My Inquiry
My Account
Analog Devices Inc./Maxim Integrated MAX802LEPA+
- Part No.:
- MAX802LEPA+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- 8-DIP (0.300", 7.62mm)
- Datasheet:
-
MAX802LEPA+.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 8DIP
- Quantity:
- Payment:
- Shipping:
Inventory:821
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
MAX802LEPA+ from Maxim Integrated is a microprocessor supervisory circuit providing power-on reset, battery-backup switching, watchdog timer, and power-fail detection for +5V systems. It asserts active-low RESET during power-up (VCC ≥ 1V), brownout (VCC < 4.65V), and watchdog timeout (1.6s), with guaranteed RESET assertion down to VCC = 1V. Designed for industrial embedded controllers requiring reliable power monitoring and RAM backup.
For engineers reviewing the MAX802LEPA+ datasheet, MAX802LEPA+ pinout, MAX802LEPA+ application, or MAX802LEPA+ equivalent, this page delivers verified technical context, exact pin functions, real-world use scenarios, and validated alternative options - all grounded in Maxim's official specifications for the -40°C to +85°C extended-temperature 8-pin PDIP variant.
Technical Context
The MAX802LEPA+ integrates four core functions on a single die: a precision 4.65V ±2% reset threshold detector with 200ms pulse width, a 1.6s watchdog timer cleared by WDI edges or RESET assertion, a battery switchover circuit with 40mV hysteresis and 80Ω VBATT-to-VOUT switch, and a 1.25V reference-based power-fail comparator (PFI/PFO) with 400ns response time.
Its internal architecture uses a P-channel MOSFET for VOUT switching and a dedicated comparator chain for independent reset and power-fail signaling. The device operates across VCC = 1.0V–5.5V and supports battery-backup mode with only 50nA quiescent current when VCC = 0V and VBATT = 2.8V, enabling long-term CMOS RAM retention.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold | 4.65V ±2% (guaranteed over temperature); ensures reliable μP reset before +5V rail collapse |
| Reset Pulse Width | 200ms nominal; provides sufficient hold time for full μP initialization sequence |
| Watchdog Timeout | 1.6s ±37.5%; detects firmware lockups without requiring external timing components |
| VCC Supply Current | 200–500µA (−40°C to +85°C); enables low-power operation in battery-backed systems |
| Battery-Backup Current | 50nA typical at TA = +25°C; extends lithium battery life beyond 10 years in standby |
| Power-Fail Accuracy | ±2% (MAX802L family); enables precise early-warning detection of supply degradation |
| Operating Temperature | −40°C to +85°C; qualified for industrial control, instrumentation, and automotive under-hood environments |
Pinout & Package
MAX802LEPA+ is housed in an 8-pin plastic DIP (PDIP) package with 0.300" wide body and 0.100" lead pitch, RoHS-compliant with lead-free finish (indicated by '+' suffix).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - VOUT | CMOS RAM supply output | Switches between VCC (via 5Ω PMOS) and VBATT (via 80Ω PMOS) based on reset threshold crossing and hysteresis |
| 2 - VCC | +5V main supply input | Primary power source; powers internal circuitry and triggers reset when falling below 4.65V |
| 3 - GND | Circuit ground reference | Common return path for all analog and digital functions; must be low-impedance for noise immunity |
| 4 - PFI | Power-fail comparator input | Monitors external voltage divider; asserts PFO low when input falls below 1.25V reference |
| 5 - PFO | Power-fail open-drain output | Signals impending supply failure to μP interrupt line; requires external pull-up resistor |
| 6 - WDI | Watchdog timer input | Edge-sensitive; resets internal 1.6s timer on rising/falling transitions; floating disables watchdog |
| 7 - RESET | Active-low reset output | Push-pull output; guarantees logic-low state down to VCC = 1V; pulses low for 200ms on any trigger event |
| 8 - VBATT | Backup battery input | Connects to lithium cell (3.0–3.6V); enables automatic switchover to preserve RAM during main supply loss |
Key Features
| Feature | Design Value |
|---|---|
| Precision reset threshold | 4.65V ±2% over −40°C to +85°C; eliminates need for external trimming resistors in critical applications |
| Guaranteed RESET assertion | Valid down to VCC = 1V; ensures μP remains held in reset even during deep brownout conditions |
| Battery switchover hysteresis | 40mV; prevents oscillation during slow VCC ramp-down and avoids repeated switching near threshold |
| Ultra-low backup current | 50nA typical in battery mode; enables >10-year shelf life with standard CR2032 coin cell |
| Integrated 1.25V reference | Stable internal reference for PFI comparator; removes dependency on external voltage references |
Applications
| Industrial Programmable Logic Controllers | Medical Diagnostic Handhelds |
|---|---|
Use Scenario: PLC CPU module powered from 5V DC-DC converter with onboard SRAM and real-time clock. IC Role / Device Role / Timing Role: Supervisory IC monitors 5V rail, asserts RESET on undervoltage, switches SRAM to lithium backup during AC loss, and signals power-fail via PFO to initiate safe shutdown. Use Value: Prevents corrupted configuration data and RTC drift during grid interruptions; meets IEC 61000-4-28 immunity requirements for sustained brownout. |
Use Scenario: Portable ultrasound imager using ARM Cortex-M7 with 512KB SRAM and battery-backed real-time clock. IC Role / Device Role / Timing Role: Provides 200ms reset pulse on cold start, enables seamless transition to coin-cell backup during USB power removal, and triggers firmware save routine via PFO interrupt before shutdown. Use Value: Ensures zero data loss during hot-swap battery replacement; maintains timestamp continuity across power cycles per FDA 21 CFR Part 11 audit trails. |
| Smart Energy Meters | Railway Signaling Controllers |
Use Scenario: DIN-rail mounted electricity meter with metrology ASIC, EEPROM, and tamper-detection circuitry. IC Role / Device Role / Timing Role: Monitors 5V auxiliary supply derived from mains; asserts RESET if transformer output sags below 4.65V; uses WDI to detect firmware hang during tariff update execution. Use Value: Guarantees meter reboots cleanly after lightning-induced surges; satisfies EN 50470-3 Class B voltage dip immunity (0.5 cycle @ 70% Vn). |
Use Scenario: Wayside signal controller operating in −40°C to +85°C ambient with dual-redundant 5V supplies. IC Role / Device Role / Timing Role: Dual MAX802LEPA+ units supervise primary and backup 5V rails independently; RESET outputs feed into safety-critical FPGA voting logic. Use Value: Enables SIL-2 compliance per EN 50129 through deterministic reset behavior and guaranteed sub-1V assertion margin. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX802MESA | 4.40V reset threshold (vs. 4.65V); same SO-8 package; identical temp range (−40°C to +85°C) | Used where system tolerates lower reset point (e.g., +5V ±10% supplies); not drop-in for +5V ±5% designs | Select MAX802MESA only if VCC tolerance allows 4.40V trip; verify brownout margin against worst-case regulator dropout. |
| MAX813LCSA | Same 4.65V threshold and 200ms pulse; adds manual reset input (/MR) and watchdog output (WDO); SO-8 package | Required when system needs external reset button or separate watchdog status flag; higher pin count not needed here | Choose MAX813LCSA only if manual reset or independent WDO signal is mandatory; adds complexity and cost without benefit for basic supervision. |
Compared with MAX802MESA and MAX813LCSA, the MAX802LEPA+ offers optimal balance of industrial temperature rating, precise 4.65V reset accuracy, and minimal footprint - making it ideal for space-constrained, high-reliability +5V systems where no manual reset or extra outputs are required.
Availability
MAX802LEPA+ is available at Aetrix Electronics and suitable for industrial programmable logic controllers, medical handheld diagnostics, smart energy meters, railway signaling controllers, and other applications requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for MAX802LEPA+ 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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, communications, and computing markets.
The MAX802L series belongs to Maxim's microprocessor supervisory product line, designed specifically to replace discrete reset circuits in +5V μP systems while delivering guaranteed timing, precision thresholds, and robust battery backup - targeting reliability-critical embedded applications.
FAQ
What is the guaranteed minimum VCC voltage at which MAX802LEPA+ asserts RESET?
The MAX802LEPA+ guarantees RESET assertion down to VCC = 1.0V across its full operating temperature range of −40°C to +85°C. This ensures the microprocessor remains held in reset during deep brownout conditions where the supply may sag significantly below the 4.65V reset threshold. The specification is explicitly confirmed in the Electrical Characteristics table under "RESET Output Voltage" for MAX69_AE/M and MAX802_E variants, matching the MAX802LEPA+ ordering code.
Does MAX802LEPA+ support battery backup for CMOS RAM, and what is the maximum allowable VBATT voltage?
Yes, MAX802LEPA+ provides automatic battery backup switching for CMOS RAM via its VOUT and VBATT pins. The maximum allowable VBATT voltage is 4.80V, as specified in Table 2 of the datasheet for MAX802L devices. Exceeding this voltage risks excessive substrate diode conduction when VCC is near the reset threshold, potentially causing unintended current paths or latch-up.
What is the watchdog timeout period for MAX802LEPA+, and how is it triggered?
The MAX802LEPA+ features a fixed 1.6s watchdog timeout period, with a guaranteed range of 1.00s to 2.25s. It is triggered when the WDI pin remains continuously high or low for longer than this interval - not by missing edges, but by absence of transitions. The timer clears on any rising or falling edge at WDI, on RESET assertion, or when WDI is three-stated (floating), ensuring robust firmware health monitoring.
Can MAX802LEPA+ monitor a negative supply rail, and how is this implemented?
Yes, MAX802LEPA+ can monitor a negative supply rail using the PFI/PFO comparator pair. As shown in Figure 7 of the datasheet, a resistor divider referenced to VCC and GND applies a scaled positive voltage to PFI. When the negative rail degrades (becomes less negative), the PFI voltage rises above 1.25V, causing PFO to go high - providing a clean logic-level alert. Accuracy depends on resistor tolerance and PFI input current (≤25nA max).
Is MAX802LEPA+ pin-compatible with earlier MAX690 series devices?
Yes, MAX802LEPA+ is pin-compatible with the MAX690 and MAX694, as stated in the General Description section. All share identical 8-pin DIP/SO pinouts and function mapping: VOUT, VCC, GND, PFI, PFO, WDI, RESET, and VBATT occupy the same positions. This allows direct replacement in legacy designs without PCB modification, provided the 4.65V reset threshold and extended temperature range meet system requirements.
MAX802LEPA+ 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:
- 4.65V
- Output:
- Push-Pull, Totem Pole
- Reset:
- Active Low
- Reset Timeout:
- 140ms Minimum
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 8-PDIP
MAX802LEPA+ FAQ
1.How can I place an order for MAX802LEPA+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX802LEPA+ 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 MAX802LEPA+ reliable?
The price and inventory of MAX802LEPA+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX802LEPA+ is usually 5 days.
3.What payment methods are accepted for MAX802LEPA+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX802LEPA+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX802LEPA+?
MAX802LEPA+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX802LEPA+ 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 MAX802LEPA+?
For technical support, including MAX802LEPA+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX802LEPA+ requirements.
6.How does Aetrix verify that MAX802LEPA+ is sourced from the original manufacturer or authorized distributors?
All MAX802LEPA+ 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 MAX802LEPA+ meets industry standards.
7.What is the process for return or replacement of MAX802LEPA+?
All MAX802LEPA+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX802LEPA+, 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 MAX802LEPA+ part is unused and in its original packaging.
Return procedure for MAX802LEPA+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX802LEPA+ 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…
