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Analog Devices Inc./Maxim Integrated MAX819MESA+
- Part No.:
- MAX819MESA+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- -
- Datasheet:
-
MAX819MESA+.pdf
- Description:
- IC SUPERVISOR MPU 5V 8-SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,387
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Product details
Overview
MAX819MESA+ from Maxim Integrated is a +5V microprocessor supervisory circuit with manual reset input, active-low reset output, battery backup switchover, and power-fail comparator functionality. It features a 4.40V ±10% reset threshold, 200ms reset timeout, 11µA quiescent supply current, and operates in 0°C to +70°C temperature range. It is used in portable embedded controllers requiring reliable brownout protection and battery-backed RAM retention.
For engineers reviewing the MAX819MESA+ datasheet, MAX819MESA+ pinout, MAX819MESA+ application, or MAX819MESA+ equivalent, this page delivers verified functional scope, exact pin roles, real-world timing behavior (e.g., 200ms reset delay, 1.6s watchdog timeout), and validated alternative options for µP supervisory design in battery-powered industrial and portable systems.
Technical Context
The MAX819MESA+ integrates a precision reset comparator with 4.40V threshold and 25mV hysteresis, a manual reset input with internal 63kΩ pull-up, and a dedicated power-fail comparator (PFI/PFO) independent of the reset path. Its battery switchover circuit uses dual PMOS switches (5Ω VCC-to-OUT, 80Ω BATT-to-OUT) activated when VCC falls below both VRST and VBATT.
Unlike MAX817/MAX818, the MAX819MESA+ excludes watchdog timer and chip-enable gating but adds MR input with 120ns minimum pulse width immunity and 150µA max input current. Reset assertion persists for 200ms after MR returns high, and PFO can be wired to MR to convert power-fail events into system resets.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold | 4.40V ±10% - triggers reset when VCC drops below this level; optimized for +5V systems with looser tolerance. |
| Reset Timeout Period | 200ms - guarantees processor remains held in reset long enough for stable power recovery and clock stabilization. |
| Supply Current | 11µA typical - enables multi-year operation on coin-cell batteries in portable instrumentation and metering devices. |
| Manual Reset Pulse Width | 120ns minimum - rejects EMI-induced glitches while supporting pushbutton or logic-driven reset initiation. |
| Battery Switchover Threshold | VCC < VBATT - ensures seamless transition to backup power only when main supply collapses below battery voltage. |
| Power-Fail Comparator Threshold | 1.25V - allows external resistor divider to monitor auxiliary supplies (e.g., 3.3V, 2.5V rails) for early warning before VCC failure. |
| Operating Temperature | 0°C to +70°C - qualified for commercial-grade embedded applications including point-of-sale terminals and smart sensors. |
Pinout & Package
MAX819MESA+ is housed in an 8-pin µMAX package (3mm × 3mm, 0.8mm height), surface-mount, lead-free compliant. Pinout is identical across MAX817/MAX818/MAX819 families in µMAX/SO/DIP formats.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 OUT | Supply Output | Switches between VCC and BATT to power CMOS RAM; low-impedance source during VCC operation (5Ω), battery-backed during brownout. |
| 2 VCC | Main Supply Input | +5V system rail input; powers internal circuitry and enables VCC-to-OUT switch; must exceed 4.40V for reset deassertion. |
| 3 GND | Ground Reference | 0V reference for all analog comparators, reset logic, and output drivers; requires low-impedance PCB connection. |
| 4 PFI | Power-Fail Input | Analog input for external undervoltage detection; compared to 1.25V internal reference; connect to resistor divider for secondary rail monitoring. |
| 5 PFO | Power-Fail Output | Open-drain output asserting low when PFI < 1.25V or VCC < VBATT; can drive MAX819's MR pin to generate power-fail-initiated reset. |
| 6 WDI | Watchdog Input | Not functional in MAX819 - left unconnected or tied to VCC/GND; no watchdog timer present per Selector Guide. |
| 7 RESET | Active-Low Reset Output | Push-pull output driving µP reset pin; asserts low for ≥200ms on power-up, brownout, or MR activation; sinks 3.2mA min. |
| 8 BATT | Backup Battery Input | Accepts 2.0V–5.5V battery or supercap; powers internal circuitry and OUT when VCC fails; leakage <1µA in backup mode. |
Key Features
| Feature | Design Value |
|---|---|
| Manual Reset Input (MR) | Internal 63kΩ pull-up enables direct pushbutton interface without external components; supports TTL/CMOS logic drive. |
| Power-Fail Comparator | Dedicated 1.25V reference and PFI/PFO pair allows independent monitoring of non-5V rails (e.g., 3.3V I/O supply) without affecting reset behavior. |
| Battery Freshness Seal | Enables OEMs to isolate backup battery until first power-up; activated via controlled VCC ramp and PFO grounding sequence. |
| Low-Power Switchover | Sub-µA battery standby current (<1µA when VCC < VBATT − 0.2V) extends shelf life of sealed portable instruments. |
| Transient Immunity | Designed to ignore fast VCC transients ≤600µs at 4.40V overdrive - prevents spurious resets in noisy power environments. |
Applications
| Portable Data Loggers | Smart Energy Meters |
|---|---|
Use Scenario: Battery-powered field instrument recording sensor data for weeks between uploads. IC Role / Device Role / Timing Role: Supervises 5V system rail, asserts reset on brownout, and switches RAM to coin-cell backup during mains loss. Use Value: Prevents data corruption during power interruption; 11µA supply current enables >5-year battery life in sleep mode. |
Use Scenario: Utility meter with tamper-proof RTC and nonvolatile memory requiring guaranteed power-fail response. IC Role / Device Role / Timing Role: Monitors 5V DC-DC output and 3.3V logic rail via PFI divider; triggers reset within 200ms of undervoltage event. Use Value: Ensures secure timekeeping and metering register integrity during grid instability or capacitor discharge. |
| Industrial HMI Panels | Medical Diagnostic Handhelds |
Use Scenario: Touchscreen control panel powered by 5V adapter with optional Li-ion backup. IC Role / Device Role / Timing Role: Provides manual reset via front-panel button (MR pin), detects VCC collapse, and gates RAM supply (OUT) to preserve configuration. Use Value: Eliminates need for external reset supervisor IC and discrete power-switching MOSFETs; reduces BOM count by 3 components. |
Use Scenario: Portable ultrasound device with flash memory storing calibration profiles and patient history. IC Role / Device Role / Timing Role: Enables battery freshness seal to guarantee full CR2032 capacity at first clinical use; monitors VCC and auxiliary rails simultaneously. Use Value: Meets IEC 62304 safety requirement for predictable power-loss behavior; avoids field failures due to premature battery depletion. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX819TESA+ | Same functionality and pinout, but rated for -40°C to +85°C extended temperature range. | Suitable for outdoor or automotive-adjacent industrial enclosures where ambient exceeds +70°C. | Select MAX819TESA+ when operating temperature must span -40°C to +85°C; otherwise MAX819MESA+ suffices for commercial environments. |
| MAX692AESA+ | Includes watchdog timer and higher reset threshold (4.65V); lacks manual reset input and power-fail comparator. | Applicable where software watchdog supervision is required but manual reset and auxiliary rail monitoring are unnecessary. | Choose MAX692AESA+ only if watchdog functionality is mandatory and MR/PFI features are expendable; not drop-in compatible due to missing MR pin function. |
Compared with MAX819MESA+, MAX819TESA+ offers broader thermal qualification without altering electrical behavior, while MAX692AESA+ trades MR/PFI capability for watchdog support - making it unsuitable for designs requiring user-initiated reset or multi-rail monitoring.
Availability
MAX819MESA+ is available at Aetrix Electronics and suitable for portable instrumentation, smart energy meters, industrial HMIs, and medical handhelds requiring stable component supply with long-term lifecycle assurance.
Supply support for MAX819MESA+ 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 power, sensing, and connectivity applications in industrial, automotive, and computing markets.
The MAX817/MAX818/MAX819 product line delivers integrated µP supervisory functions-including reset, battery switchover, and power-fail detection-for compact, low-power embedded systems operating from +5V rails.
FAQ
What is the reset threshold voltage for MAX819MESA+?
The MAX819MESA+ has a factory-trimmed reset threshold of 4.40V ±10%, specified for +5V systems with looser tolerance requirements. This value is fixed and cannot be adjusted externally. The threshold is guaranteed over temperature (0°C to +70°C) and exhibits 25mV hysteresis to prevent chatter during slow VCC transitions. It is distinct from the 4.65V version used in MAX819LESA+ variants.
Does MAX819MESA+ include a watchdog timer?
No, the MAX819MESA+ does not include a watchdog timer. Per the official Selector Guide and functional diagram, watchdog input (WDI) and timeout functionality are exclusive to MAX817 and MAX818 variants. In MAX819MESA+, the WDI pin is unused and must be left floating, tied to VCC, or grounded - it has no internal connection to timing circuitry.
Can MAX819MESA+ monitor a 3.3V supply rail?
Yes, MAX819MESA+ can monitor a 3.3V rail using its dedicated power-fail comparator. Connect the 3.3V rail to PFI through a resistor divider that scales it to ≤1.25V - for example, R1 = 165kΩ and R2 = 100kΩ yields 1.25V at PFI when VIN = 3.3V. PFO then asserts low when the scaled voltage drops below threshold, enabling power-fail warning or reset initiation via MR.
How is the manual reset function implemented on MAX819MESA+?
The MAX819MESA+ implements manual reset via the MR pin, which features an internal 63kΩ pull-up resistor. Driving MR low (e.g., via momentary switch to GND) asserts RESET for as long as MR is held low plus 200ms after release. The pin accepts TTL/CMOS logic levels and requires no external debounce components. MR must remain high or open to enable the battery freshness seal feature.
What package type is used for MAX819MESA+?
MAX819MESA+ is supplied in an 8-pin µMAX package (3mm × 3mm, 0.8mm height), RoHS-compliant and lead-free. This space-saving surface-mount package is pin-compatible with the 8-pin SO and DIP versions of the same family (e.g., MAX819MSA+), allowing flexible layout reuse across form factors while maintaining identical electrical behavior.
MAX819MESA+ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- *
- Package/Case:
- -
- Packaging:
- Tube
- Product Status:
- Active
- Programmable:
- Not Verified
- Type:
- -
- Number of Voltages Monitored:
- -
- Voltage - Threshold:
- -
- Output:
- -
- Reset:
- -
- Reset Timeout:
- -
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- -
- Supplier Device Package:
- -
MAX819MESA+ FAQ
1.How can I place an order for MAX819MESA+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX819MESA+ 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 MAX819MESA+ reliable?
The price and inventory of MAX819MESA+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX819MESA+ is usually 5 days.
3.What payment methods are accepted for MAX819MESA+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX819MESA+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX819MESA+?
MAX819MESA+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX819MESA+ 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 MAX819MESA+?
For technical support, including MAX819MESA+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX819MESA+ requirements.
6.How does Aetrix verify that MAX819MESA+ is sourced from the original manufacturer or authorized distributors?
All MAX819MESA+ 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 MAX819MESA+ meets industry standards.
7.What is the process for return or replacement of MAX819MESA+?
All MAX819MESA+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX819MESA+, 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 MAX819MESA+ part is unused and in its original packaging.
Return procedure for MAX819MESA+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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