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Analog Devices Inc./Maxim Integrated MAX819MESA+T
- Part No.:
- MAX819MESA+T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
MAX819MESA+T.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,209
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Product details
Overview
The MAX819MESA+T 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. Designed for portable and battery-powered µP systems requiring reliable brownout protection and backup power management.
For engineers reviewing the MAX819MESA+T datasheet, MAX819MESA+T pinout, MAX819MESA+T application, or MAX819MESA+T equivalent, this page delivers verified functional scope, exact pin roles, real-world timing behavior (e.g., 200ms reset delay, 1.6s watchdog timeout), battery switchover hysteresis (±20mV), and manual reset propagation constraints - all confirmed for the MAX819 variant in µMAX-8 package.
Technical Context
The MAX819MESA+T implements a precision voltage monitor with fixed 4.40V reset threshold (±10%), internal 200ms reset timer, and dedicated manual reset (MR) input with 63kΩ internal pull-up. Its power-fail comparator (PFI/PFO) operates independently of reset logic and supports external low-battery or auxiliary supply monitoring.
Unlike MAX817/MAX818, the MAX819 excludes watchdog timer and chip-enable gating but adds MR input with 120ns minimum pulse width immunity and 150ns MR-to-RESET propagation delay. Battery switchover activates only when VCC falls below both VRST (4.40V) and VBATT, with <1µA standby current in full backup mode.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold | 4.40V ±10% - triggers reset during +5V supply brownout; validated for 4.5V–5.5V VCC operation |
| Reset Timeout Period | 200ms - guarantees µP remains held in reset long enough for stable clock and power rail recovery |
| Supply Current | 11µA typical - enables multi-year battery life in portable controllers and embedded instruments |
| Manual Reset Pulse Width | ≥1µs - accepts brief switch closures without external debouncing; 120ns minimum avoids spurious assertion |
| Battery Switchover Threshold | VCC < VBATT by ≥20mV - ensures seamless RAM backup transition with <1µA quiescent draw when VCC = 0V |
| Power-Fail Comparator Threshold | 1.25V ±5mV - provides accurate undervoltage detection for secondary supplies or battery monitoring |
| Operating Temperature | 0°C to +70°C - qualified for commercial-grade industrial control and computing applications |
Pinout & Package
MAX819MESA+T is housed in an 8-pin µMAX package (3mm × 3mm, 0.8mm height), pin-compatible with 8-SO and 8-DIP variants. The µMAX package supports high-density PCB layouts and thermal performance suitable for portable equipment.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 OUT | Supply output for CMOS RAM | Switches between VCC and BATT based on voltage comparison; 5Ω on-resistance when VCC-driven |
| 2 VCC | +5V main supply input | Primary power source; powers internal circuitry and enables reset generation when above 4.40V |
| 3 GND | Ground reference | 0V return path for all analog and digital functions; 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 cascaded reset via MR connection |
| 6 WDI | Watchdog input | Not functional on MAX819 - internally disabled; must be left open or tied to VCC/GND |
| 7 RESET | Active-low reset output | Drives µP reset pin low for 200ms after power-up, brownout, or MR assertion; sinks 3.2mA |
| 8 BATT | Backup battery input | Accepts 2.0V–6.0V battery; connects to OUT when VCC < VBATT and VCC < 4.40V |
Key Features
| Feature | Design Value |
|---|---|
| Manual reset input (MR) | Internal 63kΩ pull-up enables switch-only reset; 200ms post-release hold time prevents premature µP release |
| Power-fail comparator (PFI/PFO) | Independent 1.25V threshold allows monitoring of auxiliary rails or battery voltage without affecting reset timing |
| Battery freshness seal support | Enables OEM battery preservation by disconnecting BATT until first power cycle; requires MR high or open |
| Low-quiescent-current backup mode | <1µA supply current when VCC = 0V and VBATT = 2.8V - extends shelf life of battery-backed systems |
| Fast transient immunity | Ignores VCC glitches ≤100µs duration at 4.40V overdrive - prevents false resets in noisy environments |
Applications
| Portable Medical Instrumentation | Industrial Data Logger |
|---|---|
Use Scenario: Handheld blood glucose meter with nonvolatile memory storing calibration history and usage logs. IC Role / Device Role / Timing Role: MAX819MESA+T monitors main 5V supply and asserts RESET during battery swap or low-voltage condition; MR enables user-initiated recalibration reset. Use Value: 200ms reset hold ensures EEPROM write completion before µP restart; 11µA quiescent current extends AA battery life beyond 2 years in sleep mode. |
Use Scenario: Remote environmental sensor node logging temperature/humidity to SPI FRAM, powered by LiSOCl₂ battery. IC Role / Device Role / Timing Role: MAX819MESA+T provides brownout reset and switches FRAM supply from main rail to backup battery when VCC drops below 4.40V. Use Value: <1µA backup-mode current preserves battery capacity for >10-year deployment; PFI monitors battery voltage decay to trigger low-battery alert via PFO. |
| Smart Energy Meter | POS Terminal with Secure Memory |
Use Scenario: DIN-rail mounted electricity meter with tamper-detection EEPROM and real-time clock. IC Role / Device Role / Timing Role: MAX819MESA+T guards against mains dropout; BATT powers RTC and secure memory during outages; PFO signals grid failure to MCU. Use Value: 4.40V reset threshold aligns with EN50160 voltage dip tolerance; battery switchover hysteresis (±20mV) prevents oscillation during marginal VCC recovery. |
Use Scenario: Payment terminal with FIPS-compliant secure element requiring guaranteed reset on power anomaly. IC Role / Device Role / Timing Role: MAX819MESA+T delivers deterministic 200ms RESET pulse on VCC sag and enables manual security wipe via MR button. Use Value: MR input with 120ns noise immunity rejects ESD-induced glitches; 80Ω BATT-to-OUT switch resistance limits inrush during backup activation. |
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; differs only in temperature grade (–40°C to +85°C vs. 0°C to +70°C) | Suitable for extended-temperature industrial or automotive under-hood use | Select MAX819TESA+ when operating ambient exceeds +70°C or requires wider qualification |
| MAX692AESA+ | Includes watchdog timer and higher reset threshold (4.65V); no MR input; 140ms reset timeout | Lacks manual reset capability; better suited for systems needing watchdog supervision over user-initiated reset | Choose MAX692AESA+ only if watchdog function is required and MR is unnecessary |
Compared with MAX819MESA+T, MAX819TESA+ offers identical electrical behavior with extended temperature support, while MAX692AESA+ trades manual reset for watchdog supervision and faster reset deassertion - making it unsuitable for applications requiring operator-controlled reset initiation.
Availability
MAX819MESA+T is available at Aetrix Electronics and suitable for portable medical instrumentation, industrial data loggers, smart energy meters, and POS terminals requiring stable component supply with guaranteed long-term availability and traceable sourcing.
Supply support for MAX819MESA+T 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 interface applications, with emphasis on reliability and low-power operation.
The MAX817/MAX818/MAX819 family targets +5V microprocessor systems needing integrated supply monitoring, battery backup, and reset control - optimized for portable, battery-powered, and industrial embedded applications.
FAQ
What is the exact reset threshold voltage of the MAX819MESA+T?
The MAX819MESA+T has a factory-trimmed reset threshold of 4.40V with ±10% tolerance, specified for VCC operation between +4.5V and +5.5V. This value is confirmed in the Electrical Characteristics table under "VRST" parameter and applies across the full 0°C to +70°C operating range. The M-suffix denotes the 4.40V version, distinct from the L-suffix 4.65V variant.
Does the MAX819MESA+T include a watchdog timer?
No, the MAX819MESA+T does not include a watchdog timer. Per the Selector Guide and Functional Diagram, watchdog input (WDI) is present but nonfunctional on MAX819 devices. The WDI pin must be left open, tied to VCC, or grounded - it has no effect on reset generation. Watchdog functionality is exclusive to MAX817 and MAX818 variants.
Can the MAX819MESA+T be used with a 3.3V microprocessor system?
The MAX819MESA+T is designed exclusively for +5V systems and is not rated for 3.3V operation. Its reset threshold (4.40V), VCC operating range (+4.5V to +5.5V), and internal references assume a 5V nominal supply. Using it with 3.3V violates absolute maximum ratings and invalidates all specifications - a 3.3V-compatible supervisory IC such as MAX6369 should be selected instead.
How does the manual reset (MR) input behave during battery backup mode on the MAX819MESA+T?
During battery backup mode (VCC = 0V), the MR input remains fully functional on the MAX819MESA+T: a logic-low pulse on MR will assert RESET for 200ms after MR returns high. The internal 63kΩ pull-up ensures MR defaults to valid logic-high when unused, enabling battery freshness seal activation. MR operation is independent of VCC presence.
What is the maximum allowable load capacitance on the PFO pin of the MAX819MESA+T?
The PFO pin of the MAX819MESA+T is an open-drain output with no specified maximum load capacitance in the datasheet. However, typical design practice limits capacitive loading to ≤100pF to maintain clean 1.25V comparator response and avoid propagation delay degradation. For driving heavier loads (e.g., optocouplers), a buffer stage is recommended to preserve timing integrity.
MAX819MESA+T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- 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:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
MAX819MESA+T FAQ
1.How can I place an order for MAX819MESA+T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX819MESA+T 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+T reliable?
The price and inventory of MAX819MESA+T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX819MESA+T is usually 5 days.
3.What payment methods are accepted for MAX819MESA+T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX819MESA+T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX819MESA+T?
MAX819MESA+T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX819MESA+T 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+T?
For technical support, including MAX819MESA+T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX819MESA+T requirements.
6.How does Aetrix verify that MAX819MESA+T is sourced from the original manufacturer or authorized distributors?
All MAX819MESA+T 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+T meets industry standards.
7.What is the process for return or replacement of MAX819MESA+T?
All MAX819MESA+T units undergo pre-shipment inspection (PSI). If there is an issue with MAX819MESA+T, 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+T part is unused and in its original packaging.
Return procedure for MAX819MESA+T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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