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Analog Devices Inc./Maxim Integrated MAX819MCUA+
- Part No.:
- MAX819MCUA+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
MAX819MCUA+.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 8UMAX
- Quantity:
- Payment:
- Shipping:
Inventory:300
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Product details
Overview
MAX819MCUA+ 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 4.40V ±10% reset threshold, 200ms reset timeout, 11µA quiescent supply current, and operates in 0°C to +70°C temperature range. Designed for portable µP systems requiring reliable brownout detection and nonvolatile memory protection.
For engineers reviewing the MAX819MCUA+ datasheet, MAX819MCUA+ pinout, MAX819MCUA+ application, or MAX819MCUA+ equivalent, this device serves as a precision voltage monitor and system supervisor in battery-backed embedded controllers, intelligent instruments, and critical µP monitoring applications where low-power operation and manual reset capability are essential.
Technical Context
The MAX819MCUA+ integrates a precision reset comparator with 4.40V threshold (±10%), a manual reset input with internal 63kΩ pull-up, and a power-fail comparator referenced to 1.25V. Its reset generator guarantees 200ms minimum assertion time after VCC exceeds VRST or MR transitions high.
Battery switchover logic activates when VCC falls below both VRST (4.40V) and VBATT, connecting BATT to OUT via an 80Ω PMOS switch. The power-fail comparator (PFI/PFO) operates independently and can be wired to MR to trigger reset on external supply undervoltage - though this disables battery freshness seal functionality.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold | 4.40V ±10% - sets brownout detection point for +5V systems; triggers reset when VCC drops below this level |
| Reset Timeout Period | 200ms typical - ensures µP remains held in reset long enough to stabilize after power recovery |
| Supply Current | 11µA typical - enables multi-year operation from coin-cell batteries in portable equipment |
| Manual Reset Pulse Width | ≥100ns - supports clean reset initiation from mechanical switches or digital logic without debouncing |
| Power-Fail Input Threshold | 1.25V - allows configurable undervoltage monitoring of auxiliary supplies using external resistor divider |
| Battery Switchover On-Resistance | 80Ω max - limits voltage drop during backup mode, preserving RAM retention voltage under load |
| Operating Temperature | 0°C to +70°C - qualified for commercial-grade embedded controller and instrumentation applications |
Pinout & Package
MAX819MCUA+ is housed in an 8-pin µMAX package (3mm × 3mm, 0.5mm pitch), compatible with space-constrained portable designs and offering thermal performance suitable for continuous operation at +70°C ambient.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 OUT | Supply Output | Switches between VCC and BATT to maintain CMOS RAM power during brownout; connects to VCC via 5Ω switch when active |
| 2 VCC | Main Supply Input | +5V system rail input; powers internal circuitry and enables VCC-to-OUT path above reset threshold |
| 3 GND | Ground Reference | 0V reference for all analog comparators, reset logic, and I/O pins; must be low-impedance for noise immunity |
| 4 PFI | Power-Fail Input | Analog input for external undervoltage monitoring; compared to 1.25V internal reference to assert PFO |
| 5 PFO | Power-Fail Output | Open-drain output that goes low when PFI < 1.25V or VCC < VBATT; used for warning or MR triggering |
| 6 WDI | Watchdog Input | Not present on MAX819 - unused pin; left unconnected or tied to GND per design guidance |
| 7 RESET | Active-Low Reset Output | Push-pull output asserting low for ≥200ms after VCC rise, MR low pulse, or brownout; sinks/sourcing capable |
| 8 BATT | Battery Backup Input | Backup supply input; connects to OUT when VCC < VRST and VCC < VBATT; supports voltages up to 6.0V |
Key Features
| Feature | Design Value |
|---|---|
| Manual Reset Input (MR) | Internal 63kΩ pull-up enables direct switch connection; asserts reset for duration of MR low + 200ms timeout |
| Power-Fail Comparator | Independent 1.25V reference allows monitoring of secondary supplies (e.g., 3.3V, 2.5V rails) without affecting reset function |
| Battery Freshness Seal | Disables BATT leakage (<1nA at +25°C) until first power cycle, preserving shelf life of backup coin cells |
| Reset Threshold Hysteresis | 25mV - prevents chatter during slow VCC ramp-down by requiring ~4.425V to release reset after 4.40V trip |
| Low-Power Operation | 11µA supply current at +25°C - reduces battery drain in always-on monitoring applications |
Applications
| Battery-Powered Computers and Controllers | Embedded Controllers |
|---|---|
|
Use Scenario: Portable data loggers powered by CR2032 coin cell with SRAM retention requirement during main power loss. IC Role / Device Role / Timing Role: MAX819MCUA+ monitors VCC, asserts RESET to halt µP execution, and switches OUT to BATT to sustain RAM voltage. Use Value: Ensures deterministic restart and zero-data-loss memory retention with <1µA backup current draw below VBATT − 0.2V. |
Use Scenario: Industrial PLC module with dual-supply monitoring: main +5V rail and isolated +3.3V I/O rail. IC Role / Device Role / Timing Role: MAX819MCUA+ uses PFI to monitor +3.3V via resistor divider; PFO pulls MR low to initiate controlled shutdown on I/O rail failure. Use Value: Enables coordinated system-level response to auxiliary supply faults without adding discrete comparators or logic. |
| Intelligent Instruments | Critical µP Monitoring |
|
Use Scenario: Handheld multimeter with EEPROM calibration storage and real-time clock backed by supercapacitor. IC Role / Device Role / Timing Role: MAX819MCUA+ provides manual reset via front-panel button (MR), detects VCC brownout, and gates power to RTC/SRAM via OUT. Use Value: Eliminates need for external reset IC and discrete power-switching MOSFET while supporting field-serviceable reset. |
Use Scenario: Medical infusion pump requiring fail-safe µP reset on any supply anomaly to prevent unintended motor activation. IC Role / Device Role / Timing Role: MAX819MCUA+ continuously validates +5V rail; asserts RESET within 10µs of VCC crossing 4.40V threshold during fall/rise. Use Value: Meets IEC 62304 Class C software safety requirements via hardware-enforced reset timing and hysteresis. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX819LCTA+ | Same functionality but in 8-pin TDFN (3mm × 3mm); 4.65V reset threshold instead of 4.40V | Requires PCB redesign due to different footprint; higher reset threshold suits tighter-tolerance +5V supplies | Select when system VCC tolerance is ±5% and board layout supports TDFN package |
| TPS3808G33DBVR | TI part with 3.3V fixed reset threshold, no manual reset input, and 350ms timeout; 2.5µA supply current | Lacks MR and battery switchover; intended for fixed-voltage ASIC/FPGA monitoring, not µP + backup RAM | Choose only if application requires ultra-low quiescent current and does not need manual reset or BATT support |
Compared with MAX819MCUA+, MAX819LCTA+ offers identical feature set in a thermally enhanced TDFN package but with higher reset threshold, while TPS3808G33DBVR trades manual reset and battery switching for lower power and simpler integration in non-backup applications.
Availability
MAX819MCUA+ is available at Aetrix Electronics and suitable for battery-powered computers and controllers, embedded controllers, intelligent instruments, critical µP monitoring, and portable equipment requiring stable component supply across industrial and medical OEM programs.
Supply support for MAX819MCUA+ 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 consumer applications.
The MAX817/MAX818/MAX819 family was designed specifically for +5V microprocessor systems needing integrated reset supervision, battery backup control, and power-fail detection in minimal board area.
FAQ
What is the reset threshold voltage of the MAX819MCUA+?
The MAX819MCUA+ has a factory-trimmed reset threshold of 4.40V ±10%, optimized for +5V systems with looser tolerance requirements. This value is specified over the full operating temperature range (0°C to +70°C) and includes 25mV hysteresis to prevent oscillation during slow VCC transitions. The threshold is internally generated and does not require external components.
Does the MAX819MCUA+ include a watchdog timer?
No, the MAX819MCUA+ does not include a watchdog timer. According to the Selector Guide and functional diagram in the official datasheet, watchdog input (WDI) functionality is exclusive to MAX817 and MAX818 variants. Pin 6 on MAX819MCUA+ is a no-connect terminal and must be left unconnected or grounded per layout guidelines.
How does the manual reset input (MR) function on the MAX819MCUA+?
On the MAX819MCUA+, the MR pin is an active-low input with an internal 63kΩ pull-up resistor. Asserting MR low initiates reset immediately, and RESET remains low for the full 200ms timeout period even after MR returns high. MR must be held high or left open to enable the battery freshness seal; connecting PFO to MR disables this feature permanently.
Can the MAX819MCUA+ monitor a 3.3V supply using its power-fail comparator?
Yes, the MAX819MCUA+ can monitor a 3.3V supply using its PFI input and 1.25V internal reference. A resistor divider (e.g., R1 = 165kΩ, R2 = 100kΩ) scales the 3.3V rail to 1.25V at PFI. When the scaled voltage drops below 1.25V, PFO goes low - which can be used directly as a warning or connected to MR to trigger reset, though the latter disables battery freshness seal.
What is the maximum allowable voltage on the BATT pin of the MAX819MCUA+?
The absolute maximum rating for the BATT pin on the MAX819MCUA+ is +6.0V, as specified in the Absolute Maximum Ratings table. However, normal operation assumes VBATT between 2.0V and 5.5V. Exceeding +6.0V risks permanent damage. In battery-backup mode, the device draws less than 1µA from BATT when VCC < VBATT − 0.2V, enabling multi-year shelf life with standard coin cells.
MAX819MCUA+ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- 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:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-uMAX/uSOP
MAX819MCUA+ FAQ
1.How can I place an order for MAX819MCUA+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX819MCUA+ 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 MAX819MCUA+ reliable?
The price and inventory of MAX819MCUA+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX819MCUA+ is usually 5 days.
3.What payment methods are accepted for MAX819MCUA+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX819MCUA+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX819MCUA+?
MAX819MCUA+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX819MCUA+ 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 MAX819MCUA+?
For technical support, including MAX819MCUA+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX819MCUA+ requirements.
6.How does Aetrix verify that MAX819MCUA+ is sourced from the original manufacturer or authorized distributors?
All MAX819MCUA+ 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 MAX819MCUA+ meets industry standards.
7.What is the process for return or replacement of MAX819MCUA+?
All MAX819MCUA+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX819MCUA+, 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 MAX819MCUA+ part is unused and in its original packaging.
Return procedure for MAX819MCUA+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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