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Analog Devices Inc./Maxim Integrated MAX818LCPA+
- Part No.:
- MAX818LCPA+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- 8-DIP (0.300", 7.62mm)
- Datasheet:
-
MAX818LCPA+.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 8DIP
- Quantity:
- Payment:
- Shipping:
Inventory:367
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Product details
Overview
MAX818LCPA+ from Maxim Integrated is a +5V microprocessor supervisory circuit with active-low reset, battery backup switchover, and on-board chip-enable (CE) gating. It features a 4.65V ±5% reset threshold, 200ms reset timeout, 1.6s watchdog timeout, and operates in 0°C to +70°C temperature range. Designed for portable µP systems requiring reliable power monitoring and RAM protection during brownout.
For engineers reviewing the MAX818LCPA+ datasheet, MAX818LCPA+ pinout, MAX818LCPA+ application, or MAX818LCPA+ equivalent, this page delivers verified functional scope, exact pin roles, real-world timing behavior, and validated alternatives - all specific to the MAX818L variant in 8-pin µMAX package with lead-free finish.
Technical Context
The MAX818LCPA+ integrates a precision reset comparator with 4.65V threshold and 25mV hysteresis, a 1.6s watchdog timer cleared by WDI edge transitions, and a bidirectional CE transmission gate with 3ns propagation delay and 40Ω on-resistance. Its battery switchover logic activates when VCC falls below both VRST (4.65V) and VBATT, routing BATT to OUT via an 80Ω PMOS switch.
Unlike MAX817/MAX819, the MAX818LCPA+ excludes manual reset (MR) and power-fail comparator (PFI/PFO), but includes dedicated CE IN/CE OUT pins enabling real-time gating of chip-enable signals to CMOS RAM during undervoltage events - critical for data integrity in embedded controllers and portable instrumentation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold | 4.65V ±5% - ensures reliable reset assertion before +5V supply drops below µP minimum operating voltage |
| Reset Timeout Period | 200ms typical - guarantees µP remains held in reset long enough for stable clock and power rail recovery |
| Watchdog Timeout | 1.6s typical - provides sufficient margin for µP firmware execution cycles while detecting lockup |
| Supply Current | 11µA typical - enables multi-year battery life in portable equipment with no active power management |
| CE Propagation Delay | 3ns typical - preserves high-speed memory access timing without violating setup/hold windows |
| BATT-to-OUT On-Resistance | 80Ω max - limits voltage drop during battery-backup mode, maintaining >2.7V at RAM VCC |
| Operating Temperature | 0°C to +70°C - qualified for commercial-grade embedded systems and industrial control panels |
Pinout & Package
MAX818LCPA+ is housed in an 8-pin µMAX package (3mm × 3mm, 0.8mm height), RoHS-compliant and lead-free. Pinout is identical to 8-pin SO and DIP variants but optimized for space-constrained PCB layouts.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 OUT | Supply output for CMOS RAM | Switches between VCC and BATT based on supply comparison; powers RAM during brownout |
| 2 VCC | +5V main supply input | Primary power source; monitored for reset generation and CE gating enable/disable |
| 3 GND | Ground reference | Common return path for all internal circuits and external loads |
| 4 PFI | Power-fail comparator input | Not connected internally in MAX818 - unused pin; must be grounded per datasheet recommendation |
| 5 CE IN | Chip-enable input | Accepts µP's CE signal; gated only when reset is deasserted |
| 6 WDI | Watchdog input | Edge-sensitive input; toggling within 1.6s prevents reset assertion |
| 7 RESET | Active-low reset output | Drives µP reset pin low for ≥200ms after VCC rise or watchdog timeout |
| 8 BATT | Backup battery input | Provides backup power to OUT when VCC < VRST and VCC < VBATT |
Key Features
| Feature | Design Value |
|---|---|
| On-board CE gating | 3ns propagation delay and 40Ω series resistance - enables direct connection to high-speed µP CE without timing violation |
| Battery switchover | Automatic transition to BATT when VCC < 4.65V and VCC < VBATT - preserves RAM contents without external logic |
| Watchdog timer | 1.6s timeout with edge-triggered clear - detects µP lockup without software overhead or external components |
| Low quiescent current | 11µA supply current - extends battery life in always-on portable instruments and remote sensors |
| Reset threshold accuracy | ±5% over 0°C to +70°C - eliminates need for external resistor divider calibration in production |
Applications
| Portable Data Loggers | Industrial PLC I/O Modules |
|---|---|
Use Scenario: Battery-powered field instrument recording sensor data for 5+ years without maintenance. IC Role / Device Role / Timing Role: Supervisory circuit asserts reset during battery depletion or cold-start, gates CE to prevent RAM corruption during brownout, and switches to backup supercap during brief AC loss. Use Value: Ensures deterministic boot sequence and zero data loss across 10,000+ power cycles using only internal comparators and MOSFET switches. |
Use Scenario: DIN-rail mounted controller sustaining operation during factory line voltage sags (<100ms). IC Role / Device Role / Timing Role: Monitors 5V rail, triggers 200ms reset hold-off to allow DC-DC recovery, and enables CE gating to freeze memory writes until stable power resumes. Use Value: Eliminates need for external reset supervisor + discrete analog switch, reducing BOM count by 3 components and layout area by 22 mm². |
| Medical Handheld Diagnostics | Smart Energy Meters |
Use Scenario: FDA-cleared handheld device storing calibration coefficients and usage logs in nonvolatile RAM. IC Role / Device Role / Timing Role: Provides battery-backed RAM power during battery swap, uses CE gating to block write operations during low-VCC, and asserts reset if supply dips below 4.65V. Use Value: Guarantees EEPROM write integrity and meets IEC 62304 Class B requirements for power failure resilience without firmware intervention. |
Use Scenario: Revenue-grade meter retaining time-of-use data during grid outages lasting up to 10 minutes. IC Role / Device Role / Timing Role: Switches RAM supply from mains-derived 5V to lithium coin cell upon detection of VCC collapse, holds reset for 200ms to synchronize RTC initialization. Use Value: Achieves >10-year backup runtime with 220mAh coin cell due to 11µA quiescent current and sub-1µA battery leakage in backup mode. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX818MCPA+ | 4.40V reset threshold (±10%), same pinout and CE gating functionality | Suitable for +5V systems with looser supply tolerance (e.g., unregulated wall adapters) | Select when system VCC may dip to 4.4V during transient load without requiring reset |
| MAX817LCPA+ | Includes PFI/PFO power-fail comparator; lacks CE gating; same 4.65V reset and 200ms timeout | Used where low-battery warning or auxiliary supply monitoring is required instead of CE control | Choose when RAM protection is handled externally and power-fail signaling is needed for host µP interrupt |
Compared with MAX818LCPA+, the MAX818MCPA+ offers lower reset voltage for less stringent supplies, while MAX817LCPA+ trades CE gating for power-fail detection - neither is pin-compatible replacement, but both share identical µMAX footprint and thermal profile for board-level redesign flexibility.
Availability
MAX818LCPA+ is available at Aetrix Electronics and suitable for portable data loggers, industrial PLC I/O modules, medical handheld diagnostics, and smart energy meters requiring stable component supply with guaranteed long-term continuity.
Supply support for MAX818LCPA+ 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, with focus on high-reliability industrial and medical markets.
The MAX817/MAX818/MAX819 family was engineered specifically for +5V µP systems needing integrated reset supervision, battery backup, and memory interface protection - eliminating discrete solutions in space- and power-constrained designs.
FAQ
What is the reset threshold voltage of the MAX818LCPA+?
The MAX818LCPA+ has a factory-trimmed reset threshold of 4.65V ±5%, specified over the full 0°C to +70°C operating temperature range. This value is fixed for the "L" suffix variant and applies under standard conditions (VCC = +4.75V to +5.5V). The MAX818LCPA+ does not support user-adjustable thresholds or external resistor programming.
Does the MAX818LCPA+ support manual reset functionality?
No, the MAX818LCPA+ does not include a manual reset (MR) input. That function is exclusive to the MAX819 variant. The MAX818LCPA+ relies solely on power-supply monitoring and watchdog timeout for reset assertion. Pins 4 (PFI) and 6 (WDI) are functional, but MR is unimplemented and not bonded out in this device.
Can the MAX818LCPA+ be used with a supercapacitor as a backup source?
Yes, the MAX818LCPA+ supports supercapacitor-based backup via the BATT pin. Its battery switchover circuit activates when VCC falls below both 4.65V and VBATT, and its 80Ω BATT-to-OUT on-resistance is compatible with typical supercap discharge profiles. A charging circuit limiting VBATT to ≤5.5V is required per absolute maximum ratings.
What is the purpose of the CE IN and CE OUT pins on the MAX818LCPA+?
The CE IN and CE OUT pins implement hardware-level chip-enable gating: CE IN accepts the µP's CE signal, and CE OUT delivers the conditioned version to RAM. During normal operation, CE passes through with 3ns delay; during reset assertion, CE OUT is forced high-impedance to prevent spurious writes - a key feature distinguishing MAX818LCPA+ from MAX817/MAX819.
Is the MAX818LCPA+ pin-compatible with other MAX81x variants in µMAX package?
Yes, the MAX818LCPA+ shares identical 8-pin µMAX pinout and footprint with MAX817LCPA+ and MAX819LCPA+, including VCC, GND, RESET, BATT, OUT, WDI, PFI, and CE IN/CE OUT assignments. However, internal functionality differs: MAX817 lacks CE gating, MAX819 adds MR, and MAX818 omits PFI comparator - so electrical compatibility requires verifying signal routing per variant.
MAX818LCPA+ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 8-DIP (0.300", 7.62mm)
- Packaging:
- Tube
- 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:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 8-PDIP
MAX818LCPA+ FAQ
1.How can I place an order for MAX818LCPA+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX818LCPA+ 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 MAX818LCPA+ reliable?
The price and inventory of MAX818LCPA+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX818LCPA+ is usually 5 days.
3.What payment methods are accepted for MAX818LCPA+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX818LCPA+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX818LCPA+?
MAX818LCPA+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX818LCPA+ 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 MAX818LCPA+?
For technical support, including MAX818LCPA+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX818LCPA+ requirements.
6.How does Aetrix verify that MAX818LCPA+ is sourced from the original manufacturer or authorized distributors?
All MAX818LCPA+ 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 MAX818LCPA+ meets industry standards.
7.What is the process for return or replacement of MAX818LCPA+?
All MAX818LCPA+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX818LCPA+, 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 MAX818LCPA+ part is unused and in its original packaging.
Return procedure for MAX818LCPA+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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