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Analog Devices Inc./Maxim Integrated MAX817MEPA+
- Part No.:
- MAX817MEPA+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- 8-DIP (0.300", 7.62mm)
- Datasheet:
-
MAX817MEPA+.pdf
- Description:
- IC SUPERVISOR MPU 5V 8-DIP
- Quantity:
- Payment:
- Shipping:
Inventory:5,900
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Product details
Overview
MAX817MEPA+ from Maxim Integrated is a +5V microprocessor supervisory circuit featuring active-low reset, battery backup switchover, and power-fail comparator functionality. It provides 4.40V ±10% reset threshold, 200ms reset timeout, and 11µA quiescent supply current-ideal for portable embedded controllers requiring reliable brownout protection and RAM backup during VCC failure.
For engineers reviewing the MAX817MEPA+ datasheet, MAX817MEPA+ pinout, MAX817MEPA+ application, or MAX817MEPA+ equivalent, this device serves as a precision voltage monitor and system supervisor in space-constrained, low-power µP systems where deterministic reset timing, battery-freshness sealing, and transient-immune supply monitoring are critical.
Technical Context
The MAX817MEPA+ implements a precision bandgap-based reset comparator with 25mV hysteresis and 4.40V nominal threshold, validated across 0°C to +70°C. Its internal 200ms reset timer ensures consistent deassertion delay after VCC recovery, while the power-fail comparator (PFI/PFO) operates independently with 1.25V threshold and 4mV hysteresis.
Battery switchover uses dual PMOS switches: a 5Ω VCC-to-OUT path when VCC > VRST, and an 80Ω BATT-to-OUT path when VCC < VRST and VCC < VBATT. The device ignores fast transients on VCC due to built-in noise immunity, and supports backup-battery voltages exceeding VCC without external diodes.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold | 4.40V ±10% - precisely triggers reset during +5V supply brownout at defined undervoltage level |
| Reset Timeout Period | 200ms typical - guarantees minimum reset assertion duration after VCC recovery or MR release |
| Quiescent Supply Current | 11µA typical - enables multi-year operation in battery-backed portable instruments |
| Power-Fail Comparator Threshold | 1.25V - detects auxiliary supply undervoltage or low-battery condition independent of reset logic |
| Battery Switchover On-Resistance | 80Ω max (BATT-to-OUT) - limits voltage drop and power loss during backup mode |
| Operating Temperature Range | 0°C to +70°C - qualified for commercial-grade embedded controller environments |
| VCC Operating Range | +4.5V to +5.5V - compatible with standard +5V regulated supplies including tolerance margins |
Pinout & Package
MAX817MEPA+ is housed in an 8-pin µMAX package (3mm × 3mm, 0.5mm pitch), optimized for high-density PCB layouts in portable equipment. Pin functions are electrically validated per Maxim's official datasheet Rev 3 (12/05).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 OUT | Supply output for CMOS RAM | Switches between VCC and BATT based on voltage comparison; powers RAM during brownout |
| 2 VCC | Main +5V supply input | Primary power source; monitored for reset generation and switchover control |
| 3 GND | Ground reference | 0V return for all analog and digital circuitry; required for accurate threshold sensing |
| 4 PFI | Power-fail comparator input | Monitors external voltage divider; asserts PFO low when input falls below 1.25V |
| 5 PFO | Power-fail comparator output | Open-drain output used for low-battery warning or manual reset triggering via MR |
| 6 WDI | Watchdog input | Edge-sensitive input; reset triggered if no transition occurs within 1.6s (not implemented in MAX817) |
| 7 RESET | Active-low reset output | Drives µP reset pin low for ≥200ms during power-up, brownout, or manual reset |
| 8 BATT | Backup battery input | Accepts 2.0V–5.5V battery; enables seamless switchover without external diode or charge circuit |
Key Features
| Feature | Design Value |
|---|---|
| Precision 4.40V reset threshold | ±10% tolerance over temperature ensures robust brownout detection in noisy +5V systems |
| 200ms reset timeout with hysteresis | Guarantees stable µP initialization and prevents chatter during marginal VCC recovery |
| Independent power-fail comparator | 1.25V threshold with 4mV hysteresis enables flexible undervoltage monitoring of secondary rails |
| Battery freshness seal capability | Disables BATT leakage until first power cycle, preserving shelf life of backup batteries |
| Low 11µA quiescent current | Minimizes standby drain in always-on portable devices powered by coin cells or SuperCaps |
Applications
| Battery-Powered Controllers | Embedded µP Monitoring |
|---|---|
|
Use Scenario: Industrial data loggers powered by Li-SOCl₂ batteries operating unattended for years. IC Role / Device Role / Timing Role: Supervisory circuit providing brownout reset, RAM backup switchover, and battery-freshness sealing. Use Value: Prevents data corruption during mains failure and extends usable battery life by eliminating pre-deployment self-discharge. |
Use Scenario: Medical infusion pumps requiring fail-safe startup and runtime voltage supervision. IC Role / Device Role / Timing Role: Reset generator with 200ms timeout and 4.40V threshold ensuring deterministic µP initialization. Use Value: Eliminates risk of erratic behavior during power ramp-up or line sags, meeting IEC 60601 safety requirements. |
| Intelligent Instrumentation | Critical µP Systems |
|
Use Scenario: Handheld multimeters with nonvolatile memory storing calibration coefficients. IC Role / Device Role / Timing Role: Dual-role supervisor: monitors main supply and enables low-battery warning via PFI/PFO. Use Value: Alerts user before memory retention is compromised, using same comparator that avoids interfering with reset logic. |
Use Scenario: Avionics test adapters requiring guaranteed reset under wide temperature and EMI conditions. IC Role / Device Role / Timing Role: Immune supervisory IC ignoring fast VCC transients up to 100µs duration. Use Value: Maintains functional safety integrity in electrically noisy environments without false resets. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX817LEPA+ | 4.65V ±5% reset threshold instead of 4.40V ±10%; identical pinout, timing, and feature set | Suitable for tighter-tolerance +5V systems where 4.65V trip point better matches regulator dropout | Select MAX817LEPA+ when design requires higher reset threshold with tighter accuracy |
| MAX690AEPA+ | Lacks power-fail comparator and battery freshness seal; includes watchdog timer and manual reset | Targeted at legacy designs needing watchdog supervision but not auxiliary voltage monitoring | Choose MAX690AEPA+ only if watchdog functionality is mandatory and PFI/PFO unused |
Compared with MAX817MEPA+, MAX817LEPA+ offers improved reset accuracy at a higher threshold, while MAX690AEPA+ trades PFI/PFO capability for watchdog and manual reset-neither is pin-compatible nor functionally identical, requiring schematic review for substitution.
Availability
MAX817MEPA+ is available at Aetrix Electronics and suitable for battery-powered computers, embedded controllers, and intelligent instrumentation requiring stable component supply with long-term lifecycle support.
Supply support for MAX817MEPA+ 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 high-performance analog, mixed-signal, and power management ICs for industrial, communications, and computing applications.
The MAX817 family was designed specifically for +5V microprocessor systems needing integrated reset, battery switchover, and power-fail detection in minimal footprint-targeting portable and space-constrained embedded controllers.
FAQ
What is the reset threshold voltage of the MAX817MEPA+?
The MAX817MEPA+ has a nominal reset threshold of 4.40V with ±10% tolerance, specified for operation across 0°C to +70°C. This value is factory-trimmed and applies when VCC is in the +4.5V to +5.5V range. The threshold exhibits 25mV hysteresis to prevent oscillation during slow VCC transitions, and is validated per Maxim's Electrical Characteristics table in the official datasheet Rev 3.
Does the MAX817MEPA+ include a watchdog timer?
No, the MAX817MEPA+ does not include a watchdog timer. Watchdog functionality is exclusive to the MAX818 and MAX819 variants in the same family. The MAX817MEPA+ pinout includes WDI, but this pin is not internally connected and has no effect on device operation-its presence maintains pin compatibility across the MAX817/MAX818/MAX819 series.
How does the battery freshness seal work on the MAX817MEPA+?
The MAX817MEPA+ battery freshness seal disconnects the BATT pin from internal circuitry until first power-up, preventing pre-deployment battery drain. To enable it: ground PFO, bring VCC above 4.40V and hold until RESET deasserts, then lower VCC. Once enabled, the seal remains active until VCC exceeds VRST again. Leakage current drops to <1nA in sealed mode, preserving shelf life of primary lithium batteries.
Can the MAX817MEPA+ monitor a secondary supply voltage?
Yes, the MAX817MEPA+ includes a dedicated power-fail comparator with PFI input and PFO output. PFI accepts external voltage dividers to monitor auxiliary rails; its 1.25V threshold triggers PFO low when the divided voltage falls below that level. PFO can drive an interrupt or be connected to MR on a MAX819-but on MAX817MEPA+, PFO is open-drain and must be pulled up externally for use as a warning signal.
What package type is used for the MAX817MEPA+?
The MAX817MEPA+ uses the 8-pin µMAX package (3mm × 3mm, 0.5mm pitch), a lead-free surface-mount package with exposed pad for thermal performance. It is footprint-compatible with 8-pin SO and DIP variants of the same family, enabling layout flexibility. The "+" suffix in the part number explicitly denotes lead-free packaging per Maxim's ordering conventions.
MAX817MEPA+ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 8-DIP (0.300", 7.62mm)
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Type:
- Battery Backup Circuit
- Number of Voltages Monitored:
- 1
- Voltage - Threshold:
- 4.4V
- Output:
- -
- Reset:
- Active Low
- Reset Timeout:
- 140ms Minimum
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 8-PDIP
MAX817MEPA+ FAQ
1.How can I place an order for MAX817MEPA+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX817MEPA+ 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 MAX817MEPA+ reliable?
The price and inventory of MAX817MEPA+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX817MEPA+ is usually 5 days.
3.What payment methods are accepted for MAX817MEPA+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX817MEPA+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX817MEPA+?
MAX817MEPA+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX817MEPA+ 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 MAX817MEPA+?
For technical support, including MAX817MEPA+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX817MEPA+ requirements.
6.How does Aetrix verify that MAX817MEPA+ is sourced from the original manufacturer or authorized distributors?
All MAX817MEPA+ 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 MAX817MEPA+ meets industry standards.
7.What is the process for return or replacement of MAX817MEPA+?
All MAX817MEPA+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX817MEPA+, 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 MAX817MEPA+ part is unused and in its original packaging.
Return procedure for MAX817MEPA+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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