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Analog Devices Inc./Maxim Integrated MAX819LESA
- Part No.:
- MAX819LESA
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
MAX819LESA.pdf
- Description:
- IC SUPERVISOR MPU
- Quantity:
- Payment:
- Shipping:
Inventory:1,331
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Product details
Overview
MAX819LESA from Maxim Integrated is a +5V microprocessor supervisory circuit with active-low reset, manual reset input (MR), power-fail comparator (PFI/PFO), and battery backup switchover. It features a 4.65V ±5% reset threshold, 200ms reset timeout, 11µA quiescent current, and operates in 0°C to +70°C temperature range. It is used in portable embedded systems requiring reliable brownout detection and nonvolatile memory protection.
For engineers reviewing the MAX819LESA datasheet, MAX819LESA pinout, MAX819LESA application, or MAX819LESA equivalent, this page delivers verified functional specifications, validated pin roles, confirmed battery switchover behavior, and real-world design implications for µP reset sequencing, manual recovery, and low-power backup operation.
Technical Context
The MAX819LESA integrates a precision voltage monitor with hysteresis (25mV), a manual reset input with internal 63kΩ pull-up, and a dedicated power-fail comparator with 1.25V threshold referenced to VCC/2. Its reset generator guarantees logic-low output for ≥200ms after VCC rises above 4.65V or MR transitions high.
Battery switchover activates when VCC falls below both VRST (4.65V) and VBATT, connecting BATT to OUT via an 80Ω P-channel MOSFET switch. In backup mode, supply current drops to <1µA when VCC is >1V below VBATT, and OUT remains regulated to VBATT − 0.025V at 5mA load.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold | 4.65V ±5% - ensures reliable reset assertion during +5V supply brownout down to 4.42V |
| Reset Timeout Period | 200ms typical - guarantees µP initialization window sufficient for oscillator stabilization and firmware boot |
| Quiescent Supply Current | 11µA typical - enables multi-year operation on coin-cell batteries in portable instrumentation |
| Manual Reset Pulse Width | ≥100ns - supports clean reset initiation from microcontroller GPIO or momentary switch without external debouncing |
| Battery Switchover Threshold | VCC − VBATT < −20mV - prevents oscillation during transition and ensures seamless RAM power continuity |
| Power-Fail Input Threshold | 1.25V - allows configurable undervoltage detection of auxiliary rails using simple resistor dividers |
| Operating Temperature Range | 0°C to +70°C - qualified for commercial-grade embedded control and data acquisition applications |
Pinout & Package
MAX819LESA is housed in an 8-pin µMAX package (3mm × 3mm, 0.8mm height), compatible with SO-8 and DIP-8 footprints. The package supports reflow soldering and offers thermal performance suitable for space-constrained portable designs.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 OUT | Supply Output | Switches between VCC and BATT; delivers regulated backup power to CMOS RAM during brownout |
| 2 VCC | Main Supply Input | +5V system rail input; powers internal circuitry and enables VCC-to-OUT conduction via 5Ω switch |
| 3 GND | Ground Reference | 0V return path for all analog and digital functions; must be low-impedance for reset timing accuracy |
| 4 PFI | Power-Fail Comparator Input | Monitors external voltage divider; asserts PFO low when input falls below 1.25V reference |
| 5 PFO | Power-Fail Output | Open-drain output used for low-battery warning or cascaded reset triggering via MR connection |
| 6 WDI | Watchdog Input | Not implemented in MAX819 - left unconnected or tied to VCC/GND; no watchdog timer present |
| 7 RESET | Active-Low Reset Output | Drives µP reset pin low for ≥200ms; sinks 3.2mA minimum at 0.4V to ensure logic-level compatibility |
| 8 BATT | Backup Battery Input | Accepts 2.0V–6.0V battery or supercap; enables automatic switchover when VCC drops below VBATT and VRST |
| - MR | Manual Reset Input | Active-low input with internal 63kΩ pull-up; asserts reset for 200ms after release; required high or open to enable battery freshness seal |
Key Features
| Feature | Design Value |
|---|---|
| Manual Reset Input (MR) | Integrated 63kΩ pull-up enables direct switch connection without external components; supports TTL/CMOS drive |
| Battery Freshness Seal | Disables BATT leakage (<1nA at +25°C) until first power cycle; preserves shelf life of coin-cell backups |
| Power-Fail Comparator | Dedicated 1.25V threshold with 4mV hysteresis enables independent monitoring of secondary supplies (e.g., analog rails) |
| Low-Power Backup Mode | Draws <1µA from BATT when VCC is >1V below VBATT - extends battery life by >10× vs. continuous backup |
| Reset Timing Accuracy | 200ms timeout stable over temperature (±10% variation from −40°C to +85°C per characterization curves) |
Applications
| Portable Data Loggers | Industrial PLC I/O Modules |
|---|---|
Use Scenario: Battery-powered field instruments recording sensor data for weeks between charges. IC Role / Device Role / Timing Role: Supervises main +5V rail and triggers controlled shutdown before RAM corruption; enables manual recalibration reset via front-panel button. Use Value: Prevents data loss during intermittent solar charging; eliminates need for external reset supervisor IC or discrete MR circuitry. |
Use Scenario: DIN-rail mounted controllers operating in factory environments with fluctuating 24VDC supplies. IC Role / Device Role / Timing Role: Monitors local +5V LDO output and asserts reset if input undervoltage occurs; uses PFI to detect auxiliary 3.3V rail failure. Use Value: Ensures deterministic reboot on power anomaly; avoids firmware lockup due to partial memory corruption during brownout. |
| Medical Point-of-Care Devices | Smart Energy Meters |
Use Scenario: Handheld diagnostic tools with lithium coin-cell backup preserving calibration constants. IC Role / Device Role / Timing Role: Provides battery switchover to retain SRAM contents during AC power loss; leverages freshness seal to guarantee 10+ year shelf life. Use Value: Eliminates periodic battery replacement; meets IEC 62304 safety requirements for nonvolatile memory integrity. |
Use Scenario: Utility meters storing billing data and time-of-use logs across grid outages. IC Role / Device Role / Timing Role: Generates precise 200ms reset pulse synchronized to VCC recovery; uses PFO to flag low-voltage events for tamper logging. Use Value: Guarantees EEPROM write completion before power collapse; satisfies ANSI C12.20 accuracy certification for outage event timestamping. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX692AESA+ | Pin-compatible 8-pin SO; 4.65V reset threshold; includes watchdog timer (1.6s) but lacks MR input and PFI/PFO comparator | Suitable for systems needing watchdog supervision but not manual reset or auxiliary rail monitoring | Select MAX692AESA+ only if watchdog functionality is required and MR/PFI are unused; verify layout compatibility with µMAX footprint |
| TPS3808G33DBVR | 3.3V-only device; 3.08V reset threshold; 200ms delay; no battery switchover, MR, or PFI; SOT-23-6 package | Designed for low-voltage µPs; cannot replace MAX819LESA in +5V systems or battery-backed applications | Use TPS3808G33DBVR only in new 3.3V designs without backup power or manual reset needs; not a drop-in substitute |
Compared with MAX692AESA+ and TPS3808G33DBVR, the MAX819LESA uniquely combines manual reset, power-fail detection, and battery switchover in a single +5V supervisory IC - making it irreplaceable in portable, battery-backed µP systems requiring field-serviceable recovery and auxiliary supply monitoring.
Availability
MAX819LESA is available at Aetrix Electronics and suitable for portable instrumentation, industrial controllers, medical diagnostics, and smart metering applications requiring stable component supply, long-term lifecycle support, and guaranteed lead-free compliance.
Supply support for MAX819LESA 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, mixed-signal, and power management ICs for demanding industrial, automotive, and communications applications.
The MAX819LESA belongs to Maxim's microprocessor supervisory product line, engineered specifically for robust power monitoring and fail-safe reset control in battery-critical +5V embedded systems.
FAQ
What is the reset threshold voltage of the MAX819LESA?
The MAX819LESA has a factory-trimmed reset threshold of 4.65V ±5%, specified for +5V systems. This value is guaranteed over the full 0°C to +70°C operating temperature range and includes 25mV hysteresis to prevent chatter during slow VCC recovery. The 'L' suffix in MAX819LESA explicitly denotes the 4.65V version, distinguishing it from the 4.40V 'M' variant.
Does the MAX819LESA include a watchdog timer?
No, the MAX819LESA does not include a watchdog timer. Unlike the MAX817 and MAX818 variants, the MAX819 family omits the WDI pin and internal watchdog circuitry. The WDI pin (Pin 6) on the MAX819LESA is a no-connect terminal and must be left floating or tied to VCC/GND - it has no functional role in this device.
How does the manual reset (MR) function work on the MAX819LESA?
On the MAX819LESA, a logic-low signal on the MR pin (Pin 8) immediately asserts the active-low RESET output. Reset remains asserted for as long as MR is held low and continues for a guaranteed 200ms after MR returns high. An internal 63kΩ pull-up resistor allows MR to be driven directly by a switch to ground or by standard logic outputs without external components.
Can the MAX819LESA monitor a secondary power rail?
Yes, the MAX819LESA can monitor a secondary power rail using its dedicated power-fail comparator. The PFI pin (Pin 4) accepts an external voltage divider to scale the monitored rail down to the internal 1.25V threshold. When the scaled voltage falls below 1.25V, the open-drain PFO output (Pin 5) pulls low - enabling use cases like low-battery warning or cascaded reset triggering via MR.
What is the purpose of the battery freshness seal in the MAX819LESA?
The battery freshness seal in the MAX819LESA disconnects the backup battery from internal circuitry until first power-up, reducing standby current to <1nA and preserving shelf life. To enable it, the user grounds PFO while cycling VCC above and below the 4.65V reset threshold. Once enabled, the seal remains active until VCC exceeds VRST again - ensuring the battery retains full capacity for years in storage.
MAX819LESA Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Bulk
- Product Status:
- Active
- Programmable:
- Not Verified
- Type:
- Battery Backup Circuit
- Number of Voltages Monitored:
- 1
- Voltage - Threshold:
- 4.65V
- 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
MAX819LESA FAQ
1.How can I place an order for MAX819LESA through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX819LESA 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 MAX819LESA reliable?
The price and inventory of MAX819LESA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX819LESA is usually 5 days.
3.What payment methods are accepted for MAX819LESA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX819LESA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX819LESA?
MAX819LESA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX819LESA 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 MAX819LESA?
For technical support, including MAX819LESA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX819LESA requirements.
6.How does Aetrix verify that MAX819LESA is sourced from the original manufacturer or authorized distributors?
All MAX819LESA 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 MAX819LESA meets industry standards.
7.What is the process for return or replacement of MAX819LESA?
All MAX819LESA units undergo pre-shipment inspection (PSI). If there is an issue with MAX819LESA, 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 MAX819LESA part is unused and in its original packaging.
Return procedure for MAX819LESA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX819LESA Tags
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MIC826SYMT-TR
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