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Analog Devices Inc./Maxim Integrated MAX804SESA+
- Part No.:
- MAX804SESA+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
MAX804SESA+.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:618
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Product details
Overview
MAX804SESA+ from Maxim Integrated is a 3.3V/3.0V microprocessor supervisory circuit with active-high open-drain RESET output, 2.925V reset threshold (S-suffix), 200ms reset timeout, watchdog timer (1.6s), and battery-backup switchover-designed for reliable power monitoring in embedded controllers and battery-powered systems.
For engineers reviewing the MAX804SESA+ datasheet, MAX804SESA+ pinout, MAX804SESA+ application, or MAX804SESA+ equivalent, this page delivers verified specifications, validated pin functions, confirmed use cases in RAM backup and brownout protection, and two technically documented alternative parts with explicit functional and tolerance differences.
Technical Context
The MAX804SESA+ integrates a precision reset comparator with ±2% threshold tolerance (2.925V rising/falling), a dedicated watchdog timer that triggers reset on 1.6s WDI inactivity, and a dual-path power switch enabling seamless VCC-to-VBATT switchover at VSW = 2.40V. It supports manual reset via MR input with internal 70µA pull-up.
Its PFI/PFO pair provides independent power-fail detection with 1.237V threshold and 10mV hysteresis, while VOUT delivers regulated CMOS RAM supply through a 3Ω PMOS switch (VCC path) or 140Ω NMOS switch (VBATT path). Guaranteed RESET assertion down to VCC = 1.0V ensures robust low-voltage operation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold | 2.925V ±2% (VCC rising/falling); ensures reset assertion before 2.85V and release after 3.00V in 3.3V±10% systems |
| Reset Timeout Period | 200ms (typical); guarantees µP initialization window sufficient for oscillator stabilization and firmware boot sequence |
| Watchdog Timeout | 1.6s ±40%; prevents runaway code execution by forcing reset if WDI lacks edge transitions within this interval |
| VCC Supply Current | 40µA (typ, VCC < 3.6V); enables ultra-low-power operation in always-on battery-backed applications |
| Battery Supply Current | 1µA (max, VBATT mode); minimizes lithium cell drain during extended backup periods |
| Power-Fail Threshold | 1.237V ±20mV; allows accurate undervoltage detection of auxiliary rails via external resistor divider |
| Operating Temp Range | -40°C to +85°C (E-grade); qualified for industrial embedded environments without derating |
Pinout & Package
MAX804SESA+ is housed in an 8-pin SOIC package (SO, S8+4 outline, RoHS-compliant with '+' suffix), with gull-wing leads, 1.27mm pitch, and JEDEC MS-012AC footprint.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - VOUT | CMOS RAM supply output | Switches between VCC (via 3Ω PMOS) and VBATT (via 140Ω NMOS); no external diode needed for battery backup |
| 2 - VCC | Main system supply input | Accepts 2.72V–5.5V; powers internal circuitry and enables VOUT connection to VCC above reset threshold |
| 3 - GND | Analog/digital ground reference | Common return for all internal comparators, timers, and switches; requires local 0.1µF decoupling |
| 4 - PFI | Power-fail input | Monitors auxiliary rail via resistor divider; asserts PFO low when voltage falls below 1.237V |
| 5 - PFO | Power-fail open-drain output | Active-low flag for supply failure; can be wired to MR on MAX704/MAX806 to trigger reset on auxiliary rail fault |
| 6 - WDI | Watchdog input | Edge-sensitive (rising/falling); clears internal 1.6s timer on transition; tied high/low causes periodic reset |
| 7 - RESET | Active-high open-drain reset output | Inverse of MAX690/MAX802 RESET; requires external pull-up to VCC for µP reset signaling |
| 8 - VBATT | Backup battery input | Supports VBATT > VCC (e.g., 3.6V Li-cell); connects to VOUT when VCC drops below 2.40V or 1.75V |
Key Features
| Feature | Design Value |
|---|---|
| Guaranteed RESET assertion to VCC = 1V | Ensures fail-safe reset behavior even during deep brownout, preventing undefined µP state |
| ±2% reset threshold tolerance | Tighter than MAX690/MAX704 (±4%), enabling precise compatibility with 3.3V±10% supply specs |
| Battery switchover at 2.40V (VSW) | Enters backup mode before VOUT falls below 2.0V RAM retention threshold, maximizing data integrity |
| 1µA VBATT supply current | Extends shelf life of primary lithium cells in long-term storage or infrequent-use portable equipment |
| 200ms reset delay with restart-on-brownout | Reinitiates timing on every VCC dip below threshold-critical for noisy or unstable power environments |
Applications
| Battery-Powered Embedded Controller | Intelligent Instrument with RAM Backup |
|---|---|
Use Scenario: Industrial sensor node powered by coin-cell battery, requiring nonvolatile RAM retention during mains loss. IC Role / Device Role / Timing Role: Supervisory IC providing VCC monitoring, automatic VBATT switchover, and watchdog supervision of firmware execution. Use Value: 1µA battery current and 2.40V switchover threshold preserve >10-year battery life while ensuring RAM data integrity down to 2.0V. |
Use Scenario: Handheld multimeter with static RAM storing calibration coefficients and user settings. IC Role / Device Role / Timing Role: Power supervisor asserting RESET during power-up/down and switching VOUT to VBATT on brownout. Use Value: Guaranteed RESET to VCC = 1V prevents spurious writes to RAM during unstable power transitions. |
| Critical µP Power Monitoring | Portable Medical Device |
Use Scenario: Safety-critical controller in automated test equipment where uncontrolled µP startup must be prevented. IC Role / Device Role / Timing Role: Precision reset generator with ±2% threshold and 200ms timeout, plus manual reset via front-panel switch. Use Value: Tight reset tolerance eliminates false resets due to nominal 3.3V supply ripple, improving system uptime. |
Use Scenario: Portable ECG monitor using lithium battery and requiring continuous memory retention during charging interruptions. IC Role / Device Role / Timing Role: Dual-supply supervisor managing VCC/VBATT handoff and generating clean reset pulse for ARM Cortex-M core. Use Value: Open-drain RESET output interfaces directly to µP reset pin without level-shifting, simplifying BOM. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX804TEPA+ | Reset threshold 3.075V ±2%, same package and pinout | Designed for 3.3V ±5% supplies; asserts reset earlier during voltage droop | Select when system requires tighter margin against 3.3V nominal supply tolerance |
| MAX804RESA+ | Reset threshold 2.625V ±2%, identical SOIC-8 package and functionality | Optimized for 3.0V ±10% systems; delays reset assertion until deeper brownout | Choose for 3.0V rail monitoring where longer hold-up time before reset is required |
Compared with MAX804SESA+, MAX804TEPA+ offers higher reset voltage for stricter 3.3V supply compliance, while MAX804RESA+ lowers the trip point for extended operation on 3.0V rails-both retain identical watchdog, PFI/PFO, and battery switchover behavior.
Availability
MAX804SESA+ is available at Aetrix Electronics and suitable for battery-powered computers and controllers, embedded controllers, intelligent instruments, critical µP power monitoring, and portable equipment requiring stable component supply across industrial temperature ranges.
Supply support for MAX804SESA+ 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 industrial, communications, and computing applications.
The MAX804SESA+ belongs to the MAX80x family of microprocessor supervisory circuits, engineered specifically for reliable power monitoring, watchdog supervision, and battery-backed RAM retention in 3.0V/3.3V embedded systems.
FAQ
What is the reset threshold voltage of the MAX804SESA+?
The MAX804SESA+ has a nominal reset threshold voltage of 2.925V with ±2% tolerance over temperature and supply variations. This value applies to both VCC rising and falling conditions, making it suitable for 3.3V ±10% power systems where reset must assert before VCC drops below 2.85V and release only after it rises above 3.00V. The 'S' suffix in MAX804SESA+ explicitly denotes this 2.925V variant.
Does the MAX804SESA+ support battery backup for CMOS RAM?
Yes, the MAX804SESA+ provides integrated battery-backup switchover for CMOS RAM via its VOUT pin. When VCC falls below 2.40V (VSW), the device automatically connects VBATT to VOUT through a 140Ω switch, maintaining RAM supply without external diodes. VBATT may exceed VCC (e.g., 3.6V lithium cell), and the MAX804SESA+ draws only 1µA from the battery in backup mode.
How does the watchdog timer function on the MAX804SESA+?
The MAX804SESA+ watchdog timer triggers a reset if the WDI pin remains static (high or low) for 1.6 seconds. The timer clears on any WDI edge transition (rising or falling) and also resets while RESET is asserted. Unlike older families, the watchdog cannot be disabled. This ensures continuous firmware health monitoring in safety-critical applications where silent failure must be prevented.
What is the purpose of the PFI and PFO pins on the MAX804SESA+?
The PFI (Power-Fail Input) and PFO (Power-Fail Output) pins on the MAX804SESA+ provide an independent voltage-monitoring channel with a fixed 1.237V threshold and 10mV hysteresis. PFI accepts a divided-down version of an auxiliary supply rail; when that voltage falls below threshold, PFO goes low. PFO can drive an interrupt line or be connected to MR on compatible parts like MAX704 to initiate a system reset on auxiliary supply failure.
Can the MAX804SESA+ operate with VCC as low as 1V?
Yes, the MAX804SESA+ guarantees valid RESET assertion (active-high) down to VCC = 1.0V, provided VBATT > 1V. This ensures deterministic reset behavior during deep brownout conditions where other supervisors may lose functionality. Without a backup battery, RESET remains valid for VCC > 1V, supporting robust power-fail recovery in low-voltage embedded systems.
MAX804SESA+ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Type:
- Battery Backup Circuit
- Number of Voltages Monitored:
- 1
- Voltage - Threshold:
- 2.925V
- Output:
- Open Drain, Open Drain
- Reset:
- Active High/Active Low
- Reset Timeout:
- 140ms Minimum
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
MAX804SESA+ FAQ
1.How can I place an order for MAX804SESA+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX804SESA+ 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 MAX804SESA+ reliable?
The price and inventory of MAX804SESA+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX804SESA+ is usually 5 days.
3.What payment methods are accepted for MAX804SESA+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX804SESA+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX804SESA+?
MAX804SESA+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX804SESA+ 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 MAX804SESA+?
For technical support, including MAX804SESA+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX804SESA+ requirements.
6.How does Aetrix verify that MAX804SESA+ is sourced from the original manufacturer or authorized distributors?
All MAX804SESA+ 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 MAX804SESA+ meets industry standards.
7.What is the process for return or replacement of MAX804SESA+?
All MAX804SESA+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX804SESA+, 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 MAX804SESA+ part is unused and in its original packaging.
Return procedure for MAX804SESA+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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