external pull-up; sinks ≥1.2mA to assert reset/interrupt. |
| 8 - VCC | Power Supply Input | +2.5V to +5.5V supply; bypass capacitor (0.1µF) required near pin for EMI robustness. |
Key Features
| Feature | Design Value |
|---|---|
| First-edge startup mode | Eliminates fixed initialization timeout - timer begins only on first WDI transition, ideal for systems with variable boot time. |
| Runtime timing reconfiguration | SET0–SET2 pins can be changed dynamically without power cycle, enabling adaptive supervision in multi-phase firmware. |
| Watchdog disable function | Configurable disable via SET2=1, SET1=0, SET0=0 - allows safe firmware updates without spurious resets. |
| Low-power operation | 8µA supply current enables permanent supervision in energy-constrained applications like remote sensors. |
| No external timing components | Internal RC oscillator eliminates need for capacitors/resistors - reduces BOM count and board area. |
Applications
| Industrial PLC Controllers | Automotive Body Control Modules |
|---|---|
|
Use Scenario: Supervises main MCU during cold-start, firmware update, and runtime execution in programmable logic controllers. IC Role / Device Role / Timing Role: Watchdog timer with first-edge startup ensures supervision begins only after bootloader completes and application code starts. Use Value: Prevents false resets during extended initialization sequences while guaranteeing detection of stuck application code within ≤10s timeout window. |
Use Scenario: Monitors safety-critical CAN communication stack and sensor fusion routines in body control units. IC Role / Device Role / Timing Role: Pin-selectable 30µs–10s timeout provides granular response matching real-time task deadlines. Use Value: Enables deterministic fault recovery under ASIL-B requirements without adding software overhead or external components. |
| Medical Infusion Pumps | Telecom Remote Radio Units |
|
Use Scenario: Ensures fail-safe shutdown if motor control or dose calculation firmware hangs during therapy delivery. IC Role / Device Role / Timing Role: Open-drain WDO drives hardware reset line of dual-core safety monitor, independent of software state. Use Value: Meets IEC 62304 Class C requirement for hardware-enforced recovery with <100ms reset pulse width. |
Use Scenario: Supervises FPGA-based baseband processor in outdoor 5G small cells exposed to thermal cycling and voltage transients. IC Role / Device Role / Timing Role: 8µA quiescent current and -40°C to +85°C rating enable always-on supervision without derating. Use Value: Maintains system availability across environmental stress while consuming negligible power in standby mode. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar watchdog timer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6371KA | Fixed 60s startup delay; same open-drain WDO and 100ms pulse width; identical SOT23-8 package. | Lacks first-edge mode and sub-second startup options - suitable only for systems with predictable, long boot times. | Select MAX6371KA only when startup delay is known to be ≥60s and timing adaptability is unnecessary. |
| TPS3823DBVR | Fixed 200ms watchdog timeout; push-pull WDO (1ms pulse); 1.6V–5.5V supply; SOT23-5 package (5-pin, no SET pins). | No pin-selectable timing; requires external resistor for timeout adjustment; smaller footprint but less flexible. | Choose TPS3823DBVR for cost-sensitive, space-constrained designs where fixed timing suffices and SOT23-5 layout exists. |
Compared with MAX6371KA and TPS3823DBVR, the MAX6373KA uniquely supports first-edge startup and microsecond-scale timeout selection - critical for systems requiring both rapid fault response and variable initialization timing, without sacrificing the open-drain interface or ultra-low power consumption.
Availability
MAX6373KA is available at Aetrix Electronics and suitable for industrial controllers, automotive ECUs, and medical infusion pumps requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for MAX6373KA 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) is a semiconductor company specializing in precision analog, mixed-signal, and high-reliability ICs for industrial, automotive, and communications markets.
The MAX6369–MAX6374 family was designed specifically for robust, pin-configurable microprocessor supervision in harsh environments - emphasizing low power, timing flexibility, and hardware-level fault containment.
FAQ
What is the minimum watchdog timeout period supported by MAX6373KA?
The MAX6373KA supports a minimum watchdog timeout period of 30µs when configured with SET2=1, SET1=0, SET0=0. This value is guaranteed over the full -40°C to +85°C operating temperature range and enables supervision of high-frequency real-time tasks. The 30µs timeout is implemented using an internal precision RC oscillator, eliminating dependency on external components.
Does MAX6373KA require an external pull-up resistor on the WDO pin?
Yes, MAX6373KA requires an external pull-up resistor on the WDO pin because it features an open-drain output. A 10kΩ resistor to VCC (≤+5.5V) is recommended per the datasheet to ensure proper logic-high level while sinking ≥1.2mA during assertion. Without this resistor, WDO cannot drive a valid high state, compromising reset or interrupt functionality.
Can MAX6373KA be disabled during firmware updates?
Yes, MAX6373KA can be disabled by setting SET2=1, SET1=0, SET0=0 - a documented configuration that halts watchdog operation without power cycling. This allows safe firmware updates or debug sessions. To re-enable, simply change the SET pin states to the desired timing mode; the device enters a new startup phase after a 300µs internal setup time.
What is the purpose of the N.C. pin (Pin 3) on MAX6373KA?
Pin 3 of MAX6373KA is designated N.C. (No Connection) and is internally unconnected. It must not be tied to any signal or power rail. Best practice is to leave it floating or connect it to ground solely for mechanical stability - it has no electrical function and connecting it to active circuitry may cause unpredictable behavior or damage.
How does the first-edge startup mode work in MAX6373KA?
In first-edge mode (SET2=1, SET1=1, SET0=0 or SET2=1, SET1=0, SET0=1), MAX6373KA suspends the startup delay timer until the first valid rising or falling edge appears on WDI. This eliminates fixed timeout constraints, making it ideal for systems with highly variable boot sequences. The mode requires entering disable state first if switching dynamically during operation.
MAX6373KA Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- SOT-23-8
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Type:
- Watchdog Circuit
- Number of Voltages Monitored:
- 1
- Voltage - Threshold:
- Adjustable/Selectable
- 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-23-8
MAX6373KA FAQ
1.How can I place an order for MAX6373KA through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6373KA 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 MAX6373KA reliable?
The price and inventory of MAX6373KA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6373KA is usually 5 days.
3.What payment methods are accepted for MAX6373KA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX6373KA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX6373KA?
MAX6373KA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6373KA 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 MAX6373KA?
For technical support, including MAX6373KA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6373KA requirements.
6.How does Aetrix verify that MAX6373KA is sourced from the original manufacturer or authorized distributors?
All MAX6373KA 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 MAX6373KA meets industry standards.
7.What is the process for return or replacement of MAX6373KA?
All MAX6373KA units undergo pre-shipment inspection (PSI). If there is an issue with MAX6373KA, 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 MAX6373KA part is unused and in its original packaging.
Return procedure for MAX6373KA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX6373KA Tags
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MIC826SYMT-TR
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