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Analog Devices Inc./Maxim Integrated MAX815KCSA+
- Part No.:
- MAX815KCSA+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
MAX815KCSA+.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,808
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Product details
Overview
MAX815KCSA+ from Maxim Integrated is a high-accuracy, low-power microprocessor supervisory circuit with integrated watchdog timer, power-fail monitoring, and manual reset functionality. It features a 4.8V ±1% reset threshold, 200ms reset timeout, active-low RESET output, and independent watchdog with 1.56s timeout - designed for reliable power-up/power-down sequencing in 5V embedded systems such as medical controllers and portable instrumentation.
For engineers reviewing the MAX815KCSA+ datasheet, MAX815KCSA+ pinout, MAX815KCSA+ application, or MAX815KCSA+ equivalent, this page delivers verified technical context, exact pin roles, real-world use cases, and validated alternative parts - all grounded in Maxim's official specifications for the K-suffix +5V variant in SO-8 package.
Technical Context
The MAX815KCSA+ implements a dedicated watchdog timer with 1.56s timeout, triggered by transitions on WDI; it asserts WDO low on timeout or during VCC brownout. Its reset generator guarantees valid RESET down to VCC = 1V, with ±1% worst-case threshold accuracy at 4.8V and 200ms minimum pulse width after threshold crossing.
It integrates a 2.50V power-fail comparator (PFI/PFO), a manual-reset input (MR) with 150µA internal pullup and 1.1V logic threshold, and glitch-immune reset detection that ignores transients ≤30µs at 100mV overdrive - all operating from a single +5V supply with 75µA max quiescent current.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold | 4.80V ±1% - ensures deterministic reset initiation in +5V systems with ±4% supply tolerance, meeting worst-case IC operating voltage (VICMIN) requirements. |
| Watchdog Timeout | 1.56 seconds - provides sufficient margin to detect firmware hangs without false triggers during normal execution flow. |
| Reset Pulse Width | 200ms minimum - guarantees µP initialization completes before release, compatible with standard 8051/ARM boot sequences. |
| Supply Current | 75µA max - enables battery-backed operation in portable equipment with multi-year shelf life. |
| VCC Operating Range | 4.85V to 5.5V - supports stable supervision across full industrial-grade +5V rail variation. |
| RESET Output Type | Active-low open-drain - allows wired-OR configuration and level-shifting into diverse µP reset inputs. |
| Power-Fail Threshold | 2.50V - enables early warning of +5V supply collapse via PFI voltage divider, with PFO sinking ≥1.2mA for direct µP interrupt drive. |
Pinout & Package
MAX815KCSA+ is housed in an 8-pin SO (Small Outline) package, RoHS-compliant and lead-free (+ suffix). Pin 1 is marked with a dot or beveled corner; pin numbering follows standard SO-8 counterclockwise convention.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 MR | Manual Reset Input | Active-low CMOS input with 150µA internal pullup; triggers reset when pulled below 1.1V; debounced internally - no external RC needed. |
| 2 VCC | Positive Supply Input | +5V main power rail; device monitors this voltage for reset assertion; guaranteed RESET validity down to 1V. |
| 3 GND | Ground Reference | System ground return for all internal comparators, timers, and outputs; must be low-impedance for noise immunity. |
| 4 PFI | Power-Fail Input | Analog input referenced to 2.50V; used with external resistor divider to monitor secondary rails (e.g., +12V); asserts PFO when voltage falls below threshold. |
| 5 PFO | Power-Fail Output | Open-drain output sinking ≥1.2mA; drives µP NMI or interrupt line directly upon PFI undervoltage detection. |
| 6 WDI | Watchdog Input | CMOS input toggled by firmware; timeout occurs if no transition within 1.56s; immune to noise due to Schmitt-trigger input. |
| 7 RESET | Reset Output | Active-low open-drain output; asserted low during power-up, brownout, or MR activation; holds low ≥200ms after recovery. |
| 8 WDO | Watchdog Output | Open-drain output mirroring watchdog state; goes low on timeout or VCC brownout; no minimum pulse width - fast response for NMI signaling. |
Key Features
| Feature | Design Value |
|---|---|
| ±1% Worst-Case Reset Accuracy | Eliminates manual trimming and ensures deterministic reset across temperature (-40°C to +85°C), line, and load variations in critical 5V systems. |
| Independent Watchdog with 1.56s Timeout | Enables robust firmware health monitoring without sharing reset logic - prevents lockup even if primary reset path fails. |
| Power-Supply Glitch Immunity | Rejects negative VCC transients ≤30µs at 100mV overdrive, preventing spurious resets in electrically noisy environments. |
| 75µA Max Supply Current | Supports ultra-low-power operation in battery-powered devices, extending operational lifetime without compromising supervision integrity. |
| Guaranteed RESET Validity to VCC = 1V | Ensures clean, predictable reset behavior during deep brownout conditions where other supervisors may release prematurely. |
Applications
| Medical Monitoring Systems | Industrial Controllers |
|---|---|
|
Use Scenario: Continuous vital-sign acquisition in portable ECG or glucose meters powered by coin-cell batteries. IC Role / Device Role / Timing Role: Supervises +5V rail derived from boost converter; asserts RESET on battery sag and triggers watchdog if firmware stalls during sensor readout. Use Value: Prevents corrupted data writes during low-voltage shutdown and ensures automatic recovery from software lockups without user intervention. |
Use Scenario: PLC I/O module with isolated +5V logic supply and field-side 24V bus monitoring. IC Role / Device Role / Timing Role: Monitors both VCC and auxiliary 24V rail (via PFI divider); generates early PFO interrupt before VCC dropout, enabling safe I/O state freeze. Use Value: Delivers deterministic power-fail response with 200ms reset hold time - meets IEC 61000-4-29 immunity requirements for controlled shutdown. |
| Set-Top Box Power Management | Test & Measurement Instruments |
|
Use Scenario: Consumer STB with dual-rail power (5V logic, 12V tuner) and firmware update capability. IC Role / Device Role / Timing Role: Uses WDO-to-MR feedback loop to convert watchdog timeout into hard reset; monitors 12V rail via PFI to preempt thermal shutdown events. Use Value: Enables unattended recovery from failed OTA updates while maintaining compliance with FCC Part 15 Class B emission limits during reset transients. |
Use Scenario: Benchtop oscilloscope with FPGA-based acquisition engine and real-time display pipeline. IC Role / Device Role / Timing Role: Provides synchronized reset to FPGA, ADC, and display controller; uses LOW LINE-equivalent behavior (via PFI) to trigger graceful buffer flush before VCC collapse. Use Value: Guarantees data coherency across subsystems during AC mains interruption, eliminating waveform corruption on power loss. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX814KCSA+ | No watchdog timer; includes LOW LINE output instead of WDO; identical reset threshold (4.8V), PFI/PFO, and MR functionality. | Suitable for systems requiring early low-line warning but not firmware hang detection - e.g., battery-gauging circuits. | Select MAX814KCSA+ only if watchdog functionality is unnecessary and low-line interrupt capability is required. |
| TPS3808G33DBVR | Fixed 3.3V reset threshold; no PFI/PFO; no watchdog; 350ms reset delay; 2.5µA quiescent current; SOT-23-6 package. | Targeted at ultra-low-power 3.3V MCU supervision without auxiliary monitoring or timing safety features. | Choose TPS3808G33DBVR only for cost-sensitive, space-constrained 3.3V designs lacking watchdog or power-fail needs. |
Compared with MAX815KCSA+, MAX814KCSA+ removes watchdog capability but adds low-line detection for predictive brownout response, while TPS3808G33DBVR trades supervision flexibility and voltage range for extreme quiescent current reduction and smaller footprint - neither is pin-compatible, and both require PCB layout changes.
Availability
MAX815KCSA+ is available at Aetrix Electronics and suitable for medical monitoring systems, industrial controllers, set-top boxes, and test & measurement instruments requiring stable component supply with guaranteed long-term manufacturability.
Supply support for MAX815KCSA+ 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 power management ICs for demanding industrial, medical, and communications applications.
The MAX814/MAX815/MAX816 family was designed specifically for high-reliability microprocessor supervision in systems where deterministic reset timing, power-fail warning, and watchdog safety are mandatory - targeting medical, industrial, and portable equipment markets.
FAQ
What is the reset threshold voltage of the MAX815KCSA+?
The MAX815KCSA+ has a factory-set reset threshold of 4.80V ±1%, optimized for +5V systems with ±4% supply tolerance. This value is fixed by the 'K' suffix and confirmed in Maxim's Electrical Characteristics table for +5V parts under VCC = 4.85V to 5.5V conditions. The threshold remains stable across -40°C to +85°C operating temperature.
Does the MAX815KCSA+ include a watchdog timer?
Yes, the MAX815KCSA+ integrates an independent watchdog timer with a nominal timeout period of 1.56 seconds. It monitors transitions on the WDI pin and asserts the WDO output low on timeout or during VCC brownout. Unlike the reset generator, WDO has no minimum pulse width, enabling fast NMI signaling to the microprocessor.
What is the function of the PFI and PFO pins on the MAX815KCSA+?
The PFI (Power-Fail Input) pin accepts a divided voltage from a monitored rail and compares it to a 2.50V internal reference. When PFI falls below this threshold, the PFO (Power-Fail Output) pin - an open-drain output - pulls low and sinks ≥1.2mA, allowing direct connection to a microprocessor's interrupt input for early power-fail warning.
Can the MAX815KCSA+ operate down to 1V supply voltage?
Yes, the MAX815KCSA+ guarantees valid RESET output behavior down to VCC = 1V. Below this voltage, RESET becomes high-impedance, but above 1V - including during brownout - RESET remains a well-defined logic low (≤0.4V) with guaranteed timing. This ensures robust reset assertion even during deep supply sags.
What package type is used for the MAX815KCSA+?
The MAX815KCSA+ is supplied in an 8-pin SO (Small Outline) package, RoHS-compliant and lead-free, as indicated by the '+' suffix in the part number. It is not available in DIP; the SO-8 footprint matches industry-standard 150mil body width with 1.27mm pitch, and is compatible with reflow soldering processes.
MAX815KCSA+ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Programmable:
- Not Verified
- Type:
- Simple Reset/Power-On Reset
- Number of Voltages Monitored:
- 1
- Voltage - Threshold:
- 4.8V
- Output:
- Push-Pull, Totem Pole
- Reset:
- Active Low
- Reset Timeout:
- 140ms Minimum
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
MAX815KCSA+ FAQ
1.How can I place an order for MAX815KCSA+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX815KCSA+ 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 MAX815KCSA+ reliable?
The price and inventory of MAX815KCSA+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX815KCSA+ is usually 5 days.
3.What payment methods are accepted for MAX815KCSA+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX815KCSA+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX815KCSA+?
MAX815KCSA+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX815KCSA+ 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 MAX815KCSA+?
For technical support, including MAX815KCSA+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX815KCSA+ requirements.
6.How does Aetrix verify that MAX815KCSA+ is sourced from the original manufacturer or authorized distributors?
All MAX815KCSA+ 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 MAX815KCSA+ meets industry standards.
7.What is the process for return or replacement of MAX815KCSA+?
All MAX815KCSA+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX815KCSA+, 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 MAX815KCSA+ part is unused and in its original packaging.
Return procedure for MAX815KCSA+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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