My Inquiry
My Account
Analog Devices Inc./Maxim Integrated MAX802SCPA+
- Part No.:
- MAX802SCPA+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- 8-DIP (0.300", 7.62mm)
- Datasheet:
-
MAX802SCPA+.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 8DIP
- Quantity:
- Payment:
- Shipping:
Inventory:3,029
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
MAX802SCPA+ from Maxim Integrated is a 3.3V/3.0V microprocessor supervisory circuit with active-low reset output, precision voltage monitoring (2.925V threshold), 200ms reset timeout, watchdog timer (1.6s), and battery-backup switchover-designed for embedded controllers and battery-powered systems requiring reliable power-up/power-down sequencing.
For engineers reviewing the MAX802SCPA+ datasheet, MAX802SCPA+ pinout, MAX802SCPA+ application, or MAX802SCPA+ equivalent, this page delivers verified technical context, exact pin functions, real-world use cases in RAM backup and brownout protection, and validated alternative parts with documented tolerance and functional differences.
Technical Context
The MAX802SCPA+ integrates a precision reset comparator with ±2% threshold accuracy (2.925V 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 falls below 2.40V (VSW) and VBATT > VCC.
It features a dedicated PFI input with 1.237V threshold (±20mV hysteresis), guaranteed RESET assertion down to VCC = 1V, 40µA VCC supply current at 3.6V, and 1µA battery supply current-enabling long-term CMOS RAM retention during main supply failure without external components.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold | 2.925V (±2%) - precisely matches 3.3V ±10% supply tolerance; asserts reset before VCC drops below 2.85V. |
| Reset Timeout Period | 200ms (140–280ms over temp) - ensures µP completes power stabilization before release. |
| Watchdog Timeout | 1.6s (1.12–2.24s over temp) - detects µP lockup; cleared by rising/falling edge on WDI pin. |
| VCC Supply Current | 40µA typical at VCC < 3.6V - enables ultra-low-power operation in battery-backed systems. |
| Battery Supply Current | 1µA max (0.4–1µA) - minimizes drain on lithium backup cells during extended standby. |
| Power-Fail Input Threshold | 1.237V ±20mV - monitors auxiliary rails or divided supplies with noise-immune hysteresis. |
| VBATT Switch Threshold (VSW) | 2.40V (2.30–2.50V) - triggers switchover before VOUT drops below 2.0V, preserving RAM data integrity. |
Pinout & Package
MAX802SCPA+ is housed in an 8-pin plastic DIP (PDIP) package with 0.300" wide body, RoHS-compliant lead-free finish (+ suffix), and standard through-hole mounting.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - VOUT | CMOS RAM supply output | Switches between VCC (via 3Ω PMOS) and VBATT (via 140Ω switch); maintains >2.0V to retain static RAM during brownout. |
| 2 - VCC | Main system supply input | Operates from 2.72V to 5.5V; powers internal circuitry and enables VOUT sourcing when above reset threshold. |
| 3 - GND | Analog/digital ground reference | Common return for all internal comparators, timers, and switches; must be low-impedance for accurate threshold sensing. |
| 4 - PFI | Power-fail input | Monitors auxiliary voltage (e.g., divided rail); asserts PFO low when input falls below 1.237V ±20mV. |
| 5 - PFO | Power-fail open-drain output | Signals undervoltage condition; can drive MR on compatible devices (e.g., MAX704/MAX806) to trigger reset. |
| 6 - WDI | Watchdog timer input | Edge-sensitive (rising/falling); resets 1.6s timer; tied high/low causes periodic reset (every ~1.8s). |
| 7 - RESET | Active-low reset output | Open-drain, asserted low during power-up, brownout, or watchdog timeout; requires external pull-up. |
| 8 - VBATT | Backup battery input | Accepts up to 6.0V; connects to VOUT when VCC < 2.40V; supports lithium cells exceeding VCC in normal operation. |
Key Features
| Feature | Design Value |
|---|---|
| Precision reset threshold | ±2% tolerance (vs. ±4% in MAX690/MAX704) - tighter control for 3.3V ±10% systems. |
| Guaranteed RESET to VCC = 1V | Ensures valid reset assertion even during deep brownout, critical for fail-safe µP initialization. |
| Battery switchover with hysteresis | VSW = 2.40V with 25mV typical hysteresis - prevents oscillation during VCC transition near threshold. |
| Low-quiescent-current design | 40µA VCC supply current (typ) - extends battery life in portable equipment without sacrificing supervision fidelity. |
| Dual-supply monitoring capability | Independent PFI/PFO path - allows monitoring of secondary rails (e.g., analog supply) without affecting reset logic. |
Applications
| Battery-Powered Embedded Controller | Intelligent Instrument with RAM Backup |
|---|---|
Use Scenario: Portable data logger powered by 3.3V Li-ion battery with 256KB SRAM storing calibration data across power cycles. IC Role / Device Role / Timing Role: Supervisory IC providing brownout detection, manual reset, and seamless VBATT-to-VOUT switchover at 2.40V. Use Value: Preserves RAM contents for >10 years on coin cell; eliminates need for external diode-or circuitry or discrete reset ICs. |
Use Scenario: Handheld multimeter with real-time clock and configuration memory, operating from 3.0V supply with optional backup battery. IC Role / Device Role / Timing Role: Voltage monitor and reset generator ensuring µP restarts only after stable 3.0V rail; PFI monitors RTC supply. Use Value: Prevents corrupted measurements during low-battery conditions; 1.237V PFI threshold accurately tracks 1.8V RTC rail via resistor divider. |
| Critical µP Power Monitoring | Portable Medical Sensor Node |
Use Scenario: Industrial PLC module where µP must not execute code until 3.3V rail settles within ±5% for 200ms. IC Role / Device Role / Timing Role: Primary reset supervisor asserting RESET low for exactly 200ms post-threshold crossing. Use Value: Eliminates risk of firmware crash due to premature µP wake-up; ±2% reset threshold ensures compliance with IEC 61000-4-11 immunity. |
Use Scenario: Wearable ECG sensor using 3.3V LDO and CR2032 battery; requires RAM retention during brief battery insertion/removal. IC Role / Device Role / Timing Role: Battery switchover controller enabling hot-swap of backup source without triggering reset. Use Value: 1µA battery leakage current extends CR2032 life to >5 years; VBATT > VCC support allows direct lithium cell connection. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX802TCSA+ | Reset threshold = 3.075V (±2%), higher trip point for 3.3V ±5% systems. | Better suited for applications requiring reset assertion only below 3.00V, e.g., high-precision ADC references. | Select MAX802TCSA+ when system VCC tolerance is tighter (±5%) and brownout margin must exceed 300mV. |
| MAX804SCSA+ | Active-high open-drain RESET output (inverse logic), same 2.925V threshold and timing. | Direct interface to µPs with active-high reset inputs (e.g., ARM Cortex-M series), eliminating external inverter. | Choose MAX804SCSA+ when target µP requires active-high reset assertion and board layout prohibits pull-up + inverter. |
Compared with MAX802SCPA+, MAX802TCSA+ raises reset threshold by 150mV for stricter supply monitoring, while MAX804SCSA+ changes reset polarity to simplify interface with modern µPs-both retain identical watchdog, battery switchover, and PFI functionality.
Availability
MAX802SCPA+ is available at Aetrix Electronics and suitable for battery-powered computers, embedded controllers, and intelligent instruments requiring stable component supply with guaranteed long-term availability and full traceability.
Supply support for MAX802SCPA+ 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, medical, and communications applications, emphasizing reliability, low power, and integration.
The MAX802 series belongs to Maxim's microprocessor supervisory product line, engineered specifically for robust power monitoring in 3.0V/3.3V battery-backed systems with stringent reset accuracy and RAM retention requirements.
FAQ
What is the exact reset threshold voltage for MAX802SCPA+ and how is it specified?
The MAX802SCPA+ has a nominal reset threshold of 2.925V with ±2% tolerance over temperature and supply voltage. This means the device guarantees reset assertion before VCC falls below 2.85V (min) and will not assert reset while VCC remains above 3.00V (max), making it ideal for 3.3V ±10% systems. The threshold is measured during VCC falling and includes 10mV typical hysteresis to prevent chatter.
Does MAX802SCPA+ support battery backup when VBATT exceeds VCC?
Yes, MAX802SCPA+ explicitly supports VBATT > VCC operation. Its internal battery switchover circuit activates when VCC falls below 2.40V (VSW) and VBATT is greater than VCC, connecting VBATT to VOUT through a 140Ω switch. This allows use of standard 3.6V lithium cells directly at VBATT-even when main VCC is 3.3V-without external diodes or level-shifting.
How does the watchdog timer in MAX802SCPA+ operate and can it be disabled?
The MAX802SCPA+ watchdog timer has a fixed 1.6s timeout (1.12–2.24s over temperature) and cannot be disabled. It resets whenever WDI sees a rising or falling edge, and triggers RESET if WDI remains static (high or low) for longer than the timeout. During RESET assertion, the timer is held cleared; it resumes counting only after RESET deasserts.
What is the function of the PFI and PFO pins on MAX802SCPA+?
On MAX802SCPA+, PFI is a dedicated input referenced to a precise 1.237V internal threshold (±20mV hysteresis); when PFI voltage falls below this, PFO goes low. PFO is an open-drain output usable as a power-fail interrupt or to drive MR on compatible devices like MAX704/MAX806. Both pins operate independently of the main reset comparator.
Can MAX802SCPA+ be used without a backup battery?
Yes, MAX802SCPA+ can operate without a backup battery: connect both VBATT and VOUT pins directly to VCC. However, doing so disables battery switchover and RAM backup functionality. For pure reset supervision without backup, alternatives like MAX706SCPA+ may offer lower cost-but MAX802SCPA+ remains fully functional for reset, watchdog, and PFI/PFO monitoring in single-supply mode.
MAX802SCPA+ 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:
- 2.925V
- Output:
- Push-Pull, Totem Pole
- 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
MAX802SCPA+ FAQ
1.How can I place an order for MAX802SCPA+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX802SCPA+ 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 MAX802SCPA+ reliable?
The price and inventory of MAX802SCPA+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX802SCPA+ is usually 5 days.
3.What payment methods are accepted for MAX802SCPA+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX802SCPA+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX802SCPA+?
MAX802SCPA+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX802SCPA+ 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 MAX802SCPA+?
For technical support, including MAX802SCPA+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX802SCPA+ requirements.
6.How does Aetrix verify that MAX802SCPA+ is sourced from the original manufacturer or authorized distributors?
All MAX802SCPA+ 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 MAX802SCPA+ meets industry standards.
7.What is the process for return or replacement of MAX802SCPA+?
All MAX802SCPA+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX802SCPA+, 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 MAX802SCPA+ part is unused and in its original packaging.
Return procedure for MAX802SCPA+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX802SCPA+ Tags
-
MIC826SYMT-TR
Microchip Technology
-
APX803S-31SA-7
Diodes Incorporated
-
APX803L20-29SA-7
Diodes Incorporated
-
TPS3828-33DBVR
Texas Instruments
-
V6340RSP3B+
EM Microelectronic
-
EM6325CXSP5B-2.9+
EM Microelectronic
-
MCP120T-300I/TT
Microchip Technology
-
MCP130T-315I/TT
Microchip Technology
-
MCP120T-475I/TT
Microchip Technology
-
MCP111T-300E/TT
Microchip Technology
-
MCP120T-315I/TT
Microchip Technology
-
MCP809T-315I/TT
Microchip Technology
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
