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Analog Devices Inc./Maxim Integrated MAX805TCPA
- Part No.:
- MAX805TCPA
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- 8-DIP (0.300", 7.62mm)
- Datasheet:
-
MAX805TCPA.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 8DIP
- Quantity:
- Payment:
- Shipping:
Inventory:1,666
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Product details
Overview
MAX805TCPA from Maxim Integrated is a 3.3V microprocessor supervisory circuit with active-high open-drain RESET output, 3.075V reset threshold (T-suffix), 200ms reset timeout, watchdog timer (1.6s), and battery-backup switchover capability. It monitors VCC supply integrity, asserts reset during brownout or watchdog timeout, and switches CMOS RAM to VBATT when VCC falls below 2.40V - used in battery-powered embedded controllers requiring reliable power-fail detection and nonvolatile memory retention.
For engineers reviewing the MAX805TCPA datasheet, MAX805TCPA pinout, MAX805TCPA application, or MAX805TCPA equivalent, this page delivers verified specifications, exact pin functions, real-world use cases in portable instrumentation and critical µP systems, and validated alternative parts for design continuity and supply resilience.
Technical Context
The MAX805TCPA integrates a precision reset comparator with ±4% threshold tolerance (3.075V nominal), a 1.6s watchdog timer that clears on WDI edge transitions, and a dual-path power-switching architecture: VCC-to-VOUT via 3Ω PMOS switch and VBATT-to-VOUT via 140Ω switch activated when VCC < 2.40V. Its PFI input accepts external voltage monitoring with 1.237V threshold and 10mV hysteresis.
It operates across 0°C to +70°C, supports VCC from 3.17V to 5.5V and VBATT up to 6.0V, guarantees RESET assertion down to VCC = 1V, and draws only 40µA typical VCC supply current. The active-high RESET output requires external pull-up and is functionally inverted relative to MAX690/MAX704 series.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold | 3.075V (±4%) - triggers reset before 3.3V supply drops below system stability margin |
| Reset Timeout Period | 200ms (140–280ms) - ensures µP completes full reset sequence after power recovery |
| Watchdog Timeout | 1.6s (1.12–2.24s) - detects µP lockup without requiring software intervention |
| VCC Supply Current | 40µA typical (VCC < 3.6V) - enables multi-year operation in battery-backed RAM applications |
| Battery Supply Current | 0.4–1µA - minimizes lithium cell drain during long-term backup mode |
| Power-Fail Input Threshold | 1.237V ±20mV - supports accurate undervoltage detection of auxiliary rails via resistor divider |
| VBATT Switch Threshold | 2.40V (2.30–2.50V) - initiates battery switchover early enough to preserve CMOS RAM data |
Pinout & Package
MAX805TCPA is housed in an 8-pin plastic DIP (PDIP) package with 0.300" wide body and through-hole mounting. Pin spacing is 0.100", lead finish is lead-free (RoHS-compliant).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - VOUT | CMOS RAM supply output | Switches between VCC (via 3Ω PMOS) and VBATT (via 140Ω switch); must be decoupled with 0.1µF capacitor |
| 2 - VCC | Main system supply input | Accepts 3.17–5.5V; powers internal circuitry and drives VOUT when above reset threshold |
| 3 - GND | Ground reference | Common return for all analog and digital functions; substrate tied to higher of VCC/VBATT |
| 4 - PFI | Power-fail input | Monitors auxiliary rail via external divider; asserts PFO low when voltage falls below 1.237V |
| 5 - PFO | Power-fail open-drain output | Active-low signal indicating PFI undervoltage or VCC falling below 2.40V; can drive MR on MAX704/MAX806 |
| 6 - WDI | Watchdog input | Edge-sensitive (rising/falling); resets watchdog timer; cannot be disabled |
| 7 - RESET | Active-high open-drain reset output | Inverse of MAX690 RESET; requires external pull-up to VCC; asserts high during reset condition |
| 8 - VBATT | Backup battery input | Supports voltages exceeding VCC (e.g., 3.6V Li-cell); connects to VOUT when VCC drops below 2.40V |
Key Features
| Feature | Design Value |
|---|---|
| Guaranteed RESET assertion to VCC = 1V | Ensures fail-safe reset even during deep brownout, preventing µP execution from corrupted state |
| Battery-backup switchover with 2.40V threshold | Activates before CMOS RAM minimum retention voltage (2.0V), preserving data integrity during power loss |
| 200ms reset timeout with restart-on-brownout | Prevents premature µP release during transient dips; internal timer resets each time VCC falls below threshold |
| 1.6s watchdog timer with edge-triggered clear | Eliminates need for dedicated watchdog service pulses; responds to any µP activity (not just toggles) |
| 40µA VCC supply current (typical) | Reduces quiescent load on primary supply, extending battery life in always-on portable systems |
| 1µA max battery supply current | Minimizes self-discharge of backup cell, enabling >10-year data retention in static RAM applications |
Applications
| Battery-Powered Embedded Controller | Intelligent Portable Instrument |
|---|---|
Use Scenario: Handheld multimeter with nonvolatile configuration storage and real-time clock. IC Role / Device Role / Timing Role: Supervises 3.3V main supply, switches SRAM to lithium coin cell during battery swap, and triggers watchdog reset if firmware hangs. Use Value: Enables hot-swap of main battery without losing calibration data or RTC time, supported by guaranteed 1V reset assertion and sub-1µA battery leakage. |
Use Scenario: Portable gas detector with sensor biasing, ADC, and Bluetooth LE radio. IC Role / Device Role / Timing Role: Monitors 3.3V LDO output, asserts RESET on brownout, and uses PFI to detect failure of 5V sensor bias rail. Use Value: Prevents false alarms or missed detections during supply transients via 100µs glitch immunity and precise 1.237V PFI threshold. |
| Critical µP Power Monitoring | Industrial Data Logger |
Use Scenario: Remote telemetry node logging temperature/pressure with flash memory and LoRaWAN module. IC Role / Device Role / Timing Role: Provides power-on reset, brownout protection, and watchdog supervision for ARM Cortex-M0+ MCU. Use Value: Ensures deterministic boot and runtime recovery using 200ms reset timeout and 1.6s watchdog - eliminating silent firmware lockups. |
Use Scenario: Solar-powered environmental logger storing hourly readings in SPI FRAM. IC Role / Device Role / Timing Role: Supplies backup power to FRAM I/O buffer during solar panel shading events; monitors VCC and auxiliary 12V sensor rail. Use Value: Maintains write integrity during intermittent power using VBATT switchover and dual-rail monitoring (VCC + PFI). |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX805TSA | Same electrical specs but in 8-pin SOIC package (surface-mount); 471mW max power dissipation vs. 727mW for PDIP | Preferred for space-constrained PCBs or automated SMT assembly; identical timing and threshold behavior | Select MAX805TSA when board layout requires surface-mount footprint and thermal budget permits lower dissipation limit. |
| MAX804TCPA | Identical PDIP package and pinout, but features active-low RESET (complementary logic) instead of active-high | Requires no external pull-up resistor; interfaces directly with µPs expecting active-low reset assertion | Choose MAX804TCPA when the host processor lacks internal pull-up or mandates active-low reset signaling. |
Compared with MAX805TCPA, MAX805TSA offers identical functionality in a smaller SOIC package for modern layouts, while MAX804TCPA provides pin-compatible active-low reset output - both enable seamless migration without schematic or firmware changes beyond reset polarity handling.
Availability
MAX805TCPA is available at Aetrix Electronics and suitable for battery-powered computers and controllers, intelligent instruments, and critical µP power monitoring applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant through-hole packaging.
Supply support for MAX805TCPA 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 management, sensing, and interface applications in industrial, computing, and communications systems.
The MAX805TCPA belongs to Maxim's µP supervisory family targeting 3.0V/3.3V systems, engineered to replace discrete reset circuits with integrated reset generation, watchdog supervision, and battery switchover - specifically for reliability-critical embedded control.
FAQ
What is the reset threshold voltage of the MAX805TCPA?
The MAX805TCPA has a nominal reset threshold voltage of 3.075V, with ±4% tolerance over temperature and supply variations. This value applies to VCC falling conditions and is optimized for 3.3V systems with ±5% supply tolerance. The device guarantees reset assertion before VCC falls below 3.0V and remains asserted until VCC rises above 3.085V (rising threshold), providing 10mV hysteresis to prevent oscillation.
Does the MAX805TCPA support battery-backup switchover, and what is the switching threshold?
Yes, the MAX805TCPA supports automatic battery-backup switchover. When VCC falls below the battery switch threshold (VSW) of 2.40V (2.30–2.50V range), the internal 140Ω switch connects VBATT to VOUT, preserving power to CMOS RAM. Switchover back to VCC occurs when VCC rises above the reset threshold (3.075V), ensuring stable supply reconnection 200ms prior to RESET deassertion.
What is the function of the WDI pin on the MAX805TCPA, and can it be disabled?
The WDI (Watchdog Input) pin on the MAX805TCPA is edge-sensitive - a rising or falling transition clears the 1.6s watchdog timer. If WDI remains static (high or low) for longer than the timeout, RESET is asserted. Unlike earlier families, the watchdog function in MAX805TCPA cannot be disabled; it is always active and integral to the device's supervision capability.
How does the MAX805TCPA differ from the MAX804TCPA?
The MAX805TCPA and MAX804TCPA share identical pinout, package, reset threshold, and core supervision features, but differ in RESET output polarity: MAX805TCPA provides active-high open-drain RESET, requiring an external pull-up, whereas MAX804TCPA provides active-low RESET. Both are drop-in replacements except for reset signal interpretation in the host µP firmware or logic design.
What are the absolute maximum ratings for VCC and VBATT on the MAX805TCPA?
The MAX805TCPA has an absolute maximum rating of −0.3V to +6.0V for both VCC and VBATT pins. Exceeding these limits may cause permanent damage. Continuous operation is specified from VCC = 3.17V to 5.5V (for T-suffix) and VBATT = up to 6.0V, with guaranteed functionality down to VCC = 1V and VBATT ≥ 1.0V. All other inputs tolerate −0.3V to the higher of VCC or VBATT.
MAX805TCPA Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 8-DIP (0.300", 7.62mm)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Type:
- Battery Backup Circuit
- Number of Voltages Monitored:
- 1
- Voltage - Threshold:
- 3.075V
- Output:
- Open Drain or Open Collector
- Reset:
- Active High
- Reset Timeout:
- 140ms Minimum
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 8-PDIP
MAX805TCPA FAQ
1.How can I place an order for MAX805TCPA through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX805TCPA 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 MAX805TCPA reliable?
The price and inventory of MAX805TCPA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX805TCPA is usually 5 days.
3.What payment methods are accepted for MAX805TCPA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX805TCPA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX805TCPA?
MAX805TCPA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX805TCPA 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 MAX805TCPA?
For technical support, including MAX805TCPA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX805TCPA requirements.
6.How does Aetrix verify that MAX805TCPA is sourced from the original manufacturer or authorized distributors?
All MAX805TCPA 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 MAX805TCPA meets industry standards.
7.What is the process for return or replacement of MAX805TCPA?
All MAX805TCPA units undergo pre-shipment inspection (PSI). If there is an issue with MAX805TCPA, 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 MAX805TCPA part is unused and in its original packaging.
Return procedure for MAX805TCPA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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